Analysis of the Impact of the Minimally Invasive Access Preparation on the Fracture Resistance in Endodontics, Systematic Review of Vitro Study

Purpose of Review The accurate execution of endodontic access is crucial for the success of therapy, influencing various phases of canal treatment. Traditional approaches prioritize a convenient form and broad endodontic opening to facilitate subsequent procedures. Minimally invasive dentistry, which prioritizes dentin preservation, is increasingly being embraced. Nonetheless, the scientific evidence supporting this approach remains limited, and concerns have been raised regarding its influence on the various phases of root canal treatment. Recent findings Clinical studies explore the risk of dental fractures during endodontic treatment, considering the removal of dental tissue. Traditional openings may increase fracture risk due to reduced resistance to masticatory loads. This review aims to compare the fracture resistance of teeth prepared with minimally invasive access preparation to those treated with traditional endodontic access cavities. The review protocol was developed in accordance with the Cochrane Handbook guidelines and was registered in INPLASY, while the manuscript was drafted following the PRISMA statement; after the study identification and selection process, included a total of 5 studies. We pooled fracture-load data using the standardised mean difference (SMD) because studies used different scales. SMD > 0 favours minimally invasive access cavities (NAC) (i.e., teeth with NAC sustained a greater load than teeth with traditional endodontic access (TEC); the magnitude expresses the difference in standard deviations). Given the expected variability between studies, a random-effects model was applied alongside the fixed-effects model: 0.97 [0.65, 1.29]; Chi2 36.88, df = 9 (P < 0.0001), I2 = 76%. Summary The data derived from the meta-analyses may offer valuable insights for clinicians performing endodontic treatments using specific access cavity designs. The minimally invasive approach to endodontics with an ultraconservative or minimally invasive access preparation may be a viable solution in cases where the fracture resistance of a tooth is crucial. Future studies should focus primarily on aspects related to the increased difficulty in localizing orifices and the presence of debris that could affect the advantages obtained on fracture resistance with NAC. Ultraconservative techniques are characterized by cavity designs that show superior fracture resistance, suggesting enhanced resilience to masticatory loads when compared to traditional endodontic access cavities.