Clinical Report on an Implant-Supported Overdenture in a Parkinson's Patient.

Speaking, chewing, and swallowing difficulties can result from Parkinson's disease (PD), which frequently affects the oro-pharyngeal muscles. The reduction in food and hydration intake that is unavoidable leads to a worsening of neurological symptoms. Patients with Parkinson's disease experience significant challenges when adjusting to wearing entire dentures. Each of these problems presents a considerable challenge for the doctor in terms of prosthodontic rehabilitation. This case study describes how a patient with Parkinson's disease was able to employ flexible removable partial dentures supported by implants to replace both their full and partial set of missing teeth. A well-made prosthesis will help the patient with their psychological, functional, and aesthetic impairments.

Severe Maxillectomy Defect Rehabilitation with an Implant-Retained Obturator Prosthesis: A Case Report.

Conventional obturator prostheses might cause dissatisfaction in patients with hard or soft palate defects due to inadequate retention and function during speech, mastication, and swallowing. Thus, surgical reconstruction and implant-supported obturators are considered as alternative treatments for these patients. This case-report study describes the prosthetic reconstruction of an 88-year-old patient suffering from a hard palate defect after surgical resection of verrucous carcinoma in the left side of the hard palate. Fifteen months after radiotherapy, two implants were placed in the right side of the remaining ridge, in the second and third molar region. After the implant healing period, the implant-supported obturator prosthesis was fabricated. The patient was satisfied with the esthetics and function of the obturator at the 12-month recall visit and radiographs showed normal healing and no bone loss around the implants.

The Effect of Modified Framework Design on the Fracture Resistance of IPS e.max Press Crown after Thermocycling and Cyclic Loading.

AIM: This study aimed to investigate the effect of modified framework (MF) design on the fracture resistance of IPS e.max Press anterior single crown after thermocycling and cyclic loading. MATERIALS AND METHODS: Two types of IPS e.max Press frameworks were designed (n = 10); standard framework (SF) with a 0.5 mm uniform thickness and MF with a lingual margin of 1 mm in thickness and 2 mm in height connected to a proximal strut of 4 mm height and a 0.3 mm wide facial collar. The crowns were cemented to resin dies, subjected to 5,000 cycles of thermocycling, and loaded 10,000 cycles at 100 N. A universal testing machine was used to load specimens to fracture, and the modes of failure were determined. RESULTS: The mean and standard deviation (SD) of fracture resistance were 219.24 ± 110.00 N and 216.54 ±120.02 N in the SF and MF groups. Thus, there was no significant difference (p = 0.96). Mixed fracture was the most common failure mode in both groups. We found no statistically significant difference between the groups (p = 0.58). CONCLUSION: The MF design did not increase the fracture resistance of IPS e.max Press crown. CLINICAL SIGNIFICANCE: Framework design is an essential factor for the success of all-ceramic restorations and its modification might be regarded as an approach to increase fracture resistance. Furthermore, the modified design was evaluated in metal-ceramic or zirconia crowns while less attention was paid to the IPS e.max Press crowns. How to cite this article: Golrezaei M, Mahgoli HA, Yaghoobi N, et al. The Effect of Modified Framework Design on the Fracture Resistance of IPS e.max Press Crown after Thermocycling and Cyclic Loading. J Contemp Dent Pract 2024;25(1):79-84.

Conventional maxillary denture versus maxillary implant-supported overdenture opposing mandibular implant-supported overdenture: Patient's satisfaction.

OBJECTIVES: This study sought to determine the impact of age, gender, and use of maxillary implant-supported overdenture (UISOD) versus conventional denture (CMD) opposing mandibular implant-supported overdenture (LISOD) and the number of years the patient has used their prosthesis on the ratings of satisfaction. This study aimed to assess the long-term influence of different factors on patients' satisfaction with LISODs needing a maxillary prosthesis, helping dentists choose a treatment pathway that leads to a higher satisfaction rate. MATERIAL AND METHODS: This cross-sectional study included 84 participants. They were treated with LISOD opposing either CMD or UISOD from 2015 to 2020. They were all eligible to participate in the study. An oral health impact profile (OHIP-14) questionnaire was given to each patient and filled out by them. OHIP-14 scores were gathered and went under statistical analysis with PASS-11 software to determine the relationship between patients' satisfaction with the scores. RESULTS: Age and gender had no significant influence on how satisfied patients were. Patients with maxillary overdentures showed more satisfaction than the CMD group (p < .05). Moreover, patients' satisfaction decreased with increasing years of prostheses usage (p < .05). CONCLUSIONS: This study demonstrated that satisfaction is related to the type of maxillary prosthesis (conventional or implant-supported) used opposing LISODs and the number of years the patient had used the prostheses.

