Will there be a need for complete dentures in the United States in 2020?

Comparison of Implant-Retained Overdenture and Conventional Complete Denture: A Survey Study to Measure Patients' Satisfaction and Quality of Life in Dental School Clinics

Patient satisfaction and quality of life are integral to assessing oral health care quality. For many Americans still using conventional complete dentures (CDs) or implant-retained mandibular overdentures (IODs), it remains essential to consider improving their oral health outcomes and quality of life. Due to inexperienced student dentists providing dental care to dental school patients, patient grievances are generally considered a problem. Patient feedback and satisfaction have proven valuable resources for monitoring and improving patient safety. While CDs and IODs are the 2 leading treatment options for edentulism, more comparative studies in the literature need to compare their outcomes in a school setting. The research question that guided this comparative analysis was, "Is patient satisfaction and quality of life affected by the type of prostheses and provider?" A validated questionnaire was mailed to 520 individuals selected from records of patients who had received treatment for edentulous mandible at a student prosthodontic clinic at the University of Kentucky College of Dentistry from 2014 to 2016 with at least 1 year of follow-up time. A validated questionnaire for edentulous patients based on the Oral Health Impact Profile (OHIP-19) was used. In addition, information on patients' oral health-related quality of life, including questions related to the edentulous patients' satisfaction with their dentures, was collected. The response rate was 33% (N = 171). The study's findings confirm previous findings, suggesting that IODs may significantly impact oral health-related quality of life. Data show that 76% of the IOD group reported improvement in experience when using the implants to retain the mandibular denture. However, there were no statistically significant differences in the OHIP scores between overall CD and IOD patient groups. Males with IODs had lower physical pain, limitations, and disability scores than males with CD. However, females with IODs reported more significant concerns associated with a social disability and handicap domains. Comparing users who had experiences with both treatment options, this study discerned essential characteristics that contribute to increased patient satisfaction with IODs and identified significance in outcomes by gender. These findings guide prosthodontic practitioners' patient care practices and identify a continuing need to discuss CD and IOD treatment protocols within dental school curricula.

Treatment planning algorithm for patients with a terminal dentition

This article discusses the variables that affect the diagnostic process in patients with a compromised dentition and addresses the clinical decision of whether to extract or maintain teeth. A decision tree algorithm is proposed to guide clinicians in planning complete arch rehabilitations.

Comparative cost-analysis for removable complete dentures fabricated with conventional, partial, and complete digital workflows

STATEMENT OF PROBLEM

Comparative cost-analysis related to different manufacturing workflows for removable complete denture fabrication is seldom performed before the adoption of a new technology.

PURPOSE

The purpose of this study was to compare the clinical and laboratory costs of removable complete dentures fabricated with a conventional (workflow C), a partial digital (workflow M), and a complete digital (workflow D) workflow and to calculate the break-even points for the implementation of digital technologies in complete denture fabrication.

MATERIAL AND METHODS

Clinical and laboratory costs for each of the investigated workflows and the manufacturing options related to denture base and denture teeth fabrication were collected from 10 private Italian dental laboratories and clinics. The selected variables included the clinical and laboratory manufacturing time needed to complete each workflow (opportunity cost); costs for materials, labor, packaging, and shipping; and capital and fixed costs for software and hardware, including maintenance fees. The effect of manufacturing workflows and their options on the outcomes of interest was investigated by using generalized estimated equations models (α=.05). Cost minimization and sensitivity analysis were also performed, and break-even points were calculated for the equipment capital costs related to the implementation of workflows M and D.

RESULTS

From a laboratory standpoint, workflows M and D and related manufacturing options significantly (P<.001) reduced manufacturing time (5.90 to 6.95 hours and 6.30 to 7.35 hours, respectively), and therefore the opportunity cost of each denture compared with workflow C. Workflow M allowed variable costs savings between 81 and 169 USD, while workflow D allowed for an additional saving of 34 USD. The sensitivity analysis showed that the break-even point related to the capital investment for the equipment needed to implement workflows M and D could be reached, depending on the manufacturing options adopted, between 170 and 933 dentures for workflow M and between 73 and 534 dentures for workflow D. From a clinical standpoint, workflows C and M were almost identical. Conversely, workflow D, which included intraoral scanning, required 1 fewer appointment, saving 0.6 hours of chairside time and about 14 USD for materials compared with M.

CONCLUSIONS

Digital workflows (partial and complete digital workflows) were more efficient and cost-effective than the conventional method of fabricating removable complete dentures, with workflow D showing the lowest opportunity and variable costs and break-even point. Savings increased when stock denture teeth were replaced with milled denture teeth and still further with the adoption of 3-dimensionally (3D) printed denture teeth. Milling equipment and materials for denture base fabrication were more expensive than those for 3D-printing. Milling monobloc dentures reduced opportunity and labor costs but increased material cost.

Prevalence of complete edentulism among US adults 65 years and older: A Behavioral Risk Factor Surveillance System study from 2012 through 2020

BACKGROUND

The rapid growth of the older adult population in the United States and their increased risk of edentulism make it essential to analyze trends and factors associated with edentulism.

METHODS

Data were obtained from the Behavioral Risk Factor Surveillance System from 2012 through 2020. US- and state-level trend lines were reported. Multiple logistic regression analyses were used to evaluate the association between self-reported complete edentulism and demographic characteristics, chronic diseases, smoking status, and health insurance status. Multiple imputations were used to address the missing data.

RESULTS

A total of 771,513 (weighted n = 50,410,576) participants were included in the study. There was a significant (P = .021) downward trend in the prevalence of edentulism from 2012 (16.36%) through 2020 (13.54%). Having less than a high school education, being a smoker, being non-Hispanic Black, having an annual household income less than $75,000, and having chronic conditions, including diabetes, myocardial infarction, arthritis, depression, and stroke, were significantly associated with complete edentulism.

CONCLUSIONS

Despite a decrease in prevalence of edentulism, disparities based on race, income, and education still exist. Edentulism is associated with chronic diseases in older adults.

PRACTICAL IMPLICATIONS

Public health initiatives should be aimed at reducing the impact of edentulism and improving overall quality of life among older adults. Community health programs allocating resources to improve access to affordable care, reducing precursors to edentulism, expanding dental coverage, and promoting oral and general health awareness are vital components of these efforts.

Psychometric properties of the Arabic version of the perceived prosthodontic treatment need scale: Exploratory and confirmatory factor analyses

BACKGROUND

It is crucial to take into account the concerns of dental patients about their prosthodontic needs when planning the course of treatment. However, there is a dearth of research that examines these needs among adult dental patients.

OBJECTIVES

This study aims to translate and validate the perceived prosthodontic treatment need scale (PPTN) in Arabic.

METHODS

The 17-item PPTN scale was translated from English into Arabic and completed by 206 patients seeking prosthodontic treatment in a dental hospital in Saudi Arabia. Data collection was carried out in September and October 2023. Exploratory factor analysis (EFA) was used to ascertain the underlying factor structure; a unidimensional scale was hypothesised and tested using confirmatory factor analysis (CFA), including several multiple model fit indices. The assessment of reliability was conducted using Cronbach's alpha. The convergent and discriminant validity of the final scale were examined.

RESULTS

EFA produced an 11-item scale distributed into three factors that explain 65.43% of the total variance with eigenvalues > 1. All items showed acceptable reliability, ranging from 0.65 to 0.84. The first factor pertained to social issues, while the second item was concerning dental appearance. Lastly, the third factor included functional difficulties associated with tooth loss or dental problems. The results of the CFA demonstrate a satisfactory level of model fit, with the standardised factor loadings ranging from 0.51 to 0.89. Convergent and discriminant validity of the model factors were established.

CONCLUSION

The translated questionnaire was deemed legitimate and would be useful in comprehending patients' perceived treatment requirements, hence contributing to the advancement of prosthodontic research and practical implementation.

Comparison and Evaluation of Fracture Toughness of Milled, 3D-Printed, and Conventional Polymethyl Methacrylate: An In Vitro Study

Introduction

Dentures aim to replicate natural dentition's esthetics and functions as much as possible. With computer-aided design/computer-aided manufacturing (CAD/CAM) technology, dentistry had a new renaissance with workflow and materials.

