Written by Wynn H. Okuda, DMD Thursday, 31 May 2007 19:00
In the practice of aesthetic dentistry we attempt to create the best outcome possible for our patients. Using the best materials, methodology, and techniques, we make an effort to increase our level of success clinically. However, even with our best efforts this does not ensure 100% success (Figures 1 and 2). Although the intention is to provide successful treatment outcomes, certain factors can contribute to failed treatment.
In this article we will explore this area of aesthetic failures and how to troubleshoot problems that occur in the general practice.
WHY FOCUS ON OUR FAILURES?
Figure 1. Broken marginal ridge on existing restoration.
Figure 2. Fracture of porcelain crown.
Figure 3. Failing composite resin restoration.
Figure 4. Invisible class IV with Gradia Direct (GC America).
Many years ago my colleague and mentor, Dr. Ron Goldstein of Atlanta, Ga, expressed to me that although it is nice to teach about and showcase the beautiful work that can be accomplished with cosmetic dental procedures, education can be more profoundly achieved by sharing our failures (Figures 3 and 4). In dental practice many problems may arise and lead to aesthetic failures. From porcelain fractures to decay forming around a porcelain veneer, we are able to elevate dentistry when we take the time to understand the cause of failures and learn from them so we are able to prevent them in the future.
PHILOSOPHY OF TROUBLESHOOTING
The goal of troubleshooting is ultimately to avoid having problems from the start. This is attained by approaching each case comprehensively. By having a thorough understanding of the dental problem prior to starting treatment, a sound diagnosis and treatment plan can be implemented. By executing each case based on a methodical approach, the health, functional, and aesthetic requirements can be accurately considered. Proper selection of dental materials based on a needs assessment as well as the occlusal scheme can be methodically considered for long-term success. With this approach, at least 75% to 90% of problems can be avoided.
Despite our best efforts, some factors can lead to unsuccessful outcomes. Depending on the time frame involved and when a failure occurs, the patient may or may not be very understanding of the failed treatment. For this reason it is important to have a philosophical approach to troubleshooting these failed aesthetic situations. This approach should be based on understanding the reason for failure, immediate resolution of the problem for long-term success, and proper management so that the patient’s faith in the dentist is kept intact. Learning from each case is also essential in order to prevent further failures from occurring.
CONTRIBUTING FACTORS TO FAILURES
Through knowledge of technique, material science, and functional dentistry, clinicians can prevent many problems from occurring in cosmetic and restorative situations. Unfortunately, many problems occur because of lack of attention to detail. By controlling these extraneous factors, the dentist can ultimately avoid many potential failures that occur.
Many issues need to be taken into account during treatment. Success is due to understanding various factors that can influence treatment, and the dentist must be mindful of these contributing factors. The more factors we are able to control, the more predictable the outcome. In cosmetic and restorative dentistry there are factors that are controllable and uncontrollable.
CONTROLLABLE VERSUS UNCONTROLLABLE FACTORS
Controllable factors such as occlusion, periodontium, aesthetic-related issues, dental materials, laboratory communications, clinical application, patient management, etc, can be handled so that prevention of troubleshooting-related problems can be achieved. (These factors can be controlled if the procedure is performed correctly.) In managing these factors you are able to reduce the number of mishaps that occur, such as restorative fractures/failures, incorrect smile design, dental laboratory miscommunications, faulty clinical application, exceeding the dental materials’ capability, problematic gingival health, not meeting aesthetic expectation, etc.
Uncontrollable factors such as patient compliance, caries, oral health maintenance, idiopathic reasons for failure, and parahabitual functional problems, etc, are difficult to manage because they are based on dynamics that are not necessarily in your hands. Although some factors in dentistry are uncontrollable, with a creative approach some of these issues could still be managed, thus re-ducing the percentage of failure.
CASE STUDIES: TROUBLESHOOTING AESTHETIC FAILURES
Aesthetic failures fall into many different categories. From restorative mistakes to aesthetic design errors, the keys to troubleshooting aesthetic failures are to (1) assess the reason for failure, (2) explain the problem and proposed solution to the patient, and (3) properly trouble-shoot the problem for long-term success. Two case studies that deal with aesthetic-related failure will be discussed.
Figure 5. Fractured incisal edge on existing PFM bridge.
Figure 6. Porcelain is conditioned along the long bevel.
Figure 7. Proper composite resin sequence is sculpted with Gradia Direct.
Figure 8. Tints are used to characterize the composite resin.
Figure 9. Composite resin is smoothed prior to final light-curing.
Figure 10. Proper finishing and polishing to achieve a mirror-like finish.
Figure 11. An invisible class IV is used to troubleshoot a porcelain fracture.
The patient, a 46-year-old female, presented with an existing long-span fixed partial denture in the anterior segment. The left lateral incisor had a fractured incisal edge (Figure 5). Because the integrity of the bridge was still very stable, the patient wanted to save the existing bridge.
Prior to determining treatment, it was first important to assess the strength of the existing restoration and underlying dentition. Next, an assessment for the reason for failure was ascertained.
