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Showing posts with label Cosmetic Dentistry. Show all posts
Showing posts with label Cosmetic Dentistry. Show all posts

Tuesday, September 13, 2011

Tooth Whitening


Tooth Whitening

What Is It?
Tooth whitening lightens teeth and helps to remove stains and discoloration. Whitening is among the most popular cosmetic dental procedures because it can greatly improve how your teeth look. Most dentists perform tooth whitening.
Whitening is not a one-time procedure. It will need to be repeated from time to time if you want to maintain the brighter color.
What It's Used For
The outer layer of a tooth is called the enamel. The color of natural teeth is created by the reflection and scattering of light off the enamel, combined with the color of the dentin under it. Your genes affect the thickness and smoothness of the enamel. Thinner enamel allows more of the color of the dentin to show through. Having smoother or rougher enamel also affects the reflection of light and therefore the color.
Every day, a thin coating (pellicle) forms on the enamel and picks up stains. Tooth enamel also contains pores that can hold stains.
The most common reasons for teeth to get yellow or stained are:
  • Using tobacco
  • Drinking dark-colored liquids such as coffee, cola, tea and red wine
  • Not taking good care of your teeth
Aging also makes teeth less bright as the enamel gets thinner and the dentin becomes darker.
It is also possible to have stains inside the tooth. These are called intrinsic stains. For example, intrinsic stains can be caused by exposure to too much fluoride as a child while teeth are developing. Other causes include tetracycline antibiotics. They can stain a child's teeth if taken by a mother during the second half of pregnancy or by a child who is 8 years old or younger. Teeth are still developing during these years. Trauma may also darken a tooth.
Tooth whitening is most effective on surface (extrinsic) stains.
Preparation
Other dental problems can affect the success of tooth whitening. For example, cavities need to be treated before teeth are whitened. That's because the whitening solution can pass through decayed areas and reach the inner parts of the tooth. If your gums have receded, the exposed roots of your teeth may appear yellow or discolored. Whitening products will not make them whiter.
If you have tooth decay or receding gums, whitening may make your teeth sensitive. Whitening also does not work on ceramic or porcelain crowns or veneers.
Whitening can be done in the dental office or at home. For in-office whitening, your dentist probably will photograph your teeth first. This step will help him or her to monitor the progress of the treatment. Your dentist also will examine your teeth and ask you questions to find out what caused the staining.
Next, the dentist or a dental hygienist will clean your teeth. This will remove the film of bacteria, food and other substances that build up on your teeth and contribute to the staining. Once this is done, the whitening procedure begins.
For whitening at home, your dentist can make trays to hold the whitening gel that fit your teeth precisely. Home whitening gel usually needs to be applied daily for two to three weeks. Over-the-counter kits also are widely available for home use. They provide trays to hold the gel, or whitening strips that stick to your teeth. Talk to your dentist if you want to use these home products. Be sure to follow directions to avoid overuse and possible damage to your teeth and mouth.
How It's Done
There are two main types of whitening procedures. Non-vital whitening is done on a tooth that has had root-canal treatment and no longer has a live nerve. Vital whitening is performed on teeth that have live nerves.
Non-Vital Whitening