Aim

The aim is to compare the fracture toughness of the milled, 3D-printed, and conventional polymethyl methacrylate (PMMA) to those processed conventionally.

Materials and Methods

10 CAD MILLED PMMA BLOCKS, 10 3D PRINTED PMMA BLOCKS, and 10 CONVENTIONAL (HEAT CURE) PMMA BLOCKS.

Results

A significant difference was seen in the mean flexural module when compared among three study groups as P < 0.05. It was found to be maximum in CAD/CAM PMMA, followed by conventional heat cure and 3D-printed PMMA.

Conclusion

Formlabs and Dentca (3D-printed) were significantly weaker in fracture toughness compared to Leucitone 199 (conventional) (P < 0.05). Leucitone 199 (conventional) was significantly weaker in fracture toughness compared to Avadent (CAD CAM) (P < 0.05).

Comparison of tissue displacement in edentulous arches among three-dimensional files obtained through different impression-making methods: A retrospective study

PURPOSE

To retrospectively compare and analyze differences in tissue displacement of edentulous arches among three-dimensional (3D) files obtained using various impression-making techniques.

MATERIALS AND METHODS

Fourteen patients who underwent prosthodontic treatment for edentulous arches at Yonsei University Dental Hospital between June 2020 and April 2023 were included in the study. Three types of 3D files were used for the evaluation of each arch: a 3D scan file of a definitive cast (Group DEF), a preliminary cast (Group PRE), and an intraoral scan file (Group IOS). The files were superimposed on a reference 3D scan file of the definitive cast group through best-fit matching using metrology software. Seventeen measurement points (MP1-4, RC1-6, TB1-2, and PPS1-5 for the maxilla and RP1-2, RC1-7, BS1-4, and LS1-4 for the mandible) were selected for both the maxillary (n = 13) and mandibular arches (n = 6). The deviation considering the direction (DD) between the three groups and the absolute deviation (AD) between the three groups were recorded. Kruskal-Wallis and post-hoc Mann-Whitney tests were used for statistical analyses (α = 0.05 and α = 0.0167, respectively).

RESULTS

Concerning the DD values, at the RC4 point of the maxillary arch, Group PRE exhibited significantly higher values than Groups IOS (p = 0.006) and DEF (p < 0.001), and at the RC5 point of the maxillary arch, Group IOS exhibited significantly lower values than Groups PRE (p = 0.016) and DEF (p < 0.001). Group IOS showed significantly lower DD values in the mandibular arch than Group DEF at the RP2 and RC3 points (p < 0.167). The AD values in Groups PRE and IOS significantly differed from those in Group DEF (all p < 0.001) at all measurement points but did not exhibit significant differences between each other (p > 0.05).

CONCLUSIONS

Different impression-making methods yielded different amounts of tissue displacement. The tendency of 3D files regarding tissue displacement varied at certain residual ridge crest areas and retromolar pad areas. The absolute amount of tissue displacement observed in the intraoral scan data was comparable to that observed in the preliminary casts.

Effects of denture adhesives on denture retention and occlusal forces in complete denture wearers: A multicenter, randomized controlled trial

PURPOSE

This study aimed to determine the effects of denture adhesives on denture retention and occlusal force in complete denture wearers in a multicenter, randomized, parallel-group controlled trial.

METHODS

Two hundred edentulous patients wearing complete dentures were allocated to three groups: powder-type denture adhesive, cream-type denture adhesive, and control (saline solution). Denture adhesives and saline solution were applied to the dentures for 4 days. The retentive force of the dentures and occlusal force were measured using a force transducer occlusal force meter at baseline and after 4 days of intervention. In addition to between-group comparisons, subgroup analyses of denture retention and occlusal force were performed based on the level of difficulty of the edentulism treatment. The levels were ranked as I (easy), II, III, and IV (difficult).

RESULTS

Cream-type denture adhesives significantly improved the retentive force of the dentures (P<0.01) and occlusal force (P<0.05), with no significant differences between baseline and post-intervention forces in the powder-type denture adhesive and control groups. In within-group comparisons, cream-type denture adhesives improved both the retentive and occlusal forces at Level II (P<0.05), and powder-type denture adhesives improved the occlusal force at Level II (P<0.01).

CONCLUSIONS

Application of cream-type denture adhesives effectively improves the denture retention and occlusal force in complete denture wearers with a moderate degree of difficulty during edentulism treatment.

Reliability of Cone Beam Computed Tomography in Predicting Implant Treatment Outcomes in Edentulous Patients

Since the development of CBCT has been utilized in dentistry, the images of the CBCT can assist the surgeon to evaluate the anatomy carefully. Despite the value of radiology evaluation, implant procedures may require additional consideration rather than only evaluating the anatomical factors. The purpose of this study is to evaluate the predictability of using CBCT alone to plan for implant placement in edentulous patients digitally. CBCT images were analyzed by clinicians, measuring the maxillary and mandibular ridge heights and widths digitally of four predetermined implant sites in the maxillary and two selected implant sites in the mandibular arches of 91 patients planning for implant-supported overdenture. A total of 47 patients out of the 91 had completed implant placement on the edentulous ridge, contributing to 55 upper and/or lower arches (136 dental implants). Both predictabilities are low, implying that CBCT planning for implant placement on the edentulous ridge is not a good index and is insufficient to predict the surgical procedures as a solo method. The findings of this study indicate that digital planning by CBCT is insufficient to serve as an individual tool to predict implant procedures. Further information and evaluation must be considered for implant placement in the edentulous ridge.

Titanium versus zirconia complete arch implant-supported fixed prostheses: A comparison of plaque accumulation

STATEMENT OF PROBLEM

Complete arch implant-supported zirconia prostheses appear to have less plaque accumulation than titanium prostheses, but a comparison of the materials and the possible influence on the adjacent soft tissue is lacking.

PURPOSE

The purpose of this clinical study was to compare the plaque accumulation and soft-tissue inflammation of complete arch implant-supported fixed maxillary prostheses fabricated with either a titanium framework or monolithic zirconia.

MATERIAL AND METHODS

Twenty participants with a complete arch implant-supported fixed maxillary prosthesis were enrolled in the study. The participants were divided into 2 groups according to the prosthesis material, titanium (Ti) or zirconia (Zir). The prosthesis had to have been in function for at least 6 months, and participants were examined during at least 3 maintenance appointments at 3-month intervals. Clinical information collected in each appointment included standardized photographs to record the Plaque Area Index (PAI) of the intaglio surface of the prosthesis; clinical parameters including modified Plaque Index (mPI), modified Bleeding Index (mBI), implant mobility (MOB), probing depths ≥5 mm (PD), suppuration (SUP), keratinized tissue band ≥2 mm (KT), and an intraoral photograph of the maxillary arch without the prosthesis to evaluate the redness of the soft tissues.

RESULTS

MOB was not present at any implant at any time point. SUP could not be analyzed because it was an infrequent finding. Both groups exhibited significant increases in mBI over time. No significant differences were observed for PD between the groups at any time point. Implants in the Ti group had significantly higher KT values than those in the Zir group; levels remained constant over time for both groups. Zirconia prostheses had slightly lower PAI levels than Ti prostheses. The PAI in the Zir group significantly decreased over time (P=.035); in the Ti group, they remained constant (P=.45). Higher PAI levels were correlated with increased levels of erythema; both groups had a significant decrease in erythema values over time (P=.04).

CONCLUSIONS

Zirconia complete arch implant-supported fixed maxillary prostheses displayed a significant decrease in plaque accumulation in individuals who had received periodic maintenance and oral hygiene instructions. Ti prostheses had significantly higher plaque levels than zirconia prostheses at all time points, which was not reduced by maintenance and oral hygiene measures. The present study suggests that patients receiving zirconia prostheses respond well to plaque control measures, while plaque control for those with titanium prostheses may be more challenging.

Detection of extracranial and intracranial calcified carotid artery atheromas in cone beam computed tomography using a deep learning convolutional neural network image segmentation approach

OBJECTIVE

We leveraged an artificial intelligence deep-learning convolutional neural network (DL CNN) to detect calcified carotid artery atheromas (CCAAs) on cone beam computed tomography (CBCT) images.

