Systemic Factors Affecting Prognosis in Restorative and Prosthetic Dentistry: A Review.

The field of restorative and prosthetic dentistry focuses on restoring lost tooth structures and replacing missing teeth and lost tissue to restore or improve esthetics and oral health. Many systemic factors such as metabolic, bone, autoimmune, cardiovascular, and endocrine disorders can affect healing procedures, and bone density and impact oral health. Hence patients suffering from systemic disease when treated for prosthodontic rehabilitation can have negative prognostic outcomes. The commonest prosthodontic treatments that can be affected include dental implants, fixed prostheses, and removable prostheses. Understanding and managing these systemic factors play a key role in the success of prosthodontic treatment.

Cytokines profile in gingival crevicular fluid of subjects wearing fixed dental prostheses: a systematic review and meta-analysis.

BACKGROUND: Fixed dental prostheses (FDP) can affect the production of inflammatory cytokines causing damage to periodontal tissues. A systematic review and meta-analysis was carried out with the following two objectives: (1) to determine the prevalence and function of the different inflammatory cytokines present in gingival crevicular fluid (GCF) of teeth with metal-ceramic (M/C) and all-ceramic (A-Cs) prostheses, and (2) to analyze and compare the levels of inflammatory cytokines in GCF of teeth with M/C and A-Cs prostheses. METHODS: The protocol followed PRISMA and Cochrane guidelines and was registered in the OSF:10.17605/OSF.IO/RBHJU. A digital search was conducted in the databases PubMed/MEDLINE, Cochrane Library, Dentistry & Oral Sciences Source, Scopus, Web of Science, ScienceDirect, and Google Scholar, from July 15th, 2000 to March 1st, 2024. Study quality was assessed using the JBI tool for cross-sectional and longitudinal studies. A meta-analysis was performed using a random-effects model to evaluate the concentration of IL-1ß in GCF of teeth with FDP of M/C and A-Cs. RESULTS: The search strategy provided a total of 8,172 articles, of which 14 investigations met the inclusion criteria. The total number of patients studied was 468 of whom 53% were women and the rest (47%) were men. The ages of the patients ranged from 19 to 73 years, with a mean age ± standard deviation (SD) of 38,5 ± 12,8 years. A total of 843 fixed dental prostheses were studied, of which 407 (48,27%) were M/C prostheses and 410 (48,63%) were A-Cs prostheses. We found that the levels of IL-1ß, IL-1α, PGE2, NKA, CGRP, and CX3CL1 were increased in teeth with M/C prostheses compared to teeth with A-Cs prostheses. Meta-analysis revealed that there are no significant differences between IL-1ß levels in GCF in teeth with M/C prostheses compared to teeth with A-Cs prostheses (SMD = 13.89 pg/ml (CI = -14.29-42.08), p = > 0.05). CONCLUSIONS: A trend toward increased levels of inflammatory cytokines was found in GCF of teeth with M/C prostheses compared to teeth with A-Cs prostheses.

How the Study of "Periodontal Prosthesis" Advances Public Oral Health.

As Penn Dental School prepares for its Commission on Dental Accreditation (CODA)-approved dual-certificate periodontics/prosthodontics program, this article looks back at the roots of these specialties at the university via the renowned Periodontics and Periodontal Prosthesis program co-founded byCompendium's founding editor Dr. D. Walter Cohen as seen through the eyes of one of its graduates. The article commends the program's impact on public health today.

The Potential of Artificial Intelligence in Prosthodontics: A Comprehensive Review.

Prosthodontics is a dental subspecialty that includes the preparation of dental prosthetics for missing or damaged teeth. It increasingly uses computer-assisted technologies for planning and preparing dental prosthetics. This study aims to present the findings from a systematic review of publications on artificial intelligence (AI) in prosthodontics to identify current trends and future opportunities. The review question was "What are the applications of AI in prosthodontics and how good is their performance in prosthodontics?" Electronic searching in the Web of Science, ScienceDirect, PubMed, and Cochrane Library was conducted. The search was limited to full text from January 2012 to January 2024. Quadas-2 was used for assessing quality and potential risk of bias for the selected studies. A total of 1925 studies were identified in the initial search. After removing the duplicates and applying exclusion criteria, a total of 30 studies were selected for this review. Results of the Quadas-2 assessment of included studies found that a total of 18.3% of studies were identified as low risk of bias studies, whereas 52.6% and 28.9% of included studies were identified as studies with high and unclear risk of bias, respectively. Although they are still developing, AI models have already shown promise in the areas of dental charting, tooth shade selection, automated restoration design, mapping the preparation finishing line, manufacturing casting optimization, predicting facial changes in patients wearing removable prostheses, and designing removable partial dentures.