Vital whitening may not improve the appearance of a tooth that has had root-canal treatment because the stain is coming from the inside of the tooth. If this is the case, your dentist will use a different procedure that whitens the tooth from the inside. He or she will place a whitening agent inside the tooth and put a temporary filling over it. The tooth will be left this way for several days. You may need this done only once, or it can be repeated until the tooth reaches the desired shade.
Vital Whitening
The most common type of vital tooth whitening uses a gel-like whitening solution that is applied directly to the tooth surface. This product contains some form of hydrogen peroxide.
Tooth whitening can be done in the dentist's office or at home. In-office (chairside) whitening allows your dentist to use a more powerful whitening gel. A specialized light or laser activates the gel and allows bleaching to happen faster.
In-office whitening usually takes 30 to 90 minutes. You will need one to three appointments. The number will depend upon the method used, how severe your stains are and how white you want your teeth to be. Different types of stains respond differently to the treatment.
First, your dentist will apply a substance that covers and protects the gums around the teeth. Then, the whitening agent, usually hydrogen peroxide, will be placed on the teeth.
Some whitening agents are activated by a laser light, special lights or by the heat from these lights. After the whitening agent is applied, the dentist will shine the light on your teeth. If your teeth are badly discolored, your dentist may suggest that you continue the bleaching process at home for a few days or weeks.
For in-home whitening, your dentist will take impressions of your upper and lower teeth and will make custom mouthpieces to fit you. The mouthpiece needs to fit well. A close fit helps the whitening agent remain in contact with your teeth.
At home, you will fill each mouthpiece with a whitening gel your dentist provides. You will wear the mouthpiece for several hours every day. Many people achieve the amount of whitening they want within a week or two. However, you may need to wear the mouthpiece for four weeks or longer.
You also can buy whitening products over the counter. They contain a weaker whitening agent than the products you can get from your dentist. Therefore, whitening may take longer. The whitening agent is applied as a gel placed in a mouthpiece or as a strip that sticks to your teeth. Over-the-counter mouthpieces fit less securely than the kind you get from your dentist.
Whitening toothpastes are available as well. They contain abrasives that remove stains on the enamel. They do not actually change the overall color of your teeth.
Follow-Up
If you find that your gums are white or sore, follow up with your dentist.
Whitening is not a permanent solution. The stains will come back. If you smoke or consume a lot of staining foods or drinks, you may see the whiteness start to fade in as little as one month. If you avoid these sources of staining, you may not need another whitening treatment for 6 to 12 months.
Re-whitening can be done in the dentist's office or at home. If you have a custom-made mouthpiece and whitening agent at home, you can whiten your teeth as frequently as you need to. Discuss your whitening schedule with your dentist. You can talk about what whitening products would work best for you.
Risks
Whitening is unlikely to cause serious side effects, although some people's teeth may become more sensitive for a short while. You may get mild gum irritation as well. Women should not have their teeth whitened while pregnant. The effect of the whitening materials on the development of the fetus is not known. Since the procedure is cosmetic, it should be postponed until after delivery.
When To Call a Professional
If you feel your teeth would benefit from whitening, contact your dentist to discuss the procedure.
_____________
Request for appointment at: (415) 391 - 7751
450 Sutter street, Suite 1905
San Francisco, CA, 94108

