Survival time analysis of remaining teeth following replacement of unilateral free-end missing teeth: A comparison between fixed implant-supported prostheses and removable partial dentures.

OBJECTIVES: This retrospective study aimed to investigate the differences in tooth loss rate between fixed implant-supported prostheses (FISPs) and removable partial dentures (RPDs) in cases of unilateral free-end missing teeth. MATERIALS AND METHODS: The data of 324 patients who underwent treatment with FISPs or RPDs for unilateral free-end missing teeth and satisfied the applicable criteria, were evaluated (47 in the FISPs group and 277 in the RPDs group). After propensity score (PS) matching, which was used to extract patients with similar background factors related to prosthetic selection at baseline, survival time analyses were performed with tooth loss as the endpoint. The adjusted variables were age, sex, number of restored teeth, periodontal status, and the practicing dentist's experience in years. The remaining teeth were classified into subcategories in relation to the missing molars. RESULTS: Overall, 58 patients (29 in each group) selected by PS matching were evaluated in the final analysis. The total number of lost teeth was 35 (FISPs group: n = 10; RPDs group: n = 25). The mean (±SD) period to tooth loss and the 10-year survival rates in the FISPs and RPDs groups were 51.6 (±30.1) months and 42.3 (±29.7) months, 70.5% and 16.4%, respectively. The log-rank test showed that significantly longer survival time in FISPs compared with RPDs. CONCLUSIONS: After adjustments for confounding factors using PS matching, replacing unilateral free-end missing teeth with FISPs may exhibit a lower tooth loss rate in adjacent and contralateral teeth compared to replacing with RPDs.

Knowledge, attitudes, and practice related to tooth loss and dentures among patients with dental arch deficiencies.

BACKGROUND: Tooth loss is a common problem that affects many people worldwide. Exploring knowledge, attitude, and practice (KAP) among patients can identify barriers and challenges in following recommended practices, providing valuable insights for dental healthcare providers, policymakers, and researchers. This study aimed to explore the KAP of patients with dental arch deficiencies regarding tooth loss and dentures. METHODS: This web-based, cross-sectional study was conducted among patients with dental arch deficiencies using a self-designed questionnaire. RESULT: 3166 valid questionnaires were included. Participants' mean KAP scores were 6.84 ± 2.27 (possible range: 0 ~ 12), 39.4 ± 3.72 (possible range: 9 ~ 45), and 27.7 ± 4.36 (possible range: 8 ~ 40), respectively. Multivariable logistic regression analysis showed that knowledge (OR = 1.383), employed (OR = 1.805), family history (OR = 2.158), and treatment (OR = 1.683) were independently associated with attitude. Moreover, knowledge (OR = 1.239), attitude (OR = 1.250), female (OR = 0.619), age (OR = 0.967), college/bachelor (OR = 0.373), and master and above degree (OR = 0.418), employed (OR = 0.554) or student (OR = 0.434), with 10,001-20,000 Yuan household income per month (OR = 0.492), have been married (OR = 0.609), smoking (OR = 0.595), drinking (OR = 0.397), disease duration (OR = 0.972), with family history (OR = 1.676), and with treatment (OR = 3.492) were independently associated with practice (all P < 0.05). CONCLUSION: Patients with dental arch deficiencies have insufficient knowledge, positive attitudes, and moderate practice toward tooth loss and dentures, which might be affected by multiple demographic factors.

The association between objective and subjective oral health conditions and the presence of anorexia of aging among Japanese older Adults1.