STUDY DESIGN

We obtained 137 full-volume CBCT scans with previously diagnosed CCAAs. The DL model was trained on 170 single axial CBCT slices, 90 with extracranial CCAAs and 80 with intracranial CCAAs. A board-certified oral and maxillofacial radiologist confirmed the presence of each CCAA. Transfer learning through a U-Net-based CNN architecture was utilized. Data allocation was 60% training, 10% validation, and 30% testing. We determined the accuracy of the DL model in detecting CCAA by calculating the mean training and validation accuracy and the area under the receiver operating characteristic curve (AUC). We reserved 5 randomly selected unseen full CBCT volumes for final testing.

RESULTS

The mean training and validation accuracy of the model in detecting extracranial CCAAs was 92% and 82%, respectively, and the AUC was 0.84 with 1.0 sensitivity and 0.69 specificity. The mean training and validation accuracy in detecting intracranial CCAAs was 61% and 70%, respectively, and the AUC was 0.5 with 0.93 sensitivity and 0.08 specificity. Testing of full-volume scans yielded an AUC of 0.72 and 0.55 for extracranial and intracranial CCAAs, respectively.

CONCLUSION

Our DL model showed excellent discrimination in detecting extracranial CCAAs on axial CBCT images and acceptable discrimination on full-volumes but poor discrimination in detecting intracranial CCAAs, for which further research is required.

Survival analysis of zirconia implant-supported, fixed complete dentures: A 5-year retrospective cohort study

STATEMENT OF PROBLEM

Existing data on the mid-term to long-term survival rates of zirconia implant-supported, fixed complete dentures (Zir-IFCDs) are lacking.

PURPOSE

The purpose of this retrospective clinical study was to assess the prosthetic survival rate in patients treated with Zir-IFCDs.

MATERIAL AND METHODS

The patient record system at the Dental College of Georgia (DCG), Augusta University was searched to identify all patients treated with Zir-IFCDs from 2015 through 2022 by the DCG graduate prosthodontic, general practice residency, and Advanced Education in General Dentistry (AEGD) programs. Reasons for replacement were grouped as failure of veneering porcelain, framework fracture, implant loss, patient-driven concerns, excessive occlusal wear, and other.

RESULTS

A total of 67 arches were found that met the inclusion criteria, 46 maxillary and 21 mandibular. The median follow-up time was 8.5 months (interquartile range, 2.7 to 30.9 months). A total of 9 of the 67 arches were identified as having failed (4 maxillary, 5 mandibular), requiring replacement. Reasons for failure were as follows: 3 framework fractures, 2 implant losses, 2 patient-related concerns, 1 fracture of veneering porcelain, and 1 unknown. The combined survival rate (Kaplan-Meier, log-normal modeling) for Zir-IFCDs was 88.8% at 1 year and 72.5% at 5 years CONCLUSIONS: Based on the findings, the Zir-IFCDs investigated had a survival rate lower than that reported in similar studies, though higher than published results for metal-acrylic resin-IFCDs. The most common source of failure was fracture of the zirconia framework. Thickness of the zirconia framework, interocclusal space, cantilever length, occlusal force, and status of the opposing dentition may have been associated with framework failures and should be investigated further.

The Use of Zirconia for Implant-Supported Fixed Complete Dental Prostheses: A Narrative Review

The success of implant-supported fixed complete dental prostheses (ISFCDPs) depends on multiple factors: some are related to the fixtures, such as fixture material, surface characteristics, positioning, and type of connection to prosthetic components; others are related to the prostheses, such as design and materials used. Zirconia is a material widely used in fixed prosthodontics, whether on natural teeth or on implants, with excellent results over time. Regarding the use of zirconia for ISFCDPs, the 2018 ITI Consensus Report stated that "implant-supported monolithic zirconia prostheses may be a future option with more supporting evidence". Since CAD/CAM technology and zirconia are being continuously innovated to achieve better results and performances over time, a narrative review of the literature seems necessary to focus research efforts towards effective and durable solutions for implant-supported, full-arch rehabilitations. The objective of the present narrative review was to search the literature for studies regarding the clinical performance of zirconia-based ISFCDPs. According to the results of this review, the use of zirconia for ISFCDPs showed good clinical outcomes, with high survival rates ranging from 88% to 100% and prosthetic complications that were restorable by the clinicians in most cases.

The Single Midline Implant in the Edentulous Mandible-Current Status of Clinical Trials

The single midline implant in the edentulous mandible is a treatment concept that has often been controversially discussed. Nearly 30 years ago, the first available clinical results revealed high implant survival rates and remarkable improvements in oral comfort, function, patient satisfaction and oral health-related quality of life for edentulous patients compared to the situation with no implant. However, the clinical trials were predominantly conducted with a small number of patients over a short to medium follow-up period. Today, numerous clinical investigations on the single midline implant in the edentulous mandible, which increasingly include longer-term observation periods, are available. It is the aim of this overview to present the current literature and to highlight the clinical problems. This article is a 2023 update of a review published by the authors in the German language in 2021 in the German journal Implantologie. In total, 19 prospective clinical trials with a follow-up period of 0.5-10 years were analyzed. Over this observation period, single implants with modern rough implant surfaces in the edentulous mandible reveal high implant survival rates of between 90.9 and 100% when a conventional delayed loading protocol was applied.

Interdisciplinary Education and Health Care in Geriatric Dental Medicine

Geriatric patients are more likely to have multiple medical comorbidities, physical limitations, and mental impairments that warrant careful consideration while providing patient care. Dentistry, along with other health care professional programs, incorporate interprofessional education (IPE) experiences to provide students with skills they need to deliver collaborative care in their future practice. Health professional programs should consider geriatric training in simulated learning environments, adult day programs, nursing homes, long-term care facilities, and home care experiences to provide students valuable IPE experiences. Lastly, this article presents a call to action for professional organizations to consider offering continuing education courses in IPE.

Effect of adding a hard-reline material on the flexural strength of conventional, 3D-printed, and milled denture base materials

STATEMENT OF PROBLEM

Novel 3-dimensionally printed resin and milled polymethyl methacrylate materials have been marketed for computer-aided design and computer-aided manufacturing (CAD-CAM) denture base fabrication. However, information on the flexural strength of digitally fabricated denture base material is limited, and little is known about how they are affected by a hard-reline procedure.

PURPOSE

The purpose of this in vitro study was to assess the flexural strength of 6 digitally manufactured denture base materials and to assess the effect of a hard-reline procedure on their flexural strength.

MATERIAL AND METHODS

A total of 140 strips of denture base material were fabricated from a conventional heat-polymerized polymethyl methacrylate (L199), 3 brands of milled polymethyl methacrylate (IBC, DSL, and ADH), and 3 brands of 3D-printed resin (DFD, ADB, and DrFD) (n=20). Ten specimens in each group did not receive any treatment, and 10 were relined with a hard-reline material (ProBase Cold Trial Kit). Specimens were then subjected to a 3-point flexural strength test using a universal testing machine at a crosshead speed of 5.0 mm/min. A 1-way ANOVA test followed by the Tukey multiple comparison test was used to detect the difference in flexural strength and the strain at fracture of the different types of denture base materials (α=.05). The comparison of flexural strength between with and without hard-reline was analyzed using an unpaired t test (α=.05).

RESULTS

All materials, with or without the hard-reline, met the International Organization for Standardization (ISO) 20 795-1:2013 standard for flexural strength (65 MPa). The milled materials (DSL>IBC≈ADH) showed higher flexural strength than the 3D-printed or conventional materials (DrFD>DFD≈ADB≈L199) without a hard-reline. No statistical difference in flexural strength was found among the hard-relined denture base materials (P=.164). All 3 milled materials showed reduced flexural strength after relining, while the relined conventional (L199) and 3D-printed materials (DFD and ADB) showed notably higher flexural strength; printed DrFD showed no significant difference (P=.066). In terms of strain at fracture, the milled materials displayed higher values than those of the conventional or 3D-printed materials (P<.05).