 
 

Sunday, September 4, 2011

Cavity Preparations for Posterior Composite Resins


Cavity Preparations for Posterior Composite Resins

Read Dr. Karl F. Leinfelder's seasoned advice about working with composite.

The first attempt to substitute composite resins for amalgam restorations came nearly forty years ago. Two basic problems were identified. These included an unacceptable rate of wear and a higher incidence of caries as compared to amalgam. Furthermore the progression of caries under composites was appreciably greater than with amalgam. While the exact reason for the caries progression differential has not been identified it is interesting to note that the amalgam releases a number of ionic elements (silver, copper, tin, mercury) that might retard  the process of caries progression. Composite resins on the other hand possess no such attribute.

Fortunately the problem of wear or loss of anatomic form has been essentially resolved. By reducing in part, the dimension of the filler particle and increasing the load rate, the wear of composite resins is essentially the same as amalgam which is approximately five microns per year. The problem of secondary caries still exists. The primary reason can be attributed to a less than ideal adaptation of the restoration to the margins of the preparation. The use of dentin bonding agents as well as flowable composites has contributed appreciably to a reduction in this clinical problem.

In addition to all of these changes, modification of the cavity preparation has been most contributive to a successful posterior composite resin restoration. When composites were first used as a posterior restorative material the preparation most commonly used was designed for amalgam. Developed by G.V. Black the preparation was engineered to automatically incorporate most of the proximal region of the tooth containing the highest plaque concentration and bacteria count. Buccal and lingual extension of the preparation was limited so as not to considerably reduce the strength of the tooth itself. Extension of the preparation bucally and lingually would ensure that the margins of the restoration be positioned into an area of relatively low bacterial count. This is an important consideration since the margin of the amalgam at the time of placement averages 10 to 12 microns. Such an interfacial gap is great enough to allow the invasion of caries-producing micro-organisms. In the case of composite resins there is no such interface. The use of dentin bonding agents causes the restoration to become an integral part of the cavity preparation along the entire length of the margin. As a result, a well-placed posterior composite resin technically contains no gap or interface for microbes to enter.

When caries was present in the mesial and distal pits of a maxillary premolar, Black recommended that the entire central fissure, as well as the two pits be included in the preparation. It was argued that since the caries rate was so high (100 years ago) restoration of the two pits only would be followed by caries in the central fissure. Today caries are less frequent than it was during the time of G.V. Black. Furthermore, oral hygiene (through education) is generally much improved over that of several decades ago.

Incidentally the more conservative preparation (treatment of mesial and distal pits) involves far less removal of tooth structure than the more aggressive approach. Calculation of the amount of tooth structure removed under both conditions shows that the more conservative technique results in about 400 percent less tooth structure.

In the case of the Class II cavity preparation it is also possible to save considerably more tooth structure by using a conservative approach. In general the proximal box of the preparation is narrower than that associated with conventional amalgam cavity preparations. Furthermore, the presence of caries does not dictate the proximal margins be extended into a contact-free zone of the adjacent tooth. Also the proximal box is not extended onto the occlusal surface by more than 2 to 2.5mm beyond the location of the proximal marginal ridge. Finally, the gingival margin should be at least 2mm from the cervical line. In the case of amalgam, the gingival margin is extended until the tine of an explorer passes through the space between the margin and the adjacent tooth. These reductions in dimensions of the cavity preparation amount approximately to a 200 percent savings of sound tooth structure. Reducing the size of the restoration is clinically important since there is a strong relationship between dimension and clinical longevity. The smaller the dimension of the restoration, the greater the potential for extended longevity.

The proximal box of the cavity preparation needs special attention to prevent the potential for secondary caries. It can be identified as the Achilles' Heel of the Class II preparation. Occlusal stresses on or near the marginal ridge during mastication tend to force the proximal aspect of the restoration into the interproximal space. Release of the occlusal stress results in a return to the original location. The amount of displacement depends upon the modulus of elasticity of the composite resin which is twice as great as it is for amalgam (and therefore twice the deformation of amalgam). Displacement is also dependent upon how well the restoration is bonded to the floor of the proximal box. The deeper the proximal box, the less the amount of enamel along the gingival margin. While the immediate bond strength of dentin bonding agents is similar for dentin and enamel, those for dentin tend to decrease over a period of time.

As the thickness of the enamel decreases along the gingival margin, a special technique has been suggested to resolve the problem. Based upon the recommendation of Professor Qvist from Norway, a glass ionomer liner about 2ml in thickness is placed over the gingival floor. Procedurally the entire preparation is bonded with a dentin bonding agent. At this point a glass ionomer such as Fuji II LC is placed over the gingival box. Fuji IX is also recommended but since it is self-curing it will take longer to set.

Glass ionomers are excellent auxiliary restorative materials for a number of reasons. First of all they release fluoride ions from their surfaces. The glass ionomer fluoride ions are not only absorbed into the adjacent tooth structure but they kill microbes in the immediate vicinity. Secondly the glass ionomers effectively resist microleakage. This interesting clinical property is the result of a matched coefficient of thermal expansion between the glass ionomer and surface to which it is bonded. When the glass ionomer is completely surrounded by tooth structure and restorative material it is identified as a "closed sandwich." When one of the surfaces is exposed to the oral cavity (such as a glass ionomer on the gingival box) it is classified as an "open sandwich."

