Analysis of influencing factors for the prognosis of selectively excavated teeth

• Applicant: Professor Dr. Falk Schwendicke
• Subject Area: Dentistry, Oral Surgery
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 266676931

Treating cavitated carious lesions usually involves "complete" removal of carious tissues and subsequent restoration. Based on a changed understanding of caries, this concept is increasingly questioned. For deep lesions, selective ("incomplete") excavation (sealing pulpo-proximal carious dentin beneath a restoration) is recommended, since it reduces the risk of endodontic complications and allows to retain teeth longer at lower costs. The so far performed studies allowed to estimate the relevance of factors influencing the prognosis of selectively excavated teeth and to gauge clinical treatment thresholds. Our aim in future studies is to understand how different factors impact on selectively excavated teeth and which therapeutic relevance this has. Based on such understanding, we aim to develop strategies to increase success, safety and reliability of selective excavation. The assessment of four factors (lesion depth and bacterial contamination, radiopaque tagging treatment, application of cavity liners, restoration integrity) and their impact on the prognosis of selectively excavated teeth is planned in vitro. First, we will evaluate if differently deep, bacterially contaminated lesions can be successfully arrested by sealing them. The potential harm and inflammatory potential of metabolic products of sealed bacteria on pulpal cells will be investigated. The remineralizability of different residual lesions will be assessed. The mechanic behaviour of differently excavated teeth will be evaluated using Finite Element Analyses. All these studies will allow to understand if only limited amounts of carious dentin should be left and sealed, and if antibacterial or remineralizing treatments prior restoration could be recommended after selective excavation. Second, we will develop an application protocol for radiopaque tagging of residual lesions, as such tagging could resolve diagnostic uncertainties associated with selective excavation. This protocol should allow successful masking of deep lesions and high bond strength of dentin adhesive after the tagging treatment. Third, the antibacterial effects of different cavity liners on different sealed bacteria should be assessed. Last, the mechanism of sugar transport from the cavity into sealed lesions via the restoration interface or gaps will be explored and clinically relevant factors facilitating such transport identified. In total, six studies are planned. The results of these studies should allow to deduct recommendations for clinical practice or guide further clinical research.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Sebastian Paris