A clinical case by our Community member Dr. Shiraz Khan
The replacement event is something of a guarantee in modern restorative dentistry. Despite the advance in dental materials and technology, the use of the word ‘permanent restoration’ for any kind of restoration is, in fact, inaccurate. Rather, the use of the phrase “longer-term definitive restoration” does not imply the that any intervention that is provided is guaranteed for a lifetime. As outline by Optdam and colleagues (1), failure rates of composite restorations have been shown to be as low as 2.4%. Optimisation regarding longevity requires principles of minimally invasive dentistry to be upheld. The principle of minimally invasive dentistry requires ultraconservative management of the tooth structure in preparation for the restorative intervention (2). This follows a simple philosophy, that the less we do, the longer the teeth are likely to function throughout life (3). Although no preparation veneers are minimally invasive, studies have repeatedly shown that etching enamel with 37% phosphoric acid for 30 seconds removes approximately 10-20 um of enamel for bonding (4,5,6).
A thirty-year old female patient presented with no pain, and wanted her anterior composite veneers replaced. Medically she was fit and well, with no allergies or routine medications disclosed, and had good oral hygiene.
On examination the patient presented with generalised gingivitis and palatal caries on the 11. This had been present due to over-hanging margin associated with previous composite veneers.
Smile demonstrates high smile line and aesthetic compromise, namely marginal.
The image mesial caries on the 11, due to poor marginal control interproximally of existing composite veneers.
Aesthetically, the patient had generalised extrinsic discolouration and marginal staining of existing composite veneers. As can be seen from the beginning of this case, canine shade A3.5.
The patient was happy with the incisal edge position but not the shade of the teeth, nor the staining of the margins.
Two-weeks home whitening with 1 week of 10% and 1 week of 16% carbamide peroxide.
As we are aware bond strength can reduce by up to 20% if completed on the same day as the cessation of the whitening (7,8) a period of two weeks will allow for any hydroxyl radicals to leach out of the teeth, and for the whitening result to stabilise.
Therefore, the appointment for replacement of the composite veneers was completed two-weeks post completion of the home whitening. Pre-operative shade assessment is pivotal, to understand the value, enamel and body shades required for this case prior to dehydration. Patient, nurse and practitioner agreed that Professional CompoSite System Si 0.5 (composite on tooth 41) was the best match.
The composite veneers were scored using tungsten carbide burs.
Once isolation was achieved the remainder of the composite was removed.
Allows for an increase in retraction and access to the full labial surface, which is imperative for full labial coverage veneer restorations.
Teeth were etched with 37% orthophosphoric acid for 30 seconds (15 seconds in case of the mesial dentine of 11). Teeth were washed thoroughly for 30 seconds, then air dried. The bonding system used was Optibond FL (Kerr) and cured for 30 seconds on each tooth.
Application of Si 0.5 mass to create dentine and incisal effects. The matrix used here is a posterior matrix, used vertically to create natural curve/contour.
Si E Professional CompoSite System used as the final layer. This is applied in one increment to minimise the risk of trapped air/marginal void formation. The final cure was completed under glycerine gel and the primary finishing protocol was commenced.
The initial polishing protocol consisted of a coarse soflex disc being used to refine line angles along with the incisal edge position at low revolutions. A coarse-grit diamond bur was also used at low revolutions to smooth the labial surface along with creation of secondary anatomy.
A week later the line angles were refined, and the labial surface is polished with Astropol finishers (grey, yellow and pink). This is followed by the enhanced polishing spirals (3M) and finally the Flexibuff felt wheel (Cosmodent) with Enamelize Aluminium oxide polishing paste (Cosmodent).
Close-up of the polished restorations.
The patient smiling, satisfied with her new smile.
Before and after.
The replacement event in aesthetic restorative dentistry is often not discussed. As this case demonstrates, secondary caries due to inadequately formed contact points, usually makes the replacement event a more invasive procedure than the initial treatment. With this thought-process in mind, minimisation of invasion from the outset will not only increase restorative longevity, but also reduce biological infringement at the time such restorations require replacement. Overall, the outcome was reasonable, creating a more natural appearance in the tooth structure and form, along with incisal translucency.
The treatment process with the new Professional CompoSite System Si, was simple and straightforward and the simplistic shade system avoids restorative complication, as there is only a single enamel shade. The patient was delighted by the restorations completed and enhancement to her smile.
1. Opdam NJ, van de Sande FH, Bronkhorst E, Cenci MS, Bottenberg P, Pallesen U, van Dijken JW. Longevity of posterior composite restorations: a systematic review and meta-analysis. Journal Dental Res. 2014;93(10):943–949.
2. Bannerjee A. Minimal intervention dentistry: part 7. Minimally invasive operative caries management: rationale and techniques. British Dental Journal. 2013;214:107–111.
3. Frencken JE, Peters MC, Manton DJ, Leal SC, Gordan VV, Eden E. Minimal Intervention Dentistry (MID) for managing dental caries – a review: Report of a FDI task group. Int Dent J. 2012; 62(5):223–243.
4. Retief DH. Effect of conditioning the enamel surface with phosphoric acid. J Dent Res. 1973;52:333-41.
5. Shimada Y, Tagami J. Effects of regional enamel and prism orientation on resin bonding. Oper Dent. 2003;28:20-7.
6. Silverstone LM, Saxton CA, Dogon IL, Fejerskov O. Variation in the pattern of acid etching of human dental enamel examined by scanning electron microscopy. Caries Res. 1975;9:373-87.
7. Godoy FG, Dodge WW, Donohue M, O’quinn JA. Composite resin bond strength after enamel bleaching. Op Dent. 1993;18:144-144.
8. Nour El-din NK, Miller BH, Griggs JA, Wakefield C. Immediate Bonding to Bleached Enamel. Op Dent. 2006; 31(1): 106-114.