The future of complete dentures in oral rehabilitation. A critical review

Splintless maxillomandibular advancement for edentulous sleep apnoea patients: surgical accuracy and efficacy

The primary aim of this study was to assess the accuracy and predictability of a splintless treatment protocol for edentulous patients with moderate to severe obstructive sleep apnoea (OSA) undergoing maxillomandibular advancement (MMA). Ten consecutive edentulous patients treated with MMA were enrolled in this retrospective study. All cases were virtually planned, followed by computer-aided design of individual osteotomy cutting guides and patient-specific implants. For the maxilla, the mean discrepancy between the planned and achieved right to left, posterior to anterior, and cranial to caudal translations was 0.3 ± 0.2 mm, 1.0 ± 0.6 mm, and 0.8 ± 0.6 mm, respectively. There was a mean discrepancy of 0.5° ± 0.5°, 2.5° ± 2.0°, and 0.3° ± 0.4° for roll, pitch, and yaw of the maxilla, respectively. The mean discrepancy of the mandible osteotomy gap was 1.2 ± 1.0 mm on the right side and 0.8 ± 0.5 mm on the left. Surgical success was achieved in nine patients, one of whom met the criteria for surgical cure. On average, the apnoea-hypopnea index was reduced by 72%. The results of this study indicate that the splintless treatment protocol for MMA applied in edentulous OSA patients is highly accurate, predictable, and effective in the treatment of OSA.

Treatment of the Completely Edentulous Patient with Removable Prosthesis

Edentulism is a significant global health issue affecting over 350 million people. Tooth replacement with complete dentures can help mitigate the negative health and social impacts of edentulism. To meet this ongoing demand, efficient complete denture workflows are needed in dental education and practice. Advances in materials and technologies can improve predictability and reduce treatment time. Today, clinicians have the opportunity to combine digital and conventional workflows to find the best solutions for patients seeking removable complete and implant overdentures.

A fractal evaluation study of implant-supported overdentures

OBJECTIVE

The aim of this study is to evaluate the bone changes in the mandible of fully edentulous patients using two implant-supported overdentures after treatment, through fractal analysis (FA).

MATERIALS AND METHODS

A total of 27 patients who were treated with two implant-supported overdentures after using conventional complete dentures were included in our study. Panoramic radiographs taken during the use of conventional complete dentures formed the control group (n = 27), while radiographs taken 4 years (±1 month) after the overdenture treatment formed the study group (n = 27). In the panoramic radiographs taken before and after treatment, or during routine check-ups, three symmetrical regions of interest (ROI) were selected for each patient on the right and left sides: the mandibular condyle (ROI-1), the angle of the mandible (ROI-2), and the area anterior to the mental foramen (ROI-3). Each ROI measured 45 × 45 pixels, and the complexity of trabecular bone was measured using FA. The collected data were statistically analyzed.

RESULTS

The results indicated that there were statistically significant differences in fractal dimension (FD) measurements between the control and study groups for the selected ROIs (ROI-1, ROI-2, ROI-3) (P = .001). However, no statistically significant differences were found between the right and left sides in terms of FD measurements for ROI-1, ROI-2, and ROI-3 (P = .814), (P = .654), (P = .296).

CONCLUSIONS

Our findings suggest that the use of implant-supported overdentures leads to more complex trabecular bone structures in various regions of the mandible compared to the use of conventional complete dentures.

Differences in the Prolonged Effectiveness Between Two Denture Adhesives With Different Rheological Characteristics

Aim This study aimed to investigate the differences in long-term effectiveness between two marketed denture adhesives: adhesive A (tough-grip cream; Kobayashi Pharmaceutical Co., Ltd., Osaka, Japan) and adhesive B (tough-grip cream A; Kobayashi Pharmaceutical Co., Ltd.) with different material science characteristics. Materials and methods This study consists of the following two parts: Experiment 1 - measuring material characteristics in vitro; Experiment 2 - measuring the denture movement and subjective evaluation in participants. The adhesion strength, viscosity, dynamic viscoelastic properties, and temporal changes in adhesion strength were measured in vitro. The study also investigated denture movement and subjective evaluations (stableness of the denture, duration of stableness, inhibitory effect on wobble, and inhibitory effect on slippage) after participants used the adhesives for a prolonged period (seven hours). Twelve participants were randomly divided and assigned into two protocols: protocol A (adhesive A followed by adhesive B) and protocol B (adhesive B followed by adhesive A). Results In the in vitro study, no significant differences were observed in adhesion strength or viscosity between the two adhesives. However, the storage moduli, loss moduli, and loss tangents exhibited significant differences. With respect to changes in temporal adhesion strength, adhesive B exhibited significantly higher values in the later cycles than did adhesive A. In the in vivo study, adhesive B tended to be preferred only in terms of the "duration of stableness" on the questionnaire, more than adhesive A, when the participants compared the two adhesives after they completed the two protocols. No statistical significance was observed between the two adhesives in vertical denture movement or subjective evaluations by visual analog scale (VAS). Vertical movement significantly decreased, and subjective denture stability significantly increased after five minutes compared to baseline for both adhesives. These effects were maintained seven hours later. Conclusion Our results indicate that both adhesives have sufficient long-lasting effects in clinical conditions for patients under conditions similar to those in this study, despite demonstrating different material characteristics in some factors in the in vitro study. Denture adhesives contribute to an improved quality of life and self-esteem, even for well-fitting dentures. Further studies are required to clarify the differences between denture adhesives under more severe oral conditions.

Effect of coffee thermal cycling on the surface properties and stainability of additively manufactured denture base resins in different layer thicknesses

PURPOSE

To compare the effect of coffee thermal cycling on surface roughness (Ra), Vickers microhardness (MH), and stainability of denture base resins additively manufactured in different layer thicknesses with those of subtractively manufactured denture base materials.

MATERIALS AND METHODS

Eighty disk-shaped specimens (Ø10×2 mm) were fabricated from two subtractively (Merz M-PM [SM-M] and G-CAM [SM-G]) and three additively (NextDent 3D+ [50 µm, AM-N-50; 100 µm, AM-N-100], FREEPRINT Denture [50 µm, AM-F-50; 100 µm, AM-F-100], and Denturetec [50 µm, AM-S-50; 100 µm, AM-S-100]) manufactured denture base materials (n = 10). Ra measurements were performed before and after polishing by using a non-contact optical profilometer, while MH values and color coordinates were measured after polishing. Specimens were then subjected to 5000 cycles of coffee thermal cycling, all measurements were repeated, and color differences (ΔE00) were calculated. A linear mixed effect model was used to analyze Ra and MH data, while one-way analysis of variance was used to analyze ΔE00 data (α = 0.05). Ra values were further evaluated according to a clinically acceptable threshold of 0.2 µm, while ΔE00 values were evaluated according to perceptibility (1.72 units) and acceptability (4.08 units) thresholds. The interaction between the material type and the time interval affected both Ra and MH (p ≤ 0.001). Tested materials had their highest Ra before polishing (p ≤ 0.029). Before polishing, AM-F-100 had the highest, and SM-M and SM-G had the lowest Ra (p < 0.001). After polishing and after coffee thermal cycling, SM-G mostly had lower Ra than those of other materials (p ≤ 0.036). SM-G mostly had higher MH than that of other materials before and after coffee thermal cycling (p ≤ 0.025). Coffee thermal cycling reduced the MH of SM-M and increased that of AM-S-100 (p ≤ 0.024). AM-N-100 had higher ΔE00 than AM-F, AM-S-100, and SM-G (p ≤ 0.009), while AM-F and SM-G had lower ΔE00 than AM-S-50 and AM-N-50 (p ≤ 0.024).

CONCLUSIONS

Polishing reduced the surface roughness of all materials, whereas the effect of coffee thermal cycling was nonsignificant. Most of the tested materials had acceptable surface roughness after polishing and after coffee thermal cycling according to the reported threshold. Layer thickness only affected the microhardness of tested additively manufactured resins, which was material-dependent. Subtractively manufactured specimens mostly had high microhardness and that of nonreinforced subtractively manufactured resin decreased after coffee thermal cycling. When reported color thresholds are considered, all materials had acceptable color stability.

A systematic review on patient perceptions and clinician-reported outcomes when comparing digital and analog workflows for complete dentures

PURPOSE

To compare digitally fabricated complete dentures to conventionally fabricated dentures using patient- and clinician-reported outcome measures.

METHODS

This review was structured according to PRISMA guidelines with the protocol registered in the PROSPERO database (CRD42024526069). An electronic search of the databases with a defined search strategy was completed within PubMed/MEDLINE and Web of Science from January 2000 to March 2024. Grey literature and article references were searched. Articles were screened by title and abstract, and the remaining articles were screened by full-text review. Articles accepted for inclusion were subjected to a risk-of-bias assessment using Cochrane Collaboration tools (RoB 2 and ROBINS-I).