One of the major differences between an amalgam and composite resin restoration is the location of the pulpal floor in the case of mesial and distal pit caries (i.e. maxillary premolar). In the case of amalgam, the floor of the preparation must consist of dentin. Retention is achieved by convergence of the preparation to the occlusal surface as well as micro-mechanical retention of the prepared tooth structure. Consider the amalgam as a free-floating restoration with well-defined (microscopic) spaces at the restoration/tooth interface. As the masticatory force is introduced to the surface of the restoration, the energy is transferred though the amalgam and onto the floor of the preparation. If the floor of the preparation consists of enamel the energy will be retransferred to the occlusal surface. Constant recycling of this energy could result in premature cracking and fracturing of the restoration.

In the case of composite resin restorations, the depth of the preparation can be stopped short of the dentinal-enamel junction if the caries process also stops before the dentin is reached. In such a case the dentinal surface (floor of the preparation) acts an absorber of the masticatory energy thereby causing it to dissipate. Furthermore since the restoration is bonded to the enamel walls of the preparation, the entire tooth will serve to absorb the energy as well.

An appreciable difference exists between the preparations for composite and amalgam restorations. Almost without exception those for composites are considerably more conservative than those recommended for amalgam. Based upon years of research and clinical use it can be stated that the greater the degree of  conservatism associated with the composite, the greater the longevity. Interestingly some of the conservatism associated with the composite has been transferred to the amalgam preparation A comparison of illustrations depicted in the original text by Dr. Black with some of the more current publications on cavity designs make this finding quite apparent.
Author’s Bio
Dr. Karl F. Leinfelder earned both his Doctor of Dental Surgery and Master of Science (dental materials) degrees from Marquette University. In 1983, he joined the School of Dentistry at the University of Alabama and is the recipient of the Joseph Volker Chair. He also served as Chairman of the Department of Biomaterials until 1994. Presently he holds positions at both universities; adjunct professor at University of North Carolina and professor emeritus at the University of Alabama. Dr. Leinfelder has published more than 275 papers on restorative materials, authored more than 150 scientific presentations, two textbooks on restorative systems and has lectured nationally and internationally on clinical biomaterials.

Call Now San Francisco Dentist
Request for appointment at: (415) 391 - 7751
450 Sutter street, Suite 1905
San Francisco, CA, 94108
http://malidds.com/

How Does Tooth Whitening Work?

There are many ways to whiten your teeth — from whitening toothpastes and other products that can remove many surface stains for very little cost, to light-activated whitening techniques in a dentist's office that cost up to $1,000 and can produce dramatic results.

All whitening techniques work in one of two ways:
  1. Bleaching procedures change your natural tooth color, usually anywhere from five to seven shades brighter. In-office (chairside) whitening and at-home (tray) whitening both rely on bleaching. Bleaches contain an active ingredient, most often carbamide peroxide or hydrogen peroxide in concentrations of 10-22%, which helps remove both deep and surface stains. There are significant cost differences between different bleaching procedures:
    • A light-activated whitening session in a dentist's office, sometimes called chairside bleaching, can cost $500 or more and results in instantly and often dramatically whiter teeth. However, after a year or so of eating and drinking normally (coffee, tea, soft drinks), your teeth become slightly discolored again and develop new stains. With chairside bleaching, you have to pay the $500 to have white teeth again.
    • A custom mouthpiece created by your dentist for in-home bleaching costs around $300, and you typically wear it several hours a day or overnight for two weeks. When you notice new staining, you just wear the mouthpiece again for a night or two to take the stains off.
    • Over-the-counter products for whitening teeth (those found in a drugstore) include boil and bite tray application, whitening gels applied with a brush, and whitening strips in a price range of $10.00 to $45.00.
  2. Non-bleaching procedures work by physical and/or chemical action to help remove surface stains. All toothpastes rely on mild abrasion to remove surface stains between dental visits. Whitening toothpastes have special chemical or polishing agents that provide additional stain removal. A professional cleaning by a dentist or hygienist also uses abrasion and polishing to remove most external staining caused by food and tobacco.
Everyone responds differently to different whitening procedures. Some people respond well to whitening toothpastes, while people with gray teeth or other serious discoloration may require porcelain veneers or bonding (discussed elsewhere in this section) to achieve the smiles they've always wanted. Only your dentist or hygienist can determine what's right for you.

