Workshops of The Conference

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Just joking

Intra-Radicular Rehabilitation

The increasing predictability of endodontic treatment has made these procedures far more popular with both patients and professionals in recent decades. In particular, patient acceptance has increased as the discomfort associated with endodontic procedures has decreased; thus patients are encouraged to treat and maintain their teeth rather than having them extracted. The dental profession's very successful, long-term public education campaign focused on keeping the dentition for a lifetime has significantly affected patient attitudes.

After endodontic treatment is successfully completed, the dentist faces the task of restoring the remaining radicular structure to full form and function. In most cases, the remaining root structure is relatively intact, and the post-endodontic treatment (post-and-core followed by a full crown) is routine. A number of established techniques and materials are available for restoring the endodontically treated tooth. Typically, if the post-and-core is to succeed, the dentinal structure must be sufficiently strong to support the post/core/crown complex.

Post-endodontic restorative challenges

Not all clinical situations are ideal, however. When the remaining post-endodontic tooth structure is a flared, open, or very wide canal, the restoration to function and esthetics often requires intra-radicular rehabilitation of the tooth. These situations, some within the dentist's control and some without, present the practitioner with specific technical challenges in the clinical restoration of endodontically treated teeth. Non-ideal restorative situations may be due to a number of causes:

Young children have large canals which tend to shrink with age. When a child fractures an anterior tooth at an early age, the endodontically treated canal is typically a very large space with relatively thin dentinal walls surrounding it.

In some teeth, large canals persist to adulthood. After endodontic treatment, they present similar problems to the restoring dentist. (In both cases, the size and shape of the canal are totally outside of the dentist's control. They are simply conditions which must be treated.)

Extensive decay may have destroyed a large part of the coronal (and possibly the radicular) structure prior to endodontic treatment. In these cases, it is likely that the very little remaining dentin is a thin circumference of tooth structure surrounding the endodontic filling.

Where the operator is not conservative of tooth structure, over-instrumentation or aggressive filing can inadvertently result in a very flared canal quite similar to a young canal or one with extensive decay.

All of the above post-endodontic clinical conditions present restorative management problems.

Intra-radicular rehabilitation (IRR), prior to post insertion and cementation increases the likelihood of restorative success.

Treatment planning

The first decision is to evaluate whether the remaining dentinal structure is in fact strong enough to support the post/core/crown complex for masticatory and esthetic function.

Contraindications to intra-radicular rehabilitation include

There is inadequate remaining dentinal structure.
The remaining tooth structure is compromised.
The remaining root structure is located too far subgingivally to be practically restored.
The remaining root structure cannot be adequately isolated for effective moisture control.
In these situations, implant therapy should be considered, preferably prior to endodontics

Cementation

It is important to recognize that an ill-fitting post, whether due to the canal's shape or its condition, is less likely to be successful in retaining the prosthetic restoration. It may, in fact, fracture the remaining tooth structure when subjected to functional loads and parafunctional forces.

The post cement has often been used as a displacement material to substitute for a good fit to the remaining tooth structure. This practice is particularly prevalent with pre-fabricated posts that approximate the actual canal shape. Pre-fabricated post systems function best in situations where significant root structure, suitable for luting, remains.

Non-adhesive cements, however, are intended as luting materials, not to be used in great thickness or bulk. Non-resin cements do not contribute to the strength or the integrity of the tooth/post/core/crown monobloc complex, and as such, increasing the cement thickness may proportionally limit the longevity of the restoration.

The compromised root structure can be reinforced with intra-radicular rehabilitation, a technique that has been developed along with adhesive and composite dentistry. Utilizing the more recent advances in dentinal and enamel adhesion, it is possible to reline the internal anatomy of the remaining post-endodontic root structure in order to develop an ideal post space

Intra-radicular rehabilitation provides greatly improved post retention and pre-dictability in cases where the restorative prognosis would otherwise be very limited.

The rationale for intra-radicular rehabilitation

It has been generally accepted that posts in endodontically treated teeth do not actually strengthen the remaining radicular structure. In fact, the data indicates that placing a post actually weakens the remaining tooth structure. It is important to realize, however, that none of these studies reported on adhesive and composite techniques; they all involved traditional cast or pre-fabricated posts cemented with zinc phosphate.

More recent studies have clearly shown that fiber posts bonded with composite resin cores are less likely to cause root fractures than stainless steel posts. This indicates that the bonded post-and-core monobloc contributes to the continuing strength and integrity of the remaining tooth structure.

Practitioners agree that the ideal post should provide retention for the core and protection for the remaining radicular struture, without transmitting severe masticatory or parafunctional stresses. Current research indicates that the best design is a passive, parallel-sided post that is intimately adapted into a custom-prepared channel of sufficient length relative to the crestal height of the supporting bone. Where the prepared channel is wide and cannot be composed of natural tooth material, adhesive composite rehabilitation can serve to provide similar function and stability.

Adhesive resin can replace (non-adhesive) luting cement in post cementation; resin adhesively restores lost tooth structure. Resin cement eliminates the flaring internal anatomy of the wide canal, optimizing the post channel preparation procedure. Cementation of pre-fabricated posts with composite resin has been described. However, using the composite strictly as a cement does not capitalize on the full restorative capacities of the various resins that are available. Stronger, more highly-filled composite resin restorative materials can be utilized to increase the diametric dimension of the remaining radicular structure, increasing the thick ness of the root walls, while simultaneously developing an ideally-shaped and sized post space.

The bonding, tensile, and shear strengths of composite resin to dentin and enamel are well-established, and indicate the potential of its clinical performance in the root/ post/core/crown complex.

The basic principle for intra-radicular rehabilitation is that the polymerization contraction of composite resin is less strong than the currently available bonding strengths of adhesives to dentin and enamel. This property causes the composite resin inside the canal, as it is curing, to shrink towards the bonded radicular walls and slightly away from the light transmitting post (LTP) that guides the light down the length of the canal.

Once the curing process is completed, the composite is securely bonded to the surrounding dentinal walls while the non-adhesive LTP is somewhat loose in the central space created by the polymerization contraction of the composite. The LTP can be gently disengaged from the surrounding composite, and eased out of the tooth. This leaves an intentionally formed space that accommodates the bondable post perfectly.

Needless to say, the light transmitting post must be made of a material that is non-bondable to BIS GMA or polyurethane dental adhesive and restorative materials. If the LTP were to adhere to the rehabilitating resin, the forces of polymerization contraction over the post/cement/radicular dentin complex would concentrate on the weakest component. In many cases, these forces would be strong enough to fracture the remaining radicular dentin.

Materials

The Luminex Light Transmitting Post Kit consists of three components: a reamer, a light transmitting post (LTP), and a bondable post
All the instruments are size-mated
• The reamer creates a space that is just somewhat larger than the light transmitting post.
• The LTP, in turn, is just fractionally larger in diameter than the bonded post.
Thus, each succeeding component fits into the space created by the previous one. The sizes are noted on the instruments by a series of parallel rings.
The post bonds adhesively to composites; the single-use LTP does NOT.

