Ultrastructural investigation of intact orbital implant surfaces using atomic force microscopy.

This study examined the surface nanostructures of three orbital implants: nonporous poly(methyl methacrylate) (PMMA), porous aluminum oxide and porous polyethylene. The morphological characteristics of the orbital implants surfaces were observed by atomic force microscopy (AFM). The AFM topography, phase shift and deflection images of the intact implant samples were obtained. The surface of the nonporous PMMA implant showed severe scratches and debris. The surface of the aluminum oxide implant showed a porous structure with varying densities and sizes. The PMMA implant showed nodule nanostructures, 215.56 ± 52.34 nm in size, and the aluminum oxide implant showed crystal structures, 730.22 ± 341.02 nm in size. The nonporous PMMA implant showed the lowest roughness compared with other implant biomaterials, followed by the porous aluminum oxide implant. The porous polyethylene implant showed the highest roughness and severe surface irregularities. Overall, the surface roughness of orbital implants might be associated with the rate of complications and cell adhesion.

Laser-aided circumferential supracrestal fiberotomy and low-level laser therapy effects on relapse of rotated teeth in beagles.

OBJECTIVE: To investigate the effectiveness and periodontal side effects of laser circumferential supracrestal fiberotomy (CSF) and low-level laser therapy (LLLT) on orthodontically rotated teeth in beagles. MATERIALS AND METHODS: Eighteen mandibular incisors from nine dogs were divided into three groups by treatment (n = 6/group): A, orthodontic couple force application only (control); B, laser CSF following orthodontic couple force application; and C, LLLT following orthodontic couple force application. Both mandibular lateral incisors were rotated for 4 weeks, and the relapse tendency was observed for 4 weeks more without any retainers. The amount of relapse, sulcus depth, and gingival recession were measured at weeks 4 and 8. One-way analysis of variance (ANOVA) and Scheffé's post hoc test were used for data analysis. Tissue specimens were examined at week 8 under light microscopy after hematoxylin-eosin (H&E) and Masson's trichrome staining. RESULTS: The mean percentage of relapse was 41.29% in group A, 14.52% in group B, and 56.80% in group C (P < .001). Four weeks after laser CSF, the sulcus depth increased by 0.67 mm, but no gingival recession was observed. There was no significant difference between groups A and C in terms of sulcus depth and gingival recession. CONCLUSIONS: Laser CSF is an effective procedure to decrease relapse after tooth rotation, causing no apparent damage to the supporting periodontal structures, whereas LLLT on orthodontically rotated teeth without retainers appears to increase the relapse tendency.