Copyright © 2002, 2003 Colgate-Palmolive Company. All rights reserved.

___________________________________________________________________

Call Now San Francisco Dentist
Request for appointment at: (415) 391 – 7751 
450 Sutter street, Suite 1905
San Francisco, CA, 94108
http://malidds.com/

Self-Adhesive Resin Cements


Self-Adhesive Resin Cements

August 2011
Dr. Robert Margeas presents the advantages of self-adhesive resin cements.


by Robert Margeas, DDS

The proliferation of dental cements on the market today makes it important for dentists to have a solid understanding of their capabilities and indications. The wrong cement or the wrong technique can easily lead to problems ranging from postoperative sensitivity to debonding, which can cut into productivity and can also potentially sour the dentist-client relationship. Traditional materials can offer challenges, but in recent years, the introduction of the self-adhesive resin cement category has offered advantages in many different types of cases.

The Challenges of Traditional Materials

Conventional resin cements have been a popular choice in the past, albeit a technique-sensitive one. Because traditional resin cements typically necessitate the use of a bonding agent, it is not uncommon for the material to penetrate the dentin tubules and result in post-operative sensitivity.¹ Resin modified glass ionomer (RMGI) cements, while not associated with the same sensitivity issues as resin cements, come with their own drawbacks. These materials do not offer the same level of strength as resin cements, and also are not appropriate for some types of ceramic restorations due to the fact that they expand when seated and some can cause breakage of the restoration.²

Previously, dentists often had to compromise by choosing between a material that did not offer great strength and a material that had a strong chance of causing sensitivity. In fact, the rate at which sensitivity was reported in the 1990s was cause for concern in the dental community, with one survey finding 37 percent of patients reporting sensitivity in the first year after crown placement. Even more concerning, up to 11 percent of the teeth treated in this study required endodontic treatment within the first year.³

As dentists know, a moderate to high level of post-operative sensitivity can be extremely frustrating for patients, with pain caused by anything from temperature variances to bite pressure. Several solutions have been proposed for this problem in conjunction with the traditional resin cement bonding technique, including or use of a self-etching primer and bonding agent.¹ However, the introduction of self-adhesive resin cements gave the dental community a much simpler way to prevent this issue.


A Better Alternative

Self-adhesive resin cements were initially introduced in 2002, with RelyX Unicem Self-Adhesive Resin Cement from 3M ESPE. This category was developed as an alternative to the traditional cementation options of conventional resin cement and RMGI cements. The introduction of self-adhesive resin cement offered dentists a new tool for cementation that had greater ease of use than the existing materials at the time, as well as this category combined technologies from glass ionomer materials, adhesives and composite cements to create a universal cement appropriate for a long list of indications, including inlays, onlays, crowns, bridges, posts, pins and screws made of ceramics, composite or metals.4 These materials also offered dentists the advantages of having choices of shades and translucencies, making them more useful and aesthetic for thin restorations, as opposed to the opaque look of older cements.

To eliminate the need for etching, priming and bonding, this material was formulated with phosphoric acid modified methacrylate monomers, which enable the cement to self-adhere to the tooth surface. At the same time, the monomers also create a crosslinked cement matrix during radical polymerization, which contributes to greater mechanical and dimensional stability.4

These cements undergo a unique change from acidic to neutral from the time they are initially mixed to 24 hours after application, which is what enables them to adhere to tooth structure but also maintain long-term strength. For example, the original RelyX Unicem cement has a pH level of approximately 2 immediately after and also enables a high moisture tolerance. This low pH level and accompanying hydrophilicity allow the material to adapt well to the tooth structure. However, the cement quickly increases in pH value and after 24 hours achieves a neutral level of 7. At this pH, the cement is characterized as hydrophobic. This property makes it resistant to water uptake, helping prevent staining and cracking and adding to its long-term stability.4

In addition to their ease of use and strong mechanical properties, a primary advantage of this class of cements is the "near total elimination of post-operative sensitivity" reported with their use, thanks to their one-step demineralization and infiltration of dentin.5,6