CONCLUSIONS

All digitally fabricated denture base materials were within acceptable limits for clinical use, even after hard relining. Flexural strength was highly dependent on the type of material. Hard relining affected the flexural strength of most of the digitally fabricated denture base materials.

Introducing dental students to complete denture treatment in times of COVID-19: Students' responses

OBJECTIVES

The COVID-19 pandemic required changes in the complete denture courses to comply with lock-in and social distancing requirements. The objectives were to assess (a) dental students' interest in a required complete denture course and the prosthodontics specialty, (b) how much time students spent on studying background, lab, and clinical content, and (c) how difficult and helpful course components were. Additionally, open-ended responses concerning what the students liked and what they wanted to have changed were analyzed as well.

METHODS

After this "complete denture" course, 81 of 109 students responded to a web-based survey with questions about course content and design. This hybrid course consisted of weekly asynchronous virtual lectures, in-person simulated laboratory (sim lab) exercises, and synchronous virtual workshops.

RESULTS

Exactly 53.7% were much/very much interested in this course, with nobody considering prosthodontics as their specialty. The students studied on average of 79.61 minutes for 1 hour (of background-related lecture, 69.92 minutes for a lab-based lecture, and 77.00 minutes for a clinical-content lecture (p < 0.001). They evaluated clinical content as most difficult, lab content as less difficult, and background material as least difficult (3-point scale with 1 = not at all difficult: means = 1.90/1.85/1.80; p < 0.001). They rated background lectures as least helpful, clinical material as more helpful, and lab content as most helpful (5-point scale with 1 = most helpful: means = 2.33/2.67/2.96; p < 0.001). Open-ended answers showed exceptionally positive responses for content and pedagogy of sim lab and clinical content.

CONCLUSIONS

Gaining a better understanding of students' responses to hybrid "complete denture" courses is critical for optimally teaching this material in times of COVID-19.

Survival rates, patient satisfaction, and prosthetic complications of implant fixed complete dental prostheses: a 12-month prospective study

PURPOSE

To determine the survival rate, incidence of prosthetic complications, and patient satisfaction of implant fixed complete dental prostheses (IFCDPs) after a mean observation period of 1.4 years.

MATERIALS AND METHODS

Twenty-eight (28) eligible participants were recruited according to specific inclusion and exclusion criteria. The definitive metal-acrylic resin IFCDPs consisted of titanium bars veneered with acrylic resin and acrylic denture teeth. Prosthodontic complications, divided into major and minor, were monitored. Parameters such as gender, jaw location, bruxism, and occlusal scheme were evaluated. Moreover, a questionnaire was administered throughout the study to assess patient satisfaction. Poisson regression as well as repeated measures ANOVA were used for statistical analysis.

RESULTS

Fourteen (14) males and 14 females were enrolled and followed-up at 3, 6, and 12 months. All IFCDPs survived (100% survival rate). The most frequent minor complication was the loss of material used to close the screw access hole (20% out of total complications). The most frequent major complication was chipping of the acrylic denture teeth (77.14% out of total complications). Gender (p = 0.008) and bruxism (p = 0.030) were significant predictors for the total major complications (major wear and major chipping) while occlusal scheme was a significant predictor for major chipping events (p = 0.030).

CONCLUSIONS

While IFCDPs demonstrated high prosthetic survival rates, they also exhibited a high number of chipping events of the acrylic veneering material, especially in males, bruxers, and individuals with canine guidance occlusion. However, the occurrence of these prosthetic complications did not negatively affect patient satisfaction.

The Shear Bond Strength between Milled Denture Base Materials and Artificial Teeth: A Systematic Review

The data about bond strength between digitally produced denture base resins and artificial teeth are scarce. Several studies investigated shear bond strength values of milled denture base resins and different types of artificial teeth. The purpose of the present study was to compare and evaluate the available evidence through a systematic review. A bibliographic search was conducted in PubMed, Scopus, and Web of Science to assess adequate studies published up to 1 June 2022. This review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The appropriate studies that determined the shear bond strength values between milled denture base resins and artificial teeth were selected. The initial search identified 103 studies, which were included in the PRISMA 2020 flow diagram for new systematic reviews. Three studies met the inclusion criteria, and all of them present a moderate risk of bias (score 6). Two studies found no statistical differences between heat-polymerized and CAD/CAM (milled) denture base materials when attached with different types of artificial teeth, while one study showed higher values of CAD/CAM (milled) denture base materials. Bonding agents ensure bonding strength at least similar to the conventional methods. In order to improve the quality of future studies, it would be advantageous to use a larger number of specimens with standardized dimensions and a blinded testing machine operator to decrease the risk of bias.

Patient Satisfaction and Impact on Oral Health after Maxillary Rehabilitation Using a Personalized Additively Manufactured Subperiosteal Jaw Implant (AMSJI)

Subperiosteal implants (SIs) were first developed by Dahl in 1941 for oral rehabilitation in case of severe jaw atrophy. Over time, this technique was abandoned due to the high success rate of endosseous implants. The emergence of patient-specific implants and modern dentistry allowed a revisitation of this 80-year-old concept resulting in a novel "high-tech" SI implant. This study evaluates the clinical outcomes in forty patients after maxillary rehabilitation with an additively manufactured subperiosteal jaw implant (AMSJI^®). The oral health impact profile-14 (OHIP-14) and numerical rating (NRS) scale were used to assess patient satisfaction and evaluate oral health. In total, fifteen men (mean age: 64.62 years, SD ± 6.75 years) and twenty-five women (mean age: 65.24 years, SD ± 6.77 years) were included, with a mean follow-up time of 917 days (SD ± 306.89 days) after AMSJI installation. Patients reported a mean OHIP-14 of 4.20 (SD ± 7.10) and a mean overall satisfaction based on the NRS of 52.25 (SD ± 4.00). Prosthetic rehabilitation was achieved in all patients. AMSJI is a valuable treatment option for patients with extreme jaw atrophy. Patients enjoy treatment benefits resulting in high patient satisfaction rates and impact on oral health.

Intaglio surface trueness of milled and 3D-printed digital maxillary and mandibular dentures: A clinical study

STATEMENT OF PROBLEM

While the dimensional accuracy of the intaglio surface of a removable complete denture is key to its adaptation, comfort, and clinical performance, information on the ability of milling and 3D-printing workflows to accurately reproduce this surface is lacking.

PURPOSE

The purpose of this clinical study was to compare the trueness of the intaglio surface of milled and 3D-printed removable complete digital dentures.

MATERIAL AND METHODS

Intraoral scans were obtained from 14 participants for a total of 20 edentulous arches. Ten maxillary and 10 mandibular denture bases were then designed and fabricated with a completely digital workflow, both with milling and 3D-printing. Fabricated dentures were digitized with the same intraoral scanner used to obtain intraoral digital scans of the edentulous arches. Standard tessellation language (STL) files of the printed and milled denture bases were used for 3D analysis and comparisons with the STL file of the corresponding designed denture base. Specifically, a reverse engineering software program was used to trim and extract intaglio surfaces, align them, and measure their global mean 3D distance. In order to evaluate the homogeneity of production accuracy of each manufacturing process, the intaglio surfaces were also divided into several regions of interest and the corresponding 3D distances measured. Within- and between-group differences and maxillary and mandibular dentures differences were assessed with parametric and nonparametric tests (α=.05).

RESULTS

Milling showed a global better trueness of the entire intaglio surface (-0.002 mm) than 3D-printing (0.018 mm), both for the whole data set (P<.001) and for maxillary (P=.032) or mandibular (P=.049) denture base subgroups. Within each fabrication technology, maxillary (P<.11) and mandibular dentures (P=.2) showed no significant difference in trueness. Measured deviations were significantly different from zero for the 3D-printed dentures (P<.001), but not for the milled dentures (P=.487). Additionally, for milled dentures, no significant difference in trueness was found among the 11 regions of interest identified for the maxillary dentures (P=.085) and the 13 regions of interest for the mandibular dentures (P=.211). Conversely, 3D-printing showed significant variations in trueness among the same zones of interest, both in maxillary (P<.001) and mandibular (P=.004) dentures.