RESULTS

From an initial pool of 704 articles, 15 studies met the selection criteria, of which the majority were published within the past 3 years. Within the included studies, there was inconsistency in the assessment methods of patient- and clinician-reported outcomes, making it challenging to draw definitive conclusions. Generally, digital dentures had superior cost-effectiveness and prosthesis fabrication time. Patient satisfaction and denture quality were not consistently improved with digital technology.

CONCLUSIONS

Studies showed indications of patient satisfaction with digital and conventional dentures. Digital technology may enhance clinical workflows. A trend emerged that milled dentures performed better than printed dentures. Clinicians adopting digital technology into removable prosthodontics may have a learning curve to overcome, and they should consider the patient-clinician relationship in addition to clinical outcomes to achieve patient satisfaction. Additional studies with standardized tools for assessing patient satisfaction are required to enable meaningful comparisons between digital and conventional workflows.

In vitro bonding strength of denture teeth to denture base in CAD/CAM-milled, 3D-printed and conventional manufacturing processes

OBJECTIVES

To investigate the survival rates and fracture resistance of dentures made from different teeth (milled, 3D-printed, fabricated), bases (milled, 3D-printed, pressed) and bonding combinations.

MATERIALS AND METHODS

Specimens (11 groups, n = 8 per group) were fabricated from combinations with a denture tooth (anterior tooth 21) and a denture base material. The groups consisted of combinations of teeth (6x), denture base materials (5x) and adhesive bonding options (4x). The teeth were printed, milled or prefabricated. The denture base was produced conventionally or was milled or 3D-printed. Two dentures were milled from one industrially produced block. The dentures were subjected to thermal and mechanical loading (TCML) and subsequent fracture test.

STATISTICS

ANOVA, Bonferroni-test, Kaplan-Meier survival, Pearson correlation; α = 0.05.

RESULTS

Mean loading cycles varied between 221,869 (8), 367,610 (11), 513,616 (6) 875,371 (3) and 9,000,030 (4). ANOVA revealed significant (p ≤ 0.001) different surviving cycles. Log Rank test showed significantly (p < 0.001) different loading cycles. Fracture force after TCML varied between 129.8 +/- 97.1 N (3) and 780.8 +/- 62.5 N (9). ANOVA comparison revealed significant (p < 0.001) different fracture loadings between the individual systems. Correlation was found between fracture force and loading cycles (0.587, p < 0.001).

CONCLUSIONS

Different survival rates and fracture forces were found for dentures made of different teeth (milled, 3D-printed, prefabricated), bases (milled, 3D-printed, pressed) and bonding combinations. Milled, pressed and prefabricated systems provided longer survival and fracture force than the other tested systems.

CLINICAL RELEVANCE

 Optimal tooth-base combinations can help to produce a denture that is stable and resistant during clinical application.

Biomechanical Finite Element Analysis of Two Types of Short-Angled Implants Across Various Bone Classifications

The aim of this finite element analysis (FEA) was to investigate the distribution of von Mises stress within dental implant components, as well as trabecular and cortical bone. The study considered various bone qualities that influence cortical thickness in contact with the implant, specifically examining cortical thicknesses of 0.5, 1.5, and 3 mm, corresponding to Bergkvist's classifications IV, III, and II, respectively. A simplified 3D model of the bone was developed for the analysis. Two short implants were inserted into the model: one with a 30° inclined abutment (IA) and another positioned at a 30° angle featuring a straight abutment (II). A vertical force (120 N) was applied to the upper surface of the abutments. FEA software was employed to assess the stresses on the peri-implant tissues and the implants. The findings indicated that a reduction in cortical bone thickness results in an increase in stress within the cortical bone. For IA, the stresses recorded 32.56, 56.12, and 96.14 MPa for cortical thicknesses of 3, 1.5, and 0.5 mm, respectively. Conversely, II exhibited increased stresses across all bone qualities (52.32, 76.15, and 126.32 MPa for the same cortical thicknesses). It is advisable to avoid II in cases of poor bone quality and thin cortical due to the heightened risk of overload-induced bone resorption; however, it may be preferable to use IA in scenarios involving good bone quality and thicker cortical.

Reliability and validity of a Hindi version of the Oral Health Impact Profile (OHIP-EDENT-H) for edentulous subjects: A Cross-Sectional study

Aim

The study aimed to translate the OHIP-EDENT into Hindi and assess its validity and reliability.

Methods

The study included 150 participants whose demographic information was collected using the Modified Kuppuswamy Socio-economic Scale. The Oral Health Impact Profile in Edentulous (OHIP-EDENT) was translated into Hindi using the standard forward-backward method. Test-retest reliability was assessed using the Intra-class Correlation Coefficient (ICC) and internal consistency using Cronbach's alpha. The Kaiser-Meyer-Olkin (KMO) test and Bartlett's test of sphericity coefficient were used to conduct Exploratory Factor Analysis (EFA) and confirm the Construct validity. To establish Convergent validity, the relationship between the global question and the OHIP-EDENT-H subscale scores was observed.

Results

The data was analyzed with a confidence level of 95 %, and statistical significance was interpreted as a p-value of less than 0.05. The Cronbach's alpha score for OHIP-EDENT-H was 1.00, indicating high internal consistency. The corrected item-total correlations ranged from 0.665 to 0.923, and the total ICC score was 0.763, demonstrating good reliability. The subscales' intra-class correlation coefficient values ranged from 0.968 to 0.997, indicating high reliability. However, items 4, 6, 13, 17, 18, and 19 had factor loadings below the acceptable threshold of 0.40 in the factor analysis. Additionally, the total and subscale scores of the OHIP-EDENT-H showed significant correlations with global question, with correlation coefficients ranging from 0.665 to 0.923.

Conclusion

The Hindi version of OHIP-EDENT is a reliable and valid tool for evaluating the OHRQoL of Hindi-speaking edentulous individuals.

How to restore lower complete edentulism with implant-supported overdentures: an evidence-based clinical management

This clinical report demonstrates how a two-implant mandibular implant-supported overdenture is planned and executed. The following steps feature the dual scan technique as part of implant planning and a radiographic-turned-surgical stent to guide a freehand, two-stage surgical placement of two implant fixtures on the bilateral canine positions of the mandibular arch.

Single mandibular implant study - impact on dietary habits after 5 years of observation in patients with immediate and delayed loading protocols

OBJECTIVES

Single midline implants in the edentulous mandible can be used to support existing complete dentures to improve patients' satisfaction and masticatory efficiency. The impact on patients' dietary habits and the influence of the loading protocol of the implants was the subject of this study.

MATERIALS AND METHODS

In this prospective randomized clinical trial, edentulous patients with existing complete dentures in both jaws were treated with a single midline implant in the mandible. In group A, the implants were loaded immediately, in group B the loading was delayed after three months. Patients were asked to report on their nutritional intake before implant placement and 12, 24 and 60 months after loading using a standardized two-part questionnaire.

RESULTS

Nutritional intake regarding the frequency of consumption of the requested food items did not change significantly during the 60-months study period, regardless of the loading protocol. In contrast, the second part of the questionnaire revealed that after 60 months, there was a significant decrease in avoidance of food, that had a coarse and hard texture in both groups. This significant decrease was observable in the group A in the first 12 and 24 months and in the group B after 60 months.

CONCLUSION

A change in the patients' dietary habits due to the insertion of a single midline implant in the mandible to support the existing complete denture cannot be observed, independently to the loading protocol.

CLINICAL RELEVANCE

Improving the chewing efficiency by single midline implants in the edentulous mandible does not lead to a change in dietary habits.

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

BACKGROUND

Wearing complete denture in one or both arches can impact enjoyment of eating and affect quality of life compared with being dentate. Clinicians focus on issuing technically sound dentures but ignore the impact of wearing dentures on the eating-related quality of life which affects the success of treatment.

OBJECTIVES

The aim of this research was to qualitatively explore ERQoL in Australian adults wearing complete dentures using a validated questionnaire and through focus groups.

METHODS

Complete denture wearers (n = 44) were recruited from dental clinics and invited to complete the self-administered Emotional and Social Issues Related to Eating questionnaire. Responses were categorised under the six questionnaire domains. A subsample of 20 participants who completed the questionnaire were invited to participate in focus groups to identify emerging themes.

RESULTS

Twenty-three participants (52.3%) completed the questionnaire. Most participants expressed a decline in enjoyment of eating due to reduced ability to eat, longer chewing times and the need to frequently clean dentures while eating. Focus groups (n = 2 × 4 participants) indicated educational materials on eating with dentures would increase recognition of eating problems with dentures and reduce trial and error approaches to dealing with these.

CONCLUSION

ERQoL is adversely affected by wearing complete dentures due to functional limitations, restricted food choices and adaptive eating behaviours. Patient support for eating well with a complete denture/s wearers is required.

