The effect of the surgical microscope on the outcome of root scaling.

The benefits of using a surgical microscope in periodontal therapy were mainly based on subjective statements made by patients or periodontists. We aimed to provide laboratory evidence for the advantages of using a surgical microscope during root scaling on periodontitis teeth. In the present study, the extracted teeth were categorized into four groups: normal teeth (normal control [NC] group), untreated periodontitis teeth (periodontitis control [PC] group), root surface scaled without magnification (macro group), and root surface instrumented with a microscope (micro group). To analyze both the mechanical and biological properties of the root surfaces, we performed nanoindentation in addition to the traditional methods. We found that by using a surgical microscope, we improved the clearance of bacterial deposits and calculi on periodontitis root surfaces. Nanoindentation results revealed that the nanotopography pattern, elastic modulus, and nanohardness of the root surface in the micro group were closest to those in the NC group. The immunofluorescence assay and cell proliferation analyses revealed improved morphology and enhanced adhesion and proliferation of periodontal ligament cells on the root surface in the micro group compared with the macro group. After instrumentation, the expression levels of interleukin-6 and interleukin-8 decreased when compared with the PC group. Our results demonstrated that surgical microscope application could improve the outcomes of periodontal treatment, implying that a surgical microscope can be a powerful tool for periodontists to seek accurate clinical periodontal performance and gain better biocompatibility of the treated root surfaces.