New designs for cavity preparations in posterior composites

Twenty-five years after their inception, posterior composites remain unpredictable. In comparison to amalgam restorations, posterior composites show significantly higher failure rates, are more costly, take longer to place, have more postoperative symptoms leak, stain, chip and cause food impaction

What's wrong with posterior composites

Endodontists joke that posterior composites are the number one killer of pulps, that leaking composites are their "number one" referral source. Most studies have shown that Class I and Class II composites have a significantly higher failure rate than amalgam restorations. The AMA, ADA, FDA, US Public Health service, CDC, NIH and WHO have all declared amalgam safe. In light of this evidence and overwhelming opinion, how can we in good conscience continue to place posterior composites? So let's ask one more time, what's wrong with posterior composites Why are we content to provide a posterior composite restoration that essentially cripples the tooth in the name of esthetics, knowing that there is no proven systemic health benefit compared to amalgam

The G. V. Black Era

G. V. Black was a consummate dentist/scientist and his exquisite designs for cavity preparation were a huge step forward for dentistry. Unfortunately, we are discovering today that those cavity shapes weaken the posterior dentition and lead to fracturing in even the most conservative applications
A two-year study -planned for future publishing- utilized 16 X magnifications to evaluate each posterior tooth that was treated for replacement of an amalgam or posterior composite, Found

Sharp internal line angles are only a small part of the problem

Joining the occlusal to the interproximal is the worst possible design for crack avoidance and the most common area for crack initiation

Most fractures initiate in dentin at the line angles

Interrupted cavities were more crack resistant than connected cavity preparations

One of dentistry's myths is that amalgam expansion causes tooth fracture. Expansion failures have never been proven. The fracture problem does not originate with amalgam, per se. It originates in iatrogenic GV Black cavity preparations. And just as many of us feared, we are seeing the same pattern of fracturing in teeth with posterior composites now that enough time has elapsed to assess their longevity

The Simonson Transition

Dr. Richard Simonson is widely recognized as a pioneer in new cavity preparation shapes for minimally invasive, bonded, resin-based posterior composites. In spite of his innovations, the GV Black preparations that taught in school twenty years ago have been only slightly modified for posterior composites in the typical dental practice and in most dental schools

A flat metal matrix, traditional wedge, boxy cavity shapes, biofilm that is difficult to remove just past the margins and incremental composite loading combine to give the common result. The Clark Class II shape, aggressive "sanding" of the interproximal with a lightning strip prior to placing the matrix, an anatomic, translucent matrix that allows the composite to form an ideal feather edge, and injection molded single phase composite placement combine for a superior result

Problems associated with current posterior composite

Composite is a poor biological space filler. A biological space filler such as amalgam or gold foil does not require any adhesion to the tooth surface. Composite on the other hand must be sealed 360 degrees and from inside to out

Unlike amalgam and gold foil techniques, "packing composite into a hole" is not a predictable method. Excellent clinicians have been dealt an unfair hand when it comes to Class II composites. Most of the features of the traditional cavity preparations such as parallel walls, resistance and retention form work against posterior composites What we have observed at CRA and under the microscope is that polymerization shrinkage cannot be eliminated, only mitigated. The best margin is no margin, and when composite extends slightly past the cavo-surface margin, it is generally well sealed with no white line. When we polish back to the margin, the white line often appears. "Composite sealing" with thin resins applied after filling the cavity may reduce wear. However, trying to seal an imperfect margin after the fact is futile. As explored these white lines, they generally extend completely to the pulpal floor, far beyond the reach of a sealer.

C factor has been oversimplified and remains a significant problem.

Posterior composites should go "on" not "in" the tooth.

Minimally Traumatic dentistry should be considered as an upgrade of "Minimally Invasive" dentistry. Well meaning dentists are promoting minimally invasive dentistry The best long term outcomes are more important than the race to minimize the micrograms of tooth structure that are removed. For example, the tunnel preparation preserves the enamel of the marginal ridge but unnecessarily weakens the tooth and impedes clinical visualization. Incomplete caries removal combined with excessive tooth weakening are unacceptable casualties of the noble mission to save marginal ridge enamel.

The Fissurotomy and "Cala Lilly" Class I; The Clark Class II

The fissurotomy class I, Cala Lilly Class I and the Clark Class II are fairly radical departures from GB Black's system of preparing and restoring posterior teeth. These new cavity designs are based on adhesive composite restorative materials and engineered to resists tooth fracturing. The new primary goal of first-time interproximal caries restoration is to avoid connecting the occusal to the interproximal a concept that Simonson first advocated
The different sizes of the occlusal portion of the new Clark Class II cavity preparation are summarized as follow

Small defects; Fissurotomy shaped

Moderate lesion; Cala Lilly shape

Large sized lesion or amalgam replacement; cusp tip to cusp tip splinting Cala Lilly shape

A New Fissurotomy Technique (Occlusal Portion

This new technique has five important components

First, the concept of "sealing over" caries and grossly contaminated pits and fissures is questioned, and replaced by exacting micromechanical instrumentation

Second, the size and shape of fissure preparation burs is completely modernized with the development of the Fissurotomy Bur System (SS White, Lakewood, NJ). The #556 is unfortunately the most utilized operative bur in dentistry and is largely responsible for the current "epidemic" of cracked teeth. Today this protocol involves the use of both the Fissurotomy Original Bur as well as the narrower Fissurotomy NTF Bur. Fissurotomy Burs are scientifically developed instruments for the diagnosis and treatment of hidden caries and should be utilized to create proper preparation form and function for the placement of composite restorations. The Fissurotomy NTF Bur is ideal for ultraconservative micro preparations of pit and fissure defects. The thin carbide tip of the Fissurotomy Burs will not "strip" quickly like thin diamonds

Third, each occlusal defect is addressed separately, wherein the clinician should avoid the temptation to "connect the dots

Fourth, the restorative material of choice is a robust, filled composite such as a flowable composite and/or heated paste composite

Fifth, the use of advanced clinical magnification ranging from 3.5X to 16X is imperative

The Calla Lilly (occlusal portion): The Cala Lilly, a beautiful trumpet shaped flower Its name was used to describe the new cavity shape for medium to large sized Class I composites. Traditional parallel walled cavity preparations have not been shown to provide the adequate volume of enamel rod engagement. Compounding the problem is parallel cavity walls that do not afford proper angle of intersection of enamel rods to provide long term splinting of posterior tooth

The Clark Class II (Interproximal portion

The goal of first-time interproximal caries restoration is to avoid connecting the occlusal to the interproximal, which is a concept that Simonson first advocated. The next evolution of this design is the saucer shape with serpentine/disappearing margins The final change is discarding and replacing old filling techniques, matrixing systems and curing techniques

Can These Things Last

Early posterior composites showed unacceptable wear. Microfills like Heliomolar had excellent wear resistance but mediocre strength. Marginal ridge fracture was common Many modern composites now exhibit excellent strength and wear resistance. In several studies, composite/enamel bonding has exhibited very lengthy in vitro success that does not deteriorate over time. The key is that the initial bond must be exquisite and engage large areas of enamel, such as seen in enamel-based porcelain and composite veneers

Composites Are Being Warmed Up

As the dental profession has turned increasingly to composite restorations, there has been a demand for improved clinical properties. A significant part of recent dental research has been focused specifically on eliminating practitioner concerns in the areas of material quality, ease-of-use, and finishing. The goal of both dentists and manufacturers is a restorative material that is relatively easy to place (not technique sensitive), convenient to polymerize (rapid and effective), long lasting and aesthetic

The major objectives in composite restoration include

Reduction of required light curing or polymerization time - many practitioners rush this step

Increased depth of cure - not every layer of composite is the suggested 2mm or less

