Methods: A three-unit bridge master model was fabricated using cold-cure acrylic resin. Four combinations of different viscosities of PVS impression materials - regular body (monophase) alone, light body with regular body, light body with heavy body, and light body with putty - were used to make an impression of the master model. Ten impressions from each group were taken and Type IV gypsum stone was used to generate the dies. The dies were measured at the inter-abutment distance, occlusogingival length, and shoulder width with a measuring microscope and were compared with the master model using one-way analysis of variance and Tukey (honest significant difference) test.
Results: Differences were found for inter-abutment distance between the master model and the light body with regular body and light body with putty dies (both P < 0.02). A difference was found for shoulder width between the master model and the regular body alone die (P = 0.01). No differences were found for occlusogingival distance (all P > 0.08).
Conclusion: Results suggested inter-abutment distance was most accurate when using a PVS light body combination. Occlusogingival length was accurate using any of the studied PVS combinations, and shoulder width was more accurate when using the regular body PVS.
Relevance for patients: These results should be considered when choosing the viscosity of the PVS to use for producing impressions of high accuracy and fabricating a well-fitting fixed prosthesis.
Methods: In this prospective pilot study, patients seeking restorative treatment were screened for dental anxiety and dental concern about treatment using the Dental Anxiety Scale-Revised (DAS-R) and Dental Concern Assessment (DCA) questionnaires. Participants with a DAS-R score of 9 or above were randomly assigned to an experimental or control group. The patients in the experimental group received two psycho-logical interventions (psychoeducation and progressive muscular relaxation) prior to dental treatment. Dur-ing treatment, patients received another psychological intervention (music distraction). No psychological interventions were given to control patients. DAS-R and DCA scores were used to assess dental anxiety and concern, respectively, before treatment, after treatment, and at follow-up. Nonparametric tests were used for intergroup and intragroup statistical analyses.
Results: Out of 64 patients surveyed, 33 (51.6%) had experienced dental anxiety. Of those, 2 were exclud-ed, and 31 patients with a mean ± SD age of 41.2 ± 15.9 y completed the study. No intergroup differences in dental anxiety were found in terms of pretreatment, posttreatment, and follow-up treatment. The mean rank value of the dental anxiety score was less in the experimental group (13.53) than the control group (18.31), albeit not significant. More specifically, differences (Kruskal-Wallis %2 = 14.82, P = 0.001, effect size = 0.33) were found in the experimental group for pretreatment, posttreatment, and follow-up treatment levels of dental anxiety for extraction (P = 0.01), injection (P = 0.02), and sound/vibration of the drill (P = 0.00). No significant intragroup differences between pretreatment, posttreatment, and follow-up treatment were found in the control group.
Conclusions: The combined brief psychological interventions reduced dental anxiety.
Relevance for patients: The psychological interventions of the present study could be applied right before or during dental treatment to reduce the dental anxiety of patients. However, additional research involving larger groups is needed to replicate the results of this pilot study.