RESUMEN
BACKGROUND: Air abrasion of the implant abutment surface improves the bond strength of luting agents. However, the effect of acid etching and combination of air abrasion and acid etching on the bond strength of various luting agents under masticatory load is yet to be documented. PURPOSE: The purpose of this study was to evaluate the effect of implant abutment surface modifications on the tensile bond strength (TBS) of cast metal copings (CMCs) luted with different luting agents, subjected to cyclic fatigue loads. MATERIALS AND METHODS: A total of 150 Ni-Cr CMCs were made on commercially pure titanium (Cp-Ti) laboratory analogues. The samples were categorized into three groups based on surface modifications and five subgroups for luting agents. The CMCs were cemented to the respective surface-modified groups, stored in distilled water at 37°C for 24 hours, and then subjected to load cycling, followed by tensile loading. One-way analysis of variance (ANOVA) was used to compare the mean bond strength between luting agents. RESULTS: Self-adhesive resin cement showed the highest TBS followed by resin-modified glass ionomer cement, zinc polycarboxylate, and zinc phosphate cement. Non-eugenol temporary cement showed least TBS values on all modified abutment surfaces. CONCLUSION: Air abrasion + acid etching (HY) provided the greatest TBS followed by acid-etched (AE) surface only. Air-abraded (AA) surface yielded the least TBS for luting agents.
RESUMEN
AIM: The aim of this in vitro study was to evaluate and compare the microleakage of restorations using low shrinkage silorane-based dental composite and methacrylate-based dental composites in Class II cavity at the occlusal and gingival margins. MATERIALS AND METHODS: Sixty mandibular molars were collected and divided into three experimental groups and one negative control group. Class II slot cavity was prepared on the mesial surface. Experimental groups were restored with Group I: silorane-based microhybrid composite, Group II: methacrylate-based nanohybrid composite, and Group III: Methacrylate-based microhybrid composite, respectively. Group IV: negative control. The samples were thermocycled, root apices were sealed with sticky wax and coated with nail varnish except 1 mm around the restoration. This was followed by immersion in 2% Rhodamine-B dye solution under vacuum at room temperature for 24 h. Then, the samples were sectioned longitudinally in the mesiodistal direction and evaluated under stereomicroscope ×40 magnification. Scoring was done according to the depth of dye penetration in to the cavity. Statistical analysis of the data was done. RESULTS: The results were that no statistically significant difference in the microleakage at the occlusal margin for all the restorative materials, whereas at the gingival margin, silorane-based microhybrid composite showed less microleakage than the methacrylate-based nano- and micro-hybrid composites. CONCLUSION: In general, silorane-based microhybrid composite had less microleakage among the other materials used in this in vitro study.
RESUMEN
AIM: The aim of this study to evaluate the effectiveness of pain control by employing transcutaneous electrical nerve stimulator (TENS) over conventional injectable local anesthesia for children requiring restorative procedures under rubber dam. MATERIALS AND METHODS: The study design considered was the split mouth design, in experiment (right) side, dental procedures under rubber dam was performed under TENS and in control (left) side, dental procedures under rubber dam was performed under conventional injectable local anesthetic (LA). The level of comfort and discomfort experienced during TENS and conventional LA was determined using visual analog scale (VAS) and heart rate. RESULT: Increase in mean heart rate associated with TENS (0.78%) was significantly less compared to increase in heart rate with administration of conventional local anesthesia (11.78%). In VAS, the mean values for pain indicate that minimum pain was felt with TENS, which was closely followed by LA. CONCLUSION: TENS can offer many safer and psychological advantages and is a valuable alternative to conventional LA for children.