Teaching-learning in clinical education based on epistemological orientations: A multi-method study.

INTRODUCTION: Teaching-learning is the heart of medical education in the clinical setting. The objective of this research was to develop a conceptual model of effective clinical teaching in undergraduate medical education and conceptualize its operational framework based on the best fit approach. MATERIALS AND METHODS: This research consisted of three sub-studies conducted using a multi-method approach. The first sub-study was conducted using a qualitative meta-synthesis approach. The second sub-study used Clarke's situational analysis approach as a postmodern version of grounded theory. Finally, the third sub-study was designed in two stages. First, it was conducted using the expert panel, in the second step, framework of synthesis based on best fit, and the framework of Ottenhoff- de Jonge et al., which formed the basis of this study. RESULTS: In the first sub-study, qualitative evidence on the factors of effective teaching-learning in clinical education was synthesized into five dimensions. Based on the second sub-study, the clinical teaching-learning situation in undergraduate medical education in Iran was represented in three maps, including situational, social worlds/arenas, and positional. Finally, in the third sub-study, based on model modification and development in the expert panel, the effective teaching-learning dimensions were developed into behavioral, social, pedagogical, technology, contextual, educational leadership, and financial dimensions. In the second step, based on the framework of Ottenhoff- de Jonge et al., a three-dimensional matrix was developed concerning epistemological orientations about teaching and learning. DISCUSSION: Moving from a single teaching-centered and learning-centered orientation to a teaching-learning-centered orientation is required for effective teaching-learning in clinical medical education.

Knowledge and practice of Iranian prosthodontists regarding the diagnosis and treatment of sleep apnea: Design and development of a questionnaire.

Background: The present study was conducted to develop a standard questionnaire to assess the knowledge and practice of prosthodontists regarding the diagnosis and treatment of obstructive sleep apnea syndrome (OSA). Materials and Methods: This study had questionnaire designing and cross-sectional-descriptive phases. Questionnaire domains were identified by a panel of eight experts. The face and content validity of the questionnaire was assessed by experts and four laypeople. The internal consistency reliability of the questionnaire was checked using Cronbach's alpha coefficient. Moreover, its stability was tested using the test-retest method. The questionnaire was completed online by 282 Iranian prosthodontists and the relationship between different variables and scores of knowledge and practice of them with simple and multiple linear regression tests was were analyzed. Results: A 32-item questionnaire was designed. The Scale Content Validity Index was >0.8 for clarity, simplicity, and necessity in all domains and the content validity of all questions was above 0.8. As for reliability, Cronbach's alpha coefficient was above 0.7 on average. Faculty members had more knowledge (P = 0.04) and better practice (P = 0.001) compared to others. Prosthodontists who participated in sleep disorders training courses had higher scores in knowledge (P = 0.001) and practice (P = 0.001). Prosthodontists who referred patients to sleep disorders clinics had higher knowledge (P = 0.001) and practice (P = 0.001) than those who did not. Conclusion: The questionnaire developed in this study can be considered a comprehensive and executable scale with appropriate reliability and validity. There is a positive relationship between being exposed to information and the level of knowledge and practice of prosthodontists about OSA.

Effect of Preparation Design on Marginal Integrity and Fracture Resistance of Endocrowns: A Systematic Review.

Objectives: Endocrown restorations were introduced for endodontically treated teeth as a conservative treatment. However, data about the effect of preparation design on marginal integrity and fracture resistance of endocrowns are lacking. The purpose of this systematic review was to investigate the effect of preparation design of endocrown restorations on marginal integrity and fracture resistance. Materials and Methods: Based on PICO question and the search terms, PubMed, Embase, Scopus, and the Cochrane Library were searched. After including studies matched to predefined inclusion and exclusion criteria, the extracted data were tabulated in a table provided by the authors. Two reviewers assessed the methodological quality of each included study independently. Ten articles were selected for extracting the quantitative data. All included studies were in vitro. The potential risk of bias of the selected studies was assessed using the modified MINORS scale. Results: Four studies assessed the marginal adaptation, five studies evaluated the fracture resistance and just one investigated both the marginal integrity and fatigue resistance of the specimens. The evaluated influencing items in preparation design were as follows: cavity depth, occlusal thickness, ferrule effect, internal divergence angle, type of finish line, and adding vents inside pulp chamber. Meta-analysis could not be done due to heterogeneity of preparation designs and evaluation methods. Conclusion : Marginal discrepancy of endocrowns is intensified with adding preparation features, higher cavity depth and increasing the divergence. Fracture resistance of endocrowns is increased with more occlusal reduction and cavity depth. However, it is still beyond the normal clinical force range.