CONCLUSIONS

Within the limits of the manufacturing methodologies used for complete dentures, milling can provide a slightly better trueness of the intaglio surface than 3D-printing, with less variation across several zones of interest. However, given the magnitude of such differences, they may be reasonably considered to be of limited, if any, clinical significance.

Prospects on Tuning Bioactive and Antimicrobial Denture Base Resin Materials: A Narrative Review

Denture base resin (DBR) materials are used in dentistry in constructing removable dentures and implant-supported prostheses. A plethora of evidence has demonstrated that DBR materials are associated with a high risk of denture stomatitis, a clinical complication where the soft oral tissues underneath the resin-based material are inflamed. The prevalence of denture stomatitis among denture wearers is high worldwide. Plaque accumulation and the infiltration of oral microbes into DBRs are among the main risk factors for denture stomatitis. The attachment of fungal species, mainly Candida albicans, to DBRs can irritate the underneath soft tissues, leading to the onset of the disease. As a result, several attempts were achieved to functionalize antimicrobial compounds and particles into DBRs to prevent microbial attachment. This review article explored the advanced approaches in designing bioactive and antimicrobial DBR materials. It was reported that using monomer mixtures, quaternary ammonium compounds (QACs), and organic and inorganic particles can suppress the growth of denture stomatitis-related pathogens. This paper also highlighted the importance of characterizing bioactive DBRs to be mechanically and physically sustainable. Future directions may implement a clinical translational model to attempt these materials inside the oral cavity.

Prosthetic complications and survival rates of metal-acrylic implant fixed complete dental prostheses: A retrospective study up to 10 years

STATEMENT OF PROBLEM

Long-term data are sparse on the use of metal-acrylic resin implant-supported fixed complete dentures.

PURPOSE

The purpose of this retrospective clinical study was to assess the prosthetic survival and complication rate in patients treated with metal-acrylic resin implant-supported fixed complete dentures (ma-IFCDs).

MATERIALS AND METHODS

The patient record system at the Dental College of Georgia was searched from 2006 to 2020 to identify all patients treated with ma-IFCDs by the graduate prosthodontic and general practice residents during this time. Variables collected were date of delivery of the prosthesis, arch treated (maxilla, mandible), date of the last visit, status of the opposing arch (complete arch fixed implant-supported prosthesis, complete denture, removable implant-supported overdenture, teeth and removable partial denture, teeth and implants, teeth only), date of replacement, and reason for replacement. Reasons for replacement were grouped as fracture of the framework, implant loss, patient-related concerns, catastrophic acrylic resin fracture (judged to be beyond predictable repair by the clinician), and extensive occlusal wear (judged to have worn to the point of requiring replacement).

RESULTS

A total of 84 arches in 55 patients who met the inclusion criteria were identified from the electronic health review. Of the 84 complete arch prostheses, 43 were maxillary and 41 were mandibular. The median follow-up time was 2.8 years (interquartile range [IQR] 0.95, 4.65). A total of 31 of the 84 arches were identified as having failed, requiring replacement. The most frequent reason for replacement was catastrophic fracture of the acrylic resin (61%), followed by excessive occlusal wear (19%). It was found that 13% of the failures were associated with patient-related concerns, and 7% with the loss of an implant. Survival rates were analyzed based on the opposing arch. The combined survival rate (Kaplan-Meier, log-normal modeling) for ma-IFCDs was 54% at 5 years (95% confidence interval [CI] 42%, 66%) and 32% at 10 years (95% CI 20%, 47%).

CONCLUSIONS

Mid- to long-term survival rates for ma-IFCDs are concerningly low. The findings suggest that the status of the opposing arch plays a role in the survival rate of ma-IFCDs. The most common complication was catastrophic fracture of the acrylic resin superstructure, followed by wear of the acrylic resin denture teeth.

Zinc-modified phosphate-based glass micro-filler improves Candida albicans resistance of auto-polymerized acrylic resin without altering mechanical performance

Colonization of auto-polymerized acrylic resin by pathogenic Candida albicans is a common problem for denture users. In this study, zinc-modified phosphate-based glass was introduced into an auto-polymerized acrylic resin at concentrations of 3, 5, and 7 wt.%. The mechanical or physical properties (flexural strength, elastic modulus, microhardness, and contact angle), surface morphology of the resultant materials, and the antimicrobial effect on C. albicans were investigated. There were no statistical differences in the mechanical properties between the control and the zinc-modified phosphate-based glass samples (p > 0.05); however, the number of C. albicans colony-forming units was significantly lower in the control group (p < 0.05). Scanning electron microscopy revealed that C. albicans tended not to adhere to the zinc-modified-phosphate-based glass samples. Thus, the zinc-modified materials retained the advantageous mechanical properties of unaltered acrylic resins, while simultaneously exhibiting a strong antimicrobial effect in vitro.

Patient Satisfaction and Oral Health-related Quality of Life (ohrqol) of Edentulous People after Mandibular Denture Relining With a Soft-liner Material: A Pilot Study

Background:

Oral health-related quality of life indicators have been effectively used to assess the influence of a range of dental treatments and interventions on patient satisfaction and acceptance.

Objectives:

The purpose of this study was to evaluate the impact of the relining of mandibular dentures with a soft-liner material, using the Oral Health Assessment Index (OHIP-14).

Methods:

Forty-two full denture wearers were selected from patients who attended 9 private prosthetic clinics in New South Wales, Australia. All participants had their lower dentures relined with a soft-liner material, according to the manufacturer’s instructions. Oral health-related quality of life was evaluated before and 1 month after relining using the Oral Health Assessment Index questionnaire. A simple descriptive quantitative analysis of the survey results was undertaken, including a comparison of median scores using the Wilcoxon paired test and binomial probability test.

Results:

In all the outcome variables measured, there was a noticeable positive effect from the denture relining. Specifically, mandibular denture relining with a silicon-based soft-liner material has a positive impact on patient satisfaction and oral health-related quality of life (OHRQoL) of edentulous patients.

Conclusion:

Patient satisfaction and oral health-related quality of life (OHRQoL) of edentulous patients can be significantly improved by the use of soft-liner materials.

Algorithm for Designing a Removable Complete Denture (RCD) Based on the FEM Analysis of Its Service Life

(1) Background: The paper addresses the computer simulation and prediction of the service life of the base of removable complete dentures (RCDs) under typical loads caused by biting and chewing food. For this purpose, the finite element method (FEM) was used. It is assumed that various blocks of teeth, such as incisors, canines, premolars and molars, are subjected to cyclic impacts during a human life. (2) Methods: Both symmetric and asymmetric mastication (two- and one-sided loads, respectively) cases were considered. The load level was assumed to be 100 N, which corresponds to the average muscular compression force of typical human jaws. (3) Results: The FEM analysis of the stress-strain state evolution for RCDs under cyclic loads was carried out. Maps of equivalent lines were drawn for the denture base in terms of its durability. A multi-axial criterion was implemented to determine the number of cycles prior to failure by the mechanism of a normal opening mode crack. The FEM-based assessment of the service life of RCDs enabled us to establish the critical stress concentration areas, thereby allowing for further planning for the correction of an occlusal scheme or teeth inclinations. As a result, the service life of RCDs under cyclic loading can be improved. (4) Conclusions: An algorithm for designing RCDs in the case of edentulism based on the FEM simulation using commercial software as part of the procedure is proposed.

Effect of surface treatment on shear bond strength of relining material and 3D-printed denture base

PURPOSE

This study aimed to analyze the shear bond strength between the 3D-printed denture base and the chairside relining material, according to the surface treatment.

MATERIALS AND METHODS

Cylindrical specimens were prepared using DENTCA Denture Base II. The experimental groups were divided into 6 (n = 10): no surface treatment (C), Tokuyama Rebase II Normal adhesive (A), sandblasting (P), sandblasting and adhesive (PA), sandblasting and silane (PS), and the Rocatec system (PPS). After bonding the chairside relining material to the center of the specimens in a cylindrical shape, they were stored in distilled water for 24 hours. Shear bond strength was measured using a universal testing machine, and failure mode was analyzed with a scanning electron microscope. Shear bond strength values were analyzed using one-way analysis of variance, and Tukey’s honest significant difference test was used for post-hoc analysis (P < .05).

