Finite element analysis of heat generation from different light-polymerization sources during cementation of all-ceramic crowns.

STATEMENT OF PROBLEM: Exothermic composite resin chemical reactions and visible light generators can produce heat during a restorative polymerization process. These thermal changes in restored teeth may cause pain and irreversible pulpitis. PURPOSE: The purpose of this study was to analyze the temperature distribution and heat flow patterns of a crowned mandibular second premolar tooth model using 3 different light-polymerization technologies and a finite element technique. MATERIAL AND METHODS: A 2-dimensional finite element model was used to simulate a clinical condition. Heat flow and thermal stress distribution in a tooth during cementation of an all-ceramic crown using 4 commercially available light-polymerization units (LPUs), each with different wavelengths (Elipar TriLight, Elipar Freelight, Apollo 95 E, and ADT 1000 PAC), were investigated. The temperature values were measured at 3, 10, 12, and 40 seconds for each light-polymerizing unit (LPU) at 6 different finite element nodes. Two-dimensional temporal and spatial distribution of the thermal stress within the tooth, including the thermal coefficients and boundary conditions of the dental materials, were obtained and evaluated. RESULTS: The temperature at the nodal points did not exceed 42 degrees C, which is a threshold value for tissue vitality within the recommended operating periods at the dentin and pulp surface for all LPUs, except for Elipar TriLight. In the case of Elipar TriLlight, the temperatures at the dentin and pulp surfaces were 47 degrees C and 42 degrees C, respectively. CONCLUSIONS: When the light-polymerization units were used according to the manufacturers' operating procedures and without prolonged operating periods, with the exception of Elipar TriLight, the investigated LPUs did not produce significant heat. However, when the operating periods were prolonged, unacceptable temperature increases were observed, especially with the high-intensity LPUs.

Dental anxiety among adults in Turkey.

AIM: This aim of this study was to investigate the prevalence of dental anxiety and related factors in a Turkish population. METHODS AND MATERIALS: The Turkish translation of the Dental Fear Scale (DFS) and the Modified Dental Anxiety Scale (MDAS) were administered to 115 dental patients consisting of 21 subjects who had dental phobia and of 94 patients who did not. The scales were also administered to a non-clinical general population (N=183). RESULTS: The Turkish version of the DFS was internally consistent and reproducible. The scale had strong correlations (r=0.80, p<0.001 ) with the MDAS. Female participants scored higher (45.2+/-18.1) on the scale than men (38.2+/-15.7). The DFS had a negative correlation (r=-0.25, p<0.001) with education level. There was a statistically significant difference between dental phobics and the remaining groups on the DFS total score. At a cut-off point 55, the sensitivity of the scale was 0.80, specificity 0.80, positive predictive value 0.48, and negative predictive value 0.95. Thirty-nine subjects (21.3%) in the general population had total scores above this cut-off point. CONCLUSION: Dental fear is common in clinical and non-clinical settings in Turkey. The good psychometric characteristics of the DFS among Turkish participants supports its cross-cultural validity.

Reliability and validity of the Modified Dental Anxiety Scale (MDAS) in a Turkish population.

OBJECTIVES: Fear of dentistry is a common obstacle to obtaining dental care in Turkey. The aim of this study was to assess the reliability, validity and psychometric characteristics of the Turkish translation of the Modified Dental Anxiety Scale (MDAS) and compare it to the Dental Fear Survey (DFS) scores obtained in the same population. METHODS: The Turkish translated version of the MDAS was administered to 115 dental patients; 21 subjects who suffered from dental phobia, requiring general anesthesia for dental procedures, and 94 who did not have dental anxiety, in addition to 442 subjects from the general population. RESULTS: The Turkish translated version of the MDAS was internally consistent and reproducible. The patients with dentist phobia had the highest score. The Turkish MDAS correlated with the DFS (r = 0.80, P < 0.001). The MDAS scale correlated inversely (r = -0.14, P < 0.005) with level of education; however, it did not correlate with economic status. Women scored higher than men on the scale (mean = 12.3, SD = 5.2 vs. mean = 10.9, SD = 4.5, P < 0.005). At a cut-off point > or = 15, sensitivity was 0.80, specificity 0.74, positive predictive value 0.41 and negative predictive value 0.94. CONCLUSION: Although the specificity values were low, the Turkish MDAS demonstrated acceptable sensitivity, positive and negative predictive values. Thus, high reliability and validity of the MDAS supports its cross-cultural validity and indicated that it may be a valuable tool in quantifying fear of dentistry among Turks.

ITI implants and Dolder bars in the treatment of large traumatic defect of mandible: a clinical report.

The development of more sophisticated implant techniques to produce satisfying results improves the precise planning of both the surgical phase of the implantation and the following prosthetic rehabilitation. Ball and bar attachments are the main retainer systems for implant-bearing overdentures to achieve a successful treatment in the partial or full edentulism. In this clinical report, a 23-year-old male patient, presented with a large traumatic defect in the anterior mandible, was treated with ITI implant and ITI Dolder bar combinations. The reason to prefer this kind of treatment depends on the highest retention capacity and cleaning facilities of the system.