International Journal of Computerized Dentistry, 01/2006

In a German dental practice, 299 patients were treated with 1011 ceramic fillings between June 1987 and October 1990. The restorations were produced according to the Cerec method and in each case inserted adhesively at the same appointment. The clinical success was continuously observed and documented. The period in place was between 15 and 18 years. Event criteria were loss of the tooth or of the restoration, fracture with partial loss of tooth and/or restoration, marginal caries, marginal repair and endodontic complication. The probability of success according to the Kaplan-Meier method was reduced after 16.7 years to a value of 84.4%. No further event was observed up to the final time of 18.3 years. If "restoration still in place" is made the basis for the survival analysis, ie, therapeutic measures such as trepanation and marginal correction with composite remain unconsidered, then the Kaplan-Meier value for the observation period is 89%. The size of the filling had no influence on the success prognosis. Premolars achieved a better result than molars. Vital teeth prove to be better than non-vital teeth. The use of dentin adhesives increased the probability of success. A total of 121 events, 86 of these losses of restoration , occurred in the observation interval. The most frequent causes were ceramic and tooth fractures. Keywords: Cerec restorations, clinical long-term study, 18-year results, failure analysis, practical suitability

The planning of dental implant position and its transfer to the operation site can be considered as one of the most important factors for the long-term success of implant-supported prosthetic und epithetic restorations. This study compares computer-assisted fabricated surgical templates as the static method with intraoperative image guided navigation as the dynamic method for transfer of threedimensional pre-operative planning. For the static method, the systems Med3D, coDiagnostix/ gonyX, and SimPlant were used. For the dynamic method, the systems RoboDent und VectorVision2 were applied. A total of 746 implants were inserted between August 1999 and December 2005 in 206 patients. The static approach was used most frequently, accounting for 611 fixtures in 168 patients. The failure ratios within the first 6 months were 1.31% in the statically controlled insertion group compared to 2.96% in the dynamically controlled insertion group. Complications related to an incorrect position of the implants have not been observed so far in either group. All computer-assisted methods included in this study were successfully applied in a clinical setting after a certain start-up period. The indications for application of computer-assisted methods in implantology are currently given in difficult anatomical situations. Due to uncomplicated handling and low resource demands, the static template technique can be recommended as the method of choice for the majority of all cases falling into this category. Keywords: dental implants, computer tomography, digital volume tomography, surgical templates, intra-operative navigation, imaging methods, implant planning, implant insertion