Implants sites with concomitant bone regeneration using a resorbable or non-resorbable membrane result in stable marginal bone levels and similar profilometric outcomes over 5 years.

OBJECTIVES: To assess clinical and radiographic outcomes as well as the profilometric contour alterations of peri-implant hard and soft tissues around single implants treated with simultaneous guided bone regeneration (GBR) at 5 years. MATERIALS AND METHODS: Twenty-seven patients presenting with a single tooth gap in the esthetic zone received a two-piece implant. GBR was randomly performed using a resorbable (RES) or a non-resorbable membrane (N-RES) combined with a bone substitute material. Follow-up examinations were performed at baseline (BL = crown insertion), 1 year (FU-1), 3 years (FU-3), and at 5 years (FU-5) including clinical and radiographic parameters as well as profilometric changes. Statistics were performed by means of parametric and nonparametric tests. RESULTS: At 5 years, 20 out of 27 patients (9 RES, 11 N-RES) were re-examined. Median values for probing depth changed insignificantly between BL and FU-5 in both groups. The median marginal bone levels were located 0.23 mm (0.06; 0.46; RES) and 0.17 mm (0.13;0.28; N-RES) below the implant shoulder at FU-5 (changes over time p < .05). The calculated median profilometric change between BL and FU-5 was -0.28 mm (-0.53;-0.20; RES; p = .016) and -0.24 mm (-0.43;0.08; N-RES; p = .102; intergroup p = .380). The horizontal bone thickness decreased significantly between re-entry and FU-5 for group RES at all measured levels (p < .05) measuring 0.87 mm (0.0; 2.05) at the implant shoulder, whereas the decrease for group N-RES was insignificant (p = .031) with 0 mm (0; 0.84) at the implant shoulder at 5 years. CONCLUSIONS: Implants sites with concomitant GBR using a resorbable or non-resorbable membrane revealed stable marginal bone levels and clinical outcomes. Profilometric changes were clinically negligible over 5 years. The observed change in hard tissue thickness was partially compensated by an increase in soft tissue thickness.

Repairability of CAD/CAM high-density PMMA- and composite-based polymers.

OBJECTIVE: The study aimed to analyse the shear bond strength of computer-aided design and computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA)- and composite-based polymer materials repaired with a conventional methacrylate-based composite after different surface pretreatments. METHODS: Each 48 specimens was prepared from six different CAD/CAM polymer materials (Ambarino high-class, artBloc Temp, CAD-Temp, Lava Ultimate, Telio CAD, Everest C-Temp) and a conventional dimethacrylate-based composite (Filtek Supreme XTE, control) and aged by thermal cycling (5000 cycles, 5-55 °C). The surfaces were left untreated or were pretreated by mechanical roughening, aluminium oxide air abrasion or silica coating/silanization (each subgroup n = 12). The surfaces were further conditioned with an etch&rinse adhesive (OptiBond FL) before the repair composite (Filtek Supreme XTE) was adhered to the surface. After further thermal cycling, shear bond strength was tested, and failure modes were assessed. Shear bond strength was statistically analysed by two- and one-way ANOVAs and Weibull statistics, failure mode by chi(2) test (p ≤ 0.05). RESULTS: Shear bond strength was highest for silica coating/silanization > aluminium oxide air abrasion = mechanical roughening > no surface pretreatment. Independently of the repair pretreatment, highest bond strength values were observed in the control group and for the composite-based Everest C-Temp and Ambarino high-class, while PMMA-based materials (artBloc Temp, CAD-Temp and Telio CAD) presented significantly lowest values. For all materials, repair without any surface pretreatment resulted in adhesive failures only, which mostly were reduced when surface pretreatment was performed. CONCLUSIONS: Repair of CAD/CAM high-density polymers requires surface pretreatment prior to adhesive and composite application. However, four out of six of the tested CAD/CAM materials did not achieve the repair bond strength of a conventional dimethacrylate-based composite. CLINICAL RELEVANCE: Repair of PMMA- and composite-based polymers can be achieved by surface pretreatment followed by application of an adhesive and a conventional methacrylate-based composite.

Zirconia reconstructions cemented on non-original titanium bases may result in increased bleeding on probing, probing depth values and varying mean marginal bone levels.

PURPOSE: To assess the clinical, technical, and esthetic outcomes of directly veneered zirconia abutments cemented onto non-original titanium bases over 3 years. MATERIALS AND METHODS: A total of 24 healthy patients with a single missing tooth in the maxilla or mandible (incisors, canines, or premolars) received a two-piece implant with a screw-retained veneered zirconia restoration extraorally cemented on a titanium base abutment. Baseline measurements and follow-up examinations were performed at 6 months, 1 year, and 3 years following loading. Radiographic, clinical, technical, and esthetic parameters were assessed. Wilcoxon signed rank test was used to analyze the data. RESULTS: Mean marginal bone levels measured 0.54 ± 0.39 mm (median: 0.47 mm, range: 0.07 mm to 1.75 mm) at baseline and 0.52 ± 0.39 mm (median: 0.39 mm, range: 0.06 mm to 1.33 mm) at 3 years. Mean probing depth around the implants increased from 3.0 ± 0.6 mm at baseline to 3.8 ± 0.8 mm at 3 years (P = .001). Bleeding on probing changed from 27.1% ± 20.7% (baseline) to 51.5% ± 26.1% (3 years) (P = .001). The mean plaque control record amounted to 11.1% ± 21.2% (baseline) and 14.4% ± 13.89% (3 years) (P = .261). Two implants were lost at 3.5 and 30 months postloading due to peri-implantitis, resulting in a 91.7% implant survival rate. Patient satisfaction was high at 3 years. CONCLUSION: Zirconia restorations cemented onto the tested non-original titanium bases should not be recommended for daily clinical use, as they were associated with significant increases in BOP and PD values and varying marginal bone levels 3 years after placement.