Association between number of teeth, dental prostheses, and self-reported dysphagia in brazilian old people: a population-based study. / Associação entre número de dentes, próteses dentárias e disfagia autorreferida em idosos brasileiros: estudo populacional.

PURPOSE: To investigate the association between the number of permanent teeth and the use of removable dental prostheses with self-reported dysphagia occurrence in individuals aged 60 years or older. METHODS: A population-based cross-sectional study was conducted with 5,432 old individuals who participated in the baseline of the Brazilian Longitudinal Study of Elderly Health (ELSI-Brazil). The outcome "dysphagia" was associated with the number of permanent teeth and the use of removable dental prostheses. Sociodemographic independent variables (age, sex, and race/ethnicity) and clinical history variables (no morbidity, one morbidity, or more than two morbidities) were analyzed using Poisson Regression with robust variance and their respective 95% confidence intervals (CI). RESULTS: The prevalence of self-reported dysphagia in non-institutionalized old individuals was 30%. The group of old individuals with 10 - 19 natural teeth showed a 52% increased risk of self-reported dysphagia complaint (PRadj 1,565 IC95% 1,34;1,826) compared to their counterparts with more teeth. CONCLUSION: An association was found between a lower number of teeth and removable prostheses with the occurrence of dysphagia.

OBJETIVO: Verificar a associação entre o número de dentes e uso de prótese dentária removível e a ocorrência de disfagia autorreferida em idosos de 60 anos ou mais. MÉTODO: Estudo transversal de base populacional com 5.432 idosos, que participaram da linha de base do Estudo Longitudinal da Saúde do Idoso (ELSI-Brasil). O desfecho "disfagia" foi associado ao número de dentes permanentes e ao uso de prótese dentária removível. As variáveis independentes sociodemográficas (idade, sexo e cor/raça) e de histórico clínico (nenhuma morbidade, uma morbidade ou mais de duas morbidades) utilizando Regressão de Poisson com variância robusta e seus respectivos intervalos de confiança (IC) de 95% foram analisados. RESULTADOS: A prevalência de disfagia autorreferida nos idosos não institucionalizados foi de 30%. O grupo de idosos com 10 ­ 19 dentes permanentes apresentou um risco de 52% de queixa de disfagia autorreferida (RPaj 1,565 IC95% 1,34;1,826) se comparado com seus pares com mais dentes. CONCLUSÃO: foi encontrada associação entre o menor número de dentes e próteses removíveis com a ocorrência de disfagia.

Virtual sketching-based dental anatomy module improves learners' abilities to use computer-aided design to create dental restorations and prostheses.

Dental anatomy education for dental technology students should be developed in alignment with digital dental laboratory practices. We hypothesized that a virtually assisted sketching-based dental anatomy teaching module could improve students' acquisition of skills essential for digital restoration design. The second-year dental technology curriculum included a novel virtual technology-assisted sketching-based module for dental anatomy education. Pre- and post-course assessments evaluated students' skill sets and knowledge bases. Computer-aided design (CAD) scores were analyzed after one year to assess how the skills students developed through this module impacted their subsequent CAD performance. Participants who undertook the dental sketching-based teaching module demonstrated significantly improved theoretical knowledge of dental anatomy, dental aesthetic perception, and spatial reasoning skills. A partial least squares structural equation model indicated that the positive effects of this module on subsequent CAD performance were indirectly mediated by dental aesthetic perception, spatial reasoning, and practice time. A virtually assisted sketching-based dental anatomy teaching module significantly improved students' acquisition of skills and knowledge and positively mediated dental technology students' CAD performance.

Forensic study of the mechanical properties of prosthetic materials: Submersion in mangrove environment - A pilot study.