Whether the reason for failure is incorrect material selection, adhesive failure, occlusal-related failure, or a preparation design-related failure, it is important to understand the cause in order to prevent the problem from being recreated. Finally, a restorative solution was recommeded to the pa-tient with long-term success in mind.
It was proposed to have an invisible class IV restoration placed to correct the situation immediately. The porcelain had fractured in such a way as to shear through it, leaving a stable base of porcelain without any exposure of the opaque layer or metal core. A light preparation, which included a long, oblique facial bevel, was performed so that blending of the final composite resin to the existing porcelain restoration could be attained.
There are several “keys” to achieving a successful class IV restoration. Proper understanding of composite resin shade selection, preparation design, and sequence of composite resin layering is important to attain an accurate blending of the composite resin to the existing restoration. In addition, correct finishing and polishing technique is equally essential to obtain a seamless and invisible aesthetic restoration.
In troubleshooting this problem the prepared site was first cleaned with flour of pumice, micro-etched (Danville Engineering), then etched with 37% phosphoric acid (Uni-Etch [BISCO]; Figure 6). Then, using a porcelain repair kit (Clearfil Repair [Kuraray]), adhesive was placed on the porcelain surface. Using the latest generation of micro-filled hybrid composite resin (Gradia Direct [GC America]), a sequence of composite resin layering was done to blend the composite resin to the existing porcelain and create a polychromatic effect (Figure 7). The placement of shade AO2 along the lingual aspect assisted in blocking out any shine-through of light. Then, B-1 body shade was sculpted with an emphasis on placing internal anatomy to simulate natural dentition. After placement of subtle characterizations with tints (Kolor + Plus [Kerr]), Gradia Direct shade WT was used as the final layer to create the chameleon effect to the porcelain restoration (Figures 8 and 9).
After final light-curing, aesthetic contours were refined using aluminum oxide finishing disks (Sof-Lex [3M ESPE]), finishing burs (composite finishing and polishing kit [Brasseler USA]), and finishing paste (micro-diamond polishing paste [Ultradent]; Figure 10). Using proper technique and state-of-the-art dental materials, the problem was immediately troubleshooted to the patient’s satisfaction (Figure 11).
Figure 12. Recurrent decay on an exisitng indirect resin restoration.
Figure 13. Caries detector is used to remove necessary carious dentition.
Figure 14. Minimal intervention preparations were completed.
Figure 15. Contouring burs are used to anatomically finish the premolar prior to restoring the molar.
Figure 16. A dentinal adhesive is placed over the resin-modified glass ionomer.
Figure 17. A flowable resin is used to seal the gingival box.
Figure 18. A micro-filled hybrid is placed for ideal strength and polishability.
Figure 19. Final polishing is completed using a composite finishing kit.
Figure 20. The existing indirect restoration was troubleshooted using minimal intervention techniques.
A 36-year-old female patient presented with decay along the interproximal aspect of the lower right premolar and molar. The molar cavitation was associated with an already existing indirect resin restoration. It was assessed that the strength of the existing indirect resin restoration was not affected by the decay. Therefore, the troubleshooting procedure would include restoring a carious failure around the existing restoration (Figure 12).
After anesthesia and rubber dam placement, the decay along both premolar and molar was removed with the assistance of a caries detector (Seek [Ultradent]; Figure 13). Careful attention was placed on ensuring that caries in proximity to the existing indirect resin was removed. In accordance with minimal intervention guidelines, only the infected dentin was removed, leaving the unaffected dentin untouched (Figure 14). Both cavity preparations were disinfected with a chlorhexidine gluconate scrub (Cavity Cleanser [BISCO]). Then, a resin-modified glass ionomer (Fuji II LC [GC America]; Fuji Filling LC [GC America]) was placed as a dentin substitute/base in both cavity preparations.
The premolar was first restored using a freehand method. A sixth-generation adhesive (G-Bond [GC America]) was applied and light-cured prior to bonding a micro-filled hybrid composite resin (Gradia Direct). Because of its unique chameleon effect only a single shade was needed. Using proximal contouring burs (H50A, H50AF, and H50AUF finishing burs [Brasseler USA]), the anatomical contour of the premolar was finalized prior to restoring the molar (Figure 15). An interproximal sectional matrix ring (Composi-Tight [Garrison Dental Solutions]) was placed so that a proper contact was established. After placing the adhesive, a flowable composite resin (Gradia Direct LoFlo) was first placed and light-cured to seal the gingival box (Figures 16 and 17). Then, the micro-filled hybrid composite resin (Gradia Direct) was sculpted, light-cured, and finished with posterior contouring burs (OS2 [Brasseler USA]). The result of troubleshooting this aesthetic/restorative problem was a predictable outcome that was completed in a single appointment (Figures 18 to 20).
By increasing our understanding of aesthetic dentistry, dentists are able to achieve great success. However, aesthetic failures will occur. Through proper assessment and understanding of the cause for failure, immediate correction can be done for long-term success. The way the dentist approaches troubleshooting these failures will reduce the risks associated with a problematic case.
Using the state-of-the-art materials and techniques, troubleshooting an aesthetic failure can be done predictably. With a methodical approach we are able to elevate dentistry when we take the time to understand the cause of failures and learn from them so we are able to prevent them in the future.
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