Anorexia of aging is a risk factor for malnutrition among older adults. This study aimed to evaluate the association between objective and subjective oral health and anorexia among independent older adults. This cross-sectional study targeted independent older adults aged ≥65 years who participated in the Japan Gerontological Evaluation Study conducted in 2022. The outcome variable was the presence of anorexia, as assessed by the Simplified Nutritional Appetite Questionnaire. Exposure variables were dental status (≥20 teeth, 10-19 teeth with/without dentures, and 0-9 teeth with/without dentures) as objective oral health and oral health-related quality of life measured by five items of the short version of the Oral Impacts on Daily Performances (OIDP) (eating, speaking, smiling, emotional stability, and enjoying with others) as subjective oral health. We fitted the Poisson regression model, including possible confounders, and estimated prevalence ratios (PRs) and 95% confidence intervals. Among 19,787 participants (mean age: 74.6 years [1SD = 6.2], male: 48.5%), 9.0% were classified as having anorexia. After adjusting possible confounders, those with ≤19 teeth had a higher proportion of experiencing anorexia compared to those with ≥20 teeth; however, the association was less pronounced among those with dentures (0-9 teeth with dentures: PR = 1.48 [1.31-1.68], and 0-9 teeth without dentures: PR = 2.08 [1.65-2.63]). Even after adjusting for dental status, each item of OIDP was significantly associated with the presence of anorexia (all p < 0.05). The results showed that both objective and subjective poor oral health were significantly associated with a higher probability of developing anorexia of aging. Therefore, improving both objective and subjective oral health through appropriate dental care could contribute to maintaining appetite in later life.

Influence of denture-bearing conditions on masticatory function and patient-reported outcomes measures.

PURPOSE: To investigate the influence of different denture-bearing conditions on the masticatory function and patient-reported outcome measures (PROMs) of complete denture wearers. METHODS: Sixty edentulous patients were selected and allocated into two groups according to the American College of Prosthodontics' (ACP) classification: non-atrophic (NAT) (Classes I and II) (n = 24) and atrophic (AT) (Classes III and IV) (n = 36). All patients received new complete dentures (CDs). The objective variables (masticatory performance and swallowing threshold) were assessed as well as the PROMs (oral health-related quality of life (OHIP-EDENT), patient satisfaction) and quality of the prosthesis, at baseline (using the old CD) and after 4 months new prostheses use. Data were analyzed by Mann-Whitney test followed by the Generalized Equations Estimation (GEE), linear regression and Chi-square test. RESULTS: Higher masticatory performance was observed in the NAT group (p < .05) for both time points, baseline and after 4 months. However, compared to baseline, both groups showed significant masticatory improvement after 4 months (p < .05). Satisfaction and overall quality of life improved after 4 months with no difference between groups (p > .05). Regarding the quality of the CD, baseline results were significantly (p < .05) lower in the AT group, but after 4 months, no significant differences were found between groups and in intragroup analysis (p > .05). CONCLUSIONS: The denture-bearing conditions seems to impact masticatory function, but the PROMs are barely affected.

The impact of wearing complete denture in one or both arches, on eating-related quality of life and patients' perceived need for advice to support eating well: Results from a qualitative study.

BACKGROUND: Wearing complete denture in one or both arches can impact enjoyment of eating and affect quality of life compared with being dentate. Clinicians focus on issuing technically sound dentures but ignore the impact of wearing dentures on the eating-related quality of life which affects the success of treatment. OBJECTIVES: The aim of this research was to qualitatively explore ERQoL in Australian adults wearing complete dentures using a validated questionnaire and through focus groups. METHODS: Complete denture wearers (n = 44) were recruited from dental clinics and invited to complete the self-administered Emotional and Social Issues Related to Eating questionnaire. Responses were categorised under the six questionnaire domains. A subsample of 20 participants who completed the questionnaire were invited to participate in focus groups to identify emerging themes. RESULTS: Twenty-three participants (52.3%) completed the questionnaire. Most participants expressed a decline in enjoyment of eating due to reduced ability to eat, longer chewing times and the need to frequently clean dentures while eating. Focus groups (n = 2 × 4 participants) indicated educational materials on eating with dentures would increase recognition of eating problems with dentures and reduce trial and error approaches to dealing with these. CONCLUSION: ERQoL is adversely affected by wearing complete dentures due to functional limitations, restricted food choices and adaptive eating behaviours. Patient support for eating well with a complete denture/s wearers is required.

Dental prosthesis plaque index of Augsburger and Elahi: Expansion and standardisation in community-dwelling frail older people.

