Prospective Randomized Clinical Trial on the Survival and Quality of Survival of Lithium Disilicate Posterior Partial Crowns Bonded Using Immediate or Delayed Dentin Sealing a 3- Year Follow up

Micromechanical and chemical retention of ceramic fixed prosthesis to tooth structure introduced minimal invasive preparation to dentistry. As a result, biomechanically or aesthetically compromised teeth can be restored at a lower biological price, saving sound tooth tissues. A slow but steady (mind) shift from full metal and metal-ceramic restorations that require conventional cementation and substantial tooth loss (Edelhoff en Sorensen, 2002) to less destructive partial all ceramic restorations that require adhesive cementation is seen in the clinical field.

The clinical success of ceramic restorations relies heavily on the quality of their adhesion to dentin, which remains a clinical challenge to date. Improvements in this field over the years have brought about better cements and more effective methods to condition both substrates and teeth.

Immediate Dentin Sealing (IDS) is a technique that presumably improves adhesion of ceramic fixed prosthesis to tooth structure which results in a better marginal adaptation to dentin and less postoperative sensitivity compared to conventional adhesive cementation, also referred to as Delayed Dentin Sealing (DDS).(Pashley et al, 1992; Paul en Scharer, 1997; Magne et al, 2005; Magne et al, 2007; Breschi et al, 2008; Lee en Park, 2009). The main difference between the IDS and DDS technique lies in the fact that in IDS, a thin layer of bonding resin is applied immediately after tooth preparation and prior to impression taking, whereas in DDS this layer is applied immediately before cementation of the restoration. At first glance this may appear a minor difference, but it is presumed to be of major clinical importance. The effectiveness of IDS is studied as an adjunct to conventional adhesive cementation of ceramic indirect restorations. A split mouth clinical trial comparing ceramic restorations cemented with either IDS or DDS after one year of clinical service is executed. For each patient two all ceramic indirect restorations are made. One is cemented by means of DDS (control group) and the other one is cemented by means of IDS (experimental group). Clinical evaluation is performed shortly after cementation and after 1 and 3 year(s) of clinical function.