Combined conventional and regenerative treatment in molars with coexistent closed and open apices: A case series.

Regenerative endodontic treatment (RET) may not be suitable in some necrotic young permanent molars due to coexistent roots with closed and open apices, and/or inadequate apical bleeding in one or more roots. Here, we present a combined treatment approach utilising conventional root canal treatment in the closed-apex roots and RET on the open-apex roots of necrotic young molars. The closed-apex roots of 8 molars received root fillings, and their open-apex roots were treated with a regenerative endodontic procedure. In another molar, the failed RET on one root was retreated by conventional root canal filling, preserving other revitalised roots. After 4-6 years, all teeth showed periapical healing in the absence of clinical symptoms. The combined conventional and regenerative treatment approach can yield favourable healing outcomes in necrotic, young molar roots with different levels of apical closure. Likewise, failed revitalised roots can be retreated separately with conventional root filling.

A micro-computed tomographic assessment of root canal preparation with conventional and different rotary files in primary teeth and young permanent teeth.

BACKGROUND: Root canals of primary teeth are commonly prepared with endodontic files that are originally manufactured for permanent teeth. AIM: This micro-computed tomography (micro-CT) study evaluated and compared the changes in root canal morphology after preparation with different conventional and rotary files in primary teeth and young permanent teeth. DESIGN: Seventy-two extracted primary and permanent molars were selected and randomly assigned to three subgroups according to the file systems used (n = 12/each). After pre-scanning of teeth with micro-CT, root canals were prepared with One Shape and Revo-S rotary systems and conventional endodontic files. After rescanning procedure, changes in canal volume, surface area, uninstrumented surface area, and apical transportation were evaluated. Mann-Whitney U test, Kruskal-Wallis test, and Conover's multiple comparison test were used for statistical analysis (P = .05). RESULTS: Instrumentation with rotary files resulted in significantly greater volume and surface area of root canals and less uninstrumented areas (P < .001) than with manual files (P < .001). Primary molars showed significantly less apical transportation than permanent teeth (P < .001). CONCLUSIONS: Preparation of canals with rotary files could be a viable alternative to conventional files in primary teeth. Regardless of the file system used, uninstrumented areas still exist in both primary teeth and permanent teeth.