INTRODUCTION: It is crucial for dental surgeons to use the mechanical properties of dental prosthetic materials to correlate the submersion time in a mangrove environment. OBJECTIVE: This study aimed to submerge dental prosthetic materials, such as acrylic resin and zirconia, contained within acrylic resin disks in a mangrove environment, and analyze the alterations in mechanical parameters, such as surface roughness and microhardness, to estimate submergence time in similar forensic situations. MATERIALS AND METHODS: A total of 6 specimens was embedded in acrylic resin disks numbered from 1 to 6. The materials were polished for initial parameter readings a day before submersion, and new readings were obtained 1after submersion. All specimens were subjected to surface roughness analysis, in addition to Knoop microhardness analysis for acrylic resin and Vickers microhardness analysis for zirconia. After the experiment, the data were computed for statistical comparation of the materials properties different parameters. RESULTS: There was a significant increase in surface roughness and Knoop microhardness was reduced in the Acrylic Resin samples (p< 0.05); however, no statistically significant differences were observed in the roughness or Vickers microhardness values of the zirconia samples. CONCLUSION: Zirconia prosthetics were more resistant to degradation when submerged in a mangrove environment compared to acrylic resin ones; however, owing to the obstacles inherent in this study, we suggest further research on the properties of prosthetic materials submerged in mangroves or other environments, which could bolster the work of dental professionals in forensic medical institutes.

Percepción de la calidad de vida y satisfacción en pacientes portadores de dentadura parcial removible: Revisión de Literatura Sistematizada / Perception of quality of life and satisfaction in patients with removable partial denture: Systematized Literature Review

RESUMEN Introducción: Diversos autores mencionan que una correcta planificación de una dentadura parcial removible incrementa la satisfacción de los pacientes, en cuanto a estética y función. En casos donde la estética es prioritaria, se plantea un diseño sin retenedores visibles. En estos casos, la elaboración de la dentadura no demanda mayores costos, basta con establecer el diagnóstico correspondiente valorando los pilares, eje de inserción, áreas retentivas entre otros y establecer el diseño más conveniente según sea el caso. Objetivo: El objetivo fue realizar una revisión sistematizada sobre la percepción de la calidad de vida y satisfacción en pacientes portadores de dentaduras parciales removibles. Materiales y métodos: Se incluyeron 13 artículos científicos mediante la metodología PRISMA para la identificación, revisión e inclusión de los textos que formaron parte del estudio. Se seleccionaron tomando en cuenta el título, resumen y objetivo. Fueron considerados: revisiones sistemáticas, metaanálisis, estudios comparativos y revisiones de literatura que evaluaran diferentes criterios acerca de la satisfacción en pacientes portadores de dentadura parcial removible. Los artículos fueron leídos íntegramente, se analizaron objetivos, metodología y conclusión de cada uno de ellos, y posteriormente fueron analizados. Resultados: La queja más común fue el resultado estético, seguida del dolor durante la masticación. Se recomienda ofrecer un control periódico de la prótesis parcial removible para evaluar el correcto funcionamiento y ajuste de esta. Conclusión: El éxito del tratamiento con dentaduras parciales removibles se puede optimizar mediante el diagnóstico preciso del caso, considerando experiencias previas del paciente y teniendo en cuenta sus expectativas. Asimismo, comprender ciertos factores como su estilo de vida, nivel socioeconómico, estado de salud periodontal, personalidad, puede disminuir el riesgo de fracaso futuro del tratamiento con dentaduras parciales removibles.

ABSTRACT Introduction : Various authors mention that correct planning of a removable partial denture can offer adequate satisfaction in terms of aesthetics and function. In cases where aesthetics is a priority, a design without visible clasps is proposed. In addition, this elaboration does not demand higher costs, if the practitioner reaches the corresponding diagnosis and establishes the most convenient design for each specific case. Objective: The objective was to carry out a systematic review on the perception of quality of life and satisfaction in patients with removable partial dentures. Materials and methods: Thirteen scientific articles were included using the PRISMA methodology for the identification, review and inclusion of the texts that were part of this study. The articles were selected considering the title, abstract and objective. Systematic reviews, meta-analyses, comparative studies, and literature reviews that included criteria about satisfaction in patients with removable partial dentures where evaluated. The articles were read in their entirety: the objectives, methodology and conclusions of each one of them were analyzed. Results: The most common complaint was the aesthetic result, followed by pain during chewing. It is recommended to offer periodic control of the removable partial denture to evaluate its correct functioning and fit. Conclusion: The success of the treatment with removable partial dentures can be evaluated through the precise diagnosis of the case, considering previous experiences and taking into account the expectations of the patient. Also, understanding the patient's lifestyle, socioeconomic level, periodontal health status, and personality, may be factors that allow the practitioner to reduce the risk of future failure for the treatment with removable partial dentures.