Enhanced conversion (polymerization) ratio

These past three decades, research has focused on parameters such as various light sources, curing light intensity, curing time, clinical positioning, and the effect of moisture in the restorative field. Evaluating direct composite placement under varying thermal conditions has not been a common direction for research. This is rather surprising, considering that the physical property advantages of heat-curing composites in the manufacture of extra-orally fabricated inlays and onlays have been long been established

Instructions typically call on dentists to store their composites in a refrigerator until immediately prior to use. This is to ostensibly increase the materials' shelf-life and clinical properties. According to the latest research, this is probably the worst possible course of action

In fact, the warming of composites to body temperature or somewhat higher immediately prior to placement, has been shown to improve composite properties and to reduce curing times significantly. While any practical means may be used to heat the composite syringe or compule to the desired temperature, the Calset Composite Heater (shown in the picture) has been specifically designed to warm the materials to one of two scientifically predetermined levels. In evaluating the bottom hardness of composites that were cured with different light sources, varying only the composite's Temperature at the Moment of Polymerization (TMP), Bortolotto and Krejci1 found that the insertion temperature had a significant influence on the hardness of a composite. The restorations that were inserted pre-warmed to 40°C (only 3°C warmer than body temperature and therefore quite comfortable even for unanaesthetized teeth) were significantly harder (Vickers scale) than the composite restorations that were inserted at room temperature (22°C). The hardness values at 40°C were approximately double those where the composite was inserted at 5°C -the approximate temperature of a commercial refrigerator

Another very significant finding was that the curing time for a layer of composite at room temperature could be halved when it was warmed to 40°C, without affecting its hardness properties
Clinical significance: pre-warming restorative composite to slightly above body temperature improves the depth of cure AND reduces curing time by 50%

Stansbury's study of composite conversion values under various thermal conditions provides even more dramatic results. A higher conversion ratio (double bond formation = polymerization) at a greater depth increases the material modulus resulting in less flexure, and less potential for restoration fracture under loading Three esthetic restorative materials (microfill, hybrid, packable) were compared under three different light curing modes (LED, halogen, plasma arc) at two different temperatures (23°C and 54.5°C). An elevated composite temperature during photopolymerization offered substantially higher immediate and final conversion values in all the tested composite materials, and with all the different curing lights Elevating the composite temperature from 23°C to 54.5°C decreased the required curing time by 50-80%

Clinical significance: pre-warming restorative composite improves the conversion rate, with a concomitant improvement in the fracture resistance, of the material AND reduces curing time by 50% or more

Rueggeberg indicates that composite TMP significantly impacts polymerization time Once the restorative is warmed to body temperature, the next 20°C does not significantly reduce the curing time, however. At 58°C, there is a major upward step in the conversion ratio, remaining constant until 68°C, at which point another significant increase is noted. Ideal polymerization temperatures are found at the lower end of each thermal window: body temperature (37°), medium heat (54-58°C), and higher heat (68°C). Warmed composites exhibit no increase in polymerization when halogen curing is adjusted between 20-60 seconds

Clinical significance: ideal restorative composite pre-warming temperature points are scientifically established AND curing times For Pre-Warmed Composite Can Be Significantly Reduced

Littlejohn et al measured composite conversion at various TMP levels. a significant improvement in conversion was observed warming composite from room temperature to body temperature

Clinical significance: composite pre-warmed to at least body temperature offers a better restoration with improved physical properties, both in the short and the long term

Flowable resins help to achieve better marginal adaptation in large posterior restorations. This technique involves a clinical compromise, however. The flowable's decreased filler content provides the low viscosity; this requires a larger resin component, thereby increasing polymerization shrinkage

Visco-elastic composite resins exhibit decreased viscosity and greater flowability at higher temperatures. Rueggeburg5 demonstrated that a composite's film thickness is reduced by 30% as it is heated to 54°C. Thus, a pre-warmed micro-hybrid composite both flowable and highly filled, placed at the gingival margins of a deep restoration eliminates the technical compromise of flowable resins

Overheating the pulp is always a concern (iatrogenic damage can result). Rueggeberg measured the maximum intrapulpal temperature rise from the application of a 57.2°C composite material; the observed 1.6°C increase well within the established pulpal tolerance of more than 10°C

Clinical technique for pre-warming composite

Turn Calset unit on (press control switch once). The amber LED indicates normal function

Green LED flashes to indicate composite warming 10 minutes to reach 54°C

Green LED shines steadily to indicate pre-set temperature

Heated compule is loaded into the syringe gun and applied directly to the tooth preparation

For added convenience, the top portion of the Calset unit is removable from the heater and transportable to a remote location. The top segment acts as a heat sink that keeps the composite warm for several minutes. Neither extended warming (up to eight hours) nor repeated thermocycling of composites has any deleterious effects on the material's properties

Dental technicians have been placing and polymerizing composites under elevated thermal conditions in the fabrication of extra-oral composite restorations for many years

This technique is now available for direct intraoral composite restorations, as well

Pre-warming composites is a practical means predictably improving composite properties in dental restorations

Nociceptive Trigeminal Inhibition Reflex

TMD, Bruxism, chronic tension headaches, migraine, all are controlled and/or moderated by the Trigeminal Nerve System

The trigeminal nerve is the largest of the cranial nerves

Its name derives from the fact that it has three major branches: the ophthalmic nerve (V1), the maxillary nerve V2), and the mandibular nerve (V3). The ophthalmic and maxillary nerves are purely sensory. The mandibular nerve has both sensory and motor functions

All three divisions feed into the Trigeminal Sensory Nucleus

The current understanding of the nature of migraine is that it results froma disorder of "sensory modulation", meaning that information received by the Sensory Nucleus is misinterpreted, thereby resulting in either a disproportionate response, or an inappropriate response altogether. For example, during a migraine attack, the simple pressure changes of the fluid that surrounds the brain (resulting from the beatingof the heart), is perceived as "pounding
The therapeutic goal in migraine prevention is to limit the amount of noxious sensory input(that is, to limit your migraine "triggers") to the Trigeminal Sensory Nucleus, so that itis not perceived as nociception. Essentially, the goal is to limit as much negative inputto the Trigeminal Sensory Nucleus as possible

Temporomandibular disorders all have one perpetuating and/or causative factor in common: an excessive motor activity of the mandibular division of the trigeminal nerve, that is, excessive occluding of the teeth

;Four factors dictate the presenting signs and symptoms

Intensity of the occluding

Frequency of the occluding

Duration of the occluding

Degree of condylar translation and direction of the pull on the condyle by the lateral pterygoid during the occluding event

Of those four factors, the most significant is the intensity of the event

The ideal occlusal splint (left) cannot reduce the intensity of nocturnal clenching, in fact, it allows clenching to exceed voluntary maximum
Due to the bilateral intensity of elevation, (that is, clenching), neither lateral pterygoid has the ability to translate its condyle and disclude the teeth. Only until the temporalis' relax do all the teeth disclude.When temporalis relaxation and ipsilateral translation of the condyle occurs unilaterally (right), the remaining scheme of occluding teeth becomes an influential factor in the presenting signs and symptoms, of which, contacting canines during mandibular depression canine rise) is highly desirable, as it minimizes condylar translation and muscle intensity, while directing the vector pull on the condyle more anteriorly than a posterior contact. (The ideal directional pull of the LP's on the condyle is anteriorly, and the more translated the condyle is during parafunctional occluding events, the more pathologic strain on the condyle and shearing load to the disc there is

