Search Results (58)

Polymers are essential materials in the fabrication of partial and complete dentures, where their mechanical properties directly impact durability, comfort, and clinical performance. This study examines the influence of different manufacturing temperatures on the surface hardness of polymeric materials used in dental applications. A total of 60 experimental samples with a rectangular shape of Vertex ThermoSens polymer (Vertex Dental, 3D Systems, Soesterberg, The Netherlands) were fabricated through injection molding at 280 °C and 300 °C and analyzed over time to assess changes in their properties. Hardness measurements, conducted using the EQUOTIP Shore D hardness tester (Proceq SA, Schwerzenbach, Canton of Zürich, Switzerland), indicated increased hardness over time, with higher values observed in samples fabricated at 300 °C. A two-way ANOVA was performed to evaluate the statistical significance of temperature and time on hardness, revealing a significant effect (F = 14.73, p = 0.0185). These findings suggest that processing polymers at elevated temperatures improves surface hardness, significant for denture longevity and patient comfort. Increased hardness contributes to greater wear resistance. Optimizing polymer manufacturing conditions can thus lead to improved clinical outcomes, ensuring more durable and biocompatible dental prostheses. Full article

Background: The rapidly growing elderly population in Sri Lanka faces multiple challenges, including the ill effects of tooth loss. Tooth loss and denture wear could both affect the amount and variety of food intake of the elders, leading to a state of compromised health. Therefore, it is essential to identify whether both tooth loss and denture wear affect the nutritional status of the elderly. This study evaluated the associations between tooth loss, denture-wearing status, and nutritional levels among a sample of the elderly population attending the Dental Teaching Hospital in Peradeniya, Sri Lanka. Methods: An analytical cross-sectional study was carried out at the Dental Teaching Hospital in Peradeniya, Sri Lanka. Using the G*Power v3.1 statistics software, a sample size of 61 patients aged 60 years and above was determined as the minimum sample size. Data were gathered by means of a self-administered questionnaire, patients’ files, and an examination to identify height and weight for assessing body mass index (BMI). Minitab v18.0 statistical software was used for analysis of data, and a p-value < 0.05 was considered statistically significant. Results: One hundred patients were recruited for this study, and the majority (sixty-seven) were female. The majority (71%) were between the ages of 60 to 69 years. The majority (60%) were denture wearers and 8% had nine or more occluding pairs (of natural teeth), 25% had five to eight, and 67% had four or fewer occluding pairs. Fifty-two percent (52%) were of normal weight, while 40% were over-weight and 8% were underweight, respectively. No statistically significant associations were identified between BMI and the denture status or number of missing teeth (p-values > 0.05). There were no statistically significant associations between the underweight or overweight status and denture wearing or occluding pairs (p-values > 0.05). However, the frequency of grain intake and the number of occluding pairs were significantly associated with each other (p-value = 0.024). Also, the frequency of taking snacks was associated with denture wearing (p-value = 0.006). Conclusions: The nutritional status (BMI) of the elderly does not necessarily correlate with their denture-wearing status or the number of existing occluding pairs/number of missing natural teeth. There is no significant association noted between the denture-wearing status and the food avoidance (soft, hard food, fruits, and grains, except snacks). There is no significant association between the number of occluding pairs available in natural dentition and the avoidance of soft foods or snacks, except for grains. Given the limitations of this study, it can be suggested that nutritional strategies for the elderly population could be designed universally, irrespective of their dentate or denture status. However, further research with a larger cohort is needed to validate these findings. Full article

Background: Mandibular movement is inherently complex, involving both lateral and vertical components. In older adults, this complexity is compounded by diminished neuromuscular coordination and reduced proprioceptive feedback, often impairing effective mastication. Objectives: This study aimed to review dental literature on the influence of masticatory parameters in the formation of wear facets on acrylic resin denture teeth. Methods: A targeted literature review was conducted, analyzing peer-reviewed studies from 1991 to 2024 through PubMed and Scopus. The review focused on masticatory parameters, age-related neuromuscular adaptations, chewing patterns, and preferred-side denture tooth wear, affecting older adults using complete removable dentures. Results: Mandibular movement characteristics—particularly velocity, duration, and cycle frequency—were found to significantly influence denture tooth wear, often resulting in reduced bite force and masticatory efficiency. Contemporary denture materials demonstrated improved wear resistance, aiding in the regulation of chewing frequency and velocity. These factors are increasingly important as age-related changes impact the stomatognathic system. Notably, wear facets were most prominent on the maxillary first molars, regardless of the occlusal scheme. Conclusions: This review provided a comprehensive overview of existing research, analyzed current evidence, and offered insights into the role of masticatory function and wear characteristics in older complete denture wearers. Full article