BACKGROUND: Inadequate daily oral hygiene care of dental prostheses could worsen general health of frail older people. The index of Augsburger and Elahi is often recommended to assess maxillary dental prosthesis plaque (DPP). OBJECTIVE: To assess the reliability of an expanded and standardised DPP index of Augsburger and Elahi in trained and untrained examiners, and to determine the applicability of the index in community-dwelling frail older people. METHODS: Ten community-dwelling frail older persons with complete and partial removable dental prostheses (RDPs) (mean ± SD age = 87.9 ± 8.4 years) participated. Seven persons were revisited after 3 months. The index was expanded with mandibular RDPs. Standardisation was achieved with a specially designed reference sheet. The RDPs were photographed after plaque colouring. Two trained examiners scored the photographs; thereafter, two untrained examiners. One trained examiner scored the photographs again after 3 weeks. Changes in DPP over the 3-month period were assessed with Wilcoxon signed-rank test. Inter- and intra-examiner reliability was assessed with intraclass correlation coefficients (ICCs). RESULTS: The DPP scores did not change significantly over time (Z = -0.594, p = 0.553). Inter-examiner reliability was excellent in the trained examiners (ICC = 0.859-0.947), and fair-to-good in the untrained examiners (ICC = 0.671-0.703). Intra-examiner reliability was excellent (ICC = 0.941-0.962). CONCLUSION: The proposed expansion and standardisation of the DPP index has an excellent inter- and intra-examiner reliability when performed by trained examiners, and a fair-to-good inter-examiner reliability by untrained examiners. Therefore, the index could be recommended for application in dental prostheses-wearing older persons and could be useful for awareness and education of professional and informal caregivers and the older persons themselves. TRAIL REGISTRATION: The Netherlands Trail Register NTR6159.

Unveiling denture-induced oral lesions: A comprehensive study on classification and pain assessment.

BACKGROUND: Denture-induced oral Lesions (DIOLs) often manifests shortly after the placement or adjustment of new or realigned dentures, frequently resulting in severe pain and discomfort. OBJECTIVES: This study aimed to classify DIOLs placing a particular emphasis on assessing the associated pain. METHODS: A prospective case study was conducted involving 126 patients who were fitted with a total of 193 dentures of various types at the Hadassah School of Dental Medicine. All patients underwent comprehensive intra-oral examinations within 1-8 weeks following denture delivery, completed symptom questionnaires and had their medical records reviewed. Key variables documented included age, gender, overall health status, denture type, and a detailed description of the DIOLs. The description encompassed factors such as lesion location, shape, colour, size, border characteristics, ulcerative appearance, membrane coverage, 3D morphology (elevated, immersed and flat) and patient-reported Verbal Pain Score (VPS) when touching the DIOLs, when wearing the denture, and when not wearing the denture. RESULTS: Notably, 25.4% of denture wearers required no adjustments, while 14.4% necessitated more than three revisions. A majority (71.8%) of DIOLs cases were associated with mandibular complete dentures, primarily situated on the alveolar ridge. The mean VPS indicated a pain intensity of 7 ± 2.1, with temporary dentures in both jaws causing the most discomfort. Implant-supported overdentures were particularly painful when placed in the mandible. Additionally, VPS scores were higher among older individuals and those with prior prosthetic experiences. A significant correlation was observed between pain intensity and presence of chronic health condition (0.036). CONCLUSIONS: This study revealed distinct characteristics of DIOLs and highlighted the multifactorial nature of pain experienced following the development of DIOLs. Insights into the influence of patient and denture characteristics on DIOLs and pain intensity can guide healthcare professionals in optimising patient comfort and satisfaction.

The cantilever contact-point resin bonded bridge; adhesion 2.0.

AIM: When young patients are congenitally missing anterior teeth, different treatment modalities can be used to complement the dental arch. This article proposes a new treatment modality for the replacement of anterior teeth, the cantilever contact-point resin bonded bridge (CCP-RBB). MATERIALS AND METHODS: In this proof of principle study, CCP-RBB's delivered by one operator were clinically assessed. Patients who were missing maxillary incisors and had suitable intra-oral conditions for a contact-point cantilever RBB were included. Three cases are presented to describe all adhesive steps. This proof of principle clinical study is presented with up to 60 months follow-up of the cantilever contact resin bonded bridges. RESULTS: A total of 19 CCP-RBB's were evaluated after a mean period of 29.8 months. None of the restorations exhibited failure, carious lesions or fractures during the follow-up periods, demonstrating an absence of restoration debonding or the need for repair. CONCLUSION: The new cantilever contact-point resin bonded bridge exhibited an excellent treatment modality without failure or debonding up to 5 years. More and extended duration in vivo studies are needed to evaluate this new treatment modality. CLINICAL SIGNIFICANCE: In this proof of principle the new cantilever contact-point resin bonded bridge obtained excellent results up to 5 years of clinical follow-up.