When lateral pterygoids bilaterally protrude the mandible (left: while teeth are still occluding), or when there is an incisor-to-incisor contact during functional closure, clenching (elevation) intensity is minimized. The force vectors of the pull of the lateral pterygoids on the condyles brace and support the condyle anteriorly against the slope of the eminence

Therefore, the provision of "incisal guidance" is the optimal goal of nocturnal occlusal splint therapy

In July 1998, the U.S. Food and Drug Administration (FDA) granted approval for the "NTI Clenching Suppression System" (now: "Nociceptive Trigeminal Inhibition Tension Suppression System": NTI-tss

According to the manufacturer, the NTI-tss device is indicated for the prevention and treatment of bruxism, temporomandibular disorders (TMDs), occlusal trauma, tension-type headaches and/or migraine

The NTI-tss device is a small pre-fabricated anterior bite stop which covers – in its most widely used form – the two maxillary (or mandibular) central incisors. The fit along the teeth is accomplished at the chair side by filling either an autopolymerizing acrylate or a thermoplastic material into the base of the device, which is subsequently adapted along the central incisors, thereby increasing the vertical dimension between the upper and lower jaw. Adjustments along the outer surface of the bite stop are made by the dentist to ensure that at jaw closure and during excursive movements tooth contacts are present only between the intraoral device and the incisal embrasures of the antagonistic teeth. This "miniature anterior bite appliance" is typically worn during the night, although two variations of the bite stop are offered for daytime use

Rationale

Chronic symptoms of the head and neck can often be attributed to

A) Headache -- the temporalis muscle (it closes and clenches the jaw

B) Sinus pressure and pain -- the lateral pterygoid muscles (it moves the jaw side to side and/or forward

C) Neck stiffness and pain -- trapezius muscle (it stabilizes the skull during jaw clenching and grinding

The NTI device snaps into place and fits comfortably on either the upper or lower front teeth. It is worn during sleep and prevents the intensity of muscular Para function. For migraine sufferers, there is a more discreet version for daytime use, which is usually required (in addition to nighttime device) for 6 to 8 weeks for best results

HOW DOES IT WORK

The Nociceptive Trigeminal Inhibition Tension Suppression System (NTI-tss) takes advantage of a protective reflex which suppresses the temporalis muscles from contracting with their fullest intensity

Here are a couple of examples of this protective reflex. Let's say you've just taken a candy bar out of the freezer. How do you know if it's too hard to eat? Easy, you bite on it with your front teeth. If it's so hard that your lower front teeth can barely make a dent in it without hurting, you know it needs to thaw out a bit. But what if you're really hungry and just can't wait any longer? Simple, just use your back molars and start crushing away! How about when you're eating carrots? You can nibble on the skinny ones with your front teeth, but the big fat ones need to go between your back teeth in order to break off a piece because it would hurt to use your front teeth. Or imagine you're having a bowl of thick'n'chunky beef stew. If you accidentally bite the spoon with your lower front teeth...yeow!You instantly open your mouth. What if there is a piece of bone in the stew? Unfortunately, you may discover it by chewing on it with your back teeth and splitting a molar in half

Here's what's happening. lower incisors are designed to warn you that what you're about to eat may be too hard to chew on. Whenever the lower incisors are put under moderate to severe pressure, they signal the temporalis muscles to relax before pain and damage can happen to them. This is called the jaw-opening-reflex. It is designed to prevent you from putting something too hard into your mouth that may be damaging to your back molar teeth. The back molars, on the other hand, do practically the opposite. Whenever something comes in contact with them (like frozen-solid Snickers Bars, a piece of bone, or TMJ splints), the back molars signal the jaw-closing muscles to bite down hard because they figure, since there's something between them; it must be time to chew

The NTI-tss device takes advantage of the jaw-opening reflex by only allowing contact to be made on only one or two of the lower front teeth (incisors), and never allowing any of the back teeth (or canine teeth) to touch. (The prevention of allowing canine and posterior teeth from contacting is probably just as important as the lone contact on the incisors

The reaserch shows that the contacting of either the canine or posterior teeth instantly allows a significant increase in temporalis contraction. Thus, when the mouth is being closed, a lower incisor will touch the NTI-tss appliance, suppressing the temporalis muscles' ability to contract! Of course, the NTI-tss appliance cannot be worn when actual eating and chewing are taking place

Tension headache and common migraine sufferers develop a habit of pressing some or all of teeth together when concentrating on something. They may squeeze our teeth together just a little bit or go for a full-on clench. Jaw may be lined up in the middle, or they may hold it off to the side a bit, and we have no idea we're doing it. By definition, they usually have absolutely no awareness of their habit. No one else is aware that they are doing anything abnormal because their clenching (whatever the degree) is a silent and motionless act (especially when sleeping, unlike "grinding" of teeth
There are two versions of the NTI-tss appliance, one for sleeping, and one for when awake. Daytime clenching activity by itself really doesn't cause anything, but acts as an irritant to pre-existing condition…one that was developed while asleep. Wearing the daytime appliance for a month or so (except when chewing) allows them to have a more intimate awareness of their habit and most importantly, frequently allows the signal to be sent to suppress the musculature (every time you "tap" on the device). Although clenching activity during sleep is impossible to stop, the nighttime

NTI-tss device allows for a suppressed or reduced intensity of muscle contraction (which may also by a function of not allowing for canine and posterior teeth to touch). It's important to point out that in the muscular parafunction world, it's the intensity of contraction that creates and perpetuates the symptoms
It's during certain stressful parts of the day (like during scary movies, driving, balancing your checkbook, when the sympathetic nervous system makes its presence felt.) and especially at night, when high intensity temporalis contraction occurs that the NTI-tss appliance is worn

Essentially, the NTI-tss appliance is a simple habit-breaking device for daytime, and prevents the sleep disorder of intense temporalis contraction at night

Contra indications

An anterior midline point stop (as provided by the NTI) has been shown to decrease (suppress) muscle activity, and allow the optimum musculoskeletally stable (anterior-superior) condylar position. In the event the patient’s condylar position is not optimal, the patient’s condyle may re-position more posteriorly/superiorly during resolution of their symptoms. This may result in a change of the patient’s occlusal scheme. Although this is not a result of "supraeruption", it may appear that way, due to the mandible pivoting at the distal most molar, possibly creating a lone contact which may be adjusted through equilibration

In the presense of MINIMAL INCISAL OVERLAP (for example, 1 or 2 mms, which is not uncommon following orthodontic therapy, as the mandibular incisor's brackets limit the degree of overlap), the potential for the development of an Anterior Open Bite is at its greatest
This fact should be pointed out to the patient. If they do not consent to the possibility of a change of occlusal scheme (even though symptoms have improved), this method of therapy is CONTRA-INDICATED

In the presence of advanced periodontal disease, the NTI alone should be used with caution
An opposing device should be considered

Not all occlusal schemes are compatible to the application of an NTI device without significant modifications to the device, such as in the case of severe flaring and/or rotation of the central incisors. A custom device may need to be fabricated instead

Following any apical or alveolar surgery to any of the teeth that support the NTI, discontinue use until completely healed

In the event of severely worn centrals (for example, a loss of 50% of tooth structure) an unaltered typical NTI device is contraindicated, due to lack of available undercut for retention

