Opinions of Dental Technologists in Nigeria on Quality of Work Authorization for Removable Dental Prosthesis.

BACKGROUND: When fabricating a removable dental prosthesis, clear and sufficient communication between the dentist and dental laboratory technologist is crucial to ensure a successful outcome. OBJECTIVES: To evaluate the quality of communication between dentists and dental laboratories via work authorizations for the fabrication of removable prosthesis across the six geographical zones in Nigeria. MATERIALS AND METHODS: A cross-sectional descriptive study was conducted among dental technologists in Nigeria. A 22- item, online survey questionnaire was sent to all the participants through their respective states and the National Dental Technologist Association across the six geographical zones in the country. Data obtained were analyzed. Association between variables was carried out using the Chi-square test. Binary logistic regression was used to predict group membership. RESULTS: A total of 62 dental technologists participated in this study; the highest percentage of respondents, 29.1% was from South West. Only 21% of the respondents reported that they received work authorizations with adequate information to complete a denture setup most time. Also, 16.1% of the technologists received casts with adequate rest seats and guide planes prepared on the abutment teeth. Eighteen respondents (29%) stated that the authorization card does not contain all the required information. Fabrication of more than 7cast RPDs could be used to predict dental technologists who hold a positive view on the provision of quality work authorization by dentists. (P≤0.05).

CONTEXTE: Lors de la fabrication d'une prothèse dentaire amovible, une communication claire et suffisante entre le dentiste et le technologue de laboratoire dentaire est cruciale pour garantir un résultat satisfaisant. OBJECTIFS: Évaluer la qualité de la communication entre les dentistes et les laboratoires dentaires par le biais d'autorisations de travail pour la fabrication de prothèses amovibles dans les six zones géographiques du Nigeria. MATÉRIEL ET MÉTHODES: Une étude descriptive transversale a été menée auprès des prothésistes dentaires au Nigeria. Un questionnaire d'enquête en ligne de 22 questions a été envoyé à tous les participants par l'intermédiaire de leurs États respectifs et de l'Association nationale des technologues dentaires dans les six zones géographiques du pays. Les données obtenues ont été analysées. L'association entre les variables a été réalisée à l'aide du test du chi carré. La régression logistique binaire a été utilisée pour prédire l'appartenance à un groupe. RÉSULTATS: Au total, 62 technologues dentaires ont participé à cette étude ; le pourcentage le plus élevé de répondants, soit 29,1 %, provenait du Sud-Ouest. Seulement 21% des répondants ont déclaré avoir reçu des autorisations de travail avec des informations adéquates pour réaliser un montage de prothèse dentaire la plupart du temps. De plus, 16,1 % des technologues ont reçu des moulages avec des sièges de repos et des plans de guidage adéquats préparés sur les dents piliers. Dix-huit répondants (29 %) ont déclaré que la carte d'autorisation ne contenait pas toutes les informations requises. La fabrication de plus de sept prothèses dentaires de recouvrement pourrait être utilisée pour prédire les technologues dentaires qui ont une opinion positive sur la fourniture d'une autorisation de travail de qualité par les dentistes. (P≤0.05). CONCLUSIONS: La qualité de l'autorisation de travail pour la fabrication de prothèses dentaires amovibles était moins qu'adéquate dans les six zones géographiques du Nigeria. Cela laisse généralement une grande partie de la prise de décision aux technologues de laboratoire dentaire. MOTS-CLÉS: Technologue dentaire, prothèse dentaire amovible, autorisation de travail.

In vitro comparison of guide planes for removable partial dentures prepared with CAD-CAM-assisted templates, guiding rod templates, and freehand.

