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Purpose: To compare abutment screw loosening in 24-degree angulation-correcting and straight implants subjected to nonaxial cyclic loading. Materials and Methods: Seven external connection 24-degree angulation-correcting implants (AI) and seven external connection straight implants (SI) were embedded in acrylic resin within a brass housing. A hemispherical titanium fatigue abutment was secured to each implant using a titanium abutment screw tightened to 32 Ncm. Each implant-abutment complex was positioned within a tooth wear machine and subjected to 1,000,000 cycles of 50-Ncm nonaxial loading to simulate 1 year of function. The abutment screw removal torque values were measured before and after cyclic loading, and the differences were statistically analyzed using two-way ANOVA and post hoc pairwise Dunn tests. Scanning electron microscopy and finite element analyses were performed to assess the wear of the abutment screws. Results: The mean torque loss for the AI group was 21.44% (P < .001) compared to 24.56% (P < .001) for the SI group. There was a statistically significant difference between the AI and SI groups (P = .006). Conclusions: Both groups exhibited significant abutment screw loosening. Within the limitations of this study, 24-degree angulation-correcting implants resisted screw loosening significantly more than straight implants. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to assess the effectiveness of the best performing interpretable machine learning models in the diagnoses of leukoplakia and oral squamous cell carcinoma (OSCC). Methods: A total of 237 patient cases were analysed that included information about patient demographics, lesion characteristics, and lifestyle factors, such as age, gender, tobacco use, and lesion size. The dataset was preprocessed and normalised, and then separated into training and testing sets. The following models were tested: K-Nearest Neighbours (KNN), Logistic Regression, Naive Bayes, Support Vector Machine (SVM), and Random Forest. The overall accuracy, Kappa score, class-specific precision, recall, and F1 score were used to assess performance. SHAP (SHapley Additive ExPlanations) was used to interpret the Random Forest model and determine the contribution of each feature to the predictions. Results: The Random Forest model had the best overall accuracy (93%) and Kappa score (0.90). For OSCC, it had a precision of 0.91, a recall of 1.00, and an F1 score of 0.95. The model had a precision of 1.00, recall of 0.78, and F1 score of 0.88 for leukoplakia without dysplasia. The precision for leukoplakia with dysplasia was 0.91, the recall was 1.00, and the F1 score was 0.95. The top three features influencing the prediction of leukoplakia with dysplasia are buccal mucosa localisation, ages greater than 60 years, and larger lesions. For leukoplakia without dysplasia, the key features are gingival localisation, larger lesions, and tongue localisation. In the case of OSCC, gingival localisation, floor-of-mouth localisation, and buccal mucosa localisation are the most influential features. Conclusions: The Random Forest model outperformed the other machine learning models in diagnosing oral cancer and potentially malignant oral lesions with higher accuracy and interpretability. The machine learning models struggled to identify dysplastic changes. Using SHAP improves the understanding of the importance of features, facilitating early diagnosis and possibly reducing mortality rates. The model notably indicated that lesions on the floor of the mouth were highly unlikely to be dysplastic, instead showing one of the highest probabilities for being OSCC. [ABSTRACT FROM AUTHOR]