RESULTS

Group PPS exhibited significantly higher shear bond strength than all other groups. Groups P and PA displayed significantly higher bond strengths than the control group. There were no significant differences between groups PS and A compared to the control group. Regarding the failure mode, adhesive failure occurred primarily in groups C and A, and mixed failure mainly in groups P, PA, PS, and PPS.

CONCLUSION

The shear bond strength between the 3D-printed denture base and the chairside relining material exhibited significant differences according to the surface treatment methods. It is believed that excellent adhesive strength will be obtained when the Rocatec system is applied to 3D-printed dentures in clinical practice.

Influence of dental implantation on bone mineral density distribution: a pilot study

PURPOSE

Masticatory loading triggers active bone remodeling, altering alveolar bone mineral density (BMD). While dental implants are placed to bear masticatory loading, their influence on changing bone properties has not been fully investigated. Objective of this pilot study was to examine whether the dental implantation has an effect on BMD distribution of bone by comparing dentate, edentulous, and edentulous patients with implants.

MATERIALS AND METHODS

Cone beam computed tomography (CBCT) images of 19 partially edentulous patients (Dent), 19 edentulous patients (Edent), and 16 edentulous patients who received implants in the mandible (Edent+Im), were obtained. CBCT images were also obtained from 5 patients within Edent+Im group, before implant placement and after implant loading. Basal cortical bone region of the mandible was digitally isolated. A histogram of gray levels proportional to BMD was obtained to assess mean, histogram standard deviation (HSD), fifth percentile of low and high values (Low₅ and High₅) of the BMD distribution. Multivariate analysis of variance and paired t-test were used to compare the BMD parameters among the 3 dental status groups and between pre- and post-implantation, respectively.

RESULTS

Edentulous patients with implants had significantly greater HSD and High₅ values compared to edentulous patients (P < .013). All other comparisons were not significant (P > .097). Mean, HSD, and High₅ values significantly increased after receiving implants (P < .022).

CONCLUSION

The current findings suggested that receiving dental implants promoted oral bone mineralization for edentulous patients. The longitudinal investigation could provide valuable information on understanding the effects of implantation on the behavior of oral bone quality.

Novel 3D printing method to reinforce implant-supported denture fiberglass as material for implant prosthesis: A pilot study

Objectives

Despite a large amount of materials and methods to make an implant‐supported denture, nowadays there is no gold standard. Every solution has pros and cons that guide the clinician and the technician to choose the best solution for a single case. The aim of this study was to evaluate the mechanical characteristics of the fiber‐reinforced composite superstructure made by using a novel three‐dimensional (3D) printing technology able to create a reinforcing structure patient‐specific, more reliable, structurally optimized, and faster than conventional methods.

Materials and Methods

To evaluate mechanical performances of 3D‐printed fiberglass, mechanical characterization of 3D‐printed material was performed. Before proceeding with the realization of the final prosthesis, five specimens were created on which the tensile test and volumetric fiber content measurement were performed. Then denture reinforcement 3D printing process began. Initially, the robot prints layers of fiber. Finally, the obtained 3D‐printed reinforcement structure was finalized in the lab.

Results

The prosthesis obtained through this process was lighter than a traditional prosthesis, there was a greater chemical adhesion between resin and 3D‐printed reinforcement structure and a better result was obtained from an esthetic point of view.

Conclusions

The outcomes we obtained endorse its performance both mechanical and esthetic. The entire process is automatic and does not require human operation thanks to specific software programming.

Cytotoxic Potential of Denture Adhesives on Human Fibroblasts—In Vitro Study

(1) In recent years, there has been a significant increase in the availability of denture adhesives for stabilizing removable dentures. The aim of the present study was to assess the cytotoxicity of three denture adhesives on human fibroblasts. (2) Methods: Three denture adhesives were analyzed. Fibroblast cultures were established for the study and control groups in order to assess the incidence of necrosis and to evaluate the microscopic intracellular alterations induced. Following incubation with (study groups) or without adhesives (control group), trypan blue dye exclusion assay was used to determine the number of viable and/or dead cells. Microscopic specimens were stained with haematoxylin and eosin, scanned, digitally processed and then analyzed by a histopathologist. (3) Results: All three denture adhesives analyzed demonstrated various toxic effects in vitro on human fibroblast: quantitative evaluation—45.87–61.13% reduction of cell viability (p = 0.0001) and slight to moderate cytotoxicity in qualitative evaluation. (4) Conclusions: Denture adhesive creams demonstrated a toxic effect on human fibroblasts in vitro in quantitative and qualitative evaluation. In vivo observations are needed to find out if denture adhesives present a cytotoxic effect in patients.

Spectrometric Analysis of the Wear from Metallic and Ceramic Dental Implants following Insertion: An In Vitro Study

Titanium wear is a growing area of interest within dental implantology. This study aimed to investigate titanium and zirconium wear from dental implants at the time of insertion using X-ray-fluorescence spectrometry (XRF) and an in vitro protocol utilizing artificial bovine bone plates. Five groups were analyzed using XRF-spectrometry: groups 1–4 (titanium implants) and group 5 (zirconia implants). The implants were inserted into two bone blocks held together by a vice. The blocks were separated, and the insertion sites were analyzed for titanium (Ti) and zirconium (Zr). Statistical descriptive analyses of Ti and Zr concentrations in the coronal, middle and apical bone interface were performed. A comparative analysis confirmed differences between the implant’s surface stability and Ti accumulation within the insertion sites of the bone block. There was a direct relationship between implant length and the quantity of titanium found on the bone block. The data generally indicates greater quantities of titanium in the coronal thirds of the implants, and less in the apical thirds. The titanium and zirconium found in the bone samples where the group 5 implants were inserted was not of statistical significance when compared to control osteotomies. The results of this study confirm wear from metallic, but not ceramic, dental implants at the time of insertion.

Association of Dental and Prosthetic Status with Oral Health-Related Quality of Life in Centenarians

To date, there is little evidence on centenarians’ dental and prosthetic status or their oral-health-related quality of life (OHRQoL). Therefore, the aim of this study was to assess possible associations between sociodemographic and oral health factors, including prosthetic needs in this special age group and their potential influence on OHRQoL. Persons born before 1920 were recruited from population registries in south-western Germany. Fifty-five centenarians participated and underwent a comprehensive oral examination. Cognitive capacity was evaluated using the short Mini-Mental State Examination (S-MMSE, max. 21 points). At an S-MMSE > 10, an analysis of OHRQoL by means of the Geriatric Oral Health Assessment Index (max. ADD-GOHAI score 60 points) was performed (n = 43). Bivariate statistics and a linear regression model were used after variable selection to analyze data. Centenarians presented with a mean (SD) of 22 (7.2) missing teeth. Complete (65.5%) or partial dentures (21.8%) in at least one jaw were most common. One-third of the dentures needed repair/replacement; 16% of the centenarians presented with denture sores. In 60% of cases, OHRQoL was rated unsatisfactory (ADD-GOHAI < 57). Trouble biting or chewing resulted in the lowest levels of OHRQoL. Fewer remaining teeth, reduced functional capacity and removable prostheses correlated with an impaired OHRQoL (r_s = −0.36, p = 0.01; r_s = −0.34, p = 0.01; r_s = −0.29, p = 0.03, respectively). After variable selection, the final linear regression model included only the number of missing teeth, the associated ADD-GOHAI score decreasing by 0.3 points per missing tooth. In conclusion, tooth loss and removable prostheses in need of repair or replacement are highly prevalent in centenarians. These factors seem to modulate OHRQoL negatively, assumedly due to impaired chewing function. Larger confirmatory studies are needed to validate these first results.

Relationship between perceived chewing ability, oral health related quality of life and depressive symptoms among completely edentulous individuals

Background

Edentulism affects the chewing ability of a person and can engender nutritional deficiencies which can affect the overall quality of life and depression.

Aim

Our aim was to evaluate the association between perceived chewing ability, oral health-related quality of life (OHRQoL) and depressive symptoms among completely edentulous patients with and without dentures.