OBJECTIVES: This study aimed to evaluate the accuracy of computer-aided design and computer-aided manufacturing (CAD-CAM)-assisted templates (CCAT), guiding rod templates (GRT), and freehand (FH) preparation of guide planes. METHODS: Forty-five identical maxillary resin casts were divided into three groups, in which the guide planes of the two abutment teeth were prepared using a CCAT (n=15), GRT (n=15), and FH (n=15). The CCAT and GRT were digitally designed on a digital cast of virtually prepared guide planes and fabricated using three-dimensional printing (3DP) technology. To assess the 3D trueness, the prepared guide planes were digitally scanned and compared to the virtually designed guide planes. The angle deviation was measured to assess the trueness of the direction of the guide plane preparation. Shapiro-Wilk and Levene's tests were used to check the normality and equivalence of the variance of the data. The data were compared by using the Kruskal‒Wallis H test (α=0.05). RESULTS: The CCAT group exhibited significantly better 3D trueness (78.5±19.8 µm) than the GRT group (211.3±42.4 µm, p<0.05) and the FH group (198.9±44.3 µm, p<0.05). Additionally, the CCAT group (1.31±0.50°) showed significantly smaller direction trueness compared to the GRT (4.65±0.72°, p<0.05) and FH (5.64±0.70°, p<0.05) groups. CONCLUSIONS: The novel CAD-CAM-assisted template significantly improved the quality of the guide planes compared with the GRT and FH procedures. This enhancement suggests that removable partial dentures can be predictably inserted immediately after guide plane preparation. CLINICAL SIGNIFICANCE: CAD-CAM-assisted templates improve the quality of guide plane preparation.

[Comparative assessment of the intensity of caries among dental patients of older age groups in need of removable prosthetics, registered by a phthisiatician and their perception of an artificial ageist situation.]

Improving the quality of life of older age groups is an urgent problem of medicine, including its components: gerontology, phthisiology and dentistry. The objectives of the study are: to establish the importance of tuberculosis as an infection that causes the intensity of caries among patients of older age groups; assessment using the Palmore scale of gerontological ageism «The ageism survey¼ and patients' perception of an artificial situation of age inequality. The study involved elderly (n=122) and senile (n=121) persons with partial secondary adentia who needed removable dentures. The control groups of older people included patients who denied being under the supervision of a phthisiologist, and the study groups confirmed this. To solve the first problem, a comparative assessment of the values of the components of the CPI index in the control and study groups was carried out. To solve the second problem, an artificial situation of age inequality was simulated in the process of dental admission. The results of its effects were evaluated based on the response of patients to questions № 9, 10 of the Palmor scale. The absence of a difference in the values of K and N components between the control and study groups indicates the absence of a significant effect of mycobacteria on the development of caries. The large values of component Y in the studied groups may indicate the detrimental effect of mycobacteria on periodontal disease. The absence of an increase in the intensity and stability of the perception of age inequality among patients who are under the influence of an artificially created situation proves the great effectiveness of background age inequality. At the same time, it is impossible to exclude the low sensitivity of the Palmor scale in the process of diagnosing age inequality in Russian society.

Clinical evaluation of a one-piece polyetheretherketone removable partial denture fabricated using a novel digital workflow: A self-controlled clinical trial.

PURPOSE: To explore the clinical application of one-piece polyetheretherketone (PEEK) removable partial dentures (RPDs) fabricated using a novel digital workflow and to evaluate their weights and fits in vivo and patient satisfaction. MATERIALS AND METHODS: Fifteen cases with posterior partially edentulous situations were selected, and each patient received two types of RPDs, including a novel digital workflow (test group) and a conventional workflow (control group). For the test group, one-piece RPDs were designed through three-dimensional (3D) methods by scanning stone casts and fabricated by milling PEEK discs. Each RPD was weighed. The gaps between the oral tissue and RPDs in each group were duplicated using a polyvinylsiloxane (PVS) replica and measured by 3D analysis. A visual analog scale (VAS) was used to evaluate the patient's satisfaction. Paired t-tests were used to compare the differences in the weight, the gaps of each RPD, and VAS values between the two groups. One-way analysis of variance tests was used to compare the differences in the gap among different components in each group. RESULTS: The RPD in the test group weighed less than that in the control group (p < 0.01). No statistically significant differences in the gaps of denture bases and rests (p > 0.05) were found between the two groups, but the gaps of major connectors in the test group were significantly smaller than in the control group (p < 0.05). The VAS scores for comfortableness and masticatory efficiency were not significantly different between the two groups (p > 0.05) but the scores for the aesthetic appearance of the clasps in the test group were significantly higher than that in the control group (p < 0.05). CONCLUSIONS: One-piece PEEK RPDs manufactured using a novel digital workflow weighed less than conventional RPDs and exhibited a clinically acceptable internal fit. Although the aesthetic appearance of the PEEK clasps was superior to the control, there is still room for improvement.

