Yavuz Aslan

In-patient comparison of immediate and conventional loaded implants in mandibular molar sites within 12 months.

OBJECTIVES The aim of this prospective clinical study was to evaluate the clinical outcomes of dental implants placed in the mandibular molar sites and immediately functionally restored compared with conventionally loaded controls in an in-patient study. MATERIAL AND METHODS Twenty-four dental implants were placed in 12 patients who had first molar loss bilaterally in the mandibular area. One site of the patient was determined as immediately loaded (IL) and the other side was conventionally loaded (CL). Resonance frequency analyses for implant stability measurements, radiographic examinations for marginal bone levels and peri-implant evaluations were performed during the clinical follow-up appointments within 12 months. RESULTS During the 12-month follow-up period, only one implant was lost in the IL group. The mean implant stability quotient values were 74.18+/-5.72 and 75.18+/-3.51 for Groups IL and CL at surgery, respectively, and the corresponding values were 75.36+/-5.88 and 75.64+/-4.84 at 1-year recall, respectively. The difference was not statistically significant between the two groups during the 12-month study period (P>0.05). When peri-implant parameters were evaluated, excellent peri-implant health was demonstrated during the 1-year observation period and all implants showed less than 1 mm of marginal bone resorption during the first year. CONCLUSIONS In the present study, immediate functionally loading did not negatively affect implant stability, marginal bone levels and peri-implant health when compared with conventional loading of single-tooth implants.

Monopoly coating on acrylic resin surfaces: a bacteriologic study.

In an open bulb of a buccal flange obturator, it is almost impossible to polish the inner surface of the bulb. Because it cannot be cleaned easily, oral and nasal secretions lead to odors. To obtain a smoother surface, it is suggested that monopoly be painted on the unpolished surface of the open bulb. In this study, the effect of a monopoly coating on bacteria retention and washability of acrylic resin surfaces was investigated. Coated and uncoated acrylic resin samples were prepared and both were contaminated with Escherichia coli. After standard washing, the remaining viable E. coli colonies were counted. The statistical results showed that the difference in the number of E. coli colonies between coated and uncoated groups was highly significant (p less than 0.001). It was suggested that monopoly should be applied to the acrylic resin surfaces where mechanical polishing cannot be done.

Effect of root canal sealers on the push-out bond strengths of tooth-colored posts to root dentine

Objectives: This study evaluated the effect of different root canal sealers on the push-out bond strength of tooth-colored posts to root dentin. Material and methods: Eighty human mandibular premolar teeth with single roots were decoronated and randomly divided into two groups according to post material: G1–G5: Cytec blanco; G6–G10: Cosmopost. In each group, the specimens were further subgrouped according to the filling material plus sealer (n = 8): G1, G6: Gutta-percha + AH Plus; G2, G7: Resilon + Epiphany SE; G3, G8: Gutta-percha + Sealite; G4, G9: Gutta-percha + iRoot SP; and G5, G10: control (unobturated). Cytec blanco and Cosmopost of 1.4 mm diameter were adhesively luted to samples using Variolink II. Push-out test was performed in a universal testing machine, and failure modes were examined under stereomicroscope. Data were analyzed with the two-way ANOVA and post hoc Tukey’s tests. Statistical significance was set to 0.05. Results: Roots obturated with AH Plus (3.48 ± 1.41 MPa), Sealite (3.47 ± 0.65 MPa), and Resilon (3.36 ± 1.23 MPa) had the lowest bond strength (p < 0.005). iRoot SP and control group samples showed the highest bond strength values (7.38 ± 0.89 MPa and 6.43 ± 1.16 MPa, respectively) (p < 0.05). Significant differences were observed among tooth-colored posts and sealers (p < 0.05). Adhesive failures were predominant in all groups (48%). Conclusions: When the resin cement Variolink II was used, the types of root canal filling materials and sealers could affect the retentions of the fiber/zirconium posts; the fiber post revealed the higher bond values than the zirconium post; and the calcium silicate-based sealer (iRoot SP) revealed the highest bond strengths.

Effect of manufacturing techniques on the marginal and internal fit of cobalt-chromium implant-supported multiunit frameworks

Statement of problem. Subtractive and additive computer‐aided design and computer‐aided manufacturing (CAD‐CAM) systems have been used in the fabrication of cobalt‐chromium (Co‐Cr) long‐span restorations. However, the accuracy of fit of multiunit frameworks is unclear. Purpose. The purpose of this in vitro study was to compare the marginal and internal fit of implant‐supported, cement‐retained 3‐unit, 4‐unit, and 5‐unit Co‐Cr metal frameworks fabricated by the lost wax (LW), CAD‐CAM milling, and selective laser melting (SLM) techniques. Material and methods. A total of 90 Co‐Cr metal frameworks were fabricated for 3‐unit, 4‐unit, or 5‐unit implant‐supported cement‐retained restorations on stock abutments with 3 different manufacturing technique subgroups (LW, CAD‐CAM milling, and SLM). The silicone replica technique was used to evaluate the marginal and internal discrepancy values. By using a light microscope at ×45 magnification and a digital measurement program, the thickness of the silicone layer was measured at 16 reference points on each abutment for a total of 3360 measurements. The effect of manufacturing techniques and number of units (groups) on discrepancy values was evaluated using a full factorial ANOVA model. Group and manufacturing technique effects were analyzed separately by 1‐way ANOVA in case of significant interactions. Pairwise comparisons were evaluated using the Tukey post hoc test (&agr;=.05). Results. The mean marginal discrepancy of 3‐unit frameworks showed no statistically significant differences in the LW (35 &mgr;m) and SLM (25 &mgr;m) techniques; however, the frameworks manufactured by CAD‐CAM milling (68 &mgr;m) had the highest marginal discrepancy values (P<.001). The mean marginal discrepancy values were 40 &mgr;m (LW), 33 &mgr;m (CAD‐CAM milling), and 25 &mgr;m (SLM) for 4‐unit frameworks, and no significant differences were found among the manufacturing techniques. For 5‐unit frameworks, CAD‐CAM milling techniques had the widest mean marginal discrepancy values (85 &mgr;m), and copings manufactured by the LW technique had the lowest mean marginal discrepancy values (36 &mgr;m). For all manufacturing techniques, axial discrepancy values were not affected with respect to the unit number (P=.526). The highest internal discrepancy values were measured at the occlusal area in all groups. Conclusions. CAD‐CAM milling had the poorest marginal fit values for 5‐unit frameworks, whereas the LW technique demonstrated the best results. Unit number had no significant influence on the marginal and internal fit of the LW manufactured frameworks.