Exploring experiences of living with removable dentures-A scoping review of qualitative literature.

OBJECTIVE: Examine the literature on the experiences of living with removable dentures (complete or partial) to identify any gaps and provide a map for future research. BACKGROUND: Increasing proportions of society are living partially dentate with some form of restoration, including removable dentures. Previous studies have reported on the location, materials and usage of these prostheses, along with effects on oral-health-related quality of life (OHRQoL). However, less is known about experiences with removable dentures from a patient-centred perspective. METHODS: A scoping review of the qualitative literature was undertaken using the framework of Arksey and O'Malley, updated by Levac et al. Literature searches were carried out using Medline and Web of Science. Papers were screened by title and abstract using inclusion and exclusion criteria. Remaining papers were read in full and excluded if they did not meet the required criteria. Nine papers were included in the final review. FINDINGS: Key themes from these papers were: impact of tooth loss and living without teeth, and its impacts in relation to social position, appearance, confidence and function (chewing and speaking); social norms and tooth loss, including attitudes to tooth retention and treatment costs, and changes in intergenerational norms towards dentures; expectations of treatment, including patients being more involved in decision making, viewing the denture as a "gift" and dentures helping to achieve "an ideal"; living with a removable denture (complete or partial), including patient preparedness for a denture, adaptation and impacts on activities and participation; and the dentist-patient relationship, including issues with information and communication, and differing priorities between patients and dentists. CONCLUSION: Little qualitative research exists on experiences of living with a removable denture. Existing literature demonstrates the importance of dispersed activities in differing social, spatial and temporal contexts when wearing removable dentures. Focusing on processes of positive adaptation to dentures and OHRQoL, rather than deficits, is also required to fully understand patients' experiences. Additionally, more complex technological advances may not always be in the best interest of every patient.

Fabrication of complete dentures for an older patient with mobility impairment in three appointments: A dental technique.

OBJECTIVE: To describe the clinical procedures of complete denture set fabrication in three appointments. BACKGROUND: Simplified approaches have proven not to be inferior to conventional ones in terms of quality, patient satisfaction and masticatory ability. MATERIALS AND METHODS: The patient was a 77-year-old edentulous adult with mobility impairment seeking dental rehabilitation in a small number of appointments due to commuting difficulties. RESULTS: A set of complete dentures was delivered within three appointments. The second appointment was dedicated to set-up trial due to the patient's aesthetic demands. CONCLUSION: Under certain circumstances and after a thorough study of each case, dental clinicians may propose the fabrication of complete dentures in a three-appointment protocol incorporating a set-up trial session.

Stereophotometric facial changes in edentulous older adults after rehabilitation with complete dentures.

OBJECTIVES: To evaluate the facial characteristics of edentulous older adults who underwent rehabilitation using complete dentures, and to compare them with dentate individuals. BACKGROUND: Edentulism rehabilitation with complete dentures aims to restore occlusion and facial aesthetics. MATERIALS AND METHODS: The study included 102 edentulous participants needing prosthodontic rehabilitation with complete dentures and 30 with a natural dentition (aged >65). The 3D facial scans were performed using an Artec optical scanner. Superficial facial landmarks were identified, and 16 parameters were calculated. Regional analysis with the superimposition of two scans was used to calculate the average distances and percentage of non-matching surfaces in the 11 regions. Paired and independent t-tests (α = .05) were used to test for group differences, as appropriate. RESULTS: After rehabilitation with complete dentures, facial changes were most noticeable in the perioral region: wider rima oris, longer upper lip, wider upper vermilion, and more protruded profile. The comparison of facial regions without and with dentures showed fuller and curvier cheeks, with no direct influence of dentures. The edentulous faces with dentures appeared shorter and more retruded than those of dentate individuals. A narrower lower vermilion, retruded upper lip, and more flattened facial profile were observed in females with dentures than in their dentate peers. CONCLUSION: Besides the expected positive influence of rehabilitation with complete dentures on facial appearance in the perioral region, there are some unexpected changes, such as fuller cheeks, but there is still deficiency in vertical facial dimensions and a more flattened facial profile.

