Assessment of bone regeneration after maxillary radicular cyst enucleation with or without bone grafting materials: a retrospective cohort study.

OBJECTIVE: The limitations of spontaneous bone healing underscore the necessity for exploring alternative strategies to enhance bone regeneration in maxillary radicular cyst cases. This retrospective study aimed to assess the impact of a bone substitute material (i.e., Bio-Oss) on bone volume regeneration following maxillary radicular cyst enucleation using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Seventy-three patients with maxillary radicular cysts were divided into two groups: one undergoing guided bone regeneration (GBR) with Bio-Oss and absorbable collagen membrane (n = 35), and the other receiving cyst excision alone (n = 38). Volumetric measurements using Amira software on CBCT scans evaluated bone regeneration, with cystic lesion shrinkage rates calculated. Intergroup comparisons utilized independent sample t-tests (P < 0.05), and linear regression analysis assessed the influence of preoperative cyst volume and group on bone healing. RESULTS: Both groups showed similar success rates in bone formation at the 12-month follow-up, with no significant differences between them (mean (SD), control: 75.16 (19.17) vs. GBR: 82 (20.22), P > 0.05). Linear regression analysis revealed a negative correlation between preoperative cyst volume and bone regeneration in both groups (P < 0.05). CONCLUSION: Bio-Oss may not significantly enhance bone augmentation in maxillary radicular cysts. In addition, preoperative cyst volume negatively affected the shrinkage rate of cystic lesions. CLINICAL RELEVANCE: Clinicians should consider patient-specific factors such as anatomy and lesion size when determining the need for bone substitute materials. Future research could focus on optimizing treatment protocols and alternative regenerative strategies to improve patient outcomes in maxillary cyst cases.

Cyclic fatigue resistance of different nickel-titanium instruments in single and double curvature at room and body temperatures: A laboratory study.

The aim of this study was to compare the cyclic fatigue resistance of nickel-titanium instruments inside single and double-curved canals at different temperatures. 160 HyFlex EDM #20.05 (HEDM), VDW.ROTATE #20.05 and #25.06, Mtwo #25.06 were randomised (n = 10) for the dynamic cyclic fatigue tests according to the curvature (i.e. single and double) at 20° ± 1°C and 35° ± 1°C. The number of cycles to fracture (NCF) was analysed by two-way ANOVA with p < 0.05. Fatigue resistance of all instruments significantly decreased at body temperature in single and double curvatures, except for HEDM in double curvature. The NCF was significantly lower in double curvature than single at both temperatures for all files, except for VDW.ROTATE #20.05 at 35° ± 1°C. Within the study limitations, temperature significantly impaired cyclic fatigue resistance of all files except HEDM #20.05 in double curvature. Similarly, double curvature had a detrimental effect on cyclic fatigue resistance of all files except for VDW.ROTATE #20.05 at body temperature.

Accumulated Hard Tissue Debris and Root Canal Shaping Profiles Following Instrumentation with Gentlefile, One Curve, and Reciproc Blue.

INTRODUCTION: This laboratory study aimed to evaluate the accumulated hard tissue debris (AHTD) and shaping performance following root canal instrumentation with a novel stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with two single-file nickel-titanium instruments of different kinematics through micro-computed tomography (micro-CT) analysis. METHODS: Thirty isthmus-containing mesial roots of human mandibular molars with a curvature of 15°-35° were scanned with micro-CT at an isotropic resolution of 12 µm and randomly assigned to three groups (n = 10) according to the instruments used for canal preparation: Gentlefile (GF; #23/.04), One Curve (OC; #25/.06; Micro-Mega, Besancon, France), and Reciproc Blue R25 (RB; #25/.08; VDW, Munich, Germany). The AHTD, unprepared canal surface area, volume changes, surface area changes, and transportation were evaluated by comparing preoperative and postoperative micro-CT images. In addition, the time required for canal preparation was recorded. Data were statistically analyzed using the one-way analysis of variance (ANOVA) test or the Kruskal-Wallis test at a significance level of 5%. RESULTS: No significant differences were observed in the percentage of AHTD or in the unprepared canal surface area between the three groups (P > .05). The RB group demonstrated a significantly greater percentage increase in volume and surface area than the GF group (P < .05). The GF and OC groups showed significantly less transportation at 3 mm from the apex than the RB group (P < .001). The OC group required significantly less time for instrumentation than the RB and GF groups (P < .05). CONCLUSIONS: Instrumentation with GF (#23/.04), OC, and RB yielded similar levels of AHTD and unprepared surface area in isthmus-containing curved canals. GF achieved this with less dentin removal and apical transportation, at the expense of a longer preparation time.