Factors determining longevity of dental ceramics

Relevance of the problem. The loss of hard tooth structures especially in the posterior region due to carious and non carious lesions, age related changes and wear of the tooth or loss of tooth structures after endodontic treatment is a relevant problem in dentistry today. In order to restore these defects in a long term manner with high quality and recover lost function of the tooth, all ceramics especially inlays and onlays are now widley used restorations. They are not only extremely aesthetic, but compared with conventional restorative materials like composites are much harder, more resistant to wear and pressure. Aim of the work. To analyze what factors: clinical stages, materials used, personal care and risk factors determine the longevity of ceramic restorations – inlays and onlays. Materials and methods. Anonymous questionnaire survey for dentists about clinical steps and materials used; clinical examination of the ceramic inlay/onlay acoording to modified USPHS criteria, the measurment of Silness and Loe oral hygene index and a quastionaire about the patients‘ oral care and hygiene. 75 questionnaires were completed and compiled, statisticaly calculated using the IMB SPSS Statistics system and MS Ecxell 2010. Results. A statistical analysis using modified USPHS criteria found that over a period of 5 years the clinical succsess rate of IPS e.Max ceramic inlays and onlays was 68% of which not all complications were critical. By evaluating only the fracture of the restouration alone clinical success is 90%. Marginal adaptation is good at 91%, postoperative tooth sensitivity was felt at 9%. Considering the small sample size statisticaly significant coorelations between: the materials used, surface preparation and tooth sensitivity (p > 0,05); preparation site, depth etc. and tooth fracture (p > 0,05); secondary caries (n =1) and oral cavity hygene (p > 0,05) were not determined. Conclusion. All ceramic restorations are durable, aesthetic, bio – compatible and perfectly suited to tooth tissues. According to the study, there is a good long – term prognosis and clinical sucess. Factors that potentially affect their stability are poorly established adhesive coherences, incorrect parameters for future restoration preparation