Exploring lived experiences on the usage of removable complete dentures among edentulous patients attending Makerere University Dental Hospital, Kampala, Uganda.

BACKGROUND: Edentulism remains a major disability worldwide, especially among the elderly population, although the prevalence of complete edentulism has declined over the last decades. In Uganda, the prevalence of edentulism in people aged 20 years and above is 1.8%. The therapy for edentulous patients can be realized through the use of conventional removable complete dentures, implant-supported prostheses, and computer-aided design and computer-aided manufacturing (CADCAM), however, the provision of removable complete dentures continues to be the predominant rehabilitation for edentulous patients. However, no published study has explored the lived experiences with removable complete dentures among the Ugandan population. The aim of the present study was to explore patients' lived experiences on the usage of removable complete dentures among Ugandan edentulous patients attending Makerere University Dental Hospital. METHODS: This was a qualitative study approach using purposive sampling. Fifteen (15) respondents were selected across social demographics. Interviews were recorded and transcribed and themes were generated to draw a deeper meaning to the usage of removable complete dentures. A qualitative statistical package, Atlas Ti software was used to generate themes from the interviews followed by an interpretation of the generated data and the results were presented as text and in a table. RESULTS: The reported key positive experiences due to removable complete denture rehabilitation were the improvement in speech, eating ability, regaining good facial appearance, better oral hygiene management, self-esteem and confidence to smile in public, and a feeling of completeness. However, respondents complained of pain and discomfort due to the looseness of dentures, inability to eat certain foods, and regular cleaning of dentures. The respondents did not go through proper informed consent processes before getting removable complete dentures. CONCLUSION: The study found that patients were satisfied with their removable complete dentures rehabilitation due to the positive experiences registered, such as the ability to eat and talk well, and restoration of self-esteem, all of which improved their quality of life. However, they experience pain and discomfort due to the looseness of dentures.

Effect of thermocycling on tensile bond strength of autopolymerized, heat-polymerized, milled, and 3D printed denture base materials bonded to 4 different denture liners: an in vitro study.

BACKGROUND: Digitally fabricated dentures may require relining due to continual alveolar ridge resorption. However, studies evaluating the tensile bond strength (TBS) of digitally fabricated dentures bonded to denture liners are lacking. This study aimed to evaluate the TBS of autopolymerized, heat-polymerized, milled, and 3D printed denture base materials bonded to 2 acrylic-based and 2 silicone-based denture liners, both before and after thermocycling. Additionally, the impact of thermocycling on the TBS were also evaluated. METHODS: The TBS of 4 different denture base materials (Palapress (PL), Vertex Rapid Simplified (VR), Smile CAM total prosthesis (SC), and NextDent denture 3D+ (ND)) bonded to 2 acrylic-based (GC Soft-Liner (GC) and Tokuyama Rebase II (RB)) and 2 silicone-based (Ufi Gel P (UP) and Sofreliner Tough M (ST)) denture liners were tested. Specimens (n = 8) were divided into non-thermocycling and thermocycling groups. Non-thermocycling specimens were tested after 24-hours water immersion, while thermocycling specimens were underwent 5000 cycle and were immediately tested. Mode of failure was examined under a stereomicroscope. Data were analyzed using 2-way ANOVA and Tukey HSD tests (α = 0.05), and independent samples t test (α = 0.05) for TBS between non-thermocycling and thermocycling groups. RESULTS: For the non-thermocycling groups, within the same denture liner material, no significant differences were found between denture base materials, except the ND + RB group, which had significantly lower TBS. For the thermocycling groups, within the same denture liner material, the TBS in the PL group exhibited the highest and the ND group exhibited the lowest. Within the same denture base material, in both non-thermocycling and thermocycling groups, the TBS in the ST group exhibited the highest; in contrast, that in the GC group exhibited the lowest. No significant differences were observed in TBS between non-thermocycling and thermocycling groups, except for denture base materials bonded to the ST group, SC + UP, and ND + UP groups. CONCLUSIONS: Milled denture base can be relined with acrylic-based or silicone-based denture liner. However, cautions should be exercised when relining 3D printed denture base. Thermocycling did not affect TBS between acrylic-based denture liners and denture bases. In contrast, it affected the bond between silicone-based denture liner and denture base.

