Cosmetic dentistry beauty & science

there’s a viable alternative? Why not attempt to save the good and just replace the bad? Direct composites and laboratory composite resin sys- tems are valuable and worthwhile options to preserve tooth structure and long-term dental health. After all, preserving a patient’s natural tooth, whenever possible, is always in his or her best interest. It has been our experience that providing multiple, large interproximal posterior compos- ites directly can be difficult to achieve on a con- sistent basis in the oral environment, especially when replacing amalgams. Why? Because they take a lot of chair time. Amalgams require bulk. That’s why we were taught the block type prepa- rationtoprovidethenecessarybulkforstrength. Furthermore,becauseamalgamsdonotbond, we were taught to create undercuts and “exten- sion for prevention.” As mercury contracts and expands with cold and hot temperature changes over time, cracks form in the glasslike nature of teeth. Most of the time, these large preps are diffi- cult to restore with direct composite. There are isolation and contamination issues, and it is dif- ficulttoreplicatenatureinthemouthinatimely, cost-effective and predictable manner for every case, every time. In addition, curing in layers makes for a long appointment and increases the possibility of contamination. It is uncomfortable for patients to keep their mouths open for the prolonged amount of time necessary. Often, large direct posterior composite resins yield unsatisfactory results in terms of esthetics, and especially long-term function, due to curing and contamination issues. However, when we do same day inlay/onlays out of the mouth and in the laboratory, we find that multiple posterior restorations are easier, stronger and more anatomically correct. Be- cause they are processed at the same time, they can be even more time efficient than using a CAD/CAM system and reduce tooth movement during the transitional phase that can result in altered contact or occlusion. Not having to deal with provisional resto- rations absolutely eliminates those untimely emergencies when temporaries break or come off. Those costly, non-productive, uncomfort- ableandunhappysecondappointmentscanalso be avoided, saving everyone time and money. In addition, without concerns about retention of temporaries, preparation can be even more conservative. _Case 1 In this case, the patient came to our office on an emergency basis with a broken tooth on the upper right molar. It was no surprise that the tooth had a previously placed MO amalgam with recurrent decay that caused the mesiobuccal cusp to fracture off completely (Figs. 1 & 2). Often, teeth that have had old amalgam fillings tend to break due to cracks caused by the ex- pansion and contraction of the metal alloy in the tooth’s glasslike substance. In addition, caries detectors were non-exis- tent when the bulk of amalgam restorations were placed so many teeth have recurrent decay under the old amalgam fillings. After thorough clinical and radiographic ex- aminations were performed, it was determined with the patient’s input that a same-day onlay would be the most prudent option for this tooth. This way, he would be receiving the maximum amount of care in the least amount of time. The procedure After placing topical anaesthetic, articaine HCl 4 % with 1:1,00,000 epinephrine was ad- Fig. 5_Silicone model. Fig. 6_Sectioned model. Fig. 7_Silicone model, buccal view. Fig. 8_Tooth ready to bond. Fig. 9_Expasyl placed interproximally prior to seat. Fig. 10_Onlay seated, palatal view. Fig. 11_Onlay seated, buccal view. I 07 CE article _ adhesive dentistry I cosmeticdentistry 3_2013 Fig. 11 Fig. 8 Fig. 9 Fig. 10