These cements have become enormously popular in the past decade, thanks not only to the properties described above, but also their high bond strengths. An easy-to-use material is no advantage if it does not perform well. The bond strengths of self-adhesive resin cements make them well-suited for most indications.7,8,9

Choosing the Best Option

As these materials have advanced – so too have their delivery systems – making them even more convenient to use in practice. Perhaps most convenient are automix delivery systems, which are available with several brands of these cements, including G-CEM Automix and Biscem Self-Adhesive Luting Cement. 3M ESPE has also recently introduced a second generation of its self-adhesive resin cement in an automix version – RelyX Unicem 2 Automix Self-Adhesive Resin Cement. This cement is based largely on the formula of the original, but with changes to its monomer makeup and filler particles, as well a new rheology modifier, all of which optimize the formula for use in an automix dispenser. Testing of the material has also shown increased mechanical properties and strong adhesion performance. In addition to automix dispensers, other dispensing alternatives include unit-dose capsules that are mixed in a triturator and dispensed onto the bonding surface, and a dual-chambered dispenser that automatically dispenses the proper ratios of the cement components so the dentist can then mix them on the pad.Dentists will find their individual preferences for each of these systems. In my own multiple-unit cases, I find automix systems are especially helpful. This delivery method is also very well-suited for root canal cases, as the dispensers are designed with small tips to fit directly in the canal. For a one- or two-unit case, a triturator capsule or clicker-style dispenser provides a convenient size and reliable mix.It's important to know the limits of any  material, however, and there are a few clinical situations in which I advise against the use of a self-adhesive resin cement. The most important is in a case with a non-retentive crown. In a case such as this, the etching, priming and bonding steps of a traditional resin cement are better suited to the situation. However, crowns with good retention can be very easily seated with self-adhesive resin cement.

Dependability and Predictability

Long-term results for self-adhesive resin cements have been excellent, with one five-year study showing a debonding rate of just 0.8 percent. The same study found just 1.8 percent of patients reported occasional temperature sensitivity.10 Another five-year study on post-cementation found similar success, with just one restoration failing during the period due to fracture of the abutment tooth.11 The long-term track record of this category of materials should be reassuring to dentists who seek products with proven safety and performance. Dentists are always in need of reliable and convenient materials that will serve patients well over long-term use. In the case of cements, there is certainly no shortage of material options, but the class of self-adhesive resin cements provides distinct advantages in many clinical situations. A material that offers such high performance and extreme simplicity of use is one that should have a valuable place in any operatory.

References


  1. Christensen GJ. Resin cements and postoperative sensitivity. J Am Dent Assoc. 2000 Aug; 131(8):1197-9.
  2. Christensen GJ. Should resin cements be used for every cementation? J Am Dent Assoc. 2007 Jun; 138(6):817-9.
  3. Clinical Research Associates. Filled polymer crowns: 1- and 2-year status reports. CRA Newsletter 1998; 22 (10): 1-3.
  4. 3M ESPE. Technical Data Sheet: RelyX Unicem – Self-Adhesive Resin Cement in the Clicker Dispenser. http://solutions.3m.com/wps/portal/3M/en_US/3M-ESPE-NA/dental- professionals/  products/category/cement/relyx-unicem/
  5. Christensen GJ. Why use resin cements? J Am Dent Assoc. 2010 Feb; 141(2):204-6.
  6. Guarda GB, Gonçalves LS, Correr AB, Moraes RR, Sinhoreti MA, Correr-Sobrinho L. Luting glass ceramic restorations using a self-adhesive resin cement under different dentin conditions. J Appl Oral Sci. 2010 Jun; 18(3):244-8.
  7. PD Dr. A Piwowarczyk, University of Frankfurt/Main, Germany, data submitted for publication, 2006. RelyX Unicem Technical Data Sheet.
  8. Prof Dr. M. Behr, University of Regensburg, data submitted for publication, 2006. RelyX Unicem Technical Data Sheet.
  9. Physical characteristics of new universal self-etching resin luting cements, E. Sakalauskaite, L. Tam, D. McComb, Restorative Department, Faculty of Dentistry, University of Toronto, Toronto, Ont. Canada; abstract #1894, AADR Orlando, 2006.
  10. 3M ESPE RelyX Unicem Self-Adhesive Universal Resin Cement 5-Year Clinical Performance. The Dental Advisor, No. 6, May 2008
  11. M. Naumann, A. Franke, T. Dietrich, G. Sterzenbach. Rigid vs. Flexible Endodontic Posts: 5-Year Results of a RCT. Published in: IADR 2008, Toronto, #1607
 