Purpose. To evaluate the influence of edible liquids on the characteristic properties of 3D printable materials compared to conventionally used dental resin acrylic. Method. Dental polymethyl methacrylate (PMMA) specimens were fabricated from preformed molds while polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) specimens were 3D printed using fused deposition modelling at 0.1 mm layer thickness. All specimen forms adhered to ISO 37:2017 and ISO 604:2002 specifications. Specimens underwent controlled immersion for 180 hr into different media (no immersion (control), oil, soda, milk, and caffeine). Changes in mass (g), plastic deformity (N/mm2), ultimate tensile stress (N), flexural deformity (N/mm2), and break force (N) were evaluated using analysis of variance. Results. There was an increase in mass for all specimens following immersion with significant interactions between immersion media and the materials. The materials exhibited significant differences in plastic deformity (F (df) = 156.632(2), P < 0.001), ultimate tensile stress (F (df) = 109.521(2), P < 0.001), and break force (F (df) = 319.785 (2), P < 0.001) with no significant interactions with immersion media (P > 0.05) on both accounts. Materials showed no significant differences in flexural deformity (F (df) = 2.693(2), P = 0.074) but with significant interactions (F (df) = 4.984(8), P < 0.001) between acrylic and immersion media. Conclusion. Commercially available 3D printable PLA and PETG filaments printed at 0.1 mm thickness possess approximately half the mechanical resilience as dental PMMA with comparable flexural deformity after exposure to edible liquids. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the precementation mean marginal gap, fracture resistance, and mode of failure of monolithic zirconia endocrowns cemented to endodontically treated molar teeth with butt joint porcelain margins and added ferrule preparation designs.Materials and Methods: A total of 20 mandibular molars were endodontically treated and prepared to receive endocrown restorations. The teeth were randomly divided into two groups: Group B had a butt joint porcelain margin, while Group F received additional axial reduction with a shoulder finish line that added ferrule. Monolithic zirconia endocrowns were milled, and the marginal gaps were measured at four locations prior to cementation with resin cement. All samples were subjected to thermocycling, followed by compressive static loading. The maximum load causing fracture and mode of failure were recorded.Results: The mean load to failure for Group B (5,616 ± 1,503 N) was not significantly different compared to Group F (5,762 ± 1,618 N) (P = .84). Both groups recorded high rates of irreparable fractures (P = .2699, df = 2). The mean marginal gap in Group B (48.20 ± 12.37 μm) was not statistically significantly different compared to Group F (45.14 ± 8.45 μm) (P = .527).Conclusion: The addition of ferrule to the preparation design had no significant effect on the precementation mean marginal gap, fracture resistance, or mode of failure of monolithic zirconia endocrowns cemented to endodontically treated molar teeth. Monolithic zirconia endocrowns failed predominantly in an irreparable manner, but these failures were at high failure loads. The precementation mean marginal gap for both groups was small in comparison to other materials. [ABSTRACT FROM AUTHOR]

Adolescent pregnancy continues to be a major concern for policy-makers, programme developers, helping professionals and society generally in the USA, especially in light of the US federal government's legislative emphasis on abstinence-only sex education until recently. Studies have found that abstinence-only programmes do not succeed in preventing young people from becoming sexually active or pregnant; most young people have sexual intercourse in their teenage years long before they even contemplate marriage. The purpose of this qualitative study was to explore how 32 teenage mothers learned about sex and their related views about pregnancy and birth control. Findings indicate that they have often received little accurate information about sex from their parents and schools. Findings also reveal their widely varying views about birth control and pregnancy. Overall, the findings support the need for comprehensive sexuality education that addresses the topics covered in this study in an age-appropriate manner. The findings also suggest ways that helping professionals in other settings besides schools can help young people address these issues.

Introduction: Providing undergraduate dental students with a range of clinical experiences in fixed prosthodontics procedures is an important component of dental education. The aim of this retrospective study was to analyse the types of laboratory‐fabricated fixed prosthodontics clinical units completed by undergraduate students over 10 consecutive years and determine any significant trends. Materials and Methods: The fixed prosthodontics treatment registers from 2012 to 2021 were reviewed and the different types of completed fixed prosthodontics units and total number of fixed prosthodontics units were recorded for each year. Completed units were categorised according to the type of restoration and expressed in whole numbers and as a percentage of the total number of units completed in each year. The data were presented in table and graph form. Mann‐Kendall tests were performed to statistically analyse for trends in the different restoration types. Results: Throughout all study years, porcelain bonded to metal (PBM) crowns (48.25%, range 35.70%–59.91%) were the most frequently completed fixed prosthodontics unit followed by full gold crowns (FGC) (20.84%, range 14.89%–27.30%) and all‐ceramic crowns (ACC) (12.70%, range 3.67%–24.41%). Collectively, PBM, FGC and ACC comprised 81.80% of all completed fixed prosthodontics units. There were observed trends of increased use of all types of all‐ceramic containing restorations, all types of all‐gold containing restorations, all types of partial coverage restorations and specifically ceramic onlays and gold onlays. There were observed trends of reduced use of cast gold post‐cores and all types of bridges. Conclusion: PBM crowns were the mainstay laboratory‐fabricated fixed prosthodontic unit completed over 10 years of undergraduate student fixed prosthodontics clinical practice. [ABSTRACT FROM AUTHOR]

Key Clinical Message: The conservative prosthodontic construction of an ocular prosthesis utilizing our novel threaded iris fabrication technique required high time and prosthodontic resource inputs and produced a lifelike aesthetic result. Patients with ocular defects frequently present with significant local anatomical deficiencies and complex histories and require extensive time and resource inputs to treat. This case report describes the conservative management of an ocular defect completed in a postgraduate prosthodontics clinical residency program utilizing a novel threaded iris fabrication technique. [ABSTRACT FROM AUTHOR]