Impact of Denture Use on Oral Health-Related Quality of Life in Yemeni Patients: A Cross-Sectional Analysis.

BACKGROUND We used the 14-item Oral Health Impact Profile-14 (OHIP-14) questionnaire to evaluate the association between sociodemographic variables and oral health-related quality of life in 241 wearers of removable partial or complete dentures attending a single center in Yemen. MATERIAL AND METHODS A total of 241 partial dentures (PD) and complete dentures (CD) wearers were enrolled from the Department of Prosthodontics at the Faculty of Dentistry, Sana'a University, and the University of Science and Technology. Data were collected before the commencement of denture wearing and after 3-6 months of denture use. The questionnaire consisted of sociodemographic information and denture type, and another for the OHIP to assess oral health-related quality of life (OHRQoL), oral health impact profile scale comprises 7 subscales, each evaluating different aspects of oral health and functionality. Descriptive statistics were calculated for participants. Independent t tests were performed to compare different patient groups, focusing on PD and CD wearers. Paired-sample t tests were used to examine changes within patient groups before and after removable denture use. RESULTS Among all participants, 67.6% were male, wearers of CDs were 74.6% male, PDs were 58.3%, and was consistent for CD (71.0%) and PD (72.8%) wearers. The wearing prostheses significantly impacted the OHRQoL of patients using both PDs and CDs (P<0.01). Among CD wearers, 4 of these subscales (3-6) were statistically significant, but the handicaps subscale showed evident reductions in physical pain after treatment among PD wearers. CONCLUSIONS Wearing dentures positively affects the OHRQoL of patients, influencing various aspects of their health, including functional, physical, psychological, and social well-being.

Application of digital impression and model in removable partial dentures for Kennedy classâ andâ ¡dentition defects.

OBJECTIVES: This study aimed to evaluate the application of digital impression and resin model technology in removable partial dentures (RPD) for Kennedy classⅠandⅡdentition defects. METHODS: Patients with Kennedy classⅠorⅡdental defect were selected and grouped in accordance with the following denture production processes: digital impression/resin model/cast cobalt-chromium alloy framework group (group A), digital impression/resin model/laser printed titanium framework group (group B), alginate impression/plaster model/cast cobalt-chromium alloy framework group (group C), and alginate impression/plaster model/laser printed titanium framework group (group D), with 40 cases in each group. The final RPD was examined in place in the mouth, and the evaluation indicators included the retention force of clamp ring, the tightness of connector and base, and the accuracy of occlusion. The evaluation scores of each index were used for analysis on the Kruskal-Wallis rank-sum test. RESULTS: No statistically significant difference in the score of each index was found among the four groups in RPD. CONCLUSIONS: The cast cobalt-chromium alloy and laser-printed titanium framework RPD using digital impression and resin model can meet the clinical restoration requirements of patients with Kennedy classⅠandⅡdentition defects.

Longevity of acrylic and cobalt-chromium removable partial dentures-A ten-year retrospective survival analysis of 1246 denture-wearing patients.