Author Bios
Dr. Robert Margeas received his DDS from the University of Iowa College of Dentistry in 1986 and completed an AEGD residency in 1987. He is an adjunct professor in the Department of Operative Dentistry at the University of Iowa. He is board-certified by the American Board of Operative Dentistry and is a fellow of the Academy of General Dentistry. He has authored numerous articles on implant and restorative dentistry and lectures on those subjects. He is the director of The Center for Advanced Dental Education and maintains a private practice in Des Moines, Iowa. He can be reached via e-mail at rcmarge@aol.com or by phone at 515-277-6358.

Direct Composite Restorations Just Got a Lot Easier



August 2011

Dr. Ara Nazarian describes a simplified technique to constantly restore posterior teeth with a new composite in a fast, easy and predictable manner.


by Ara Nazarian, DDS

Over the years, the utilization of composite resin systems for intracoronal restoration of posterior teeth has increased dramatically with the improvements in physical and mechanical properties of these resin systems and patient demand for tooth-colored restorations. Restorative dentistry continues to evolve through innovations in these bonding systems and restorative materials that help the clinician establish proper function, shape, contour and color. Because of these advancements, contemporary restorative materials and techniques allow minimal preparation of tooth structure and improvement in the longevity and aesthetics of the restoration.

There have been many different posterior composite techniques described in the literature that layer different opacities of composite (dentin, enamel, translucent) to mimic the multiple layers in a tooth. Personally, I have found this to be time consuming in a busy general practice and requires a larger assortment of composite material. However, a new composite material, SonicFill (Kerr), makes it possible to use a simpler technique involving a single shade of composite to restore most posterior teeth with excellent aesthetic results. This article describes a simplified technique to consistently restore posterior teeth with this new composite in a fast, easy and predictable manner.

Case Presentation

A patient presented for a routine hygiene visit and periodic oral examination. Upon clinical examination and probing, it was evident that tooth #3 had occlusal decay due to a stick with the explorer. Also, the radiograph exhibited some interproximal decay extending slightly past the dento-enamel junction. The patient complained of occasional discomfort when flossing and to cold. In order to educate the patient, we captured an image of this tooth on the intraoral camera (RF Systems Lab), and indicated the areas of concern on the flat screen monitor (Fig. 1). Using the DemoDent (DemoDent, Inc.) patient-education model we described what was occurring in the tooth (Fig. 2).
"There are three layers in a tooth as illustrated in this model. The white is the enamel, the yellow is the dentin and the pink is the nerve. Your cavity is in between two teeth, where food and debris like to collect. When the cavity is in the enamel (white layer) you usually do not have any pain or sensitivity with it. In fact, by catching the cavity early, we can clean it out without any difficulty. Once the cavity has gone through the enamel and into the dentin (yellow layer), it spreads much more quickly. Patients might experience some sensitivity to hot, cold and sweets depending on how deep it has extended. Once the cavity gets into the nerve (pink layer), patients experience constant throbbing pain. We want to prevent this by stopping the cavity as soon as possible."

After explaining the situation using the image on the screen and the anatomical model, I have found that patients seem to understand their dental condition better and are very eager to get started. The patient elected to have the restoration replaced with a bonded composite restoration using SonicFill (Kerr).

