Background. The aim of the present study was to compare coronally advanced flap (CAF) plus amniotic membrane (AM) to CAF with connective tissue graft (CTG) in the treatment of Miller’s class I and II gingival recessions.Methods. Eleven healthy subjects with thirty Miller’s class І and ІІ gingival recessions ≥3 mm, were selevted for this research and randomly assigned to two groups in a split-mouth design. In the control group gingival recessions were treated with CAF and CTG; however, in the test group the lesions were treated with (AM) and CAF. The clinical parameters, including recession depth (RD), recession width (RW), keratinized tissue width (WKT), probing depth (PD) and clinical attachment level (CAL), were measured at baseline and 1, 3 and 6 months postoperatively. Statistical significance was set at P < 0.01.Results. Position changes of RD, RW, CAL, and MGJ were significant between baseline and one month after surgery (P < 0.01) in both the test and control groups and these values remained unchanged at 3- and 6-month follow-ups. There were no statistically significant differences in PD and WKT between baseline and 1-, 3- and 6-months intervals postoperatively. The mean root coverage values after 6 months were 75.5% and 63.1% for two groups, respectively. The mean recession depth reductions were 2.63±0.63 mm and 2±1.4 mm in the test and control groups, respectively. Conclusion. The results of this research showed that application of AM instead of connective tissue decreased surgical operation time and patient discomfort but the amount of root coverage was not significantly different between the two methods.

Background. The aim of the present study was to evaluate the effect of Corega and 2.5% sodium hypochlorite cleansing agents on the shear and tensile bond strengths of GC soft liner to denture base. Methods. A total of 144 samples (72 samples for tensile and 72 for shear bond strength evaluations) were prepared. The samples in each group were subdivided into three subgroups in terms of the cleansing agent used (2.5% sodium hypochlorite, Corega and distilled water [control group]). All the samples were stored in distilled water, during which each sample was immersed for 15 minutes daily in sodium hypochlorite or Corega solutions. After 20 days the tensile and shear bond strengths were determined using a universal testing machine. In addition, a stereomicroscope was used to evaluate fracture modes. Data were analyzed with one-way ANOVA, using SPSS 16. Results. The results of post hoc Tukey tests showed significant differences in the mean tensile and shear bond strength values between the sodium hypochlorite group with Corega and control groups (P=0.001 for comparison of tensile bond strengths between the sodium hypochlorite and control groups, and P<0.001 for the comparison of tensile bond strengths between the sodium hypochlorite and Corega groups and the shear bond strengths between the sodium hypochlorite and Corega groups, and sodium hypochlorite and control groups).The majority of failures were cohesive in the control and Corega groups and cohesive/adhesive in the sodium hypochlorite group. Conclusion. Immersion of soft liners in Corega will result in longevity of soft liners compared to immersion in sodium hypochlorite solution and sodium hypochlorite solution significantly decreased the tensile and shear bond strengths compared to the control and Corega groups.

Aims: The present study aimed to evaluate the stress distribution of porous tantalum implant and titanium solid implant assisted overdenture (IAO) in mandibular bone by utilizing three-dimensional (3D) finite element (FE) analysis. Materials and Methods: In this FE study, an existing cone-beam volumetric tomography scan of a patient without any maxillofacial anomaly with an available acceptable IAO for mandible was used to attain the compartments of a completely edentulous mandible. Zimmer trabecular implants and locator attachment systems were selected as the case group (Model B), and Zimmer Screw-Vent implants and locator attachment system were chosen for the control (Model A), as overdenture attachments in the present study. The mandibular overdenture was scanned and digitized as a FE model. Two 3D FE models were designed as edentulous lower jaws, each with four implants in the anterior section of the mandible. Three forms of loads were directed to the IAO in each model: Vertical loads on the left first molar vertical molar (VM). Vertical loads on the lower incisors (VI). Inclined force buccolingually applied at left first molar (IM). Results: Under all loading conditions, the maximum strain values in peri-implant bone in Model A were less than Model B. Under VI, the greatest stress value around abutments in both models was about 2–3 times higher than the other loads. Under VM and IM loads, no significant difference was observed between models. Conclusion: Using trabecular metal implants instead of solid implants reduces strain values around both cortical and trabecular bone.

Background. Acentric double pedicle graft is an alternative to double pedicle graft, which can improve clinical outcomes by removing tension in sutures. This study examined the effect of using platelet-rich fibrin (PRF) on the success rate of acentric double pedicle graft in treating patients with Miller Class I and II recessions. Methods. A total of 16 Miller Class I and II lesions were studied in 8 patients. The samples were divided into two groups in terms of PRF use: with PRF and without PRF. Indices, including recession depth, width of keratinized gingiva and pocket depth, were measured with a standard Michigan O probe with Williams marking. Six months later, Kolmogorov-Smirnov test and Wilcoxon nonparametric test were applied with SPSS17 to analyze data. Results. The recession depth, width of keratinized gingiva, and increased root coverage exhibited a significant difference between the two groups after surgery, but no significant difference was found in pocket depths. Conclusion. Applying PRF with acentric double pedicle graft reduced the recession depth, increased the width of keratinized gingiva and enhanced the extent of root coverage when compared with the situation where PRF was not used. Therefore, this study supports the use of PRF with acentric double pedicle graft in root coverage treatments.