Comparison of Er:YAG Laser and Ultrasonic Scaler in the Treatment of Moderate Chronic Periodontitis: A Randomized Clinical Trial

Introduction: Periodontitis is an inflammatory periodontal disease that leads to tooth loss. Recently laser has been introduced as an alternative treatment for periodontitis. The aim of the present study was to compare the effect of Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser with ultrasonic scaler in patients with moderate chronic periodontitis.Methods: In this randomized single-blind clinical trial, 27 patients with moderate chronic periodontitis were selected. One quadrant of the patients was treated by Er:YAG laser and the other one by ultrasonic scaler. Clinical parameters, including periodontal pocket depth (PPD), papillary bleeding index (PBI) and clinical attachment level (CAL) were measured before, as well as 6 and 12 weeks after treatment. Data were analyzed by SPSS 20 software using Friedman test, paired t test, independent t test and Mann-Whitney test. The significance level was set at 0.05.Results: The means of clinical parameters in both groups were significantly improved in the first and second follow-ups (P < 0.001). Although the means of PPD, PBI and CAL were slightly higher in the laser group than in the ultrasonic group, the differences were not statistically significant between these two groups (P > 0.05).Conclusion: Although both ultrasonic scaler and Er:YAG laser could effectively improve clinical periodontal parameters, the results did not reveal the superiority of Er:YAG laser over ultrasonic scaler or vice versa

Stress Distribution in Luting Cement Layer in Implant Supported Fixed Partial Dentures Using Finite Element Analysis

Background and Aim : Luting cements are necessarily used to increase retention and enhance the marginal seal of fixed partial dentures (FPDs) . In this study, the finite element method (FEM) was used to investigate the effect of different types of luting agents on stress distribution in the luting cement layer i n a three-unit implant-supported FPD .   Materials and Methods : A three-dimensional (3D) FE model of a FPD was designed from the maxillary second premolar to the second molar teeth using CATIA V5R18 software, and analyzed by ABAQUS/CAE version 6.6 software . Three load conditions were statically applied to eight points in each functional cusp in horizontal (57.0 N), vertical (200.0 N) and oblique (400.0 N, θ=120°) directions. Five luting agents including glass ionomer, zinc polycarboxylate, polymer-modified zinc oxide eugenol (ZOE), composite resin and zinc phosphate were evaluated .   Results : The stress distribution pattern in the luting cement layer was almost uniform in all luting cements. In addition, the maximum von Mises stress in the luting cement layer (39.96 MPa) was at the cervical one-third of the palatal side of the second premolar when oblique force was exerted on zinc phosphate cement . Moreover, the minimum von Mises stress in the luting cement layer (0.41 MPa) was at the lateral side of the coronal one-third when the horizontal force was applied to the Polymer-modified ZOE cement. Likewise, the luting cement layers in the premolar tooth showed greater von Mises stress than that in molar tooth .   Conclusion : The type of luting cement has no significant effect on the stress distribution pattern in the luting cement layer however, von Mises stress values were different in various types of luting agents. USE of zinc phosphate cement is associated with more limitations

Comparison of the Efficacy and Side Effects of Chlorhexidine Mouthrinses with (Hexidine) and without (Epimax) Alcohol

Introduction: Chlorhexidine mouthrinses have widely been recognized for their contribution in maintaining plaque control. Most of them contain alcohol that makes them impractical for many patients. Alcohol-free mouthwashes may have fewer side effects but may be less efficient. The current study was aimed to compare the effectiveness and side effects of chlorhexidine mouthrinses with and without alcohol. Materials and Methods: In this double-blind clinical trial, 32 patients with moderate and severe gingivitis were recruited. For all patients, full prophylactic procedures, such as removal of plaque, calculus, and stains on the teeth, were performed. Each patient was asked to use 15 mL of the mouthrinse for 60 s twice daily. The patients were divided into two groups, one group used Hexidine (0.12% chlorhexidine and 10% ethanol) mouthwash and the other group used Epimax (0.12% chlorhexidine and 0.05% sodium fluoride) mouthwash. After 14 days, plaque (PI), gingival (GI), and stain indices were analyzed. The obtained data were analyzed by using SPSS 16 using covariance [Analysis of covariance (ANCOVA)] and t-test. Results: Both mouthwashes significantly reduced the mean scores of plaque (P < 0.0001) and gingival (P < 0.032) indices after 2 weeks; however, Hexidine mouthrinse was shown to be more effective. The extent of stain was the comparable in both groups. While Epimax mouthrinse caused severe stains on the teeth, Hexidine mouthrinse caused burning mouth. Conclusion: Although Epimax mouthwash did not show any side effects, it was less suitable and caused more dental stain. Ethanol-free Hexidine mouthwash seems to be more proper for gingivitis, but its side effects are required to be taken into consideration