A comparative evaluation of physical properties of CAD/CAM complete denture resins- an in vitro study.

BACKGROUND: In dentistry, there is a growing preference for computer-aided design and computer-aided manufacturing (CAD/CAM) systems over traditional laboratory procedures. However, there is not much literature comparing various CAD/CAM materials. Thus, this study aimed to assess and compare the color stability and hardness of gingival and tooth colored milled and 3D-printed acrylic resins. MATERIALS AND METHODS: Four types of CAD/CAM materials were prepared: 3D-printed pink shade (PP), milled polymenthymethacrylate (PMMA) pink shade (MP), 3D-printed tooth shade (PT) and milled PMMA tooth shade (MT) (n = 6). For hardness, disc shaped samples of 15 mm × 2 mm and for color stability, bar shaped samples of 65mmx10mmx2.5 mm were prepared and polished. Vickers hardness test was performed in a microhardness tester. Color stability test was done by immersing in coffee solution and coca cola for 7 days. Day 0 and day 7 measurements were recorded using a digital spectrophotometer and the change in color was calculated. For statistical analysis, one-way ANOVA and Tukey's post hoc tests were done. RESULTS: For color stability, milled PMMA was superior to 3D-printed resin samples. Milled pink and tooth shade samples had similar color stability, whereas 3D-printed tooth shade samples were more color stable as compared to pink shade 3D-printed samples. For hardness, milled tooth shade PMMA was the most superior one, followed by 3D-printed tooth shade, whereas pink shade milled PMMA and 3D-printed resin samples had similar hardness values and were inferior to the tooth shade CAD/CAM materials. CONCLUSION: Color stability of milled PMMA is superior to that of 3D-printed resins. Hardness of tooth shade milled and 3D-printed resins is more than that of pink shade milled and 3D-printed resins.

Causal effects of denture wearing on epigenetic age acceleration and the mediating pathways: a mendelian randomization study.

BACKGROUND: The epigenetic-age acceleration (EAA) represents the difference between chronological age and epigenetic age, reflecting accelerated biological aging. Observational studies suggested that oral disorders may impact DNA methylation patterns and aging, but their causal relationship remains largely unexplored. This study aimed to investigate potential causal associations between dental traits and EAA, as well as to identify possible mediators. METHODS: Using summary statistics of genome-wide association studies of predominantly European ancestry, we conducted univariable and multivariable Mendelian randomization (MR) to estimate the overall and independent effects of ten dental traits (dentures, bleeding gums, painful gums, loose teeth, toothache, ulcers, periodontitis, number of teeth, and two measures of caries) on four EAA subtypes (GrimAge acceleration [GrimAA], PhenoAge acceleration [PhenoAA], HannumAge acceleration [HannumAA] and intrinsic EAA [IEAA]), and used two-step Mendelian randomization to evaluate twelve potential mediators of the associations. Comprehensive sensitivity analyses were used to verity the robustness, heterogeneity, and pleiotropy. RESULTS: Univariable inverse variance weighted MR analyses revealed a causal effect of dentures on greater GrimAA (ß: 2.47, 95% CI: 0.93-4.01, p = 0.002), PhenoAA (ß: 3.00, 95% CI: 1.15-4.85, p = 0.001), and HannumAA (ß: 1.96, 95% CI: 0.58-3.33, p = 0.005). In multivariable MR, the associations remained significant after adjusting for periodontitis, caries, number of teeth and bleeding gums. Three out of 12 aging risk factors were identified as mediators of the association between dentures and EAA, including body mass index, body fat percentage, and waist circumference. No evidence for reverse causality and pleiotropy were detected (p > 0.05). CONCLUSIONS: Our findings supported the causal effects of genetic liability for denture wearing on epigenetic aging, with partial mediation by obesity. More attention should be paid to the obesity-monitoring and management for slowing EAA among denture wearers.

Evaluation of open-face maxillary complete denture for patients with prominent premaxilla: a crossover study.