Effectiveness of commercially available denture adhesives on retention of mandibular complete denture in resorbed mandibular ridge: an in vitro study / Efectividad de los adhesivos disponibles comercialmente sobre la retención de prótesis removibles completas mandibulares en el reborde mandibular reabsorbido: un estudio in vitro

Background: Denture adhesives are alternatives used to improve retention, stability, comfort and satisfaction in patients with complete dentures. Evidence on the effectiveness of denture adhesives on resorbed mandibular ridges is scarce. Among the many commercially available denture adhesives, the ideal material for the severely resorbed mandibular ridge remains in dispute. Objective: The aim of this study was to evaluate the effectiveness of different quantities of four commercially available denture adhesives on the retention of mandibular complete dentures in severely resorbed ridges. Materials and Methods: A resorbed edentulous mandibular ridge model was manufactured in acrylic resin. A denture base was made and three loops were attached to it. Four commercially available denture adhesives (Fixodent, Perlie White, Fiftydent and Polident) were tested in amounts of 0.2 g, 0.4 g, 0.6 g, 0.8 g and 1.0 g. The acrylic resin model was evenly moistened with 1 ml of water and a weighted amount of adhesive material was applied to the denture base. The universal testing machine engaged the loops fixed on the denture base and applied the vertical displacement force. The maximum vertical displacement force values were recorded for each denture adhesive material at different amounts. Statistical calculation was performed using Kruskal Wallis with Bonferroni post hoc correction. Results: Statistically significant differences were observed in the mean values of the vertical displacement force for adhesive amounts of 0.2 g, 0.4 g, 0.6 g and 1.0 g (p<0.05) between the four adhesive materials tested. Statistically significant differences were observed when four denture adhesives were compared to each other in different amounts (p<0.05). Statistically significant differences were observed between different amounts for each of four denture adhesives (p<0.05). Conclusions: Among the four materials tested, Polident showed greater effectiveness at 0.6 g and 0.8 g, Fittydent at 0.6 g, 0.8 g and 1 g, Fixodent at 0.4 g and 0.6 g and Perlie White at 1 g and 0.8g quantity to resist vertical displacement. forces on the severely resorbed mandibular crest. Using an appropriate amount of denture adhesive allows for proper retention of the denture; Replacement of this adhesive is necessary once a day.

Introducción: Los adhesivos para prótesis dentales son alternativas utilizadas para mejorar la retención, la estabilidad, la comodidad y la satisfacción en los pacientes con prótesis completas. La evidencia sobre la efectividad de los adhesivos para prótesis dentales en los rebordes mandibulares reabsorbidos es escasa. Entre los muchos adhesivos para prótesis dentales disponibles comercialmente, sigue estando en disputa cuál es el material ideal para el reborde mandibular severamente reabsorbido. Objetivo: El objetivo de este estudio fue evaluar la efectividad de diferentes cantidades de cuatro adhesivos para prótesis dentales disponibles comercialmente sobre la retención de prótesis dentales completas mandibulares en reborde mandibular reabsorbido severamente. Materiales y Métodos: Se fabricó un modelo de reborde mandibular edéntulo reabsorbido en resina acrílica. Se hizo una base para la prótesis y se le colocaron tres bucles. Se probaron cuatro adhesivos para dentaduras postizas disponibles comercialmente (Fixodent, Perlie White, Fiftydent y Polident) en cantidades de 0,2 g, 0,4 g, 0,6 g, 0,8 g y 1,0 g. El modelo de resina acrílica se humedeció uniformemente con 1 ml de agua y se aplicó la cantidad correspondiente de material adhesivo sobre la base de la dentadura. La máquina de prueba universal enganchó los bucles fijados en la base de la dentadura postiza y aplicó la fuerza de desplazamiento vertical. Se registraron los valores máximos de fuerza de desplazamiento vertical para cada material adhesivo para dentaduras postizas en diferentes cantidades. El cálculo estadístico se realizó utilizando Kruskal Wallis con corrección post hoc de Bonferroni. Resultado: Se observaron diferencias estadísticamente significativas en los valores medios de la fuerza de desplazamiento vertical para cantidades de 0,2 g, 0,4 g, 0,6 g y 1,0 g (p<0,05) entre los cuatro materiales adhesivos para prótesis dentales probados. Se observaron diferencias estadísticamente significativas cuando se compararon cuatro adhesivos para prótesis dentales entre sí en diferentes cantidades (p<0,05). Se observaron diferencias estadísticamente significativas entre diferentes cantidades en los cuatro adhesivos para prótesis (p<0,05). Conclusión: De los cuatro materiales probados, Polident mostró mayor efectividad a 0,6 g y 0,8 g, Fittydent a 0,6 g, 0,8 g y 1 g, Fixodent a 0,4 g y 0,6 g y Perlie White a 1 g y 0,8 g para resistir fuerzas de desplazamiento vertical en la cresta mandibular severamente reabsorbida. El uso de una cantidad adecuada de adhesivo para dentaduras postizas permite una retención adecuada de la dentadura postiza; El reemplazo de este adhesivo es necesario una vez al día.