OBJECTIVES: to assess the survival rates of removable partial dentures (RPDs) and identify factors impacting their longevity. METHODS: electronic health records were retrieved of patients aged ≥18 who received RPDs between 2010 - 2021 with a follow-up of ≥ three months. Data extracted included demographics, medical history, dental charting, periodontal screening and recording scores, prostheses details and related interventions, including new dentures/denture remakes, and maintenance. Multivariate Mixed-Effect Cox regression was performed to identify potential RPD survival risk factors. Reduced model selection was reached using a backward step-down by comparing the performance of these multivariable models using the ANOVA test. RESULTS: 1893 RPDs from 1246 patients were included, with a median follow-up of 21.8 months (range from 3 to 131.3 months). Three hundred and twelve patients received a maxillary RPD, 460 received a mandibular RPD, and the remaining 474 patients received both maxillary and mandibular RPDs. Metal-based RPDs had a median survival of 73 months (95%CI: 70 - 82) versus 45 months (95% CI: 37-67) for acrylic ones. Multivariable mixed effects Cox model showed that the lifespans of RPDs were longer amongst patients receiving more maintenance care within three months [Hazards Ratio (HR)=0.89 (0.83, 0.96)] and after three months [HR=0.53 (0.46, 0.61)] of denture delivery, patients wearing both maxillary and mandibular RPDs [HR=0.67 (0.52, 0.87)], and patients receiving metal-based RPDs [HR=0.31 (0.23, 0.42)]. CONCLUSIONS: Metal-based dentures, dual arch restoration, and increased maintenance positively impact the survival of RPDs. CLINICAL SIGNIFICANCE: Adapting consent and warranty practices is advised to reflect RPD performance variations.

Effect of two esthetic digitally produced materials used in fabrication of extracoronal attachments on the stresses Induced in removable partial dentures.

BACKGROUND: Preservation of the remaining structures while maintaining an esthetic appearance is a major objective in removable partial prosthodontics. So, the aim of the current study was to compare the stresses induced on the supporting structures by two digitally produced esthetic core materials; Zirconia and Polyetheretherketone when used as an extracoronal attachment in distal extension removable partial dentures using strain gauge analysis. METHODS: A mandibular Kennedy class II stone cast with the necessary abutments' preparations was scanned. The mandibular left canine and first premolar teeth were virtually removed. An acrylic mandibular left canine and first premolar teeth were prepared with heavy chamfer finish line and scanned. Virtual superimposition of the acrylic teeth in their corresponding positions was done. Two strain gauge slots were designed: distal to the terminal abutment and in the residual ridge. Two models and two sets of scanned teeth were digitally printed. The printed teeth were then placed in their corresponding sockets in each model and scanned. The attachment design was selected from the software library and milled out of Zirconia in the model ZR and Polyetheretherketone in the model PE. Five removable partial dentures were constructed for each model. The strain gauges were installed in their grooves. A Universal testing machine was used for unilateral load application of 100 N (N). For each removable partial denture, five measurements were made. The data followed normal distribution and were statistically analyzed by using unpaired t test. P value < 0.05 was considered to be statistically significant. RESULTS: During unilateral loading unpaired t test showed statistically significant difference (p = 0.0001) in the microstrain values recorded distal to the abutment between the models ZR (-1001.6 µÎµ ± 24.56) and PE (-682.6 µÎµ ± 22.18). However, non statistically significant difference (p = 0.3122) was observed in the residual ridge between them; ZR (16.2 µÎµ ± 4.53) and PE (15 µÎµ ± 3.74). CONCLUSIONS: In removable partial dentures, Polyetheretherketone extracoronal attachment induces less stress on the supporting abutments compared to the zirconia one with no difference in the stresses induced by them on the residual ridge.

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.

Effects of various prosthetic methods for patients with Kennedy Class I partial edentulism on oral hypofunction, subjective symptoms, and oral health-related quality of life.

PURPOSE: This propensity score matching, multicenter, cross-sectional study was performed to examine the effects of various prosthetic methods for dental clinic outpatients with Kennedy Class I partial edentulism (KCIPE) on oral hypofunction, subjective frailty symptoms, and oral health-related quality of life (QOL). METHODS: Patients (n = 348) were classified into the following three groups for analysis: NT, patients with natural dentition providing intermaxillary contact in four occlusal supporting zones; RPD, patients with KCIPE who received removable partial dentures; and ISFP, patients with KCIPE who received implant-supported fixed prostheses. Participants' basic characteristics were recorded, and oral function tests were conducted. Subjective symptoms of physical and oral frailty were investigated via questionnaire. Oral health-related QOL was assessed using the Japanese short version of the Oral Health Impact Profile (OHIP-JP16). Propensity score matching was performed to adjust for patient background factors that could influence oral hypofunction in each group. RESULTS: Compared with the ISFP group, the RPD group had significantly higher rates of poor oral hygiene, reduced occlusal force, decreased masticatory function, and declines in swallowing function and oral hypofunction; the odds ratio for oral hypofunction was 4.67. Compared with the ISFP group, the RPD group had significantly greater subjective symptoms of physical frailty and oral frailty, as well as higher OHIP scores. CONCLUSIONS: Prosthetic treatment of KCIPE affected oral hypofunction, subjective frailty symptoms, and oral health-related QOL in dental clinic outpatients.