The Effects of the Expansion of Dental Care Coverage for the Elderly

BACKGROUND

Expanding dental care coverage for the elderly is globally recommended but not widely implemented due to its high costs and intangible benefits.

METHODS

This study examined the impact of such an expansion in Korea using the imputation-based method proposed by Borusyak et al. We analyzed data from the Korea National Health and Nutrition Examination Survey (2007-2019) on dental service utilization and chewing ability among older adults.

RESULTS

The policy resulted in a 13.5% increase in partial denture use and a 60.5% increase in dental implants among those aged 65 and above. These changes corresponded with reductions in severe chewing difficulty by 23.3% and 13.0%, respectively. No significant changes were observed in full denture use. The price elasticity of demand for partial dentures and dental implants was estimated to be -0.19 and -0.86, respectively.

CONCLUSIONS

These findings underscore the critical role of affordability in enhancing the utilization of dental implants among the elderly and highlight the importance of appropriately expanding dental insurance coverage to improve oral health outcomes in this population.

Digital workflow for fabricating an implant-supported overdenture with the custom disk method

Although methods have been developed to fabricate complete digital dentures, a digital workflow of fabrication methods for complete dentures with metal frameworks such as implant overdentures has not yet been established. The purpose of this dental technique article was to provide a comprehensive description of implant overdenture fabrication techniques using a digital workflow originally devised by applying the custom disk method. In this method, the custom disk was made of resin and contained prefabricated artificial teeth. Both the denture base and the artificial teeth in the custom disk were milled together. This described technique focuses on a 4-implant-supported overdenture with metal reinforcement for an edentulous maxilla. The aim was to establish a standard that can be widely adopted not only for implant overdentures but also for complete dentures that contain a metal framework. Advantages of this technique include that it enables the application of the custom disk method to the fabrication of implant overdentures with a metal framework as a reinforcement. In this technique, a metal framework is integrated into a resin-based complete denture fabricated by using the custom disk method, providing a better fit of the denture base and precise positioning of the artificial teeth.

Comparing Skin Tones to Shades of Upper Anterior Teeth: An Observational Study among Nigerian Adults

BACKGROUND

Skin tones may be predictive of anterior tooth shade. An analysis of the relationship of skin tone to anterior tooth shade within a population may facilitate the prescription of complete dentures with optimal esthetics and realism.

AIM

This study aimed to assess the relationship between skin tones and shades of upper anterior teeth among a diverse Nigerian adult population.

METHODS

The study was conducted between February and December 2022 among consecutive healthy adults recruited from dental clinics of five teaching hospitals in four cities located across four geopolitical zones of Nigeria. Skin tones were recorded using the National Immigration Service (NIS) Skin Color scale. The Vitapan Classic® shade guide was used to record the tooth shade of the upper central incisors and canines. Bivariate and multivariate tests of associations were performed, and predictive probabilities were developed.

RESULTS

A total of 1070 adults with a mean age of 30.8 ± 10 years participated in the study. NIS skin tones 6 (29.8%) and 5 (27.7%) were the most common, while hues A (48.7% in incisors and 48.4 % in canines) and B (41.1% in incisors and 40.1% in canines) were predominant. The values of the incisors and canines were positively related to skin tone (P = 0.001) and age (P = 0.001 for incisors and P = 0.003 for canines). Hue was also significantly associated with skin tone for canines (P = 0.01) and gender (P = 0.001). Regression models showed increasingly darker skin tones were positively related to duller values for incisor teeth (β = 0.173, OR =1.19, P < 0.001). The values for canines were more likely to be >2 (β = 0.118, OR =1.12, P = 0.01), but without significant positive relationship to increasingly darker skin tones (β = -0.99, OR =0.91, P = 0.22).

CONCLUSION

Skin tones were associated with upper anterior tooth shade. There was a positive relationship between skin tones and the shades of upper anterior teeth. Skin tones could guide the clinician in shade selection during complete denture prescriptions.

CAD/CAM versus traditional complete dentures: A systematic review and meta-analysis of patient- and clinician-reported outcomes and costs

STATEMENT OF PROBLEM

Computer-aided design and manufacturing (CAD/CAM) have been increasingly used to enhance the patient and clinician experiences with removable complete dentures (CDs). Yet, evidence from systematic reviews is lacking to validate the clinical significance of these digital prostheses.

PURPOSE

The purpose of this systematic review was to compare CAD/CAM CDs with the traditional ones in terms of patient and clinician-reported outcomes, post-insertion adjustment visits and costs.

MATERIALS AND METHODS

An electronic search of four databases [Medline (Ovid), Embase, Scopus and Cochrane CENTRAL; last update: May 2022] was performed to retrieve clinical studies comparing CAD/CAM and traditional CDs. Two independent reviewers screened the articles, extracted data (methods and outcomes) and assessed risk of bias of the included studies. The following outcomes underwent meta-analysis (random-effects model): overall patient and clinician satisfaction, oral health-related quality of life (OHRQoL), number of post-insertion adjustment visits, as well as laboratory and total costs.

RESULTS

This review included 11 studies. Meta-analysis revealed that CAD/CAM CDs are comparable to the traditional CDs in terms of overall patient satisfaction and OHRQoL. Clinician-reported data depended on the manufacturing technique: whereas milled CDs performed better than traditional CDs in terms of clinician satisfaction and number of adjustments, 3D printed and traditional CDs were similar. Fabrication of CAD/CAM CDs required significantly less laboratory and overall costs than the traditional CDs.

CONCLUSIONS

There is some evidence showing that CAD/CAM CDs are at least comparable to traditional CDs. Further well-designed randomized clinical trials are needed to evaluate the performance of specific CAD/CAM approaches for manufacturing CDs, however.

Immediate Loading Implant-Supported Fixed Full-Arch Rehabilitation Using a New Clinical Decision-Support System: A Case Series

Background Implant-supported full-arch rehabilitation is an effective treatment for edentulous patients. It restores mastication, facial aesthetics, and psychological well-being. Patient-related outcome measures support the validity of this approach, emphasizing the importance of effective prosthodontic interventions for this patient population. This study aims to present a case series for fixed implant-supported full-arch rehabilitation using the new Carames classification (CC). Methods A total of seven patients with generalized periodontitis or non-restorable multiple teeth were indicated for extraction and replacement with a fixed full-arch implant-supported prosthesis. According to the Carames classification, most cases were categorized as CCI or CCII classes for both the upper and lower jaws. Before the surgery, screw-retained provisional complete dentures were constructed and adjusted for the vertical occlusal dimension and smile lines. After the extractions, 70 implants were immediately placed in one or both arches for the seven patients, followed by bone grafts with the dual-zone grafting technique. Multi-unit abutments were then placed and welded to a metal bar for stable fixation. The provisional denture was fitted snugly over the metal bar for immediate functional loading. After three months of healing, it was used as a biocopy to fabricate the final prosthesis. The implant loss and the peri-implant marginal tissue health status were assessed annually for three years. Statistical analysis compared the marginal bone loss as a change from the baseline over the year. Results No implant or prosthesis loss was reported over the three years. Peri-implant marginal tissue health showed promising results without bleeding and suppuration on probing and probing depths between 3 and 3.5 millimeters. Marginal bone loss was minimal over the three years, with some cases showing bone gain. Conclusion Using the Carames classification as a clinical decision support system in implant-supported full-arch rehabilitation showed promising results in peri-implant tissue health and no implant loss during three years of follow-up. The implant placement and prosthesis fabrication protocol in this study could be valuable for further research.

Changes in masticatory performance and bite force after treatment with mandibular overdentures retained by four titanium-zirconium mini implants: One-year randomised clinical trial

OBJECTIVE

This prospective study is part of a randomised clinical trial and reports the changes in masticatory performance (MP) and bite force, and explores their influential factors, 1 year after the provision of mandibular overdentures retained by four titanium-zirconium mini implants.

METHODS

Edentulous patients received conventional complete dentures, followed by placement of four mini implants (Straumann® Mini Implant System) in the anterior mandible and converting the conventional prosthesis into a mandibular overdenture. Treatment protocols were randomised using a 2×2 factorial design combining different surgical (flapped vs. flapless) and loading (immediate vs. delayed) protocols. MP was assessed using a two-colour mixing ability test and a colorimetric analysis to measure the level of colour mixing (Variance of Hue-VoH). Maximum voluntary bite force (MBF) was measured by a digital gnathodynamometer in the posterior and anterior regions. Sex, age, surgical and loading protocols and ridge morphology were tested as independent variables. MP and MBF tests were performed at baseline (pre-treatment) and the 3-, 6- and 12-month after implant loading. Descriptive statistics, independent t-test, and linear mixed-effect model (LMM) regression were used for data analysis.

