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
BACKGROUND: Establishment of optimal vertical dimension of occlusion (VDO) for prosthetic patients, either complete denture or fixed full mouth rehabilitation, is a vital step to discern at a pleasing esthetics and harmonious function. None of the experiments in the literature studied the hopeful inheritance of the VDO from a parent to offspring. PURPOSE: The aim of this study was to establish the dominant mode of inheritance of VDO from parents to offspring using cephalometric landmarks. MATERIALS AND METHODS: Following the inclusion criteria, 20 families were selected and explained about the study design. Individual cephalograph of father, mother, and offspring were traced out of bony landmarks. The reference planes were delineated for the measurements from maxillary incisal (I) tip and mesio-palatal cusp tip of maxillary first molar (M) to palatal (PP) and inter-foramina (IFP) planes. RESULTS: In all the distances measured, there exists a statistically significant difference between both father and son and mother and son. For the measured IPP, MPP, and IIFP distances, there is no statistically significant difference existed between father and daughter. However, in MIFP distance, there is a significant difference between father and daughter. Except for the IIFP distance between mother and daughter (P = 0.08), in all other measured distances, there existed a statistically significant difference. CONCLUSION: There is no dominant mode of inheritance from the parent to the son with respect to the measured parameters. Inheritance was observed to be stronger between father and daughter than between mother and daughter.
RESUMEN
BACKGROUND: Masticatory forces cause fatigue to the dental luting agents, adversely affecting the retention of these cement-retained crowns. Sandblasting (SB) and diamond abrading the abutment surface improves the bond strength of luting agents. However, the effect of acid etching (AE) on the implant abutment surface and the effect of other surface modifications under masticatory load are yet to be documented. PURPOSE: The aim of the study was to evaluate the effect of abutment surface modifications on the retention of cement-retained restorations subjected to cyclic fatigue loads. MATERIALS AND METHODS: Forty Ni-Cr copings were made on Cp-titanium laboratory analogs. The specimens were divided into two groups as Group I: Uniaxial tensile loading (UTL) and Group II: Offaxial cyclic loading followed by uniaxial tensile loading [CTL]. Further subgrouped as, subgroup I: Control (C), subgroup II: SB, subgroup III: AE, and subgroup IV: SB + AE. The copings were luted with Zn2(PO4)3 and subjected to uniaxial tensile loading. Copings were recemented, and CTL was conducted. Two-way analysis of variance was used as the statistical test of significance. RESULTS: In relation to the subgroups, the bond strength of Zn2(PO4)3 was higher in Group I than in Group II. The bond strength in subgroup IV was superior in both Group I and Group II (547.170 N ± 5.752 and 531.975 N ± 6.221 respectively). CONCLUSIONS: For both UTL and CTL, abutment SB + AE elicited maximum coping retention followed by AE. Off-axial cyclic loading adversely affected the retention irrespective of the surface modifications.