Background: Mucostatic impressions have been always indicated in thin, sharp, or flabby ridges, and have been addressed for their beneficial effect on long-term residual ridge stability. Nonetheless, a purely mucostatic impression was not possible until intraoral scans became available. This provides an option for digital removable denture which is biologically sensible but might reduce retention in comparison with a mucocompressive impression with border molding. On the other hand, pressure applied to the mucosa may have harmful effects on the long-term residual ridge stability, causing higher resorption and ultimately reduced denture retention. Hence, the possibility to merge mucostatics and mucocompressive philosophies would be a clinically and biologically sensible option for oral rehabilitation in aging populations where patients will potentially wear dentures for longer periods. This possibility is demonstrated in this technical report with a cast-free digital workflow. Technique: Baseplates for occlusion rims, closely adapted to the mucosa, were designed on intraoral scans of edentulous arches and, once 3D-printed, used to register maxillomandibular relations and information for tooth arrangement, as well as to perform border molding. Occlusion rims were then scanned and, within the 3Shape Dental System 2024 software program, the intaglio surfaces of their baseplates were segmented and inverted to obtain the digital master casts which incorporated the precise reproduction of the molded borders. Then, denture design was performed and manufactured; no limitations regarding manufacturing options are applicable to the presented technique. Conclusions: The potential benefits (i.e., improved retention in the initial period after denture delivery and the preservation of tissues) of the presented digital cast-free workflow, based on merging mucostatic and mucocompressive philosophies to obtain dentures with a mucostatic intaglio surface and functional borders, are sensible clinical outcomes which recommend the clinical application of the technique, although further validation, especially in the long term, is required. Full article

The aim of these in vitro studies was to determine and compare the mechanical and tribological performance of two commercially available thermoplastic materials, namely BioHPP and Biocetal, used in dental prosthetics. In order to perform the comparative tests of both materials, the dog-bone shaped samples were formed by an injection molding process as in standard polymer materials research, wherein Biocetal samples constituted the research group, and BioHPP samples served as a control group. In the presented studies, their mechanical parameters were reported and analyzed: namely, Shore’s hardness, unnotched impact strength, tensile strength, flexural strength, as well as abrasive wear resistance, obtained within appropriate tribological and mechanical tests. The Shapiro–Wilk test, Q–Q plot analysis, Grubbs test and Student’s t-test (p < 0.05) were used to statistically evaluate the results. The experimental results revealed that BioHPP material is characterized by higher hardness, impact strength, bending strength, and also lower “wet” abrasion wear if compared to Biocetal performance. However, it is subject to higher abrasive wear under “dry” conditions and reveals higher stiffness as well as lower ability to deform, which could affect a patient’s comfort during application. BioHPP, despite being a high-performance polymer material, also has some drawbacks that may affect the poorer long-term use of dentures in people producing less saliva. Full article

Background and Clinical Significance: Denture stomatitis is a clinical manifestation of oral candidiasis, often seen in individuals wearing removable dentures that lead to the formation of sub-prosthetic stomatitis. This is particularly common in maladjusted appliances that have been in use for many years. Studies have shown that patients with systemic diseases such as diabetes, or other medical complexities, have a higher likelihood of developing denture stomatitis. To address this problem, the use of implant-retained dentures with different types of attachments has been introduced, providing increased comfort and hygiene for edentulous patients. However, this solution is not without its own set of challenges, being that the prolonged contact with mucosal surfaces can lead to challenges in cleaning and managing plaque depending on the attachment. Case Presentation: In this clinical case report, we present a female patient who developed bar-retained prosthetic stomatitis induced by oral candidiasis a few months after receiving her provisional prosthesis. Conclusions: In conclusion, this case report emphasizes the need to consider both systemic and local factors when preventing and treating denture stomatitis. By understanding the risk factors involved, healthcare professionals can provide their patients with the best possible care, helping to reduce the prevalence of oral candidiasis in individuals who use implant-retained dentures. Full article