BACKGROUND: The establishment of good facial esthetics is one of the main objectives of complete denture construction. Unfortunately, it may be the caused issue for patients having a prominent premaxilla due to excessive lip support by the labial flange of the maxillary denture. Open-face dentures (OFD) may suggest suitable prosthetic management for these patients. However, clinical evidence regarding the efficiency of OFD is scarce. METHODS: A total of 38 completely edentulous participants having prominent premaxilla and skeletal class I Angle's classification were enrolled in this study. Each participant received a mandibular complete denture and 2 opposing maxillary dentures; conventional (CD) and open-face (OFD). On the day of denture insertion, the participants were divided into 2 groups; CD-OFD and OFD-CD where CD-OFD group was instructed to use the mandibular denture and the maxillary CD for 3 months and then to use the maxillary OFD for another 3 months after a wash-out period of 2 weeks. While group OFD-CD was instructed to use the mandibular denture and the maxillary OFD for 3 months then to use the maxillary CD for another 3 months after a wash-out period of 2 weeks. The dislodging force of the maxillary dentures was evaluated using the universal testing machine and the patient perception of retention, esthetics, and comfort was evaluated using the Visual Analogue Scale (VAS). Evaluation was carried out 1 day, 1 month, and 3 months after denture insertion. The Student t-test was used to compare the 2 maxillary dentures and the intervals for each denture were compared by using the ANOVA test with repeated measures followed by a Post Hoc test (adjusted Bonferroni) for pairwise comparison. RESULTS: The significance of the obtained results was judged at the 5% level (P value). The dislodging force and patient perception of retention did not show significant differences between the 2 dentures, while the perception of esthetics showed significant differences throughout the follow-up period. Perception of comfort showed an insignificant difference only at the 3-month interval. CONCLUSIONS: Open-face maxillary dentures can be a suitable alternative for patients with prominent premaxilla to achieve satisfactory retention, aesthetics, and comfort.

In vitro analysis of monomer leaching in modern dental materials: CAD milled, printed, traditional heat-processed, and auto-polymerizing denture base resins.

PURPOSE: Denture fabrication has shifted from traditional heat-processed and auto-polymerizing materials to computer-aided design and computer-aided manufacturing (CAD-CAM) milled and printed materials. The monomer in traditional materials can induce an allergic reaction in some patients. With the rise in the edentulous population and increasing demand for the fabrication of dentures, these newer materials should be studied for monomer leaching. The purpose of this study was to evaluate the ratio of residual monomer in materials being used for denture bases: CAD-milled polymethylmethacrylate (PMMA), printed denture base resin, heat-processed PMMA, and auto-polymerizing PMMA comparatively. MATERIALS AND METHODS: Milled, printed, heat-activated, and auto-polymerizing denture base specimens (n = 3 for each group, each test run three times) were fabricated according to manufacturer recommendations. Specimens were first immersed in deuterated chloroform (CDCl3), a deuterated organic solvent, to evaluate monomer leaching and to observe physical properties of the materials. NMR spectroscopy was used to evaluate the dissolution of materials and residual monomer to crosslinked polymer ratios at 1, 4, and 9 days. A second group of specimens was then immersed in deuterium oxide (D2O) to evaluate if the residual monomers would leach out of the system. The solution was then analyzed using nuclear magnetic resonance (NMR) spectroscopy for 1 month. The deuterated forms of chloroform (CDCl3) and water (D2O) were used to enable sample characterization by NMR. RESULTS: While the heat-processed, auto-polymerizing, and milled specimens possessed residual monomers, no significant monomer leaching was noted in the printed specimen, while immersed in CDCl3. Similarly, the printed specimen was most resistant to dissolution, as compared to the rest; dissolution of the specimen is indicative of little to no cross-linking. No detectable dissolution of monomer was seen when all specimens were immersed in D2O for up to 1 month. CONCLUSIONS: Residual monomers were not found in the printed denture material in this study in either CDCl3 or D2O, whereas CAD-milled and traditionally processed denture bases still have residual monomers within their respective systems when immersed in organic solvent. None of the specimens tested leached monomers into D2O.

A randomized controlled trial assessing denture adhesive efficacy on denture retention across 13 hours.

