ABSTRACT
PURPOSE: The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS: In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (alpha=0.05). RESULTS: The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION: The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces.
Subject(s)
Humans , Ceramics , Collodion , Dental Porcelain , Dentin , Molar, Third , Silicates , ToothABSTRACT
When provisional restorations are worn for long term period, the adhesion of bacteria becomes a primary factor in the development of periodontal diseases. The aims of this study were to evaluate the surface roughness and bacterial adhesion of four different provisional fixed prosthodontic materials. Ten cylindrical specimens were prepared from bis-acrylic composites [PreVISION CB and Protemp 3 Garant], a light-polymerized composite [Revotek LC], and a polymethyl methacrylate-based [Dentalon] provisional fixed prosthodontic materials. Surface roughness was assessed by profilometry. The bacterial adhesion test was applied using Porphyromonas gingivalis [P. gingivalis] and spectrofluorometric method. Statistical analysis was performed using ANOVA and Dunnett t-tests. All tested materials were significantly rougher than glass [P < 0.05]. Revotek LC had the greatest fluorescence intensity, Pre VISION and Protemp 3 Garant had moderate values and all of them had significantly more bacterial adhesion compared to glass [P < 0.05]. Dentalon had the lowest fluorescence intensity among the provisional fixed prosthodontic materials. The quantity of bacterial adhesion and surface roughness differed among the assessed provisional fixed prosthodontic materials. The light-polymerized provisional material Revotek LC had rougher surface and more bacterial adhesion compared with the others