The Periotest Method: Implant-Supported Framework Precision of Fit Evaluation

: In this study, the Periotest instrument was used to measure the precision of fit between cast high noble-metal frameworks and the supporting implants in a patient-simulation model. Three framework conditions and three implant-location variables were used to evaluate the rigidity of the assembly as measured by the Periotest method. The framework variables were (1) one-piece castings (OPC); (2) sectioned-soldered inaccurate castings (SSIC); and (3) sectioned-soldered accurate castings (SSAC). The implant-location variables were right anterior (RA), center (C), and left anterior (LA). Materials and Methods : The patient simulation model used consisted of three self-tapping BrÅnemark implants in a reasonable arch curvature in bovine bone. Three working casts were fabricated from the patient-simulation model using polyvinyl siloxane and tapered impression copings. From the working casts, three sets of three frameworks were fabricated as OPCs, SSICs, and SSACs using type 3 high noble alloy. The SSICs were fabricated with a quantitative misfit of 101.6 Μm at the facial surface, between the abutment-to-gold cylinder interface at the C implant location. Periotest value (PTV) measurements were made at the midfacial surface of the frameworks directly above each abutment-to-gold cylinder interface. Three measurements were made for each test condition. The data were analyzed to compare framework condition(s) and implant location(s) using ANOVA and Fisher's Protected Least Significant Difference Comparison Test. Results : The ANOVA showed that significant differences exist between the mean PTV data for framework condition and for implant location (p < .01). Significant differences were shown between the mean PTV data for the SSAC assemblies and the OPC and SSIC assemblies. The SSICs displayed a more positive (+) mean PTV than the OPCs. The OPC assemblies had a more positive mean PTV than the SSAC assemblies. The mean PTV data for the SSAC assemblies had a significantly different PTV (p < .01) than the other two framework condition assemblies. The OPC and the SSIC assemblies had PTVs that were not significantly different. The C implant location was significantly different from the RA and the LA implant locations (p < .01). The RA and the LA implant locations were not significantly different from each other. The C implant location always demonstrated the most positive mean PTV regardless of the framework condition being tested. Conclusions : The Periotest instrument quantified differences in the precision of fit between three framework conditions. The SSAC assemblies were significantly more rigid than the OPC and SSIC assemblies. The OPC and SSIC assemblies' mean PTVs were not significantly different. The mean PTVs for the C implant location and the RA and LA implant locations were significantly different (p < .01). The mean PTVs of the RA and LA implant locations were not significantly different. The implant-location PTVs followed the same rank order for all three framework conditions. The procedures used to fabricate a more precise fit between the framework and the supporting implants is influenced by the skill of the clinician and technician.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75096/1/j.1532-849X.1996.tb00298.x.pd

Differentiating Non-Suicidal Self-Injury and Risky Drinking: a Role for Outcome Expectancies and Self-Efficacy Beliefs

© 2017 Society for Prevention ResearchSocial cognitive theory articulates a role for two key thought processes in governing volitional behaviour: outcome expectancies and self-efficacy expectancies. These cognitions are behaviour-specific, and should thus differentiate people who engage in one behaviour over another. This paper presents the results of a study applying social cognitive theory to explore how outcome expectancies and self-efficacy expectancies differentially relate to non-suicidal self-injury (NSSI) and risky alcohol use amongst a sample of young adults. A sample of 389 undergraduate students completed self-report questionnaires assessing their engagement in NSSI, alcohol consumption, their beliefs about the anticipated consequences of self-injury and alcohol consumption (outcome expectancies), and their belief in their ability to resist self-injury or risky drinking (resistance self-efficacy). Generally, people who self-injure rather than drink are characterised by a belief in the ability to resist drinking, coupled with stronger positive, and weaker negative, NSSI expectancies. People who self-injure are less likely to think alcohol reduces tension than people who do not self-injure. People who engaged in both NSSI and risky drinking report more anxiety than participants who engaged only in risky drinking and lowered ability to resist self-injury. Overall, the findings suggest that a unique combination of beliefs differentially predict NSSI and drinking. The pattern of results suggests potential avenues for future research to delineate why people engage in one behaviour rather than another and to inform future prevention and early intervention initiatives