The device may need to be extended laterally to provide adequate retention

If the patient insists on a "more comfortable" fit, that is, not as snug, confirm that the patient CAN NOT remove the NTI without using their hands. The NTI is contra-indicated if the patient is non-compliant with the appropriate retentive adaptation

Its use is contraindicated if the supporting teeth have provisional restorations. (Use the Thermoplastic Beads instead

An unaltered NTI can not be placed in the presence of orthodontic brackets

Is endodontic treatment passé

It is easy to forget in today’s debate that competently performed endodontic therapy is one of the most predictable dental therapy forms available, with a well documented superb long-term retention of endodontically treated teeth

Dental implants are excellent treatment options in cases when natural teeth have been lost and require replacement
However, the erroneously perceived high rate of treatment success when inserting single tooth implants compared with endodontic treatment has, in recent years, often biased the general dentist’s objectivity when selecting treatment options

Minor concerns about endodontic treatment outcomes often lead to unnecessary tooth extractions and replacement with implants

Many currently published recommendations for extraction of endodontically treated teeth show a stunning ignorance about endodontic treatment outcomes
Surprisingly few official comments have been raised from the organized endodontic community to discuss this dissonance

Instead the American Association of Endodontists has clearly taken a subservient role in this discussion and issued some what ambivalent policy statements
In scientific studies of endodontic treatment outcomes, definitive unambiguous endpoints must be defined to describe treatment results

Such criteria were defined by Strindberg and have become the gold standard for outcome studies

Thus, after sufficient follow-up time, “success" (satisfactory healing) is described as a complete healing of the periradicular bone with a normal periodontal ligament and lamina dura

Teeth with failed endodontic treatment are often candidates for some form of retreatment to achieve complete elimination of periradicular disease
However, a case is often made that these teeth, scheduled for retreatment, are at high risk of repeated failure

This misunderstanding has resulted in an ever-ending large pool of teeth being candidates for single tooth implants identified by uncritical interests
There is ample evidence that in most of these cases, other treatment options are available to maintain a restorable tooth

It is somewhat difficult to understand how we got into this untenable position
Poor communication between various “guilds” of dental specialists and other interest groups is certainly one important factor
The scientific evaluation of successful endodontic treatment requires that the Strindberg criteria of complete bone healing remain the gold standard


For clinical purposes and in the daily assessment of treatment outcome, some “looser” terms, such as “healing" "functional” and “retained” may be more useful descriptions

For implant assessments, however, even the most fastidious evaluator is likely
to use “retained” as a characterization of good outcome

Confusion arises when less than precise clinical criteria of implant treatment are used to compare results when strict scientific endodontic criteria were applied

As a result, it is often wrongly stated that the long-term treatment success rate is equal for endodontic treatment and a single tooth implant

According to many recent reports on the outcomes of endodontic treatment, there are very few teeth that cannot be retained if the full scope of endodontic treatment options issued

Dental implants have been used for many years but not until recently have relatively objective studies of long-term outcomes been available in the literature
The endpoint descriptor in implant studies is often unclear and the desirable result often characterized as a retained implant

It is also rather clear that implants tend to fail in increasing numbers with time
With a 7-year retention rate close to 90% and with more stringent success criteria the rate falls to 83% again

Still, implants with signs of peri-implant infection and maintained by adapted antimicrobial treatment were not considered to be failures in that study
This is a positively biased attitude to peri-implantitis, because it is a difficult to treat chronic pathologic condition with a low rate of long-term success
Similar treatment results have been reported by others

The most convincing value of endodontic treatment is its long-term success and permanence
A periapical lesion that heals after a quality treatment, followed by proper restorative maintenance, will not fail later due to endodontic reasons
Endodontic treatment results are also improving with time
Several studies published during recent years have assessed the retention rate of endodontically treated teeth, those studies show how endodontically treated teeth are retained at

about 95%-97% after 8 years compared with 85%-90% for implant retention during a similar time period

It is also important to notice that implant data available today are from carefully controlled clinical studies with intensive maintenance
No objective long-term data are available on implant survival in a general dental practice setting

On the other hand, endodontic numbers discussed here are retention data from average non specialized dentists

Complications after restorative procedures, such as root fractures, are often mentioned as a strong negative factor against restoring and preserving endodontically treated teeth
However, these treatment complications may be more associated with substandard prosthetic work and poor material choices than with an endodontic complication

In a recent follow-up study of a substantial patient material, the life span of well constructed full crowns on cast posts was equal or higher than full crowns on teeth with vital pulp

Implant is an excellent treatment option for the replacement of a missing tooth However, it should never be an option for the replacement of an existing restorable tooth

A recent literature review and meta-analysis found that natural teeth surrounded by healthy periodontal tissues yield a very high

longevity of up to 99.5% over 50 years

Periodontally compromised teeth that are treated and maintained regularly have a rate of 92%-93 % in survival
That study concluded that oral implants, when evaluated after 10 years of service do not surpass the longevity of even compromised but successfully treated natural teeth

Therefore, an implant should not be a treatment alternative for teeth that a reasonable competent dentist can restore and care for
Endodontic orthograde or retrograde treatment should always be the first treatment choice of a tooth having ongoing endodontic disease

Conclusions of the WHITE PAPER ON THIRD MOLAR DATA of the AAOMS

A Task Force was convened by the American Association of Oral and Maxillofacial Surgeons in March 2007 to review the current literature with regard to selected aspects relating to third molars and their removal

Here are the conclusions of the final report named
WHITE PAPER ON THIRD MOLAR DATA

The Natural History of Third Molars
While it is not possible to predict eruption of third molars in all cases, adequate space
between the anterior border of the mandible and the distal of the mandibular second molar seems to be necessary to allow successful eruption to the occlusal plane Assessment of this space can be determined using a variety of radiographic techniques
However, eruption to the occlusal plane does not imply a good state of health particularly with respect to soft tissue support
Finally, third molars that remain impacted after the age of 25 may still change in position

Periodontal Considerations in Third Molar Removal
The presence of impacted third molars adversely affects the periodontium of adjacent second molars as reflected in disruption of the periodontal ligament, root resorption and pocket depth associated with loss of attachment

The removal of impacted third molars can negatively impact the periodontium of adjacent second molars
The preoperative existence of an intrabony defect, age of the patient, and level of plaque control may serve to predict adverse outcomes

No single surgical approach to the removal of third molars that will minimize loss of
periodontal attachment was identified
GTR and/or DBP may be beneficial in instances where there is evidence of significant
pre-existing attachment loss
Scaling, root planing, and plaque control have the potential to reduce post-operative loss of attachment
Further research is needed to clarify under what conditions GTR and/or DBP can
contribute to minimizing post-operative periodontal defects

The presence of visible third molars is associated with overall elevated levels of
periodontitis and that of immediately adjacent teeth
In the presence of visible third molars, periodontitis involving adjacent teeth is
progressive and only partially responsive to therapy

The evaluation of a visible third molar for removal should include an assessment of the periodontium associated with both the third molar itself and that of adjacent teeth and include anatomical limitations to mechanical removal of plaque
The presence of pocket depths of 4-5 mm and/or bleeding on probing should be recognized as possible predictors of future progression of periodontitis
The association of overall increased disease severity in the presence of visible third
molars, the progressive nature of periodontitis involving non-third molars when third
molars are present, the relationship between visible third molars and bacteria associated with severe and refractory periodontitis, and the negative impact of visible third molars on treatment outcomes all lend support to the hypothesis that third molars should be considered as a possible predictor of periodontitis
Third molars should be included in studies of periodontal disease prevalence and
severity, and in studies assessing factors that may indicate an increased risk for
periodontal disease