Prior to administration of local anesthesia, the occlusal contacts were recorded to help guide placement of the composite material (to avoid areas of centric contacts). An appropriate shade (A1) was chosen and a rubber dam (Coltene Whaledent) placed for isolation (Fig. 3). After anesthetic was administered, a carbide bur Razor 557 (Axis) was used to remove the decay. As the preparations got deeper, any remaining decay was removed using a slow-speed handpiece and large round bur H8-RA (Axis). The preparations were extended to remove the caries in the palatal fissure region (Fig. 4). A sectional matrix band (V3-Ring, Triodent) was placed over the mesial margin of tooth #3 such that its position and shape would enable placement of a composite with an optimal mesial contour. For optimal contour, gingival seal and tooth separation a wedge was inserted between teeth #3 and #4. Using the V-3 forceps, the V-3 Ring was placed over the Wave-Wedge. It was important to burnish the band in the desired contact area against the adjacent tooth and make sure there was no spring back of the band. This would ensure an excellent contact.

Once tooth #3 was isolated by the matrix band, it was dried and a sixth-generation primer/adhesive (OptiBond XTR, Kerr) was applied to all internal aspects of the preparation, including the cavosurface margins, for 20 seconds (Fig. 5). The primer was first gently agitated with a regular microbrush applicator tip (Microbrush) (Fig. 6). Because no rinsing of a separate etchant is required when using a self-etching technique, the collagen network was not subjected to the potential collapse associated with overdrying the dentin. A layer of the OptiBond XTR adhesive was placed, dried and then cured for 15 seconds with an LED curing light (Demi, Kerr).

The material selected for the composite restoration was SonicFill (Kerr) which has a chameleon effect and can also be bulk filled, allowing it to blend in with the rest of the tooth surface. Utilizing the SonicFill Handpiece (Kerr) the material was dispensed into the preparation and bulk filled (Figs. 7 & 8).

SonicFill's composite incorporates a highly filled proprietary resin with special modifiers that react to sonic energy. As sonic energy is applied through the handpiece, the modifiers cause the viscosity to drop (up to 87 percent), increasing the flowability of the composite and enabling quick placement and precise adaptation to the cavity walls. When the sonic energy is stopped, the composite returns to a more viscous, non-slumping state that is perfect for contouring. Increased levels of photo-initiators in the composite material allow a full 5mm depth of cure in 20 seconds. Studies indicate that SonicFill composite has a low 1.6 percent volumetric shrinkage and a high radiopacity (267 percent of Al).

Fig. 1: Pre-operative condition showing cavityFig. 2: DemoDent patient education model illustrating conditionFig. 3: Tooth isolated with rubber damFig. 4: Removal of cariesFig. 5: OptiBond XTRFig. 6: Application of OptiBond XTR



Fig. 7: Application of SonicFill.



Fig. 8: Application of SonicFill.

Fig. 9: Composite cured, finished and polished.
Once tooth #3 was completely built up, cured, trimmed and polished, the sectional matrix was removed. The restoration was then shaped, trimmed and finished using carbides #7408 (Axis). The occlusion was checked and verified making sure there were no interferences in lateral and protrusive movements (Fig. 9).This case is a great example of how one can achieve an acceptable aesthetic result using a single shade of composite material that blends in with the surrounding tooth structure and bulk filled at the same time as opposed to the use of two or even three different shades with a layering technique. In a busy practice, use of a universal posterior bulk-filled composite like SonicFill (Kerr) not only saves operator time, but also allows for predictable and promising long-lasting options when preservation of tooth tissue is of paramount importance.

Author’s Bio
Dr. Ara Nazarian maintains a private practice in Troy, Michigan with an emphasis on comprehensive and restorative care. He is a diplomate in the International Congress of Oral Implantologists (ICOI). His articles have been published in many of today's popular dental publications. Dr. Nazarian is the director of the Reconstructive Dentistry Institute. He has conducted lectures and hands-on workshops on aesthetic materials and dental implants throughout the United States, Europe, New Zealand and Australia. He is also the creator of the DemoDent patient education model system. He can be reached at 248-457-0500 or at www.aranazariandds.com.

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