RESULTS

Seventy-four participants were assessed and 73 completed the 1-year follow-up. Statistically significant improvements in functional parameters were observed in all follow-up periods compared to baseline (p < .001). The flapless protocol was associated with higher improvement in MP at the 3-month follow-up (p = .004), while less resorbed ridges were associated with better MP (p = .038) and higher MBF (p < .001).

CONCLUSION

The mandibular overdenture protocol using four titanium-zirconium mini implants was effective in improving MP and MBF of edentulous patients, compared to pre-treatment values. The findings also suggest that improvements in chewing function and bite force are impacted by clinical factors since better outcomes were observed for flapless surgeries and less resorbed edentulous ridges.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.Gov ID NCT04760457.

Comparison of perceived masticatory ability in completely edentulous patients treated with thermoplastic complete denture versus single implant-retained mandibular overdenture: a single-center prospective observational study

Background

This study aimed to compare the perceived masticatory ability (PrMA) in completely edentulous patients (EDPs) with thermoplastic conventional complete dentures (CDs) versus single implant-retained mandibular overdentures.

Methods

The current study was conducted in the outpatient Prosthodontic Clinic, Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt. PrMA was evaluated in 45 completely edentulous patients (46% males, mean age 50.4 ± 4.7 years). Each patient received a thermoplastic PMMA complete denture (Polyan IC TM Bredent GmbH & Co.KG, Germany). The PrMA was evaluated at one-month and six-month intervals of denture use. An immediate loading single implant was placed into the mid-symphyseal for each patient, and the denture was adjusted. Subsequently, the PrMA was reevaluated after one month and six months. The data were collected and statistically analyzed using the SPSS@V25 to assess the changes in PrMA.

Results

The PrMA demonstrated improvement after six months of thermoplastic conventional denture use. However, this improvement was not statistically significant (p = 0.405). In addition, the PrMA showed a substantial increase following a single implant placement at one and six months (p < 0.001) of the overdenture use compared to the conventional denture. The PrMA insignificantly improved (p = 0.397) after six months of the single implant retained overdenture use.

Discussion

The study's findings indicate that using immediate loading single implant-retained mandibular overdentures significantly improved PrMA in completely edentulous patients.

Estimation of alpha amylase, cortisol, and pH level in saliva of patients wearing conventional and Biofunctional Prosthetic System complete dentures: A parallel randomized clinical trial

STATEMENT OF PROBLEM

Biofunctional Prosthetic System (BPS) complete dentures have been reported to maintain a harmonious relationship with the surrounding oral structures and provide improved adaptation compared with conventional complete dentures. However, an evaluation of salivary changes and its constituents between BPS and conventional dentures is lacking.

PURPOSE

The purpose of this parallel randomized clinical trial was to evaluate the alpha amylase, cortisol, and pH levels in saliva in participants provided with conventional and BPS complete dentures.

MATERIAL AND METHODS

Sixteen completely edentulous participants were recruited for providing with conventional and BPS dentures (n=8). The levels of alpha amylase, cortisol, and pH in their saliva were evaluated by using an enzyme-linked immunosorbent assay (ELISA), colorimetric, and pH meter before insertion and 1 week and 1 month after denture insertion. The data were analyzed with repeated measure ANOVA and the Student t test (α=.05).

RESULTS

The mean ±standard deviation for pH was 6.94 ±0.22 in conventional complete dentures and 7.04 ±0.12 in BPS dentures; for alpha amylase, it was 206.75 ±14.64 and 210.88 ±15.72 IU/mL; and for cortisol, it was 0.29 ±0.05 and 31 ±0.04 nmol/L before insertion and 1 week and 1 month after denture insertion. From the repeated measures ANOVA, the mean pH and salivary cortisol were not statistically different (P>.05), but salivary amylase was statistically different (P<.05). The Student t test showed no significant difference in pH (P>.05), but a statistically significant difference in alpha amylase and salivary cortisol levels was found between the 2 groups (P<.05).

CONCLUSIONS

No significant difference in salivary pH was found in completely edentulous patients provided with conventional or BPS dentures, but significant differences were found in levels of alpha amylase and salivary cortisol.

Assessment of occlusion changes during laboratory phase of relining: An in vitro study

AIM

Assessment of occlusion changes during laboratory phase of relining is essential to evaluate the occlusal discrepancies that could get incorporated in the denture with the use of different relining materials. Since the long term stability and functional success of the denture is heavily influenced by occlusion, an In-vitro study to assess these changes after relining is warranted. The aim of the study is to evaluate the changes in occlusion during laboratory phase of relining procedure.

SETTINGS AND DESIGN

This is an in vitro study with a total of 30 specimen.

MATERIALS AND METHODOLOGY

A total of 30 maxillary standardized dentures were fabricated after mounting on a semi adjustable articulator. These samples will be divided into three groups based on the relining material used (Autopolymerizing resin, Heat-cure resin, Tissue conditioner). The vertical dimension, Centric contact points and eccentric contact points were measured before and after relining.

STATISTICAL ANALYSIS USED

The variables were tested to see if they had a normal distribution using the Shapiro-Wilk test. Parametric distribution was seen for ECP leading to further comparison using one way analysis of variance (ANOVA). Non-parametric distribution was found while testing the VD, CCP leading to adoption of Kruskal-wallis test for comparison of groups. Dunn Bonferroni test was done for VD since results were significant.

RESULTS

The results of this in-vitro study showed statistically significant difference with respect to change in vertical dimension in all groups pre and post relining (P = 0.005). The centric contact points showed lesser variation in position when comparing the pre to the post relining phase with the use of autopolymerising resins, whereas heat cure resins and tissue conditioners showed statistically significant difference in the centric point contacts post relining. No statistically significant changes were seen in eccentric occlusion post relining in all groups. Tissue conditioners showed minimum mean changes in eccentric contacts.

CONCLUSION

Within the limitations of this study, the use of autopolymerising resins depicted the most stable results with respect to occlusion, for relining of dentures.

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

BACKGROUND

Edentulism remains a major disability worldwide, especially among the elderly population, although the prevalence of complete edentulism has declined over the last decades. In Uganda, the prevalence of edentulism in people aged 20 years and above is 1.8%. The therapy for edentulous patients can be realized through the use of conventional removable complete dentures, implant-supported prostheses, and computer-aided design and computer-aided manufacturing (CADCAM), however, the provision of removable complete dentures continues to be the predominant rehabilitation for edentulous patients. However, no published study has explored the lived experiences with removable complete dentures among the Ugandan population. The aim of the present study was to explore patients' lived experiences on the usage of removable complete dentures among Ugandan edentulous patients attending Makerere University Dental Hospital.

METHODS

This was a qualitative study approach using purposive sampling. Fifteen (15) respondents were selected across social demographics. Interviews were recorded and transcribed and themes were generated to draw a deeper meaning to the usage of removable complete dentures. A qualitative statistical package, Atlas Ti software was used to generate themes from the interviews followed by an interpretation of the generated data and the results were presented as text and in a table.

RESULTS

The reported key positive experiences due to removable complete denture rehabilitation were the improvement in speech, eating ability, regaining good facial appearance, better oral hygiene management, self-esteem and confidence to smile in public, and a feeling of completeness. However, respondents complained of pain and discomfort due to the looseness of dentures, inability to eat certain foods, and regular cleaning of dentures. The respondents did not go through proper informed consent processes before getting removable complete dentures.

CONCLUSION

The study found that patients were satisfied with their removable complete dentures rehabilitation due to the positive experiences registered, such as the ability to eat and talk well, and restoration of self-esteem, all of which improved their quality of life. However, they experience pain and discomfort due to the looseness of dentures.

Oral-Health-Related Quality of Life in Elderly Edentulous Patients with Full-Arch Rehabilitation Treatments: A Systematic Review

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.

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.

Ultrasound analysis of the masseter and anterior temporalis muscles in edentulous patients rehabilitated with full-arch fixed implant-supported prostheses

OBJECTIVES

Total tooth loss is common in the aging population resulting in insufficient chewing function with subsequent weakening of the masticatory muscles. The study aims to evaluate the changes in thicknesses of the masseter and anterior temporal muscle in edentulous patients following the reconstruction of implant-supported fixed prostheses and compare them with the dentate individuals.

MATERIALS AND METHODS

The study was designed as a prospective, single-center, controlled clinical trial. A total of 60 participants were included in the present study. The patients were divided into two groups; Group I (Test Group): 30 edentulous patients who received implant-supported fixed prostheses, Group II (Control Group): 30 dentate individuals of an age and sex-matched group. Ultrasonography was used to measure the cross-sectional thickness of the left and right musculus masseter and anterior temporalis immediately after the cementation of the prosthetic rehabilitation (T1), on the 1st (T2) and 6th (T3) months after rehabilitation and at a single time point in the control group.