The Microflora Around the Second and Third Molars
Data on microflora and asymptomatic disease in the third molar region show
Absence of symptoms does not indicate absence of disease or pathology
Pathogenic bacteria (red and orange complexes) in clinically significant numbers exist in and around asymptomatic third molars
Periodontal disease as indicated by probing depths > 4 mm exists in and around
asymptomatic third molars
Indicators of chronic inflammation exist in periodontal pockets in and around
asymptomatic third molars
Periodontal disease progresses in the absence of symptoms

The Effects of Age on Various Parameters Relating to Third Molars
Periodontal defects, as assessed by pocket depths, deteriorate with increasing age in the presence of retained third molars
Caries in erupted third molars increases in prevalence with increasing age
The incidence of postoperative morbidity following third molar removal is higher in
patients > 25 years
Germectomy may be associated with a lower incidence of postoperative morbidity

Orthodontic and Prosthodontic Considerations in Removal of Third Molars
Despite good intentions, we are not able to explain, predict, or prevent dental crowding, no matter what the cause
While it is likely that third molars play a role in the etiology of crowding, they are only one factor to consider in making a clinical decision about third molar management
Therefore, it is prudent for clinicians to educate patients that the cause of dental crowding is multi-factorial and, while third molars may play a significant role in
some patients, the current state of knowledge does not allow us to identify with accuracy who is at risk
The position and disposition of unerupted teeth has been found to be dynamic and
unpredictable
Therefore, the ultimate decision regarding the management of such teeth is best made by an expert clinician after clinical examination and review of factors such as the
age of the patient, position of the tooth, anticipated difficulty of removal, type of overlying prosthesis, and risks associated with removal

Current Imaging Techniques
The exact role and indications for CT imaging for the management of impacted third molars is unclear and evolving
Additional investigations are warranted to better understand and outline the parameters for effective use of CT imaging in the management of third molars

The Possible Role of Coronectomy (also known as partial tooth removal, partial
odontectomy or intentional root retention) in Third Molar Removal
When imaging suggested an intimate relationship between the roots of the lower third molar and the IAN and the tooth still needs to be removed, consideration should be given to coronectomy with retention of the portion of the roots associated with the IAN
Since there are only five papers in the literature describing more than single cases there is no standard of care with regard to this technique, and until more information is available this technique should be considered as an alternative only

The Role of Lingual Flap Elevation and Lingual Retraction in the Management of
Third Molars
Raising a lingual flap and the use of a lingual retractor for selected indications is felt to bean acceptable technique for removal of lower third molars
The periosteal elevator must remain subperiosteal at all times
A lingual retractor must be broad and without sharp edges so as to protect and not damage the lingual nerve

Should Anything Be Placed in the Socket Following Third Molar Removal
While non-resorbable and resorbable GTR, DBP, and platelet rich plasma (PRP) work in the setting of high-risk or near high-risk third molars, DBP is the simplest to use

Nerve Damage – Prevention, Evaluation and Management in Relation to Third Molars
Occasional damage to the inferior alveolar and lingual nerve occurs following third molar surgery
At least 50 percent of cases recover spontaneously
Attempts to standardize objective evaluation of nerve injuries have been unsuccessful
The results of nerve surgery are variable, but if carried out between 4.5 and 7 months over 50 percent of patients probably show improvement
Later repairs, up to 47 months post injury, can still show some recovery
It is possible that in some cases there may be some recovery of taste in the case of lingual nerve

repair

THE FULL PAPER IS AVAILABLE AT

www.aaoms.org/docs/third_molar_white_paper.pdf

Laser Used To Help Fight Root Canal Bacteria

High-tech dental lasers used mainly to prepare cavities for restoration now can help eliminate bacteria in root canals, according to research published in the July issue of The Journal of the American Dental Association (JADA

The study, conducted by researchers in Austria, credits the development of miniaturized, flexible fiber tips for allowing the laser to be used in endodontic (root canal) treatment

Dr. Ulrich Schoop and a team of researchers in the dental school at the University of Vienna used-60 extracted human teeth with one root each to test the effects of laser irradiation on root canals using an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser.

Dr. Schoop and colleagues inoculated the root canals with one of two types of bacteria Enterococcus faecalis and Escherichia coli and then irradiated the canals using either a 1- or1.5 watt power setting.

The team found that the laser reduced the amount of E-choli at the lower power setting and reduced it to below the detection level at the higher setting. It also was effective in eliminating E. faecalis.

Researchers found, too, that the laser removed the smear layer and debris from the root canal walls and that the temperature rise during irradiation was within safe borders.

The authors concluded that the Er,Cr:YSGG laser may be suitable for cleaning and disinfecting root canals and that it can be used safely if the common precautions for using lasers are observed and the energy levels and irradiation times are within the proposed range.

They also suggested that clinical studies are needed to confirm their laboratory findings.

In a related article in July JADA, Dr. Roy H. Stevens and colleagues at the Kornberg School of Dentistry, Temple University, describe their study of an Er,Cr:YSGG laser with a new tip that emits radiation radially.Dr. Stevens and colleagues examined the efficiency of this new laser tip in disinfecting root canal dentin walls infected with E. faecalis.

They found that it significantly reduced the amount of E. faecalis in contaminated root canals

More researches will be conducted in this field, it may become the future treatment option in endodontics.

Differnt Designs of Dental Clinics

Treatment Strategies for Teeth Hypersensitivity

Clinical significance of hypersensitivity

Dentinal hypersensitivity, while neither life threatening nor a serious dental problem, can be a particularly
uncomfortable and unpleasant sensation for patients and can dictate types of foods and drinks ingested.
Patients may describe the condition as dull or sharp, vague or specific and intermittent or constant. Teet causing such symptoms are rarely considered to be as seriously affected as those affected by caries, endodontic problems or periodontal disease, however, the condition is nonetheless of sufficient concern to warrant appropriate and proper management. In most instances the condition can be managed by patients through appropriate home care using properly prescribed over the- counter products. These features of the condition negate, in the majority of cases, the need for expensive and lengthy professional care. Notwithstanding the above, the condition still requires an appropriate differential diagnosis since carious exposure of dentine surfaces, inflamed pulps or cracked cusps can produce symptoms similar to cervical dentinal hypersensitivity.

Treatment for hypersensitivity

There is a surprisingly large number of treatment options for managing dentinal hypersensitivity. Chemical or physical agents are used to either desensitize the nerve or cover the exposed dentinal tubules. The most common form of management is the placement of a topically applied agent applied either by a dental professional or by the patient at home. All currently available treatments appear to work.
Several criteria are recognized as constituting an ideal desensitizing agent. These include not irritating the pulp, being relatively painless to apply, easily applied, rapid action, permanently effective and should not discolour the teeth.20 Overall, patient responses are very subjective and thus treatment results are largely dependent upon the individual’s pain threshold.