PURPOSE: To compare the effects of two denture adhesive formulations on the bite force required to dislodge a maxillary denture in adult participants during a 13-h test period. MATERIALS AND METHODS: Twenty-two participants with a fair-to-poor fitting maxillary denture opposed by natural dentition or a stable mandibular denture were enrolled in this single-center, randomized, double-blind, two-treatment, 4-period crossover study. Participants were randomly assigned a product usage sequence so that each participant used each product twice during the 4-day test period. The test product was a denture cream adhesive formulated with an optimized calcium/zinc partial salt of polyvinyl methyl ether/maleic acid (Fixodent Ultra technology); the control product was a cream adhesive formulated with a calcium/zinc partial salt of polyvinyl methyl ether/maleic acid (Fixodent Original technology). On each study day, bite force at dislodgement was measured with a gnathodynamometer at baseline, representing the "no adhesive" score. Then, after standardized product application to the participant's existing maxillary denture by site staff, bite force measurements were retaken at 1, 3, 5, 7, 9, 11, and 13 h. The change from baseline and the 13-h area under the bite-force-change-from-baseline curve were analyzed via an analysis of variance. RESULTS: Twenty-one participants completed all test periods; one additional participant completed three test periods so 22 participants were included in the analysis. There were 15 females and 7 males with a mean age of 70 years. The mean 13-h area under the bite-force-change-from-baseline curve was 8% greater (p = 0.010) for the test adhesive (114.3 lb) than for the control adhesive (105.9 lb). Both adhesives showed a statistically significant increase in bite force (p < 0.001) at each time point compared to no adhesive. CONCLUSIONS: The optimized calcium/zinc partial salt of polyvinyl methyl ether/maleic acid test adhesive provided superior maxillary denture retention relative to that of the control adhesive across 13 h. Both adhesives increased bite force at dislodgement compared to no adhesive.

Clinical evaluation of removable partial dentures with digitally fabricated metal framework after 4 years of clinical service.

This case report describes the clinical outcomes of three patients who received removable partial dentures with a completely digitally designed and manufactured metal framework. The initial intraoral impressions were prepared, and the resulting standard tessellation language files were sent to a dental laboratory, where the alloy framework was designed using inLab software and printed using a 3D printer or milled directly from a Co-Cr disc. The quality of fit of the framework was evaluated intraorally to confirm the laboratory design. The acrylic teeth were set, and the definitive partial dentures were delivered after the acrylic resin bases were processed. The follow-up time was 4 years. No complications or failures related to the components of the partial dentures were observed.

Reinforcement of 3D-printed resins for denture base by adding aramid fibers: Effect on mechanical, surface, and optical properties.

PURPOSE: The present study evaluated the mechanical, surface, and optical properties of 3D-printed resins for removable prostheses reinforced by the addition of aramid fibers. MATERIALS AND METHODS: According to ISO 20795-1:2013 standards, specimens were printed using a digital light processing 3D printer and divided into two groups (n = 06/group): 3D-printed resin for denture base as the control group, and a group with the same 3D-printed resin in addition of 5% aramid fibers as the experimental group. Red aramid fibers were chosen for aesthetic characterization. The specimens were evaluated for their mechanical properties, such as elastic modulus (GPa), flexural strength (MPa), and superficial properties by their surface microhardness (KHN), surface roughness (µm), and surface free energy (mJ/m2). Optical properties were evaluated by the color difference (∆E00) between groups. The statistical test chosen after the exploratory analysis of the data was One-way ANOVA followed by Tukey's HSD (α = 0.05). RESULTS: The results showed statistical differences in elastic modulus (p < 0.0001), flexural strength (p < 0.0001), surface free energy polar variable (p = 0.0322), total surface free energy (p = 0.0344), with higher values for the experimental. Surface hardness and surface roughness showed no statistical difference (p ≥ 0.05). The color difference (∆E00) obtained through the CIEDE2000 calculus was below the perceptibility threshold (≤1.1). CONCLUSION: Adding aramid fibers to 3D-printed resin for denture bases resulted in better mechanical properties, without major alterations in surface properties. In addition, it is an easy-to-apply choice for mechanical reinforcement and aesthetic characterization, with the expression of small blood vessels in the 3D-printed resin for removable denture bases.