RESULTS

The results showed that there were significant comparison differences in muscle thickness at the baseline measurements between groups while at the end of the 6th month, these differences were not significant. The muscle thicknesses of both the masseter and anterior temporalis muscles increased significantly at T2 and T3 compared to T1 in the test group. The asymmetry index between the left and right muscles in the test group and the asymmetry differences between groups also decreased significantly at the end of the 6th month.

CONCLUSION

The implant-supported fixed prostheses significantly increase the thicknesses of the masseter and anterior temporal muscle together with a decrease in the asymmetry between the left and right muscles. At six months, implant-treated patients showed similar muscle thicknesses compared to dentate individuals.

CLINICAL RELEVANCE

The findings suggest that implant-supported fixed prostheses can improve the masticatory function and facial symmetry of edentulous patients.

Focus of dental sleep medicine on obstructive sleep apnea in older adults: A narrative review

PURPOSE

To review dental sleep medicine in older adults based on the literature.

STUDY SELECTION

This narrative review focuses on sleep physiology, common sleep disorders, and obstructive sleep apnea (OSA) in older adults and their management.

RESULTS

Sleep physiology differs between older and younger adults, with sleep disturbances occurring more frequently in older adults. The prevalence of insomnia increases in older adults due to age-related changes in sleep physiology. Insomnia, sleep-disordered breathing, periodic limb movement disorder, restless legs syndrome, and rapid eye movement (REM) sleep behavior disorder are common sleep disorders in older adults. OSA is more prevalent in older adults, and its effects on them are considered more substantial than those on younger adults. The treatment of older patients with mandibular advancement devices may be less effective and more complex owing to potential impairments in oral and dental health. Furthermore, the prevalence of edentulism in older adults is decreasing while life expectancy is increasing.

CONCLUSIONS

As older adults have comorbidities that affect sleep quality, dentists should consider the effects of sleep physiology and sleep disorders in these patients. OSA may decrease the quality of life and increase the risk of developing other diseases. Therefore, dentists proposing treatment with mandibular advancement devices need to inform patients of their potential lack of efficacy and the requirement for careful follow-up owing to known and unknown side effects.

Masticatory performance, self-perception of oral health, oral health-related quality of life and nutritional status of completely edentulous elderly patients submitted to different rehabilitation treatments: A cross-sectional study

BACKGROUND

The impact of treatments on completely edentulous individuals on masticatory performance (MP), oral health-related quality of life (OHRQoL), nutritional status (NS) and socio-economic profile (SP) is unclear in the literature.

OBJECTIVE

To compare the MP, OHRQoL, NS and SP of totally edentulous elderly users of bimaxillary complete dentures (CD) and users of lower implant-supported fixed complete dentures (IFCD).

METHODS

Forty participants were allocated into groups according to rehabilitation treatment (n = 20): bimaxillary CD (G1) and lower IFCD, and upper CD (G2). The evaluation of MP used almonds by the method of sieves. Four questionnaires (Geriatric Oral Health Assessment Index-GOHAI and Oral Health Impact Profile Edent-OHIP-Edent, Brazilian Economic Classification Criteria-ABEP and Mini Nutritional Assessment-MNA) were applied to assess the OHRQoL, SP and NS of the elderly, respectively. After evaluating the statistical assumptions, the Mann-Whitney (α = .05) test was applied to compare the groups regarding MP, OHRQoL, NS and SP. Spearman's correlation (α = .05) was performed to verify the correlation between the MP, the OHRQoL and the NS of the participants.

RESULTS

G2 showed better MP (p < .05) in all masticatory cycles, OHRQoL (p < .05) and NS than the G1. However, the participants' self-perception of oral health did not differ between groups (p < .05). A moderate negative correlation was found between MP and OHRQoL for 40 masticatory cycles (r2  = -0.513; p = .001).

CONCLUSION

Individuals rehabilitated with IFCD had a higher average monthly family income and achieved superior behaviour in MP and OHRQoL, in addition to lower risks of malnutrition when compared to individuals using bimaxillary CD.

Digital workflow for duplication of gold onlay anatomy to monolithic zirconia onlay for a complete denture: A technique paper

Digital replication of an existing cast gold onlay anatomy to a more esthetic material for a new complete denture is challenging. A technique is presented that uses digital technology to fabricate a new maxillary complete denture with monolithic zirconia onlays that duplicate the anatomy of an existing complete denture with cast gold onlays.

Assessment of usefulness and reliability of YouTube™ videos on denture care

INTRODUCTION

The world's population is in a demographic transition with a rising ageing population. Tooth loss is frequent among older people resulting in the replacement of natural teeth using complete or partial dentures. YouTube™ is the second most popular website in the world and is being increasingly used to access health care information. The aim of this study is to evaluate the usefulness and reliability of the information in YouTube™ videos regarding denture care.

METHODS

The YouTube™ website was used to systematically search for videos using the keyword 'denture care'. Videos meeting the eligibility criteria were assessed separately by two independent researchers. The usefulness of the videos was assessed using the Global Quality Assessment Scale and a customized usefulness scoring scheme. Based on these scores, the usefulness of the videos was categorized as low, medium and high. A modified DISCERN tool (mDISCERN) was used for assessing reliability with scores ranging from 0 to 5. Other video characteristics like source/ownership of the videos, duration, views, likes, dislikes, number of days posted, like ratio, view ratio, interaction index and Video Power Index were also obtained. Statistical analysis was carried out using the Kruskal-Wallis test, Spearman correlation test and multiple linear regression analysis.

RESULTS

A total of 120 videos were included. Based on the usefulness score, the usefulness of 65.8% of videos were classified as low, 32.5% were medium and 1.6% had high usefulness. The mDISCERN score for 74.2% of videos was 2 or below 2 indicating that the majority of videos had low reliability. Video characteristics did not differ significantly according to the usefulness of videos. Videos uploaded by dentists or dental hygienists had significantly higher usefulness scores (p < 0.001) in comparison to videos uploaded by other sources. However, reliability scores did not differ based on the sources of the videos. Video reliability was found to have a significant (B = 2.08, p < 0.001) positive association with video usefulness.

CONCLUSION

YouTube™ cannot be recommended as the only source of information for denture care as most videos received low usefulness and reliability ratings in our study. Dentists and dental health professionals could take an active part in enhancing denture care-related content on YouTube™ and enable patients to have adequate and reliable knowledge of denture hygiene practices.

CAD/CAM full-mouth rehabilitation of an elderly patient: One-piece digital complete denture meets multilayered zirconia with gradient technology

OBJECTIVE

This article highlights a CAD/CAM complete-mouth rehabilitation in an 82-year-old patient by means of a complete maxillary prosthesis and mandibular implant- and tooth-supported fixed restorations made from multilayered zirconia.

CLINICAL CONSIDERATIONS

Comprehensive complete-mouth rehabilitations in elderly patients with adaptation of the occlusal vertical dimension (OVD) often present particular challenges. This applies especially when exacting functional and esthetic requirements are to be met and the treatment should not cause the patient too much effort, still ensuring the highest level of quality and efficiency and a low intervention rate.

CONCLUSION

The digital approach used for the present patient allowed for an efficient treatment procedure, facilitated virtual evaluations using a face-scan, and enhanced the predictability of the prosthodontic outcome. The approach enabled some steps required in the conventional protocol to be omitted, resulting in a straightforward clinical treatment with minimal strain on the patient.

CLINICAL SIGNIFICANCE

Because of the comprehensive recording of extraoral and intraoral data, for example with a facial scanner, it was possible to transfer a digital replica of the patient to the dental laboratory technician. With this protocol, many steps can be performed in the absence of the real patient.

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.

Mini-implant mandibular overdentures under a two-step immediate loading protocol: A 4-6-year retrospective study

OBJECTIVES

This retrospective study to evaluate the treatment outcomes of mandibular mini-implant overdentures (MIODs) placed under a two-step immediate loading protocol.

BACKGROUND

The mini-implant overdenture emphasises the advantages of simplicity using flapless surgery and immediate loading. However, some mini-implant have lowe initial stability.

MATERIALS AND METHODS

A total of 30 participants who used mandibular MIODs and maxillary removable complete dentures (RCDs) over 4 years were included. Four one-piece mini-implants (<3 mm in diameter) were placed by a flapless surgical approach after fabrication of new RCDs, and the O-ring attachment was attached at least 8 weeks after implant placement.

RESULTS

The average observation period was 58.9 ± 9.2 months after mini-implant loading. The survival rate of the implants was 100.0%, and the overall change in mean marginal bone level (ΔMBL) was -0.9 ± 1.1 mm. The implant success rate was 83.3% at the implant level, and 66.7% at the patient level. The mean initial Periotest value was 0.9 ± 3.1, and it was positively associated with ΔMBL and implant success (P < .05). Patient satisfaction improved after conversion from RCDs to MIODs (P < .05), and mastication and pain showed greater satisfaction with longer loading time (P < .05).