Role of dental plaque

While there are many factors which can contribute to dentine hypersensitivity, plaque accumulation has often been cited as an important factor.23 Plaque accumulation on root surfaces may lead to demineralization of tooth structures which could be associated with patency of dentinal tubule orifices.23 It has been reported that patients who maintain good levels of plaque control are less likely to report dentine hypersensitivity.24 On the other hand, patients who have significant proportions of their root surfaces covered with dental plaque report more problems with dentine hypersensitivity.
Despite these findings, the influence of plaque on dentine hypersensitivity remains controversial. Interestingly, many patients with gingival recession have minimal plaque deposits yet still complain of sensitivity.

Nerve desensitization

Potassium nitrate

A number of studies have reported the efficacy of potassium nitrate for managing dentinal hypersensitivity.
While the Hodosh study was the first to report that potassium nitrate was a “superior desensitizer” this study was not well controlled and it was not until the studies of Tarbet et al that good evidence for the efficacy of potassium nitrate in managing dentinal hypersensitivity was demonstrated.
These controlled studies demonstrated that potassium nitrate at a concentration of 5% in a low abrasive toothpaste was able to desensitize dentine for up to four weeks compared to a control paste. Potassium nitrate in bioadhesive gels at 5% and 10% has also been shown to be effective in reducing dentinal hypersensitivity. Importantly, it has been shown that potassium nitrate does not induce any pulpal changes.
Despite these encouraging findings it is interesting to note that a recent Cochrane Database Systematic
Review failed to find strong evidence supporting the efficacy of potassium nitrate toothpaste for dentine
hypersensitivity.34 Nonetheless, this review did report that the differences which were noted were statistically significant in favour of treatment with potassium nitrate toothpaste.
The mechanism of action of potassium nitrate is largely unknown, although an oxidizing effect or blocking of tubules by crystallization has been proposed28 but not proven. The effect of potassium nitrate on dentinal fluid flow has been reported to be minimal even at a 30% concentration.35 A more likely explanation is that the potassium ions are the active component and that potassium nitrate reduces dentinal sensory nerve activity due to the depolarizing activity of the K+ ion,36 although this proposal has never been confirmed in intact human teeth

Anti-inflammatory agents

Corticosteroids

Anti-inflammatory agents such as corticosteroids have been proposed for use to manage dentine hypersensitivity. However, trials have not found them to be particularly useful.22 While it is presumed that these agents may induce mineralization leading to tubule occlusion, this view has yet to be validated38 and the validity of using such agents has been questioned.

Covering or plugging dentinal tubules

Calcium hydroxide

Several studies have reported on the effectiveness of calcium hydroxide in managing dentinal hypersensitivity. Its mode of action has been proposed to be via occlusion of dentinal tubules through the binding of loose protein radicals by calcium ions42 and increasing mineralization of the exposed dentine. Although immediately effective, the action of calcium hydroxide diminishes rapidly requiring multiple applications to maintain its effect.19 A negative feature of calcium hydroxide is its reported irritation of gingival tissues.

Casein phosphopeptides

A relatively new product on the market composed of casein phosphopeptides has been used for the management of dentinal hyperersensitivity. Despite a number of anecdotal case reports on various websites, to date there are no published studies reporting the efficacy of this material for dentinal hyperersensitivity.

Sodium fluoride

Many clinical studies have shown that treatment of exposed root surfaces with fluoride toothpaste and concentrated fluoride solutions is very efficient in managing dentinal hypersensitivity.43-45 The improvement
appears to be due to an increase in the resistance of dentine to acid decalcification as well as to precipitations in the exposed dentinal tubules. Tal et al.46 suggested that the probable desensitizing effects of fluoride are related to precipitated fluoride compounds mechanically blocking exposed dentinal tubules or fluoride within the tubules blocking transmission of stimuli.

Sodium monofluorophosphate

Toothpastes containing sodium monofluorophosphate have been shown to be effective in managing dentinal hypersensitivity.47,48 The mechanism of action of sodium monofluorophosphate is unclear.21 It does not appear to act by occluding dentinal tubules since scanning electronmicroscopic studies have failed to demonstrate any visual changes to the dentine surface treated with sodium monofluorophosphate.21 Any tubule occlusion which might occur does not appear to be permanent.

Stannous fluoride

Stannous fluoride in either an aqueous solution or in glycerine gelled with carboxymethyl cellulose is
effective in controlling dentinal hypersensitivity.50 The mode of action appears to be through the induction of a high mineral content which creates a calcific barrier blocking the tubular openings on the dentine surface.Alternatively, stannous fluoride may precipitate on the
dentine surface leading to occlusion of the exposed dentinal tubules.

Fluoride iontophoresis

Iontophoresis is the process of influencing ionic motion by an electric current and has been used as a desensitizing procedure in conjunction with sodium fluoride.42 Studies report that there is an immediate reduction in sensitivity after treatment with iontophoresis, but the symptoms gradually return over the ensuing six months.52 This method has enjoyed some popularity but more controlled studies are required.

Formaldehyde or glutaraldehyde

Claims have been made that formaldehyde and glutaraldehyde, through their ability to precipitate salivary proteins in dentinal tubules, can be used to manage dentinal

hypersensitivity. However, this effect
has been questioned since various formulations have been found to have little or no effect on dentinal hypersensitivity.Given that these agents are very strong tissue fixatives, they should be used with extreme
caution to ensure they do not come in contact with the vital gingival tissues.

Dentine sealers

Resins and adhesives

Sealing of dentinal tubules with resins and adhesives has been advocated for many years as a means of managing dentinal hypersensitivity.55 In general, results have been good but problems arise when the adhesive breaks away resulting in exposure of the tubules. This technique is generally reserved for cases of specific and localized dentinal hypersensitivity rather than generalized
dentinal pain.

Lasers

Both the Nd:YAG and CO2 lasers have been studied for their use in managing dentinal hypersensitivity. Both applications rely on their ability to occlude the dentinal tubules. The Nd:YAG laser has been used in conjunction with sodium fluoride varnish with encouraging results showing up to 90 per cent of the dentinal tubules being occluded through use of this combined therapy.56 CO2 laser irradiation and stannous fluoride gel has also been shown to be effective for inducing tubule occlusion for up to six months after treatment.57,58 While still largely experimental, this technique requires further scientific investigation before it becomes a clinically acceptable means of treatment.

Combination of desensitizing agents and fluoride

Because some effective desensitizing dentifrices (such as those containing potassium nitrate) were not fluoridated, people requiring relief from dentinal sensitivity and protection against dental caries needed to use both desensitizing and fluoridated dentifrices. As a result a number of well-controlled clinical studies have been carried out to determine the efficacy of potassium nitrate as a desensitizing agent in dentifrices containing fluoride.As early as 1992, the United States Food and Drug Administration granted Category 1 status to combination 5% potassium nitrate:fluoride dentifrices, indicating they were not only safe but also effective.

Restorative materials

The use of restorative materials is generally an invasive solution to the problem of hypersensitivity. Commonly used materials include composite resins and glass ionomer restorations. Generally this approach is reserved for situations where there has been significant prior loss of cervical tooth structure or as a last resort for a tooth which does not respond to other less invasive desensitizing protocols.

Periodontal surgery

There are numerous soft tissue grafting procedures which can be carried out to cover exposed root surfaces including lateral sliding grafts, free gingival grafts, connective tissue grafts and coronally repositioned flaps. While these procedures may cover exposed dentinal tubules, some are not very predictable in terms of their efficacy in root surface coverage. Soft tissue grafting for localized recession defects requires careful planning and an understanding of the anatomical defect to be treated. In general, soft tissue grafting for the management of sensitivity is not regarded as a very predictable treatment strategy.