Ill-fitting prosthesis is associated with an increased risk of elevated blood pressures.

OBJECTIVE: Previous studies focused on the benefits of adequate prosthodontic treatment, while few studies have investigated the prosthodontic-related risks to health. As a modifiable oral health indicator, the association of ill-fitting prosthesis (IFP) with hypertension has not been fully explored. METHODS: This cross-sectional study involved 158,659 adults in Beijing (2009-2017) receiving intra-oral examinations and blood pressure measurements. Logistic regression models were applied to assess the association of IFP with the prevalence of hypertension, systolic blood pressure (SBP) ≧ 140 mmHg and diastolic blood pressure (DBP) ≧ 90 mmHg, as well as subgroup analyses by different fixed IFP subgroups (according to involved teeth number) and removable IFP subgroup. We further investigated effect modifications among stratified populations. RESULTS: 158,659 individuals were included for analysis, 346 (26.86%) in IFP group and 27,380 (17.40%) in non-IFP group (p < 0.001) were hypertensive. After adjustment of sex, age, obesity, dyslipidaemia, diabetes, hsCRP, family history of CVD, self-reported smoking, self-reported drinking and WC, ORs of hypertension, SBP ≧ 140 mmHg and DBP ≧ 90 mmHg were 1.330 (95% CI: 1.162-1.522), 1.277 (95% CI: 1.098-1.486) and 1.376 (95% CI: 1.186-1.596), respectively (p < 0.05). Furthermore, after full adjustment, the number of involved teeth showed a significant incremental trend with hypertension risk in the population with and without IFP (p for trend <0.001). The IFP-blood pressure associations were more pronounced in females, 18-60 years, non-obese and diabetic participants. CONCLUSION: As a modifiable oral indicator, IFP was significantly associated with a higher risk of hypertension.

Oral health-related quality of life and reasons for discontinuing partial removable dental prosthesis usage: a cross-sectional study with one to seven years of follow-up.

BACKGROUND: In partial edentulous individuals, a partial removable dental prosthesis (PRDP) is a common dental replacement option to improve oral function and quality of life. However, some patients discontinue using their denture over time. The aim of this study was to determine the prevalence and characteristics of partial edentulous patients who no longer wear their dentures, explore their reasons, and assess their oral health-related quality of life (OHRQoL). METHODOLOGY: This cross-sectional study, conducted at Chulalongkorn University Dental School from 2013 to 2019, involved patients who received PRDP treatment. They were contacted via phone calls and asked about their denture usage. Eligible participants were patients who had stopped or rarely used their PRDPs. Data on oral status, health insurance, and PRDP variables were collected from hospital records. Telephone interviews were conducted to collect the initial reasons for seeking PRDP treatment, reasons for discontinuation, desire for a new PRDP, and OHRQoL. The Oral Impacts on Daily Performances index was used to assess the OHRQoL. The score was dichotomized into the absence or presence of oral impacts. Chi-square tests and multivariable binary logistic regression were employed to determine the associations between oral impacts and various factors in the participants who discontinued PRDP usage. RESULTS: Among the 975 contacted participants, 175 (17.9%) discontinued using their PRDPs. Most of these individuals had at least 20 remaining natural teeth and/or 4 posterior occluding pairs. The primary initial reason for seeking PRDP treatment was often based on a dentist's suggestion. Although many participants reported no impact on OHRQoL and did not express the need for new PRDPs, those experiencing oral impacts were more likely to seek replacements. CONCLUSIONS: With up to 7 years follow-up duration, individuals with partial edentulism and sufficient remaining functional dentition without oral impacts were more inclined to discontinue PRDP usage. Those with maxillary anterior teeth loss were less likely to discontinue using their PRDP. The primary initial reason for seeking PRDP treatment was often a dentists' suggestion. However, the individuals reporting oral impacts expressed their needs for new denture replacements. This highlights the significance of incorporating patient needs and preferences in prosthodontic decision-making.

Feasibility of images acquired using smartphone camera for marginal and internal fit of fixed dental prosthesis: comparison and correlation study.

