Narrow-diameter implants in the anterior region: A meta-analysis.

PURPOSE: Implants in the anterior region are challenging, and literature reporting outcomes of narrow-diameter implants (NDIs) in anterior sites is scarce. This systematic review summarized evidence of functional and esthetic performance of anterior single crowns supported by NDIs. MATERIALS AND METHODS: Ten databases were searched to find studies evaluating anterior single crowns supported by NDIs. Risk of bias was assessed, and random-effects meta-analyses were applied to analyze mean differences in survival, success, and marginal bone level (MBL). The review was registered in the PROSPERO database (CRD42018089886). RESULTS: Twenty-one studies meeting the screening criteria were included for qualitative analysis, and three for meta-analysis. A total of 892 NDIs, placed in 736 patients, were analyzed. Follow-up duration varied from 12 months to 14 years (mean: 40 months), and 16 failures (implant loss) were recorded. Fixed-effect meta-analysis (I2 = 0%) of survival rate revealed a risk difference of 0.02 (95% CI: -0.03 to 0.08), between NDIs and controls (regular-diameter implants), without differences between groups (P = .39). Success rates ranged from 84.2% to 100% (mean: 95.2%). Random-effects meta-analysis (I2 = 56%) of MBL indicated a mean difference of 0.02 mm (95% CI: -0.21 to 0.25), without differences between groups (P = .87). CONCLUSION: Single crowns supported by NDIs are a predictable treatment, since their survival rate and MBL are comparable to those supported by regular-diameter implants. Due to data shortage reporting esthetic outcomes, more studies are needed to evaluate the long-term performance of the single crowns supported by NDIs in the anterior region.

Evaluation of cell proliferation in cystic lesions associated with impacted third molars.

The purpose of this study was to evaluate the metabolism and epithelial cell proliferation of odontogenic keratocyst (OKC), dentigerous cyst (DC), and unicystic ameloblastoma (UA) by quantifying the nucleolar organizing regions (AgNORs) and Ki-67 protein immunoexpression. Forty-eight cases (16 OKC, 16 DC, and 16 UA) were evaluated retrospectively. The metabolism and epithelial cell proliferation was measured by the Ki-67 positive cell percentage index and by the mean AgNOR count in each group. The Ki-67 and AgNOR counts were significantly higher in OKC comparing to the DC and UA (p < .001). Ki-67 positive cells were observed higher in suprabasal cell layers of OKC with uniform distribution, a few of them were predominantly observed in basal cell layer in DC and UA. The AgNOR count was significantly higher in the OKC basal cell layers and observed throughout the lining epithelium of DC and UA. Ki-67 and AgNOR reinforced the aggressive character of OKC, presenting high metabolism and cellular proliferation compared to DC and UA, possibly due to its more aggressive clinical behavior and high recurrence rate. RESEARCH HIGHLIGHTS: We evidence higher metabolism and epithelial cell proliferation in OKC when compared to UA and DC, supporting its aggressive aspect and its high rate of recurrence. OKC had intense and predominant labeling of Ki-67 on the suprabasal layer unlike UA and DC.