Objective: This randomized, single-blind controlled study aimed to investigate the QoL and satisfaction of patients wearing complete dentures with lingualized (LO) and bilaterally balanced occlusion (BBO). Participants were stratified based on their prior experience with complete dentures. Methods: The study involved 131 complete denture wearers who were categorized into four groups: G1—first-time prosthesis wearers treated with LO (n = 33); G2—first-time prosthesis wearers treated with BBO (n = 31); G3—participants with prior prosthesis experience treated with LO (n = 34); G4—participants with prior prosthesis experience treated with BBO (n = 33). After wearing the prosthesis for one month, all participants completed the Oral Health Impact Profile (OHIP-14) questionnaire. A statistical analysis was conducted using the χ² test, Kruskal–Wallis analysis and Mann–Whitney test, with significance determined at p < 0.05. Results: After dividing the respondents into two groups, a statistically significant difference was observed in the distribution of scores for three questions related to oral pain severity, anxiety, and difficulty relaxing. However, the distribution of scores for all other questions did not show a statistically significant difference between the groups studied (p < 0.05). The total OHIP-14 score was also not statistically different (z = 0.469; p = 0.639). However, when respondents were divided into four groups, the median score for first-time denture wearers was 3.9 points higher in respondents who received dentures with BBO compared to those with LO (p < 0.001). Furthermore, the median score for first-time denture wearers who received BBO was higher than for those in the second group who received BBO (p = 0.013). Conclusion: Patients wearing complete dentures for the first time demonstrated significantly higher satisfaction with the LO scheme compared to the BBO scheme. In contrast, satisfaction levels between occlusal schemes did not significantly differ among patients with prior denture-wearing experience. Novice denture wearers reported heightened sensations of oral discomfort, anxiety, and difficulty relaxing regardless of the occlusal scheme compared to experienced wearers, likely due to the unrealistic expectations that first-time wearers often have about complete dentures. Full article

Background: Complete dentures should withstand occlusal forces and wear. However, over time, dentures can suffer fatigue and develop cracks, chipping, and fractures. Conventional methods for the fabrication of complete dentures involve injection molding, thermal curing, and the use of microwaves with polymethyl methacrylate (PMMA)-based materials. These methods have served well for many years. More recently, the incorporation of computer-aided design and computer-aided manufacturing (CAD/CAM) to fabricate complete dentures has been shown to enhance the dentures’ mechanical properties, including resistance to wear and impact strength. This study aims to investigate the mechanical properties and fracture types of CAD/CAM denture base materials (both milled and printed) as compared to a novel proprietary method that embeds a 3D-printed framework within PMMA-milled blocks. The null hypothesis is that incorporating a 3D-printed framework does not affect the mechanical properties of milled PMMA blocks. Methods: Three groups of bars were fabricated using CAD/CAM methods: printed (P), milled (M), and milled with a 3D-printed metallic framework reinforcement (M + F). A three-point bending test evaluated deformation, followed by an impact fracture test for fracture toughness. A descriptive fractographic analysis assessed the fracture characteristics. A statistical analysis using a paired t-test compared the differences between the groups. Results: The P group showed more elastic deformation than the M and M + F groups (p < 0.05). The M + F group achieved a higher fracture toughness as compared to the M and P groups (p < 0.05). Conclusions: Within the limitations of this experimental study, the null hypothesis can be rejected. Milled samples with an embedded 3D-printed titanium framework possess higher resistance to impact than milled samples without frameworks, and printed samples and milled samples with embedded 3d-printed titanium frameworks present increased flexural strength and lower elastic deformation as compared to milled samples without frameworks and printed samples. Full article