Settings and Design

Institutional study and cross-sectional design.

Methods

A cross-sectional study among 207 completely edentulous persons was conducted in South India. The subjects completed a self-administered questionnaire on demographics, Beck's depression inventory, oral health impact profile-edentulous (OHIP-EDENT), age when edentate, chewing ability, and denture satisfaction. Further, denture status was clinically evaluated.

Statistical Analysis

Data were summarised and analysed using the Chi-square test and multivariate logistic regression. P < 0.05 was considered significant.

Results

Persons not using complete dentures (odds ratio [OR] =3.5, P < 0.05), who reported impaired chewing ability (OR = 4.6, P < 0.05), those who became edentate before 55 years (OR = 4.6, P < 0.05) and with poor denture status (OR = 6.2, P < 0.05) were more likely to report depressive symptoms. Lesser impact in relation to OHRQoL was found to be protective against depression among completely edentulous (OR = 0.24, P < 0.05).

Conclusion

Depressive symptoms were associated with impaired chewing ability, higher impacts on OHIP-EDENT, and edentulous persons not using complete dentures. High priority must be given to enhance awareness towards oral rehabilitation among completely edentulous to reduce the chance of depression occurring due to impaired chewing ability and poor OHRQoL.

Flexural strength and impact strength of heat-cured acrylic and 3D printed denture base resins- A comparative in vitro study

Objective

The present study aimed to evaluate and compare the flexural strength and impact strength of heat-cured acrylic/Polymethyl methacrylate (PMMA) denture base resin and 3D printed denture base resin.

Methods

60 rectangular specimens were fabricated from conventional heat-cured acrylic and 3D-printed denture base resins. 15 specimens each of heat-cured acrylic and 3D printed denture base resin were tested for flexural strength and impact strength. The flexural strength was assessed using three point bend test while impact strength was assessed by Izod impact test.

Results

The mean flexural strength of heat-cured acrylic resin was 92.01 ± 12.14 MPa and 3D printed denture base resin was 69.78 ± 7.54 MPa. The mean impact strength of heat-cured acrylic resin was 1.67 ± 0.79 kJ/m² and 3D printed denture base resin was 1.15 ± 0.40 kJ/m².The differences in mean impact and flexural strength between heat-cured acrylic and 3D printed denture base resins were statistically significant.

Conclusion

Heat-cured acrylic denture base resin (DPI heat-cure) had greater flexural and impact strength than 3D printed denture base resin (Next Dent denture 3D+).

Current trends in removable partial prosthodontics education in dental colleges of Pakistan

OBJECTIVE

The objective of this study was to investigate the current trends in undergraduate teaching of removable partial prosthodontics in various dental colleges of Pakistan.

METHODOLOGY

A cross-sectional study was conducted in which a questionnaire was sent by email to head of Prosthodontics department of thirty-one dental institutes of Pakistan. The survey included multiple questions regarding current trends in removable partial prosthodontics education in undergraduate dental colleges.

RESULTS

Out of thirty-one questionnaires, twenty-six were completely filled and returned. In 19 (73%) dental colleges, removable partial denture is taught over a period of at least two years of undergraduate education. Students of only six dental colleges fabricate 10-12 removable partial dentures during their Prosthodontic rotation. Lectures and live clinical demonstration for construction of removable acrylic dentures are reported to be carried out in all the dental schools. Simple hinge articulator is the articulator of choice in 22 (84.6%) colleges. Even though twenty-four out of twenty-six colleges (92.3%) teach fabrication of cast partial dentures in lectures, none of the student fabricate these dentures during their Prosthodontic rotation.

CONCLUSION

This survey is the first to comprehensively report the teaching practices of removable denture Prosthodontics in undergraduate dental colleges of Pakistan. Faculty of all twenty-six colleges give clinical demonstrations of acrylic partial denture construction before students start working in the dental OPD. Most of the dental colleges report use of similar impression materials and techniques in removable partial denture fabrication. More than 90% of dental colleges teach cast partial dentures theoretically, but their construction is grossly neglected in all the dental colleges. It is important that this skill is taught and practised by students in order to have the necessary skill set, so they can provide comprehensive treatment to partially dentate patients once they graduate.

Assessment of Pattern of Oral Prosthetic Treatment and Prevalence of Oral Diseases in Edentulous Patients in North Indian Population: A Cross-sectional Study

Background:

The present study was undertaken for assessing the pattern of oral prosthetic treatment and prevalence of dental diseases in edentulous patients in North Indian population.

Materials and Methods:

A survey was carried out in North Indian population, and screening of the edentulous patients was done. Five hundred edentulous patients were enrolled. Complete oral and general examination was carried out. Pro forma was framed, and clinical details were recorded. Using mouth mirror and explorer, complete oral examination was carried out. Demographic profile was also evaluated. Prosthetic rehabilitation pattern of all the participants was also recorded.

Results:

Complete removable denture and removable partial denture were method of rehabilitation in 28% and 31% of the participants. Dental implant-supported complete denture was used in 8% of the patients, whereas dental implant-supported overdenture was used in 33% of the participants. Ulcerative lesions were present in 5% of the patients, whereas oral leukoplakia was present in 4% of the patients. Oral lichen planus and torus were present in 2% and 1% of the patients.

Conclusion:

Majority of the geriatric patients prefer having removable denture. Furthermore, due to nutritional deficiency associated with geriatric age, oral leukoplakia and ulcerative lesions are more common in them.

Digital Workflow for Double Complete Arch Zirconia Prostheses Utilizing a Novel Scan Body

The purpose of this clinical report is to present a complete digital workflow for the fabrication of complete arch fixed zirconia implant restorations. An intraoral scanner was used to capture the implants' position at the abutment level and also the patient's existing interim prostheses with the double digital scanning technique. A novel scan body and impression pin were utilized throughout the scanning process which allowed for the accurate and reproducible superimposition of the generated Standard Tesselation Language (STL) files. Prosthesis prototypes were digitally designed and fabricated, tried in, and verified intraorally. The definitive zirconia prostheses were then fabricated and delivered to the patient. This technique can be utilized in both arches overcoming the absence of stable intraoral landmarks for superimposition of STL files.

'Differences in self-perceived OHRQoL between fully dentate subjects and edentulous patients depending on their prosthesis type, socio-demographic profile, and clinical features'

OBJECTIVES

This observational cross-sectional study aimed to evaluate and compare the oral health-related quality of life (OHRQoL) and clinical performance between dentate subjects and edentulous patients restored with conventional dentures or implant overdentures.

METHODS

85 edentulous patients were grouped as follows: Group-1 (CD): conventional denture wearers (n= 42), and Group-2 (IO): implant-retained overdenture wearers (n= 43). For the OHRQoL comparisons, a control group of subjects with a healthy natural dentition (Group-3, ND; n= 50) was included. Participants completed three validated questionnaires (OHIP-14sp, OHIP-20sp, and QoLIP-10). Socio-demographic data, prosthesis-related factors, clinical condition of the mouth, and patient subjective evaluations, were gathered. Descriptive and non-parametric probes were run (α= 0.05).

RESULTS

The ND group was the most unsatisfied (OHIP-14sp; p≤ 0.001). The OHIP-20sp attributed significantly worse Psychological disability (p= 0.029) and Handicap (p= 0.027) to CD wearers when compared to IO wearers. The CD group showed the significantly highest need for relining (p= 0.041), and the lowest retention (p= 0.011). The OHIP-14sp disclosed a significantly worse OHRQoL for those volunteers who had a job (p= 0.003), a basic education instead of a secondary one (p= 0.022), and no partner (p= 0.006).

CONCLUSIONS

The overall OHRQoL was comparable for both prosthodontic groups, being modulated by socio-demographic and prosthesis-related features. Nonetheless, CD wearers presented prosthetic complications more frequently.