Double crown removable partial denture for a patient with ectodermal dysplasia: A clinical report after 31 years.

This clinical report describes the prosthodontic management of a 5-year-old boy with ectodermal dysplasia who had been followed for 31 years. During the first 15 years, several interim removable overdentures were fabricated and modified according to his skeletal growth. At age 20, after the completion of jaw development, 4 endosseous dental implants were inserted in the mandible with a nerve repositioning procedure. After a 6-month healing period, maxillary and mandibular double crown removable partial dentures (RPDs) using a gold electroforming system were delivered. In the 16 years since delivery, the implants and abutment teeth have shown no pathologic signs. The double crown RPDs supported by implants and natural teeth were found to be an effective, long-term stable treatment option for this patient with hypodontia. The authors are unaware of a longer follow-up period of dental rehabilitation in a patient with ectodermal dysplasia providing satisfactory functional and esthetic results.

Comparing the trueness of 3D printing and conventional casting for the fabrication of removable partial denture metal frameworks for patients with different palatal vault depths: An in vitro study.

STATEMENT OF PROBLEM: The success of a removable partial denture depends on its fit, and, with conventional casting, the framework is more distorted in patients with a deep palatal vault. Questions remain about whether the three-dimensional (3D) printing technique for fabricating a framework can improve the accuracy of fit for these patients. PURPOSE: The purpose of this in vitro study was to compare the trueness of metal frameworks fabricated by selective laser melting, 3D printing pattern casting, and conventional casting for different palatal vault depths. MATERIAL AND METHODS: A total of 30 partially edentulous maxillary casts were custom-made in 15 medium and 15 deep palatal vaults. All stone casts were scanned as reference models in digital files. For the medium palatal vault casts, Co-Cr frameworks of the conventional casting (CON) group (n=5) were fabricated with the lost wax technique. For the 3D printing pattern casting (PPC) group (n=5), wax patterns of the framework were printed, followed by metal casting. The frameworks created for the selective laser melting (SLM) group (n=5) were printed directly by using the SLM machine. The same procedures were followed for the deep palatal vault group. All the metal frameworks were scanned and superimposed with the reference casts by using the Geomagic Control X software program. Discrepancies were measured as mean ±standard deviation (trueness), and the data were statistically analyzed with a 2-way ANOVA test to evaluate the interaction of 2 independent factors (fabrication techniques and palatal vault depths) on a trueness outcome (α=.05). RESULTS: The lowest mean ±standard deviation value was 0.092 ±0.023 mm, found from the SLM framework with deep palatal vault group, while the highest value was 0.194 ±0.017 mm, found from the CON framework with deep palatal vault group. Different fabrication techniques interacted with different palatal vault depths in terms of trueness (P<.05); however, no significant differences were observed in the medium palatal vault groups (P>.05). Additionally, color mapping demonstrated the gaps of metal frameworks among the 6 groups. CONCLUSIONS: With the conventional casting technique, the accuracy of the metal framework was affected by the depth of the palate. For medium palatal vaults, all fabricated frameworks had clinically acceptable fit. For deep palatal vaults, the SLM frameworks showed the lowest discrepancy. As a result, the SLM technique is advised for fabricating a better-fitting metal framework for patients with a deep palatal vault.

Orofacial esthetics, chewing function, and oral health-related quality of life in Kennedy class I patients with mini-implant-retained removable partial dentures: A 3-year clinical prospective study.

