ABSTRACT
BACKGROUND: The incidence rate of severely curved root canals in mandibular molars is low, and the root canal treatment of mandibular molars with this aberrant canal anatomy may be technically challenging. CASE SUMMARY: A 26-year-old Chinese female patient presented with intermittent and occlusal pain in the left mandibular second molar. The patient had undergone filling restoration for caries before endodontic consultation. With the aid of cone beam computed tomography (CBCT), a large periapical radiolucency was observed, and curved root canals in a mandibular second molar were confirmed, depicting a severe and curved distolingual root. Nonsurgical treatments, including novel individualized preparation skills and techniques and the use of bioceramic materials as an apical barrier, were performed, and complete healing of the periapical lesion and a satisfactory effect were achieved. CONCLUSION: A case of severely curved root canals in a mandibular second molar was successfully treated and are reported herein. The complex anatomy of the tooth and the postoperative effect were also evaluated via the three-dimensional reconstruction of CBCT images, which accurately identified the aberrant canal morphology. New devices and biomaterial applications combined with novel synthesis techniques can increase the success rate of intractable endodontic treatment.
ABSTRACT
PURPOSE: To observe the effect of gellan gum loaded with nano-hydroxyapatite (GG/nHA) on repairing mandibular defect in rats. METHODS: Critical bone defects with 5 mm in diameter on the mandible of 16 SD rats were created and randomly divided into two groups. The bone defects in the experimental group were injected with GG/nHA and the control group were filled with absorbable gelatin sponge. The rats were sacrificed at 4 and 8 weeks after operation. The bone tissue healing was evaluated by Micro-CT. Bone tissue repairing effect was evaluated by hematoxylin-eosin (H-E) staining and Masson staining. GraphPad Prism 8.0 software package was used for statistical analysis. RESULTS: The prepared GG/nHA had a good injectability and could be delivered to the bone defect area with a syringe. Four and 8 weeks after operation, the newly formed bone and bone volume fraction (BV/TV) in the experimental group were higher than those in the control group, and the difference was statistically significant (P<0.05). Larger number of new bone were observed in the experimental group than the control group by H-E staining and Masson staining. CONCLUSIONS: GG/nHA can be injected into the mandibular defect area to promote its healing, and it is expected to be used as a novel bio-material for minimally invasive repair of oral and maxillofacial bone defects.
