Diastema closure is a frequently requested, technique sensitive cosmetic procedure. When performed correctly, enhanced dental-facial aesthetics can result, with psychological and social benefits to our patients. If incorrectly done, poor contacts, poor contour, increased plaque retention, and gingival irritation from subgingival overhangs can affect the patient’s periodontal health and the tooth – restorative margin can develop microleakage and caries. Recently a novel system, the “Bioclear Matrix” was developed by Dr. David Clark to address the various problems and shortcomings of other systems used, and simplify direct diastema closure with composite resin.
Diastema closure is a frequently sought after, technique sensitive cosmetic procedure. When performed correctly, enhanced dental-facial aesthetics can result, with psychological and social benefits to our patients.1 If incorrectly done, difficultly flossing, increased plaque retention, and gingival irritation can affect the patient’s periodontal health and the tooth-restorative margin can develop microleakage and caries.2-3 Increasingly, the medical and dental literature is noting a possible relationship between one’s periodontal health and systemic health.4-7 Care must be taken to ensure that we minimize the potential for gingival irritation and inflammation in our restorative procedures. Recently a novel system, the “Bioclear Matrix” was developed by Dr. David Clark to address the various problems and shortcomings of other systems used for conservative direct Diastema closure with composite resin. A case is presented where the Bioclear Matrix was utilized to close a diastema in a conservative manner, and achieve an aesthetic result.
The patient is an 18 year old university student who, along with his family, has been a long time patient in the author’s practice. His previous dental care has been limited to routine prophylaxis and minor restorative care. He is in good general health, and is not taking any medications. He is quite self conscious about his appearance and smile. Recently, he decided to cosmetically enhance the appearance of his central incisors, which in his words are “too small and the space between my teeth bothers me” (Figures 1-6). A 3mm.diastema is present between the central incisors. The maxillary and mandibular midlines are not co-incident. The gingival tissues are healthy, and the periodontal condition overall is good, with no pockets greater than 2-3mm. in the anterior segments or 3-4mm. in the posterior segments. The patient’s gingival biotype is thinner and somewhat friable. The frenum is fairly prominent between the central incisors, with an incisally positioned insertion point. Evaluation of the TMJ’s demonstrates normal ranges of opening/closing, with no movement deviations or joint sounds .The joints are symptom free under bi-manual load testing.8 No excessive wear facets, or evidences of erosion is present. After consultations with the patient, the decision was made to close the diastema between his maxillary central incisor crowns with direct composite resin. A frenectomy was suggested to improve gingival aesthetics and the papilla’s shape and contour, and was refused. Other treatment options included indirect porcelain veneers, or full coverage porcelain crowns. Composite resin was selected, being the most conservative treatment in terms of tooth preparation, time, cost, and reversibility. The patient was advised that the bonding might need to be repaired/repolished from time to time in the future.
At the consultation appointment, a trial mock up was performed intraorally, using composite resin, and indicated that the centrals could be enlarged and follow the ‘Golden Proportion’ for tooth aesthetics. It was noted to the patient that the maxillary and mandibular midlines would not be co-incident in the final result, in order to try to achieve symmetry between the central incisors. Orthodontics was suggested as a means to help achieve inter-arch symmetry, and was refused. The patient approved the appearance of the trial ‘mock up’ enlarging his centrals. Various shapes and incisal embrasures were tested in the mock-up, and the patient approved the selected shape. A photo of the composite resin mock-up was taken to assist the dental technician in creating the selected mold in the diagnostic wax-up. An alginate impression was taken of the pre-operative condition. The lab was instructed to create a diagnostic wax-up on the stone models, to assist in recreating the approved size and shape, at the operative appointment (Figures 7-8).
