Conservative Endodontic Cavities and Fracture Strength of Endodontically Treated Teeth

Previous findings regarding the impact of access cavity types on conserving the strength of endodontically treated teeth (ETT) have been controversial. This study aimed to determine the impact of conservative endodontic cavities (CECs) on the fracture resistance of ETT through a systematic review and meta-analysis of the literature.This study was done following the preferred reporting items for systematic reviews and meta-analysis. We searched PubMed, Embase, Cochrane Library, Web of Science, Scopus, and Proquest online databases. We also manually searched for relevant studies in the dental abstracts journal and the reference lists of relevant studies. Two authors independently performed screening, data extraction, and quality assessment using Johanna Briggs institute?s appraisal tool for randomized controlled trials, though some items were not eligible to be applied to the selected studies. Meta-analysis was conducted if similar subgroups were observed according to their tooth type, access cavity type, proximal involvement, and restorative material type. Sub-group analysis was done using random-effects model due to the heterogeneous methodologies of the included studies. Thirteen studies were included in this systematic review out of which eleven studies were suitable for meta-analysis. Fracture resistance of maxillary molars and premolars and mandibular premolars accessed with CECs or traditional endodontic cavities (TECs) and subsequently restored with hybrid composite-resin were not significantly different (p>0.05). However, mandibular molars which were accessed with CECs and subsequently restored with hybrid composite-resin demonstrated significantly more fracture resistance than the same type of teeth with the same type of restoration accessed with TECs (p<0.05). Furthermore, proximal involvement seemed to negate any potential superiority of conservative access designs over traditional ones in ETT. Within the limitations of this study, it may be concluded that the use of CECs can better conserve the strength of mandibular molars but not other types of teeth.