Novel antimicrobial denture adhesive containing S-PRG filler

The antimicrobial effects of denture adhesives containing novel surface pre-reacted glass-ionomer (S-PRG) fillers were assessed. We prepared denture adhesives containing S-PRG (particle sizes: 1 and 3 µm; quantities: 5, 7.5, and 10 wt%). We evaluated acid buffering capacity, ion release, and antimicrobial effects of denture adhesives with and without S-PRG. Significantly higher pH changes were observed in 1 µm S-PRG adhesives than in 3 µm S-PRG adhesives. Adhesives containing 7.5 and 10 wt% S-PRG exhibited significantly higher ion release than adhesives with 5 wt% S-PRG. The 1µm-10wt% S-PRG denture adhesive exhibited significantly lower colony-forming units on the denture adhesive contact surface than in the control group; additionally, it exhibited excellent acid buffering capacity, ion release properties, and antimicrobial effect against C. albicans, C. glabrata, S. mutans, and A. naeslundii. Longer contact periods resulted in significantly lower adhesion of Candida albicans to the denture base resin treated with denture adhesive.

Effects of nocturnal complete denture usage on cardiorespiratory parameters: A pilot study

STATEMENT OF PROBLEM

Sleeping without conventional complete dentures (CCDs) has been stated by some to induce negative effects on the cardiorespiratory functions of edentulous patients with obstructive sleep apnea (OSA), although others have reported the exact opposite. Therefore, a consensus on nocturnal CCD usage is lacking.

PURPOSE

The purpose of this clinical study was to assess the effects of nocturnal denture usage on cardiorespiratory stability by using pulse oximetry (PO).

MATERIALS AND METHODS

Thirty CCD wearers were enrolled in the study. The first nocturnal pulse oximetry (FNPO) recordings were made on 3 different nights while the participants were sleeping without dentures (WOD). Oxygen desaturation index (ODI) and other PO parameters of the participants, including total respiratory event (TRE), basal SpO₂ (BSpO₂), time≤88 (T88), average low SpO₂ (ALSpO₂), total pulse event (TPE), average pulse rate (APR), and heart rate variability index (HRVI), were processed and the obtained data were recorded as WOD condition values. According to the ODI scores, the OSA status of the participants was grouped as normal (ODI<5), mild (5<ODI<15), moderate (15<ODI<30), or severe (ODI>30). Complete dentures were fabricated by an experienced prosthodontist and a dental laboratory technician by following conventional procedures. At the end of the first month of the follow-up period, the second nocturnal PO recordings (SNPO) were made on 3 different nights while the participants slept wearing dentures (WID), and the data obtained were recorded as WID condition values. The comparison of mean PO values obtained from WOD and WID were analyzed with the Wilcoxon signed- rank test (α=.05).

RESULTS

Significant differences were found between WOD and WID values in terms of TRE (P=.01), ODI (P=.001), ALSpO2 (P=.006), TPE (P=.001), and HRVI (P=.001) parameters. The significance of the improvements in the WID condition increased with the severity of OSA.

CONCLUSIONS

Improvements were observed in substantial cardiorespiratory parameters such as the ODI and HRVI of the participants wearing dentures nocturnally.

Implant survival and biologic complications of implant fixed complete dental prostheses: An up to 5-year retrospective study

STATEMENT OF PROBLEM

Limited information is available on the association between prosthesis-associated risk factors and biologic complications for patients with implant fixed complete dental prostheses (IFCDPs).

PURPOSE

The purpose of this retrospective study was to assess the implant survival and biologic complications of IFCDPs up to 5 years of follow-up.

MATERIAL AND METHODS

Patients who had received IFCDPs between August 1, 2009 and August 1, 2014 were identified through an electronic health record review. Those who consented to participate in the study attended a single-visit study appointment. Clinical and radiographic examinations, intraoral photographs, and peri-implant hard and soft tissues parameters were assessed. Only prostheses which could be removed during the study visit were included. Associations between biologic complications and prosthetic factors, such as time with prosthesis in place, prosthesis material, number of implants, cantilever length, and type of prosthesis retention, were assessed.

RESULTS

A total of 37 participants (mean ±standard deviation age 62.35 ±10.39 years) with 43 IFCDPs were included. None of the implants had failed, leading to an implant survival of 100% at 5.1 ±2.21 years. Ten of the prostheses were metal-ceramic (Group MC) and 33 were metal-acrylic resin (Group MR). Minor complications were more frequent than major ones. Considering minor complications, peri-implant mucositis was found in 53% of the implant sites, more often in the maxilla (P=.001). The most common major biologic complication was peri-implantitis, which affected 4.0% of the implants, more often in the mandible (P=.025). Peri-implant soft tissue hypertrophy was present 2.79 times more often (95% CI: 1.35 - 5.76, P<.003) around implants supporting metal-acrylic resin prostheses than metal-ceramic ones, with the former type also showing significantly more plaque accumulation (P<.003).

CONCLUSIONS

Biologic complications such as soft tissue hypertrophy and plaque accumulation were more often associated with metal-acrylic resin prostheses. Peri-implant mucositis occurred more often under maxillary IFCDPs, while peri-implantitis appeared more common around mandibular implants.

Denture induced mechanotransduction can contribute to oral carcinogenesis

Mechanical stresses in the form of substrate rigidity, hydrostatic pressure, compressive, tensile and shear stress has been regarded as an important motive for the epithelial carcinogenesis brought about by the activation of Hippo signaling pathways. Masticatory forces generated in edentulous patients with dentures are transferred directly to the palatal mucosa (maxillary denture) and alveolar mucosa (mandibular denture). Thus, the oral mucosa present underneath the dentures experiences compressive, shear and tensile stresses on a day-to-day basis. These stresses can induce carcinogenesis by mechano-transduction and subsequent activation of numerous carcinogenesis relevant signaling pathways such as the HIPPO pathway. With this contention in mind, we proposed a hypothesis, which explains the pathogenesis for the presence of oral squamous cell carcinoma in denture wearer patients. Efforts were made to envisage the appropriate experimentations for the evaluation of the hypothesis. As a therapeutic implication, flexible dentures, soft denture, or medicated dentures could be prescribed for the high-risk groups having potentially malignant lesions in the oral cavity.

Interdisciplinary Education and Health Care in Geriatric Dental Medicine

Geriatric patients are more likely to have multiple medical comorbidities, physical limitations, and mental impairments that warrant careful consideration while providing patient care. Dentistry, along with other health care professional programs, incorporate interprofessional education (IPE) experiences to provide students with skills they need to deliver collaborative care in their future practice. Health professional programs should consider geriatric training in simulated learning environments, adult day programs, nursing homes, long-term care facilities, and home care experiences to provide students valuable IPE experiences. Lastly, this article presents a call to action for professional organizations to consider offering continuing education courses in IPE.

Effect of titanium dioxide nanoparticle reinforcement on flexural strength of denture base resin: A systematic review and meta-analysis

The study was designed to assess the change in flexural strength of unmodified heat cure denture base polymer resin on reinforcement with titanium dioxide nanoparticles in different concentrations. In vitro, randomized control trials reporting flexural strength of titanium dioxide nanoparticle reinforced resin were selected. The review was formulated based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses- Protocol (PRISMA-P) guidelines. Quality assessment was performed according to Consolidated Standards Of Reporting Trials (CONSORT) guidelines and risk of bias Cochrane tool. Six articles in the category of 1%, 3%, 5% weight fractions of titanium dioxide nanoparticles were subjected to a meta-analysis. A meta-analysis was performed using random-effects at a 95% confidence interval. Within the limitations of the study, it can be assumed that there is no precise conformity on the ideal titanium dioxide nanoparticle concentration required to improve the flexural strength of the polymer. Stringent use of standard ISO guidelines may help in obtaining consistent results.

Managing Edentate Older Adults

Whilst increasing numbers of older people retain natural teeth, a sizable proportion of older people are still edentate. Replacement of missing teeth is important for function, aesthetics and to facilitate social interactions. The process of providing oral rehabilitation for edentate older adults can be challenging, but clinicians can utilise a number of treatment options including removable or implant retained prostheses. In this article, complete denture construction will be described using both conventional and copy denture techniques. Recent innovations in the process for constructing complete dentures using computer aided design and manufacturing (CAD-CAM) techniques will also be discussed. Dental implants can be used to help retain removable complete prostheses for edentate patients and the use of implant-retained overdentures is presented as a treatment alternative.