This study aimed to measure marginal and internal fit using images captured with both an optical microscope and a smartphone camera, comparing the fit measurement performance of these devices and analyzing their correlation. Working casts (with 10 posterior and 10 anterior teeth) created to fabricate fixed dental prostheses were used. These working casts were scanned using a desktop scanner (E1) to design an interim crown, and the designed interim crown was fabricated using a three-dimensional (3D) printer. Utilizing the silicone replica technique, the fabricated interim crown replicated the fit, which was then captured using both an optical microscope and a smartphone camera. The captured images were used to measure the marginal and internal fit according to the imaging device. Intraclass correlation coefficients (ICC) were used for reliability analysis according to the imaging device. Furthermore, the Wilcoxon signed-rank test was adopted for the comparative evaluation of the marginal and internal fit between the imaging devices (α = 0.05). The measurement results of the marginal and internal fit according to the optical microscope and smartphone camera did exhibit a significant difference (P < 0.05). The ICC between the two devices showed an "excellent" agreement of over 0.9 at all measurement points (P < 0.001). A smartphone camera could be used to obtain images for evaluating the marginal and internal fit.

Risk factors and associated pathway for rural and urban unmet dental prosthetic needs among older adults in Central India.

AIM: This study was undertaken to evaluate the risk factors and associated pathways for unmet dental prosthetic needs among older adult population in Central India. METHODS: A total of 11,145 randomly selected older adults participated in the study; 4613 from urban region and 6532 form rural region. Oral examinations were conducted at individual households for recording dental caries, periodontal disease, prosthetic status and needs. Structural Equation Modelling (SEM) was used to examine relationship between a set of exogenous variables and unmet dental prosthetic needs with variables that remained significant in the adjusted multilevel logistic model. Path coefficients were calculated for all variables with 95% confidence interval. Goodness of fit of the model was assessed by several indices. RESULTS: A total of 8433 (75.7%) participants had never visited a dentist and 9139 (82%) had unmet dental prosthetic needs. Dental caries was observed among 3207 (69.5%) and 4644 (71.1%) study participants from urban and rural regions respectively (p < .05). Low utilization of dental services was associated with high dental prosthetic needs in upper arch and lower arch (PC = -0.05, 0.001) and DMFT was associated with lower utilization of dental services (PC = -0.09, 0.001). DMFT was also associated with age, annual income, level of education, paternal education, type of family, tobacco consumption and CPI score in the hypothesized model. The fit indices used indicated that the model was adequate. CONCLUSIONS: Dental prosthetic needs in the proposed pathway model was associated with low utilization of dental services, dental caries, periodontal disease and other socio-demographic factors.

Marginal Fit and Internal Adaptation of Monolithic Zirconia 3-Unit Fixed Dental Prosthesis: In Vitro Study.

PURPOSE: To compare the marginal and internal fit of monolithic zirconia (MZ) 3-unit fixed dental prostheses (FDPs) fabricated using two CAD/CAM workflows: full-chairside (FCH) and lab (LAB). MATERIALS AND METHODS: The right maxillary first premolar and first molar were prepared for MZ 3-unit FDPs on a typodont. CEREC Primescan digitized the typodont model 15 Omes. A total of 30 FDPs was fabricated using two processes: FCH (n = 15) and LAB (n = 15). FCH and LAB FDPs were designed using CEREC SW 4.5.1 and Exocad and milled using CEREC MC X and Zirkonzhan 600/V3, respectively. A fast-sintering protocol was used in both groups. A dual-scan technique was used to assess the cement space at the occlusal surface (OC), axial wall (AX), and margin (MA). Statistical analysis of the results was performed using univariate ANOVA with Scheff. post hoc test (a = .05). RESULTS: Measurements in the FCH and LAB groups were within the clinically acceptable marginal and internal fit. The fit of FCH FDPs at MA, AX, and OC was 77.50 ± 29.99 µm, 99.67 ± 21.58 µm, and 150.03 ± 30.78 µm, respectively. The fit of LAB FDPs at MA, AX, and OC was 100.27 ± 27.06 µm, 116.53 ± 17.90 µm, and 142.30 ± 19.00 µm, respectively. The difference between the two groups was not statistically significant. CONCLUSIONS: MZ 3-unit FDPs fabricated using FCH have clinically acceptable marginal and internal fit. This result verifies the ability of FCH workflow to fabricate MZ mulOunit FDPs in a single visit.

Impact of fixed dental prosthesis on neuroimaging: assessment of artefacts.