Teeth Preparation
Local anaesthesia was administered (to maximize comfort when the mylar matrices were placed slightly subgingivally, and during the finishing procedures). The teeth were carefully scrubbed with plain course pumice in a rubber cup, taking care not to cause any gingival bleeding or irritation. The Bioclear Matrices (Clinical Research Dental) (Figure 9) were carefully positioned slightly subgingivally (Fig.10), and lightly supported with the index finger. While the instructions indicate that the mylar matrix is supported/stabilized by the tissue, the author has found that light finger pressure helps keep the matrices from ‘floating around’ during the etching and washing steps. Phosphoric etch was applied (Figure 11), extending well beyond the areas to be bonded, and rinsed off after twenty seconds with a liberal spray of water and air. After air drying, the etched surface was carefully evaluated. Scotchbond Multipurpose adhesive (3M ESPE)) was applied, as per manufacturer’s instructions and light cured. A small amount of Grandio flowable composite (Voco), of an appropriate shade, was carefully introduced in the gingival area of the matrices and light cured both buccally and lingually (Figure12), creating small ‘ledges’ or ‘hips’ which would engage the silicone ‘Interproximator’. A small microbrush applicator was used to remove excess flowable resin, and remove any air bubbles or voids, and ensure the flowable resin was well adapted to the matrix, prior to light curing. Next, the ‘Interproximator’, lightly lubricated with liquid soap to help prevent tearing, was stretched thin and ‘flossed’ carefully between the teeth so as to be seated between the two matrices, and below the undercuts created by the initial flowable composite resin increment (Figures 13-14). The ‘Interproximator’ creates a slight separation between the teeth, and offsets the thickness of the mylar matrix material. Grandio composite resin paste (Voco) was carefully introduced into the matrices both bucally and lingually (Figure 15). A thin bladed instrument and sable hair artist’s brush, wetted slightly with bonding resin, were used to adapt and sculpt the composite into the basic desired shape. Tints and incisal translucent enamel shades of composite were applied with a thin bladed instrument and artist’s brush and blended into the base composite layer taking care to minimize any air inclusions. The overhead operatory light was turned down at this point to minimize the risk of premature polymerization.The basic shape was obtained and gross excess resin removed prior to light curing. The more attention paid at this point, the less finishing and polishing that is required at the end of the appointment. The composite resin was light cured from both directions, for sixty seconds. The Interproximator was stretched out, and one end cut, to assist in it’s removal .The Bioclear Matrices were removed, and a good contact noted. The composite resin/ tooth interface was again examined under magnification for any overhangs, flash or marginal voids. Using a selection of finishing carbide and diamond b
urs, most of the excess was cleared. A #12 Baird Parker was used to remove any subgingival flash (Figures 16-17), with a Zycra instrument (Vic Pollard Diamonds Inc.) used for gingival retraction . Various rubber polishing cups and points (Ivoclar) were used to blend the finish lines so as to make them imperceptible. Occlusion, which could not be fully verified prior to complete curing of the resin, was now evaluated, and carefully adjusted as required. The lingual surfaces were finished using a fine football shaped porcelain finishing diamond, with copious water spray, and a light intermittent touch, and the occlusion verified in both centric relation and lateral and protrusive excursions. Post-operative care instructions were reviewed, and the patient was reappointed after one week for post-op evaluation of gingival health, integrity of the composite margin-tooth interface, oral hygiene home care and any occlusal adjustments, if required.
Diastema closure with direct composite resin provide an exciting challenge to our artistic and technical abilities and calls upon our knowledge of smile design principles of proportion, symmetry, harmony and tooth morphology.9-11
Many problems exist with the use of conventional mylar matrices, and placement techniques. The results often obtained have poor contacts, poor contour, and often exhibit subgingival overhangs and/or rough plaque retentive areas. Some diastema closure techniques have eliminated the matrix altogether, and call for building the diastema closure to directly contact the adjacent tooth’s lightly lubricated, or highly polished surface. While good contacts can be achieved, the problem of developing a correct subgingival emergence profile, free of moisture and or blood contamination remains, especially if the patient’s oral hygiene is not ideal. The traditional mylar strip, with it’s flat shape, can not recreate the correct ‘bi-concave’ contour necessary for correct aesthetics and gingival health. A technique whereby the mylar strip is manipulated (gently pulled lingually), just prior to light curing to bring some composite resin subgingivally ,to improve the contour, is highly technique sensitive, and often causes bleeding at the most critical point of the procedure.
Excellent soft tissue health and correct tooth contours and emergence profiles are just as important as the actual colour of the new restoration / adjacent teeth.12
An iatrogenic source of potential chronic inflammation can be prevented and helps eliminate a potential factor in the development of many inflammatory mediated diseases.13-15
Recent literature has been supportive of a link between periodontal disease and a host of systemic diseases such as Coronary Heart Disease, Stroke, Type two Insulin Dependant Diabetes and Arthritis. While periodontal disease is multi-factorial (with bacterial, genetic, nutritional and environmental co-factors), it is often a site specific iatrogenic problem, such as that caused by dental work violating the biologic width, or open contacts interproximally.16-17 It is proposed that inflammatory mediators can spread systemically, and play a role in triggering inflammatory mediated diseases. The quality of our restorative work can play a role in initiating, or helping prevent oral inflammatory triggers, and as such, the dentist and hygienist can play an important role in disease prevention.
A case was presented utilizing the Bioclear Matrix System to achieve an aesthetic diastema closure (Figures 18-23). Predictable results can be obtained when attention to detail is paid to all steps of the treatment. Iatrogenic sources of gingival irritation/inflammation can be minimized using the Bioclear Matrix system. Direct composite resin can be used to close diastema in a highly aesthetic, conservative manner.. These types of cases can be very satisfying to our artistic natures and psychologically and functionally benefit our patients. OH
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Michael Pollak graduated from the University of Toronto in 1989. He is Past-President of the Toronto Academy of Cosmetic Dentistry. He maintains a general dental practice in Markham, Ontario, with an interest in cosmetic, restorative and implant dentistry. He is a founding member of the Canadian Academy of Esthetic Dentistry. He is a graduate of the Misch Implant Institute, The Dawson Center for Advanced Studies, and the SUNY post-graduate program in Esthetic Dentistry. He is a Fellow in the International Congress of Oral Implantologists (I.C.O.I.), and is currently working to achieve fellowship in the Academy of General Dentistry.
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