Removable denture wearers are at an increased risk of developing periodontal diseases due to biofilm deposition and microbial colonization on the denture surface. This study aimed to characterize and compare the metagenomic composition of saliva in denture wearers with different periodontal statuses. Twenty-four community-dwelling elders were recruited and grouped into denture wearers with active periodontitis (APD), non-denture wearers with active periodontitis (APXD), denture wearers with stable periodontal health conditions (SPCD), and non-denture wearers with stable periodontal health conditions (SPCXD). Saliva samples were collected and underwent Type IIB restriction-site-associated DNA for microbiome (2bRAD-M) metagenomic sequencing to characterize the species-resolved microbial composition. Alpha diversity analysis based on the Shannon index revealed no significant difference between groups. Beta diversity analysis using the Jaccard distance matrix was nearly significantly different between denture-wearing and non-denture-wearing groups (p = 0.075). Some respiratory pathogens, including Streptococcus agalactiae and Streptococcus pneumoniae, were detected as the top 30 species in saliva samples. Additionally, LEfSe analysis revealed a substantial presence of pathogenic bacteria in denture groups. In the cohort of saliva samples collected from community-dwelling elders, a remarkable abundance of certain opportunistic pathogens was detected in the microbial community. Full article

Background: The improvement of oral-health-related quality of life (OHRQoL) with different types of prosthesis for completely edentulous jaws in the elderly population is a critical factor in clinical decision making for these vulnerable patients. This review aims to evaluate the changes in OHRQoL after treatment with different types of full-arch prostheses in the elderly edentulous population to determine the prostheses that result in the greatest improvement in OHRQoL. Materials and Methods: Clinical studies of different types of full-arch prostheses that measured the OHRQoL in edentulous patients 60 years or older were searched for in the PubMed, Embase and Scopus electronic databases, with additional hand searching to summarize the outcomes of the selected studies. Result: Among the 302 identified studies, 10 studies were selected. A total of 504 patients wearing 133 complete dentures, 372 implant overdentures and 39 fixed prostheses were assessed among the selected studies. The overall OHIP and GOHAI scores were evaluated at baseline and in the 3rd, 6th, 12th and 18th months of treatment with the respective prostheses. The improved OHRQoL with overall OHIP scores associated with conventional dentures were 9.21–12.5% from the 3rd month to 1 year after treatment, whereas those associated with implant overdentures and full-arch fixed prosthesis were 9–25.26% at 1 year and 18.53–26.79 at the 18th-month follow-up, respectively. The increased overall GOHAI scores were 21.3–25.43% for conventional dentures, 36.82–41.32% for implant overdentures and 39.48–42.83% for full-arch fixed prosthesis from the 3rd month to the 6th-month follow-up. Conclusion: In general, the improvement in OHRQoL after rehabilitation with implant overdentures declined at one year, and that with full-arch fixed prosthesis declined at the 18th-month follow-up; meanwhile, the OHRQoL associated with conventional dentures improved stably up to one year, but the implant-supported prostheses resulted in an obviously greater improvement in the OHRQoL than that obtained with conventional dentures. However, studies with longer follow-up periods are still required to evaluate the long-term clinical effectiveness. Full article

Denture stomatitis (DS) is a very common disease in wearers of removable complete and partial dentures with a worldwide prevalence in the range of 20–67%. Both industrially developed and impoverished nations are affected by the illness. DS is often associated with ill-fitting dentures or a fungal infection with Candida spp. Candida is normally found in the oral cavity microbiota, but it can be harmful to the health of elderly people with underlying diseases. Therefore, the purpose of the present study is to offer the most recent information about the epidemiology, etiology, and global distribution of Candida species associated with DS through a systematic review. Several databases, including Medline, Web of Science, and Scopus, were used to conduct an extensive search of the literature published in the previous 20 years. The selection of studies was performed by two authors. The extracted data were as follows: author, year of publication, country, sample, frequency of DS, method of diagnosing stomatitis, species of Candida, risk factors, and etiology of the disease. The JBI Critical appraisal tools were used to assess the quality of the studies. Eventually, twenty-eight studies were included in the systematic review. Twenty-one studies investigated DS, while seven studies examined Candida colonization in patients using removable dentures. The results show that the main causes of DS include the type of dentures, continuous wearing of dentures, and the formation of a Candida biofilm, which is facilitated by poor dental hygiene. Additionally, previous studies have pinpointed the significance of the salivary flow, saliva composition, and salivary pH. The findings of the current review indicate that it is crucial to monitor denture wearers for the appearance of DS, especially the patients whose immunity has been impaired due to a systemic condition. Finally, frequent follow-ups should include a clinical examination and microbial swabs of the palatal mucosa and the mucosal surface of the denture. Full article