Objectives: To determine the frequency and extent of artefacts in magnetic resonance imaging and/or computed tomography scans of head caused by fixed dental prosthesis. METHODS: The retrospective study was conducted at Aga Khan University Hospital from July to December 2021, and comprised magnetic resonance imaging and/or computed tomography scans from January 2015 to December 2020 of the head of individuals with existing fixed dental prosthetic work at the time of exposure. They were analysed for the presence of artefacts. The association between artefacts and the presence of fixed dental prosthesis was explored. Data was analysed using SPSS 23. RESULTS: Of the 297 images evaluated, 173 (58%) were magnetic resonance imaging scans, and 124(42%) were computed tomography scans. The most common artefacts was grade I 148(49.8%), followed by grade II 140(47.1%) and grade III 9(3%). There was no significant association between fixed dental prosthesis and the artefacts (p>0.05). Conclusion: There should be no reservations in placing fixed metal prosthesis in individuals on account of future brain scans.

Analysis of subgingival microbiota and IL-1ß, TNF-α and CX3CL1 levels in gingival crevicular fluid of fixed dental prostheses.

Prosthetic biomaterials can affect the composition of the subgingival microbiota and consequently the production of proinflammatory cytokines, causing damage to the periodontium. A total of 40 patients were divided into two groups: 20 with monolithic zirconia (MZ) prostheses and 20 with porcelain fused to metal (PFM) with nickel-chromium (Ni-Cr) alloy prostheses. Subgingival plaque and gingival crevicular fluid samples were taken. The Checkerboard technique for DNA-DNA hybridization and the enzyme-linked immunosorbent assay technique were performed. Teeth with MZ presented a lower percentage of bleeding on probing and tooth mobility compared to teeth with PFM with Ni-Cr alloy. Prosthodontic teeth harbored higher total levels of the 18 bacterial species than non-prosthodontic teeth. There was a higher prevalence of S. gordonii and V. parvula species in PFM with Ni-Cr alloy compared to MZ. There was an increase in IL-1ß, TNF-α and CX3CL1 levels in PFM with Ni-Cr alloy compared to MZ. MZ is a candidate biomaterial with fewer negative effects on the periodontium, allowing for longer prostheses longevity in the mouth.

In vitro evaluation of shape-memory hydrogels for removable dental prostheses and optimization of phase-transition temperature for intraoral use.

STATEMENT OF PROBLEM: Removable dental prostheses require periodic relining with the loss of intaglio surface fit because of mucosal shape changes over time. Therefore, a new material with high adaptability to tissue changes over time would be beneficial. PURPOSE: This study focused on a shape-memory gel (SMG) that softens when heated, retains its shape when cooled, and returns to its original shape when reheated. The purpose was to optimize SMG for intraoral use by controlling the ratio of 2 acrylate monomers and to evaluate the changes in the shape memory and physical properties of SMG with temperature and to evaluate biocompatibility. MATERIAL AND METHODS: SMG specimens were synthesized using the following mixing ratios of 2 monomers, docosyl acrylate (DA) and stearyl acrylate (SA): 0:100, 25:75, 50:50, 75:25, and 100:0. SMG specimens were photopolymerized using a fluorescent light-polymerizing unit. To evaluate shape memory as a function of temperature, permanent deformation was measured based on the standardized compression set test for thermoplastic rubber. For evaluation of the physical properties and cytotoxicity, a 3-dimensionally printed denture base material was used as the control material. All assessments were compared between the groups by using 1-way analysis of variance followed by the Tukey-Kramer multiple comparison test (α=.05). RESULTS: SMGs with a higher amount of DA maintained their compressed shape at room and intraoral temperatures. However, the SMG matrices softened and recovered their original shapes above 60 °C. SMGs showed Shore A hardness equivalent to that of the denture-base polymer material at intraoral temperatures because of the high phase-transition temperature. The low water solubility of SMGs supported the biocompatibility test results. CONCLUSIONS: SMG, in which the phase-transition temperature was controlled by mixing acrylate monomers with different melting points, exhibited shape memory in the intraoral environment. The results indicate the feasibility of applying SMG for the fabrication of removable dental prostheses because of its high adaptability to tissue changes over time and biocompatibility.

Load bearing capacity of 3-unit screw-retained implant-supported fixed dental prostheses with a mesial and distal cantilever on a single implant: A comparative in vitro study.