CONCLUSIONS

The mandibular MIODs could be chosen as an alternative treatment under a two-step immediate-loading protocol in edentulous patients with limited alveolar bone volume. To ensure superior treatment outcomes of MIODs, initial stability of implant must be obtained using as wide a diameter as possible within the anatomically allowable limits.

Effects of build orientation and bar addition on accuracy of complete denture base fabricated with digital light projection: An in vitro study

PURPOSE

We evaluated the effects of build orientation and bar addition between lingual flanges on the accuracy of mandibular denture bases fabricated using a digital light processing (DLP) device.

METHODS

Mandibular denture bases with and without a bar at the lingual flanges were virtually designed and assigned to eight build orientations. Six dentures per condition were fabricated using a DLP device with a methacrylate-based photopolymerizable monomer (Dima Print denture base) (n=96). The fabricated denture surfaces were digitized, and intaglio surfaces were obtained. These digitized surfaces were compared via superimposition using graphical software (Artec studio12 profession) to their original designed files, and root mean square estimates were obtained. The trueness of the entire and intaglio data was statistically analyzed non-parametrically.

RESULTS

The range of trueness of the entire and intaglio denture bases was 0.15-0.31 mm and 0.11-0.38 mm, respectively. The trueness at 135° and 270° for the entire denture base and that at 270° for the intaglio data without the bar were significantly lower than those for the other build orientations. The trueness at 270° was <0.15 mm irrespective of the conditions. The trueness with the bar of all build orientations, except that of 0° for intaglio data, was significantly smaller than or equal to the trueness without the bar of the corresponding build orientations.

CONCLUSIONS

Build orientation and bar addition influenced the accuracy of the complete dentures fabricated using DLP. A build orientation of 270° is recommended for fabricating a mandibular complete denture, irrespective of the bar addition.

Effects of silver nanoparticle-based antimicrobial formulations on the properties of denture polymer: A systematic review and meta-analysis of in vitro studies

STATEMENT OF PROBLEM

Denture stomatitis and other oral infections are prevalent in denture wearers and can be treated effectively with an antimicrobial agent such as a silver nanoparticle-based polymer. However, the physical properties of the denture should not be adversely affected by the addition.

PURPOSE

The purpose of this systematic review and meta-analysis of in vitro studies was to analyze the effects of a silver nanoparticle-based antimicrobial resin on the properties of polymethyl methacrylate(PMMA)-based denture resin.

MATERIAL AND METHODS

Full-length English language articles reporting silver nanoparticle-based PMMA resin were included in the review, with no limitation on the year till May 2020. Scopus, Web of Sciences, and PubMed databases were accessed for the literature survey. The review was formulated based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and used the Consolidated Standards of Reporting Trials (CONSORT) guidelines and risk of bias Cochrane tool for quality assessment. A meta-analysis of flexural strength was performed by using a random-effects model at a 95% confidence interval. The other properties were analyzed descriptively.

RESULTS

Silver nanoparticle reinforcement caused considerable differences in the inherent physical material properties of PMMA.

CONCLUSIONS

An antimicrobial polymer nanocomposite formulation can either negatively affect or bring no improvement to the physical properties of denture resin.

3D-Printable Denture Base Resin Containing SiO2 Nanoparticles: An In Vitro Analysis of Mechanical and Surface Properties

PURPOSE

To evaluate the flexural strength (FS), impact strength (IS), surface roughness (Ra), and hardness of 3D-printed resin incorporating silicon dioxide nanoparticles (SNPs).

MATERIALS AND METHODS

A total of 320 acrylic specimens were fabricated with different dimensions according to test specifications and divided into a control group of heat denture base resin, and 3 test groups (80/test (n = 10) of unmodified, 0.25 wt%, and 0.5 wt% SNPs modified 3D-printed resin. 10,000 thermal cycles were performed to half of the fabricated specimens. FS, IS (Charpy impact), Ra, and hardness were evaluated and the collected data was analyzed with ANOVA followed by Tukey's post hoc test (α = 0.05).

RESULTS

Incorporating SNPs into 3D-printed resin significantly increased the FS, IS (at 0.5%) and hardness compared to unmodified 3D-printed resin (p < 0.001). However, the FS of pure 3D-printed and 3D/SNP-0.50% resin and IS of all 3D-printed resin groups were significantly lower than the control group (p < 0.0001). Hardness of 3D/SNP-0.25% and 3D/SNP-0.50% was significantly higher than control and unmodified 3D-printed resin (p < 0.0001), with insignificant differences between them. The Ra of all 3D-printed resin groups were significantly higher than control group (p < 0.001), while insignificant difference was found between 3D-printed groups. Thermal cycling significantly reduced FS and hardness for all tested groups, while for IS the reduction was significant only in the control and 3D/SNP-0.50% groups. Thermal cycling significantly increased Ra of the control group and unmodified 3D-printed resin (p < 0.001).

CONCLUSION

The addition of SNPs to 3D-printed denture base resin improved its mechanical properties while Ra was not significantly altered. Thermal cycling adversely affected tested properties, except IS of unmodified 3D-printed resin and 3D/SNP-0.25%, and Ra of modified 3D-printed resin.

Decision to use denture adhesive in complete denture wearers after one-month run-in period: A quasi-experimental study

OBJECTIVES

The aim of this study was to assess two patient-based outcomes of complete denture (CD) wearers who continued or discontinued using denture adhesive (DA) after one-month run-in period of DA use.

METHODS

This quasi-experimental study comprised 76 CD wearers. The two patient-based outcomes were oral health-related quality of life and masticatory performance, determined by the Thai-version of oral impacts on daily performances index and multiple sieve method of 20-stroke peanut mastication. Denture retention and stability were evaluated using the CU-modified Kapur criteria to classify the CD into acceptable or unacceptable quality. The outcomes were collected at 3 time points: 1) at baseline (T0), 2) after a 1-month run-in period of DA use (T1), at which time the participants decided whether to continue using DA, and 3) 1-month after continuing or discontinuing using DA (T2). Changes in the percentages of having an oral impact from T0 to T2 were evaluated using the McNemar's test. The effect of denture quality and the decision to use DA on peanut particle size across time points were assessed using repeated measures ANOVA. The peanut particle size changes in each group between time points were evaluated using the one-way repeated measures ANOVA and Tukey post-hoc comparison test.

RESULTS

The participants who continued using DA at T2 had greater oral impact reduction after the 1-month run-in period of DA use, whereas cleaning and emotional impacts emerged in those who discontinued using DA. At T1 and T2, the peanut particle size of the participants who continued and discontinued using DA was not significantly changed from T0, except for the acceptable CD wearers who discontinued using DA at T2, whose peanut particle size decreased from T0 to T2.

CONCLUSIONS

Baseline oral impacts and their change influenced CD wearers' decision whether to continue using DA. However, masticatory performance did not affect the patients' decision.

Toxicity potential of denture adhesives: A scoping review

STATEMENT OF PROBLEM

Denture adhesives are widely used products, but limited evidence regarding their toxicity is available.

PURPOSE

The purpose of this scoping review was to map the existing literature on the toxic potential of denture adhesives.

MATERIAL AND METHODS

This scoping review was structured based on the 5-step methodology proposed by Arksey and O'Malley and The Joanna Briggs Institute Manual for Evidence Synthesis and followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews. The methods were registered on the Open Science Framework (). The following research question was formulated: Are there any toxic effects related to the use of denture adhesives? The electronic literature search was performed independently by 2 authors in the following databases: PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library. The inclusion criteria were in vitro and clinical studies; studies that evaluated the cytotoxic properties of denture adhesives as local or systemic implications; and studies published in English.

RESULTS

The search conducted in October 2020 provided 1099 articles. In total, 33 studies were included, 14 in vitro and 19 clinical studies. Commercially available denture adhesives have a dose-dependent cytotoxic effect on fibroblasts and keratinocytes, with poor cell recovery noted in older human fibroblasts. Patients presented different levels of neurologic or hematological alterations associated with the excessive use of denture adhesives.

CONCLUSIONS

Most commercially available denture adhesives have a dose-dependent cytotoxic effect, and the use of well-adapted removable dental prostheses, proper patient follow-ups, and correct instructions for their use when indicated should be a priority.

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.