The purposes of this study are to establish and validate a finite element (FE) model using finite element analysis methods and to identify optimal loading conditions to simulate masticatory movement. A three-dimensional FE model of the maxillary and mandibular cortical bone, cancellous bone, and gingiva was constructed based on edentulous cone-beam-computed tomography data. Dental computer-aided design software was used to design the denture base and artificial teeth to produce a complete denture. Mesh convergence was performed to derive the optimal mesh size, and validation was conducted through comparison with mechanical test results. The mandible was rotated step-by-step to induce movements similar to actual mastication. Results showed that there was less than a 6% difference between the mechanical test and the alveolar bone-complete denture. It opened 10° as set in the first stage, confirming that the mouth closed 7° in the second stage. Occlusal contact occurred between the upper and lower artificial teeth as the mouth closed the remaining angle of 3° in the third stage while activating the masseter muscle. These results indicate that the FE model and masticatory loading conditions developed in this study can be applied to analyze biomechanical effects according to the wearing of dentures with various design elements applied. Full article

Symptoms of oral discomfort such as dry mouth are common in older people wearing dentures. Such symptoms are mainly treated symptomatically. Many of these symptoms are related to saliva, and associations with salivary volume have been reported. Although denture treatment improves symptoms by increasing the amount of saliva, the effects on salivary components remain unclear. This study aimed to investigate the effects of denture treatment on salivary metabolite changes based on salivary metabolome analyses. We enrolled 21 patients requiring denture treatment. At the first visit, and after completion of denture treatment, saliva outflow was measured under resting and stimulated conditions, samples for salivary metabolite analysis were collected, and masticatory efficiency was tested. In all participants, masticatory efficiency increased after denture treatment. Moreover, the amounts of resting and stimulated saliva were increased. Using salivary metabolome analysis, 61 salivary metabolites were detected. Substantial concentration changes were observed for 4 and 21 metabolites in resting and stimulated saliva, respectively. The four metabolites common to both saliva tests had significantly lower concentrations after treatment. These results suggest that the improvement in masticatory function by dentures is related not only to salivary secretion volume, but also to salivary metabolite composition. Full article

This study aimed to investigate the association between denture use, chewing ability, and cognitive function in Korean middle-aged adults, using samples representing middle-aged people at the national level. This longitudinal study included 9998 middle-aged adults using the Korea Longitudinal Study of Aging 7th special survey data. Denture use, chewing ability, health-related factors, and general characteristics were assessed using the Computer-Assisted Personal Interview. After controlling for general characteristics using a generalized estimating equation model, the association of denture use and Mini-Mental State Examination (MMSE) scores with the chewing ability of those with or without dentures and MMSE scores were analysed. Among them, 24% of participants wore dentures, and 35.1% complained of difficulty chewing when wearing dentures. Among the participants who did not wear dentures, 16.4% complained of difficulty chewing. MMSE scores were lower among denture wearers than non-denture wearers (β = −0.026, p < 0.001). In both groups, MMSE scores decreased with chewing difficulty and were significantly reduced among non-denture wearers (p < 0.05). Chewing ability was closely associated with cognitive functioning. Therefore, in order to prevent cognitive decline, chewing discomfort while wearing dentures must be eliminated, and oral health must be maintained. Full article

Background: Exhaled nitric oxide is helpful in the diagnosis of the inflammation process. The study aimed to analyze the impact of the COVID-19 disease on the oral bacterial flora of patients using complete dentures with a diagnostic device that measures the level of NO in exhaled air. Materials and Methods: The study included patients using upper and lower acrylic complete dentures. All patients participating in the study were vaccinated against COVID-19. The patients were divided into two groups. A dental examination was conducted in each group. The NO concentration was measured using the Vivatmo Pro device. An oral microbiological examination was performed by taking a swab from the bottom of the mouth. Results: There were no statistically significant differences in the distribution of NO in relation to the number of bacteria from isolated families in the study and control groups and no statistically significant correlations between the level of NO and the number of bacteria from all families in the control and study group. Significantly higher NO values were present in the vaccinated and COVID-19-positive history population compared to the vaccinated and with no COVID-19 history population (patients with no clinical symptoms of infection or unaware they had COVID-19). Conclusions: There are statistically significant differences in NO distribution in the considered populations: vaccinated and sick, and vaccinated and with a negative history of COVID-19. The measurement of NO in exhaled air can be a complementary, non-invasive diagnostic and inflammation monitoring method. Full article