OBJECTIVES: To assess the mechanical durability of monolithic zirconia implant-supported fixed dental prostheses (iFDP) design on one implant, with a distal and a mesial extension cantilever bonded to a titanium base compared to established designs on two implants. MATERIALS AND METHODS: Roxolid Tissue level (TL), and tissue level x (TLX) implants were used to manufacture screw-retained 3-unit iFDPs (n = 60, n = 10 per group), with following configurations (X: Cantilever; I: Implant, T: Test group, C: Control group): T1: X-I-X (TL); T2: X-I-X (TLX); T3: I-I-X (TL); T4: I-I-X (TLX); C1: I-X-I (TL); C2: I-X-I (TLX). The iFDPs were thermomechanically aged and subsequently loaded until fracture using a universal testing machine. The failure load at first crack (Finitial) and at catastrophic fracture (Fmax) were measured and statistical evaluation was performed using two-way ANOVA and Tukey's post-hoc tests. RESULTS: The mean values ranged between 190 ± 73 and 510 ± 459 N for Finitial groups, and between 468 ± 76 and 1579 ± 249 N for Fmax, respectively. Regarding Finitial, neither the implant type, nor the iFDP configuration significantly influenced measured failure loads (all p > 0.05). The choice of implant type did not show any significant effect (p > 0.05), while reconstruction design significantly affected Fmax data (I-I-Xa < X-I-Xb < I-X-Ic) (p < 0.05). The mesial and distal extension groups (X-I-X) showed fractures only at the cantilever extension site, while the distal extension group (I-I-X) showed one abutment and one connector fracture at the implant/reconstruction interface. CONCLUSION: Results suggest that iFDPs with I-X-I design can be recommended regardless of tested implant type followed by the mesial and distal extension design on one implant abutment (X-I-X).

Masticatory Function in Stage IV Periodontitis Patients Treated with Fixed Prosthetic Rehabilitations: A Case Series.

The present study assessed the impact of a fixed prosthetic rehabilitation on masticatory function in patients diagnosed with stage IV periodontitis. Eligible participants were adults in need of complex rehabilitation due to masticatory dysfunction. Masticatory function was evaluated using the two-colored chewing gum mixing ability test (VOH) at the diagnostic phase (T0), 1 week after delivery of the prosthetic prototype (T1), and 1 week after delivery of the final prosthetic solution (T2). Ten subjects were treated with a fixed prosthesis following periodontal and implant surgery using an individualized, fully digital workflow. Full-mouth plaque and bleeding scores, pocket depth, and clinical attachment level improved significantly. VOH was 0.472 ± 0.168 at T0, 0.358 ± 0.166 at T1, and 0.250 ± 0.123 at T2. A significant improvement in VOH was observed from T0 to T1 (difference: -0.114; 95% CI: -0.199 to -0.029; P = .014) and from T1 to T2 (difference: -0.108; 95% CI: -0.200 to -0.015; P = .027). From T0 to T2, VOH increased by 44.3%. Self-perceived assessment of masticatory function also improved from T0 to T2 (P = .002). The fixed prosthetic rehabilitation in patients with stage IV periodontitis allowed for a significant improvement in objective and subjective measurements of masticatory function.

Evaluation of photopolymer resins for dental prosthetics fabricated via the stereolithography process at different polymerization temperatures. Part II: Dimensional accuracy and fracture load of fixed dental prostheses.

STATEMENT OF PROBLEM: Prostheses printed on a 3-dimensional (3D) printer need to undergo the postpolymerization process, which can increase the working time. However, it has been not suggested for reducing workload and improving the properties of prostheses in dental clinical practice. PURPOSE: The purpose of this in vitro study was to evaluate how the printing temperature impacts the dimensional accuracy and fracture load of 3D printed fixed dental prostheses (FDPs). MATERIAL AND METHODS: Dental prostheses were printed at room temperature (RT), 50°C, and 70°C using a stereolithography 3D printer. Subsequently, after rinsing away residual monomer, the printed parts underwent the green condition (it was not subjected to any postprocessing) and postpolymerization. The mechanical properties of the printed FDPs were determined by loading to fracture (n=6). To evaluate their clinical applicability, the dimensional accuracy and fit of FDPs fabricated at various resin polymerization temperatures were measured (n=6). The 1-way analysis of variance was used to perform statistical comparisons, followed by the Tukey honestly significant difference test (α=.05). RESULTS: The specimens printed at RT and 50°C were better than those printed at 70°C in terms of dimensional accuracy and fit (P<.05). Nonetheless, the dimensional accuracy and fit of the specimens printed at 70°C were clinically acceptable. The fracture load of the 3-unit FDPs depended significantly on the printing temperature. CONCLUSIONS: The dimensional accuracy and fracture load of the 70°C group were acceptable for FDP fabrication. Thus, the temperature of 70°C without postprocessing may help make the procedure more efficient.