Oral reconstruction with hybrid implant-supported fixed prostheses in cases of mandibular defect using two methods along with 3 years of follow-up: A case report.

Ameloblastoma is an invasive odontogenic tumor, and for reconstruction, iliac graft and dental implants play an important role. This article evaluates the application of hybrid prostheses, clinical steps, and complications related to this treatment.

Effect of Glass Fiber Post Diameter on Fracture Resistance of Endodontically Treated Teeth

Abstract Objective: To determine the fracture resistance of endodontically treated teeth restored with three different diameters of glass fiber posts and metal-ceramic crowns. Material and Methods: Thirty human maxillary canines were selected and subjected to root canal therapy. The teeth were randomly divided into three groups of glass fiber posts with 1.4 mm diameter (Group I), 1.6 mm diameter (Group II), and 2.0 mm diameter (Group III). The teeth were restored with metal-ceramic crowns and subjected to the compressive load applied at 45º angle to the longitudinal axis until fracture. The mode of failure was determined. Data were analyzed using ANOVA, followed by Tukey's post hoc multiple comparisons test (p<0.05). Results: The mean fracture resistance of groups I, II and III was 574 ± 91.2 N, 617 ± 85.21 N and 467 ± 99.43 N, respectively. No significant difference was noted between groups I and II, while the fracture resistance was significantly different between groups I and III (p<0.05) and groups II and III (p<0.05). No case of post fracture alone occurred in any group. Conclusion: The diameter of glass fiber posts can affect the fracture resistance of teeth. Based on the results, increasing the diameter of the post up to 1.6 mm may increase the fracture resistance of root, although excessive diameters are not recommended.

Burden of esophageal cancer in Iran during 1995-2015: Review of findings from the Global Burden of Disease studies.

Background: Iran is located in Asian esophageal cancer belt, with age-standardized incidence rate (ASR) of approximately 7 per 100,000 for both men and women. To provide potential solution recommendations for achieving accurate estimations regarding the burden of the disease in Iran, we designed a study to assess the burden of esophageal cancer in Iran during 1995-2015 by collecting data from the Global Burden of Disease studies. Methods: Data were extracted from the Global Burden of Disease (GBD) during 1995-2015, which were published by the Institute for Health Metrics and Evaluation. For this purpose, disability adjusted life years (DALYs), incidence, and prevalence rate were applied to report burden of esophageal cancer based on gender and age group in Iran during 1995-2015. The Cochran-Armitage and t test were used to assess statistical significance. Stata Version 13 and Excel 2016 were used for data analysis. Results: During 1995-2015, in total, 304 102 DALYs (179 562 for males vs. 124 540 for females) were attributed to esophageal cancer in Iran. In both genders and all ages, the number of DALYs increased significantly from 45 018 in 1995 to 74 399 in 2015. Conclusion: Esophageal cancer is still a public health issue in Iran. Most of DALYs were due to years of life lost (YLL), suggesting the need for prevention, early detection, and screening programs. P-value was statistically significant just between male and female groups (p<0.05).

Fracture Resistance of Zirconia Restorations with a Modified Framework Design.

OBJECTIVES: Chipping is one of the concerns related to zirconia crowns. The reasons of chipping have not been completely understood. This in-vitro study aimed to assess the effect of coping design on the fracture resistance of all-ceramic single crowns with zirconia frameworks. MATERIALS AND METHODS: Two types of zirconia copings were designed (n=12): (1) a standard coping (SC) with a 0.5mm uniform thickness and (2) a modified coping (MC) consisted of a lingual margin of 1mm thickness and 2mm height connected to a proximal strut of 4mm height and a 0.3mm-wide facial collar. After veneer porcelain firing, the crowns were cemented to metal dies. Afterwards, a static vertical load was applied until failure. The modes of failure were determined. Data were calculated and statistically analyzed by independent samples T-test. P<0.05 was considered statistically significant. RESULTS: The mean and standard deviation (SD) of the final fracture resistance equaled to 3519.42±1154.96 N and 3570.01±1224.33 N in SC and MC groups, respectively; the difference was not statistically significant (P=0.9). Also, the mean and SD of the initial fracture resistance equaled to 3345.34±1190.93 N and 3471.52±1228.93 N in SC and MC groups, respectively (P=0.8). Most of the specimens in both groups showed the mixed failure mode. CONCLUSIONS: Based on the results, the modified core design may not significantly improve the fracture resistance.