Background and Aims: The range of aesthetic fixed prosthodontics materials utilizing digital manufacturing techniques has expanded in recent years ostensibly replacing traditional laboratory techniques and materials. This retrospective study conducted over eight consecutive years aimed to analyze the types of laboratory fabricated fixed prosthodontics clinical units completed in a postgraduate prosthodontics specialist training program and determine meaningful trends. Methods: The logbooks of eight postgraduate prosthodontics completions from 2014 to 2021 were reviewed and the different types of laboratory fabricated fixed prosthodontics units and total number of fixed prosthodontics units completed were recorded. The data was categorized and presented in tabulated and chart form using Microsoft Excel software (version 2016). Paired t‐tests and Mann−Kendall trend tests were performed to analyze for statistical significance between the different restoration types across the program completions. Results: Porcelain bonded to metal (PBM) crowns represented 42.05% of all fixed prosthodontics units completed over all study years followed by all‐ceramic crowns (ACC) (18.14%) and full gold crowns (FGC) (10.70%). Jointly, PBM, ACC and FGC's encompassed 70.88% of all fixed prosthodontics units. Over the 8‐year study period, there were observed trends of reduced use of PBM's, increased use of ACC's, statistically significant reduced use of FGC's (p = 0.035) and a statistically significant difference in the use of complete and partial coverage restorations (p < 0.001). Conclusion: PBM crowns were the dominant laboratory fabricated fixed prosthodontic clinical unit across postgraduate prosthodontics program completions. The trend in later years indicating ACC as the dominant crown type warrants further investigation. [ABSTRACT FROM AUTHOR]

Introduction: Research is lacking in the use of artificial teeth for post‐core techniques in undergraduate fixed prosthodontics pre‐clinical education. The aim of this study was to compare the reasons for selection and explore the direct student experiences with artificial teeth used in two pre‐clinical fixed prosthodontics post‐core technique teaching programs conducted in consecutive years. Materials and Methods: Fourth year undergraduate dental students who had completed the fixed prosthodontics pre‐clinical program were invited to complete an anonymous online surveys. Information was requested on the use and direct student experiences with artificial and natural teeth for post‐core techniques. Quantitative data was summarised and qualitative data was clustered into topics. The reasons for selection and use of artificial and natural teeth were compared within and between the two programs. Results: 36% of 70 respondents in 2020 chose to use one or more artificial teeth for the post‐core exercises in the pre‐clinical program compared with 94% of 77 respondents in 2021 (p <.05). The use was driven by difficulty in sourcing appropriate natural teeth. Respondents reported "ease of use" as the dominant positive user experience with the main negatives being "unrealistic simulation of natural teeth" and "different surface texture/feel when cutting." Conclusion: Artificial teeth were reported to provide an appropriate and realistic simulation experience compared with extracted natural teeth and were easier to source. Students focussed on the practicalities of sourcing artificial teeth, associated costs and ease of use ahead of conceivable educational benefits. Cost limited the more widespread use of artificial teeth. [ABSTRACT FROM AUTHOR]

Introduction: Research is limited in measuring the effectiveness of pre‐clinical programmes in preparing students for fixed prosthodontics clinical practice. The aim of this retrospectively study was to assess the influence of a major pre‐clinical programme restructure on undergraduate student fixed prosthodontics clinical unit completions. Materials and Methods: The fixed prosthodontics treatment registers from 2011 to 2020 were reviewed, and units completed per student (UCS) and units completed per student per session (UCSS) were calculated in the years before (2011–2013) and after (2014–2020) a major pre‐clinical programme restructure (PR). Data were summarised in Microsoft Excel software (version 2016), and Student's t‐test and paired t‐tests were performed to determine the significance of difference in UCS and UCSS in the years before and after the PR. Results: There was a significant difference in the UCS (p <.05) and UCSS (p <.01) in the years before and after the PR. The average UCS in the years before the PR was 2.20 units compared with 3.86 units after the PR, an increase of 75% per student. The average UCSS in the years before the PR was 0.15 units compared with 0.28 units after the PR, an increase of 87% per session. Conclusion: The fixed prosthodontics pre‐clinical programme restructure resulted in statistically significantly increased student clinical unit completions. [ABSTRACT FROM AUTHOR]

Examined divorced fathers (n=84) who had infrequent or no contact with their children. Found four sets of fathers: (1) those embroiled in conflict with former spouses; (2) those with personal problems or barriers; (3) those who are long-distance parents; and (4) those with teenage children with busy lives. (ABL)