Safety of commonly used at home desensitizing agents

Most “at home” desensitizing agents are generally restricted to dentifrices and mouthrinses containing one or a combination of the agents discussed above. Of these, the most common “active ingredients” are potassium nitrate, stannous fluoride, sodium fluoride, sodium monofluorophosphate and strontium chloride.For all products which are currently on the market as over-the-counter products extensive toxicity testing has already been carried out by the manufacturers and has been reviewed by various regulatory bodies to ensure both safety and efficacy. Although there is only minimal evidence to demonstrate superiority of one desensitizing agent over another, there is ample evidence that desensitizing toothpastes do provide benefit to the patients suffering from dentinal hypersensitivity. As a general rule, all well performed clinical studies published in the literature report safety assessments of the products under study.60 Moreover, in recent times, studies carried out within universities require the approval of a human ethics committee prior to commencement. All such committees require safety issues of products under investigation to be reported as part of the routine experimental protocol. Safety measures for toothpastes generally include adverse event data to elicit complaints/symptoms of the subjects at each examination time point and by evaluating changes in medical history and concomitant medications. All adverse reactions are recorded, listing the date of onset, duration, frequency, maximum intensity, seriousness, action taken and outcome. In addition, the oral soft tissues and perioral area should always be visually examined to evaluate effects that could be manifested as a tissue response to an irritant, soft tissue pathology or other clinically meaningful deviations from the normal. It is of particular note here that there are very few (if any) reports of adverse reactions to dentifrices containing the desensitizing agents listed above (Table 2). A Medline search (concluded December 2005) failed to find any citations regarding adverse reactions, toxicity or safety problems with strontium chloride or potassium nitrate. Only a few citations were found for fluoride formulations and these involved predominantly children. Since dentinal hypersensitivity is considered to be a response to a localized condition within individual teeth and is not indicative of, or related to, any known
systemic condition, management of dentinal hypersensitivity is not considered to mask or impact on any other systemic conditions which a patient might have.

There is no literature to support the concept that dentinal hypersensitivity is anything other than a well-localized dental problem. Finally, one of the most effective treatments for the majority of patients is simple daily plaque removal. Daily plaque removal over time allows demineralization of the dentinal tubules from salivary minerals and can alleviate much of the discomfort caused by exposed dentine. The use of an additional aid, such as a dentifrice containing additional agents which might expedite (or at least encourage) improved oral hygiene and daily plaque removal, is not considered harmful to either the tooth, the surrounding soft tissues, or the whole body.

CONCLUSION

Dentinal hypersensitivity is a relatively common and significant dental problem which can be successfully managed by a very wide variety of procedures, agents and formulations applied locally, either “in office” or “at home”. It is clear that some products appear to be more effective than others. For those products developed for self application at home, potassium nitrate, stannous fluoride, sodium fluoride, sodium monofluorophosphate and strontium chloride have all been extensively studied and shown to be not only safe to use but of benefit to individuals suffering from dentinal hypersensitivity.

Brushing Dentures Might Be Best Cleaning Method

Brushing dentures with a paste product might be the best way to keep them clean, better than soaking in effervescent or enzyme cleaning solutions, suggests a new review of what little dental literature exists on the topic. Keeping dentures clean and free from plaque buildup can help prevent oral infections and gingivitis; however, few clinical studies focus on the best way to clean partial or complete dentures.This scarcity of studies on real-life patients was surprising, said lead review author Raphael Freitas de Souza, D.D.S.

Studies compared different denture cleaning methods to one another or to a placebo.

Cleaning methods included soaking dentures in enzyme solutions, soaking in effervescent solutions, routine brushing with a paste product and a combination of brushing and soaking.

The studies examined the effects of each method on outcomes such as irritation in the mouth or inflammation of the gums and other oral tissue, the presence of bad breath and how much plaque was on the dentures.

Although it is not possible to draw a strong conclusion on what method works best, de Souza said, there was weak evidence that among chemical cleaners, enzyme-cleaning products were more effective than a placebo."We cannot be pretty sure what the most effective methods for denture cleaning are. But we can infer possibly that brushing can give better results," he said.

A patient with poor manual dexterity who cannot brush well might be better off using chemical cleaners and soaks, he added.

Systematic reviews such as this one draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.The results of the review are interesting, but might have little effect from a practical standpoint, said Susan Brackett, D.D.S, director of public and professional relations for the American College of Prosthodontists. She is in private practice as a prosthodontist in Oklahoma City."We give our patients a sheet of instructions and recommend that they mechanically clean the dentures by brushing with dishwashing soap to get the major debris off," she said.

All dentures should be stored in water or a cleaning solution overnight because dentures should not dry out, she added. "If they like, patients can soak the dentures in an effervescent solution overnight. You can do both mechanical and chemical, but it is not absolutely necessary."

De Souza said that professionals usually do not recommend boiling dentures because it can cause them to deform. Similarly, heating dentures in water or another solution in a microwave oven can cause damage to the dentures, Brackett said.

If using household bleach do so carefully, because it can cause discoloration in gum-colored portions of dentures, she added. "We do recommend a solution of water, bleach and Calgon to treat a yeast infection, but that is not something for routine basis," she said.Another cleaning method is an ultrasound device that vibrates the water the dentures are in. Brackett said that battery-operated ultrasound cleaners are available for about $10, but that the professional models used by prosthodontists' offices to clean dentures are better. In her office, dentures undergo ultrasonic cleaning when the patient comes in for an annual check-up, which is advisable both to check for fit and wear and tear on the dentures and to screen for head and neck cancer.

Resorption of Byond Apex Calcium Hydroxid Paste in RCT

Calcium Hydroxide is widely used in endodontics for a number of purposes. Its antimicrobial properties are attributed to its high pH (basic), destructive effects on bacterial cell walls and ability to dissolve organic tissue. It is used routinely as an intracanal medicament. It is also used for apexification, apexigenesis, treatment of root resorption.

Ca(OH)2 used in endodontics is made with Ca(OH)2 powder, a vehicle and a radiopacifier. Most common radiopacifiers are barium sulfate, bismuth or compounds containing iodine or bromine. While radiopacifiers make the calcium hydroxide more visible radiographically, some radiopacifiers are known to resorb at a slower pace, sometimes making it difficult to see the subtle changes.

While the control of a paste material at the apex of a canal can be very difficult, the resorptive properties of calcium hydroxide make it a very forgiving material. Extrusion of calcium hydroxide past the apex of a tooth is not uncommon. In fact, there are some who would recommend deliberate extrusion in the case of a large, chronic periapical lesion to help in the healing of such a lesion.

Calcium hydroxide (Ultracal - Ultradent - 35% Ca(OH)2 with barium sulfate) was used during treatment of this tooth to control exudate prior to obturation. A significant amount was extruded past the apex in close approximation to the maxillary sinuses during the endodontic treatment.




14 months later, the patient returned for treatment of #14. Our recall radiograph of #15 shows complete resorption of Ca(OH)2. The patient had no complaints and is in full function.



Sources:

Hasan Orucoglu, Funda Kont Cobankara, "Effect of Unintentionally Extruded Calcium Hydroxide Paste Including Barium Sulfate as a Radiopaquing Agent in Treatment of Teeth with Periapical Lesions: Report of a Case", Journal of Endodontics, July 2008 (Vol. 34, Issue 7, Pages 888-891)