Oral Health-Related Quality of Life Changes after Clinical Remounting of Existing Dentures

The clinical remount is an accurate and efficient way to reset the occlusion of delivered removable dentures if major occlusal correction is required. Although previous studies have reported that clinical remounting of existing dentures enhances patients’ oral function, little subjective feedback is available. This retrospective study reports short-term changes in oral-health-related quality of life (OHRQoL) and masticatory function after clinical remounting of existing dentures. Three time points were defined: before adjustment (T0), immediately after adjustment (T1), and 1 week after adjustment (T2). The medical records of seven patients were analyzed. The mean age of participants was 77.71 years, and the mean service period of their prostheses was 9.43 months. The mean scores of the OHIP-EDENT-J questionnaire at the respective time points were 35, 21.14, and 22.14. The mean readings of masticatory function at the respective time points were 76.71, 89.29, and 111.86. Significant differences in the OHIP-EDENT-J were found between T0 and T1, and T0 and T2; and in masticatory function between T1 and T2, and T0 and T2. The results indicated that after rebalancing of the occlusion of the existing dentures, the patient-reported OHRQoL was improved immediately and maintained at least for a short time, and masticatory function was enhanced over a 1-week period.

Clinical evaluation of complete denture fabricated using two different final impression techniques on masticatory efficiency and oral health-related quality of life

Aim

To compare the effect of complete denture fabricated using selective pressure impression and functional impression technique on masticatory efficiency and oral health-related quality of life (OHRQoL) in patients with resorbed ridges.

Settings and Design

A randomized two arm, parallel group study.

Materials and Methods

Forty-eight participants with set inclusion and exclusion criteria were randomly allocated into two groups. Complete denture was fabricated in Group A and Group B using selective pressure and functional impression technique, respectively. The follow-up was done at 3 months. Masticatory efficiency was measured by color-changing chewing gum, and OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI) Hindi Version.

Statistical Analysis Used

The Wilcoxon signed-rank test was applied to check the intergroup analysis for the GOHAI scores of both impression techniques. The Mann-Whitney U test was applied to compare intragroup analysis for masticatory efficiency and the GOHAI scores of both the techniques.

Results

A total of 45 participants completed the follow-up. The mean age of the total participants was 62.7 ± 3.8. No statistically significant difference (P > 0.05) was observed between the masticatory efficiency and post-GOHAI scores of both the impression techniques.

Conclusion

Selective pressure and functional impression techniques may be successfully used to fabricate complete dentures for patients with resorbed ridges.

Influence of diameter on mechanical behavior of morse taper narrow implants

Dental implants could give back function, esthetics and quality of life to patients. The correct choice of the implant, especially in borderline cases, is essential for a satisfactory result. Aim: Thus, the objective of this study was to evaluate the mechanical behavior of Morse taper implants with two different prosthetic interfaces. Methods: Twenty self-locking Morse taper implants, 2.9 mm in diameter (FAC), and 20 Morse taper implants, 3.5 mm in diameter (CM) were divided into two groups (n=10), and submitted to strength to failure test, optical microscopic evaluation of fracture, metallographic analysis of the alloy, finite element analysis (FEA) and strain gauge test. A Student’s t test (α = 0.05) was made for a statistical analysis. Results: For the strength to failure test, a statistically difference was observed (p <0.001) between FAC (225.0 ± 19.8 N) and CM (397.3 ± 12.5 N). The optical microscopic evaluation demonstrated a fracture pattern that corroborated with FEA´s results. The metallographic analysis determined that the implants of the FAC group have titanium-aluminum-vanadium alloy in their composition. In the strain gauge test, there was no statistical difference (p = 0.833) between CM (1064.8 ± 575.04 μS) and FAC (1002.2 ± 657.6 μS) groups. Conclusion: Based on the results obtained in this study, ultra-narrow implants (FAC) should ideally be restricted to areas with low masticatory effort.

Perception and attitudes of dentists regarding the complications of conventional acrylic dentures and overdentures supported by teeth or implants

This study aimed to assess the perception of dentists on the complications associated with prosthodontic treatments with acrylic dentures and overdentures in partially or complete edentulous patients. The study analyzed the complications of acrylic dentures and overdentures using a questionnaire with 24 open or closed questions, with single or multiple answers. The participants were 63 dentists, mostly women (77.8%), aged between 30 and 39 years old (52.4%), more than half of them with a clinical experience of less than 15 years. The main complications encountered were: lesions of the oral mucosa (52.4%), lack of maintenance (44.4%) or stability of dentures (39.7%), fracture of acrylic bases (14.3%), and detachment of attachment systems (44.4%). The complete maxillary acrylic dentures fractured most often (38.1%), frequently on the midline (58.7%), the main causes being accidental fall, masticatory stress, or lack of stability of the dentures. The most common intervention to correct the complications of dentures was the repair of fractured acrylic bases (33.3%). The study exposed that dentists are aware of the possible complications of acrylic dentures, which they correlate with the peculiarities of oral structures, but also with some deficiencies of prosthodontic restorations, materials and technologies. Maxillary acrylic dentures, overdentures, and partial acrylic dentures have a high risk and fracture rate, but the use of new technologies and materials can reduce the complications rate of acrylic dentures and overdentures.

Antimicrobial Properties of Silver-Modified Denture Base Resins

The surface quality of denture base resins allows for easy colonization by microorganisms including Candida albicans and Staphylococcus aureus, which cause major diseases of the oral cavity such as denture stomatitis. The widespread use of silver nanoparticles (AgNPs) in various fields of medicine has led to research of their possible application in dentistry, mostly in the prevention of bacterial adhesion, proliferation, and biofilm formation. The aim of the study was to synthesize cold and heat-curing denture base resins modified with AgNPs and AgCl, and evaluate the potential of the modified resins to reduce the growth of C. albicans and S.aureus. The produced material was characterized by Fourier transform infrared spectroscopy (FTIR). The antimicrobial potential of the modified material was demonstrated by the disc-diffusion method, microdilution method, and a modified microdilution method (i.e., disk-diffusion method in broth with viable counting). Spectroscopy confirmed the incorporation of biocidal materials into the structure of the denture base resins. The AgCl and AgNPs modified resins showed an antimicrobial effect. The significance of the study is in the potential therapeutic effects of the modified materials for prevention and threating staphylococci and candida in elderly patients, who are in most cases denture wearers and have a greater susceptibility to develop opportunistic infections. Modified denture base resins can significantly reduce the presence of infection at the point of contact between the denture and the mucous membrane of the prosthetic restoration. Biological tests of modified denture base resins will follow.

Evaluation of retention and wear of a titanium-formed stud overdenture attachment with different interimplant angulations after simulated clinical use: An in vitro study

STATEMENT OF PROBLEM

How implant alignment impacts stud attachment retention and wear-induced alterations, notably when the attachment exhibits metal-to-metal frictional interlocking, is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate the effect of the interimplant angulation on retention forces and wear changes before and after 2 years of simulated clinical use of implant overdentures retained by titanium stud overdenture attachments.

MATERIAL AND METHODS

The canine regions of 3 identical edentulous mandibular models were used to receive 2 dental implants analogs with TiTach attachments (Dental Evolutions, Inc) at interimplant angulations of 0, 30, and 60 degrees. Six identical overdentures were constructed over each model (n=6). A universal testing machine was used to determine overdenture retention forces at 0, after 1440, and after 2880 insertion and removal cycles to simulate the average insertion and removal cycles in 12 and 24 months. A stereomicroscope, a laser microscope, and a scanning electron microscope were used to evaluate the wear in the attachments. A linear regression model, ANOVA, and the Kruskal-Wallis tests were used to analyze the data (α=.05).

RESULTS

All groups demonstrated reduced retention over the study duration (P<.001). The retention forces of the 0- and 30-degree groups were not significantly different after 2880 insertion and removal cycles, but both were significantly higher than those of the 60-degree group (P=.002). Within each group, the wear pattern of the matrix cap was more noticeable than that of the patrix abutment, with increased wear changes as interimplant angulation increased (P<.001).

CONCLUSIONS

TiTach attachments could retain overdentures on parallel and divergent implants with a 30-degree angle of interimplant angulation. However, at a 60-degree angle of interimplant angulation, considerable reduction in retention forces and increased wear changes were observed after 2 years of simulated clinical use.

Perception of Edentulous Patients and Dental Professionals towards Care and Maintenance of Complete Denture Prostheses

METHODS

A descriptive qualitative study was conducted among 30 EDPs attending dental prosthetic clinics (DPCs) at the four centres in Fiji and 28 DPs at the four DPCs under purposive sampling. Semi-structured questionnaire with open-ended questions was used for in-depth interview (IDI) with EDPs via telephone and focus group discussion (FGD) with DPs virtually via Zoom. Participant responses were recorded and thematic analysis was used to manually analyze the verbatim transcripts.

RESULTS

Five themes were identified as perceptions of EDPs towards care and maintenance of CDP in Fiji: patient perceptions towards CDP, CDP care and maintenance, communication between DPs and EDPs, challenges faced in CDP, and management strategies to CDP care and maintenance. Seven themes were identified as perceptions of DPs: CDP guidelines, post-denture insertion advice, care and maintenance, challenges while treating EDPs, management strategies to challenges faced, communication and teamwork, and recommendations to improving quality of CDP delivery in Fiji.

