Giovanni Tommaso Rocca
MD. Chef en clinique, Lecturer. Unite de Terapie Conservatrice et Endodontie, Section de Medecine Dentaire, Universite de Geneve.
DMD. Professeur et Responsable de l’Unite de Terapie Conservatrice et Endodontie, Section de Medecine Dentaire, Universite de Geneve.
In the past, during millions of years, lifetime expectation of man was 30 to 40 years and one could think that evolution designed teeth for this limited period of time. However, during the last century, the lifetime expectation has drastically increased and it is now surpassing 80 years in highly developed countries. Besides challenging tooth structure as such in terms of resistance against attrition, abrasion and erosion, this development has an important impact on conservative dentistry, the goal of which is to keep teeth in the mouth of the patient during his whole life: In case a restoration is realized at the age of six or seven in a permanent tooth, it must serve for about seven to eight decades. Unfortunately, even with the best material and by using the best restorative technique, a median longevity of 70 to 80 years is not realizable today1. Thus the replacement and repair of restorations must be implemented into a modern conservative approach2. Because every replacement and even many repairs sacrifice a certain amount of nonrecoverable tooth structure, it is imperative to limit the number of retreatments to a minimum by increasing the longevity of every single restoration by highest quality and to proceed according to the rules of minimal invasivity, thus avoiding unnecessary removal of sound tooth structure. Up to now minimally invasive dentistry focused on primary restorations such as preventive resin restorations and small adhesive composite restorations. It must be stressed that the principle of minimally invasive treatment in connection with highest quality implies not only for primary restorations, but for the entire field of re-dentistry as well, thus touching large restorations on vital and, in particular, on devital teeth.
Minimal invasivity can only be achieved by using adhesive techniques, because adhesion assures sufficient retention without the need of tooth-destructive macroretentive and fricative elements. In addition, adhesive systems may seal the cavity thus minimizing bacterial penetration. In this perspective, the adhesive restoration of devital teeth is an excellent example how adhesion may completely change the restorative approach. With conventional techniques based on macroretention and friction, crowning of devital teeth was a must to protect the remaining tooth substance and to avoid crown fractures. To achieve sufficient macromechanical retention of the crown, a post-retained core build up had to be made. The high bonding performances reached by modern adhesive systems have gradually changed this dogma and it is now time to reconsider real indications for post and crowns.
The following cases illustrate the change in paradigm in the field of restorations of devital teeth by using direct and indirect adhesive composite techniques without radicular posts, thus avoiding more destructive restorative procedures.