This prospective clinical study aimed to assess self-reported orofacial esthetics, chewing function, and oral health-related quality of life (OHRQoL) over three years in the Kennedy Class I patients without posterior dentition who received free-end saddle removable partial dentures (RPDs) retained by two mini dental implants (MDIs) inserted in the canine/first premolar region. The study's robust findings reaffirm the viability of MDI-retained RPDs as a treatment modality in contemporary prosthodontics, instilling confidence in the dental community. MATERIALS AND METHODS: 92 participants with posterior edentulism in the maxilla or mandible received 184 MDIs and 92 RPDs. After one year, three participants were excluded, and another seven were excluded after three years. The final sample was 82 participants. Self-perceived orofacial esthetics was assessed by the Orofacial Esthetic Scale (OES), chewing function by the Chewing Function Questionnaire (CFQ), and the OHRQoL by the OHIP-14. Statistical analysis utilized multivariate regression analysis, standardized effect size calculation, Wilcoxon Signed Rank test, and Friedman's test. RESULTS: OHRQoL and chewing function significantly improved (p < 0.001) one month after MDI loading by the new RPDs and continued to improve over the observation period (p < 0.05). The OES also significantly improved (p < 0.001) and remained almost unchanged over the next three years (p = 0.440). CONCLUSION: Despite the limitations of this study, the MDI-retained RPD appears to be a viable treatment modality in contemporary prosthodontics from the patients' perspective.

Removable dental prostheses and difficulties with chewing among frail individuals: Results from the Swiss SAPALDIA cohort.

Oral healthcare among the frail is an underestimated geriatric care element. While neglected oral health (OH) is a well-established risk factor for frailty, frailty can be a risk factor for subsequent OH problems. The cross-sectional investigation nested into the SAPALDIA sub-cohort of citizens aged 52 years and older, aims to stimulate longitudinal research into aspects that accelerate poor OH among frail individuals. The hypothesis investigated was that (pre-) frail individuals are more likely to have missing teeth replaced with removable dental prostheses (RDP) resulting in difficulties with chewing. The study included 1489 participants undergoing geriatric assessments and oral examination. The main predictor was frailty status (non-frail; pre-frail; frail), based on Fried's frailty phenotype. The main outcomes of interest were non-functional dentition (presence of ≤ 19 natural teeth), presence of any RDP and self-reported difficulties with chewing. Pre-frailty and frailty were not associated with the presence of ≤ 19 natural teeth, but were associated with a higher RDP prevalence. The presence of at least one complete denture (CD) had 1.71 fold and 2.54 folds higher odds among pre-frail and frail, respectively, compared to non-frail individuals. Frail individuals with CD reported chewing difficulties 7.8 times more often than non-frail individuals without CD. The results are in line with the hypothesis that (pre-) frail individuals may be more likely to have tooth loss restored by RDPs. Future longitudinal research needs to assess potential barriers to oral hygiene and fixed dental prostheses among (pre-) frail and to study their oral health-related quality of life.

Rotational path removable partial mandibular resection prostheses: A case series of patients with mandibular symphyseal defects.

Rotational path removable partial mandibular resection prostheses (MRPs) offer advantages in the management of patients with acquired symphyseal defects of the mandible, including enhanced esthetics achieved through a reduced number of clasps, the provision of rigid retainers less prone to distortion compared with flexible alternatives, and the ability to engage prominent proximal undercuts in patients lacking buccal undercuts. Additionally, removable partial MRPs represent a suitable treatment option in scenarios where the cost of implant-retained prostheses is prohibitive or in patients where implant therapy is contraindicated, such as those with a history of head and neck radiation. While the use of rotational path removable prostheses has been well documented in conventional prosthodontics, its application in maxillofacial prosthetics remains less explored. This case series describes 3 patients, all of whom underwent mandibular resections involving the mandibular symphysis and subsequently received prosthetic rehabilitation incorporating rotational path removable partial MRPs.

A comparison of the prevalence of respiratory pathogens and opportunistic respiratory pathogenic profile of 'clean' and 'unclean' removable dental prostheses.