CONCLUSION

Patients' perception towards care and maintenance of CDP was low. It is highly recommended for EDPs to adhere to CDP advice given by DPs whilst for DPs, it had been recommended to provide written, oral, and visual forms of CDP care and maintenance advice to EDPs for effectiveness.

Challenges faced by edentulous patients (EDPs) during complete denture prostheses (CDP) service delivery in Fiji - a qualitative study

BACKGROUND

Edentulism is a state of having no teeth in the oral cavity, an irreversible condition popularly known as the marker of disease burden on the oral health. For edentulous patients (EDPs) Complete Denture Prostheses (CDP) is a means to improve oral health. Due to limited studies in this area, this research aimed to explore the challenges faced by the EDPs during CDP service delivery in Fiji.

METHODS

A directed descriptive qualitative study was conducted among EDPs attending Dental Prosthetic Clinics (DPCs) at the four centres in Fiji under purposive sampling. A semi-structured questionnaire with open ended questions was used for in-depth interview with EDPs who had worn CDP for 1 year via telephone. Participant responses were recorded, transcribed verbatim and analyzed manually using thematic analysis.

RESULTS

A total of 30 EDPs participated in the study. Six themes were identified as challenges faced by the EDPs during CDP service delivery in Fiji: lack of information, non-compliance, overwhelmed by illness, reduction on quality of life (QoL) financial barriers to CDP treatment care and personal acceptance. 77% of EDPs felt they did not receive adequate information on CDP when attending DPCs which indicated the non-compliance nature irrespective of using and cleaning CDP on a daily basis. The Dental Professionals (DPs) at the DPCs gave their full support in attending to the CDP challenges faced by the EDPs in Fiji during the review clinics.

CONCLUSION

The EDPs expressed a variety of challenges that was faced while seeking appropriate CDP services in Fiji. The findings demonstrate the need to explore approaches to develop patients' engagement practices during CDP service delivery by the Dental professionals (DPs), which leads to effective oral health promotion in Fiji for CDP wearers.

Adaptation to New Dentures and 5 Years of Clinical Use: A Comparison between Complete Denture and Mini-implant Mandibular Overdenture Patients based on Oral Health-Related Quality of Life (OHRQoL) and Orofacial Esthetics

Objective of work

It is unclear how long patients need to adapt to new dentures. This study assessed adaptation and five years of clinical use, comparing complete denture wearers (CDs) and mini-implant mandibular overdenture wearers opposing a maxillary CD (MDI-OD), based on oral health reported quality of life (OHRQoL) and orofacial esthetics (OES).

Material and Methods

A total of 36 subjects in the CD group (25 females) and 30 subjects in the MDI group (20 females) completed the 5-year study. All patients received new CDs, but in the MDI-OD group, four mini-implants were inserted interforaminally in the mandible before denture manufacture. Participants filled in the OHIP-EDENT and OES questionnaires one day after dentures’ delivery, on the 3^rd, 8^th, 15^th, 30^th day, and at the 1-, 3- and 5-year follow-up examinations. Statistical analysis comprised descriptive methods, X² test, independent t-test, Friedman, and Mann-Whitney test.

Results and Conclusions

Both groups' adaptation to new dentures was completed within a month. The MDI-OD group had significantly better OHRQoL in all follow-ups except for the 3^rd and 8^th day, probably due to soreness and pain, the reason why the MDI-OD group had limitation in functioning in the first days after new dentures’ delivery. Already after the third year and at the fifth year, OHRQoL worsened (p<0.01) in both groups. However it was significantly more pronounced in the conventional CD wearers (p<0.01) than in the MDI-OD group. Orofacial esthetics was highly scored in both groups. The scores dropped down only after three years, equally in both groups.

Keywords

OHRQoL, OES, prospective study, complete dentures, mini-implants, adaptation

MeSH Terms

Complete Dentures; Dental Implants; Quality of Life; Dental Esthetics

Effects of conventional complete dentures and implant-supported overdentures on alveolar ridge height and mandibular bone structure: 2-year and 6-year follow-up study

OBJECTIVES

The aim of this study was to compare the changes in mandibular bone structure in edentulous patients who were rehabilitated with conventional complete dentures (CCD) and implant supported overdentures (ISO), by evaluating alveolar bone loss (ABL), panoramic mandibular index (PMI), mandibular cortical width (MCW), gonion index (GI), antegonial index (AI), and articular eminence inclination (AEI).

MATERIALS AND METHODS

Panoramic radiographs of 63 edentulous patients using CCD, 63 edentulous patients using ISO, and 126 patients without tooth loss were evaluated. Edentulous patients had a 2-year and 6-year follow-up panoramic radiograph image. ABL (anterior, premolar, and molar regions), MCW, PMI, AI, GI, and AEI were measured in each patient. Variation between measurements was analyzed using repeated measures ANOVA test and post hoc Tukey test.

RESULTS

Both edentulous groups showed significantly lower mean than without tooth lost group in all measures (p < 0.000). ISO group showed significantly lower mean ABL than CCD group in anterior (p = 0.000), right premolar (p = 0.005), left premolar (p = 0.005), right molar (p < 0.000), and left premolar (p < 0.000) regions in short term. ISO group showed significantly lower mean ABL than CCD group in anterior (p = 0.021), right molar (p < 0.000), and left premolar (p < 0.000) regions in long-term. There is no statistically significant difference between the CCD and ISO groups in right premolar (p = 0.200) and left premolar (p = 0.134) regions in long term. Both edentulous groups showed significantly lower mean MCW (p < 0.000), PMI (p < 0.000), AI (p < 0.000), GI (p < 0.012), and AEI (p < 0.002) than the without tooth loss group. There is no statistically significant difference between the CCD and ISO groups in terms of changes in the mean MCW, PMI, AI, GI, and AEI measurement in short and long term (p > 0.000).

CONCLUSIONS

In the short and long term, edentulism reduced alveolar crest height, MCW, and AEI in individuals, but had no effect on PMI, AI, or GI. The use of prosthesis did not prevent the decrease of alveolar crest height, MCW, or AEI (CCP or ISO). In the short and long term, however, ISO created less ABL in the mandibular anterior and molar regions than CCD.

CLINICAL RELEVANCE

ABL cannot be halted in edentulous people, but by using ISO instead of CCD for rehabilitation, resorption can be reduced.

Oral Function Rehabilitation with the Simplified Lauritzen Clinical Remount Technique in a Patient with Bimaxillary Alveolar Exostoses: A Case Report

This case report describes a 70 year-old man with IVA lung cancer who required oral function rehabilitation by fabricating dentures with a simplified clinical remount technique. A pair of dentures were fabricated for a 70-year-old man with stage IVA lung cancer. Due to severe bimaxillary exostoses, the dentures could not properly extend and achieve a peripheral seal. The treatment philosophy was to stabilize the dentures and achieve proper function with optimized occlusion. The simplified Lauritzen clinical remount technique was performed at the time of denture delivery and 3 months later. After the second clinical remount procedure, the patient was able to eat meals with the dentures and maintained in a stable condition. Compared with the original technique, the simplified Lauritzen clinical remount omits the facebow transfer and keeps the condylar guidance setting and the Bennett angle unchanged during the adjustment. The prostheses are mounted to a type 3, non-arcon type articulator with anterior stop screws attached to the bilateral condylar parts. With the aid of anterior stop screws, the eccentric movement of dentures can be differentiated on a millimeter scale and balanced easily. It is effective to use occlusal-optimized dentures and the clinical remount technique, especially in difficult cases.

Comparative cost analysis of different prosthetic rehabilitations for the edentulous maxilla: early results from a randomized clinical pilot study

OBJECTIVES/AIM

To analyze and compare costs of different prosthetic rehabilitations for the edentulous maxilla.

MATERIALS AND METHODS

Patients with edentulous maxillae were rehabilitated with either of three implant-supported prosthetic protocols; removable overdenture supported by 2 implants (ISOD 2), fixed dental prostheses supported by 4 (ISFAFDP 4) or 6 (ISFAFDP 6) implants. Cost of treatment and costs during follow-up were registered and compared.

RESULTS

Twenty-four patients were included: six patients received ISOD 2 treatment, eight patients received ISFADP 4 treatment and ten patients received ISFADP 6 treatment. Initial costs for ISFAFDP 6 were higher than costs for ISFAFDP 4 and ISOD 2, but there were no differences in cost for maintenance i.e., the ISOD treatment remained the least costly treatment alternative after 1-year follow-up.

DISCUSSION

The lack of difference in cost for maintenance and repair over the first year suggests that implant-supported overdentures will remain the least costly treatment option for the edentulous maxilla, at least in a short-term perspective.

CONCLUSIONS

Removable maxillary overdentures supported by 2 implants may be a valid low cost treatment option.