OBJECTIVES: To determine and compare the opportunistic respiratory pathogenic index (ORPI) and prevalence of respiratory pathogens between clean and unclean removable prostheses. METHODS: A cross-sectional study was conducted among 97 removable prosthesis wearers at a teaching dental hospital. Participants' prosthesis hygiene was grouped into clean and unclean. After prosthesis plaque samples were sequenced using the Type IIB Restriction-site Associated DNA Sequencing for Microbiome method, the prevalence was assessed for the presence of respiratory pathogens on each sample. The ORPIs for clean and unclean prostheses were quantified based on the sum of the relative abundance of respiratory pathogenic bacteria in a microbiome using a reference database that contains opportunistic respiratory pathogens and disease-associated information. RESULTS: A total of 30 opportunistic respiratory pathogens were identified on the removable prostheses. Eighty-one (83.5 %) removable prostheses harboured respiratory pathogenic bacteria. Stenotrophomonas maltophilia (34.0 %), Pseudomonas aeruginosa (27.8 %), and Streptococcus agalactiae (27.8 %) were the top three prevalent respiratory pathogens detected in plaque samples. There was a significantly higher prevalence of respiratory pathogens residing on unclean than clean prostheses (P = 0.046). However, the ORPIs in both groups showed no statistically significant difference (P = 0.516). CONCLUSIONS: The ORPIs for both clean and unclean prostheses demonstrated a similar abundance of respiratory pathogens. However, the high prevalence of respiratory pathogens residing on unclean prostheses should not be underestimated. Therefore, maintaining good prosthesis hygiene is still important for overall oral and systemic health, even though the direct link between prosthesis cleanliness and reduced abundance of respiratory pathogens has not been established. CLINICAL SIGNIFICANCE: The association between the prevalence of respiratory pathogens and unclean removable prostheses has been demonstrated and might increase the theoretical risk of respiratory disease development.

Retention and fatigue performance of modified polyetheretherketone clasps for removable prosthesis.

PURPOSE: Polyetheretherketone (PEEK) is considered as an alternative to metal material for removable partial denture (RPD). However, the retentive force is not strong as a metal RPD. This study investigated the retention and fatigue performance of PEEK clasps with different proportions of clasp arm engaging the undercut to verify a new strategy to improve their clinical performance. METHODS: Three groups (n = 10/group) of PEEK clasps with their terminal 1/3, 2/3 and the whole of retentive arms engaging the undercut were fabricated along with a group (n = 10) of conventional cobalt-chrome (CoCr) clasps as control group. Retentive forces were measured by universal testing machine initially and at an interval of 1500 cycles for a total of 15,000 fatigue cycles. The fatigue cycles were conducted by repeated insertion and removal of the clasp using fatigue testing machine. Each clasp was scanned by Trios3 scanner before and after fatigue test to obtain digital models. The deformation of the clasp was evaluated by root mean square (RMS) through aligning the two models in Geomagic wrap (2021). Scanning electron microscopy (SEM) and finite element analysis were carried out to observe the abrasion and the von Mises stress of the clasp arm. Kruskal-Wallis H test was used to compare the retentive forces and the RMSs of the studied groups followed by Bonferroni multiple comparisons. RESULTS: The whole of PEEK clasp arm engaging the undercut provided higher mean retentive forces (7.99 ± 2.02 N) than other PEEK clasp groups (P < 0.001) and was closer to CoCr clasps (11.88 ± 2.05 N). The RMSs of PEEK clasps were lower than CoCr clasps (P < 0.05) while the differences among PEEK clasps were of no statistical significance (P > 0.05). SEM showed that evidences of surface abrasion were observed on the section that engaged the undercut for all groups of clasps. The stress concentration mainly occurred on the initial part of the retentive arm. The maximum von Mises stress of each group was below the compressive strength of PEEK. CONCLUSIONS: Proportions of PEEK clasp arm engaging the undercut positively influenced the retentive force and the fatigue resistance of PEEK clasps was superior than CoCr clasps. It is a feasible method to improve the retention of PEEK clasps by increasing the proportion of clasp arm engaging the undercut. Clinical trials are needed to further verify this innovation.