A randomised trial on simplified and conventional methods for complete denture fabrication: Masticatory performance and ability

CADCAM Versus Conventional Denture Bases: Network Meta-Analysis of In Vitro Studies Comparing Accuracy and Surface Properties

INTRODUCTION

This systematic review with network meta-analysis (NMA) analysed the current evidence on in vitro studies comparing trueness of fit, surface roughness, colour stability, surface wettability, water sorption, water solubility, and microbial adhesion between conventional and digital denture bases.

METHODS

From inception until December 2023, a systematic search of published in-vitro studies from Scopus, PubMed, and the Cochrane Central Register of Controlled Studies was conducted. The protocol was registered in PROSPERO (CRD42024531416). NMA compared properties related to dimensional accuracy and surface properties between conventional and digital dentures. The ranking was performed using the surface area under the cumulative ranking guidelines.

RESULTS

A total of 6004 articles were initially identified, of which 342 duplicates were removed, and 5566 were excluded by screening the titles and abstracts. A total of 96 articles were assessed by full-text reading, and 43 were included in the quantitative synthesis. As per the NMA results, MIL demonstrated significantly higher trueness of fit when compared with conventional compression moulding (standardized mean differences [SMD] = -2.25 [95% CI: -4.09, -0.40]), P = .017 (<.05) and TDP (SMD = -1.57 [95%CI: -3.14, -0.01]) P < .05. MIL demonstrated significantly lower surface roughness when compared with conventional compression moulding (SMD = -0.99 [95% CI: -1.72, -0.26]), P = .008 (<.05), and TDP (SMD = -1.08 [95%CI: -1.95, -0.22]) P < .05.

CONCLUSIONS

There is conclusive evidence that milled digital denture bases demonstrate higher trueness of fit and lower surface roughness than 3D-printed denture bases and conventional denture bases, as demonstrated by the concurrent network and pairwise results.

CLINICAL RELEVANCE

In vitro studies show that milled digital dentures exhibit higher accuracy and lower surface roughness. The clinical performance of milled dentures in relation to these properties needs to be evaluated by high-quality randomized controlled clinical trials.

Dental Clinicians' and Technologists' Experiences and Perspectives on Removable Complete Denture Fabrication Services in Makerere University Dental Hospital, Uganda

Background

Globally, there is growing concern regarding mouth sores, occlusion, cost, ridge resorption, and retention, in the delivery of removable complete dentures fabrication services brought about by the aging of the population and poor oral healthcare. The therapy for edentulous patients can be realized through the use of conventional removable complete dentures, implant-supported prostheses, and computer-aided design/computer-aided manufacturing (CAD/CAM). In Uganda, the therapy for edentulous patients has predominantly been realized through the use of conventional removable complete dentures. There has been a discernible difference in the number of visits and remake rate between removable complete dentures that were made conventionally and digitally. This present study, therefore, aimed to explore dental clinicians' and technologists' experiences and perspectives on removable complete denture fabrication services.

Methods

The study employed a qualitative design, 25 in-depth interviews were conducted with dental clinicians and technologists at Makerere University Dental Hospital. Both practicing dental technologists and clinicians were purposively selected after providing written informed consent. Interviews' audios were transcribed verbatim, coded in NVivo 14 and data were analyzed thematically.

Results

Clinical and socio-demographic assessments like age, oral hygiene, ridge level, underlying health conditions, and mental stability of the patient were done by dental clinicians before removable complete denture fabrication. Dental technologists and clinicians mentioned patients having a lot of expectations relating to being able to eat whatever they like and improving physical appearance. However, the patients also had fears and concerns about discomfort, and some worried that they would swallow the dentures.

Conclusion

Prior assessments were the basis for planning for complete denture therapy. Patients' fears and expectations can effectively be addressed in the consent process since adequate information can be shared and the patients can be psychologically prepared to receive the denture treatment.

The Effect of Average Value Mounting and Facebow Transfer on Condylar Guidance Settings in a Semi-Adjustable Articulator - A Comparative Study using Digital Lateral Cephalographs in Edentulous Patients

BACKGROUND

While we attempt to restore occlusion in completely edentulous patients there is a consensus among clinicians to articulate the cast using average value and avoid performing facebow transfer. Various studies question the application of facebow transfer in the fabrication of removable complete denture fabrication.

AIM

This study was therefore aimed to study the effect on condylar guidance with casts mounted by the facebow method, Bonwill's method, and radiographic method.

METHODS

A cross-sectional study was performed using casts of edentulous patients attending the Department of Prosthodontics. After establishing a tentative jaw relationship using wax occlusal rims in the edentulous participants, the casts were mounted by Bonwill's method and the facebow transfer method to a semi-adjustable articulator. Protrusive records of the subjects were used to program the articulator to obtain the condylar guidance values. Digital lateral cephalographs were made both in centric and protrusive jaw relationships. The mandibular condyles were then traced and overlapped to obtain radiographic values. The condylar guidance values obtained by Bonwill's method, facebow method and radiographic method were compared using Wilcoxon's signed rank test and Mann-Whitney U test. The SPSS Statistics for Windows (Version 21.0. Armonk, NY, USA:IBM Corp.), and, at a probability value of 0.05, the significance of every statistical test was predetermined.

RESULTS

Ten edentulous 45-70 year olds participated in the study. The mean discrepancy between radiography and facebow methods was 12.8° for the right side and 12.7° for the left (P < 0.005). The difference between radiography and Bonwill's methods was significant (P < 0.005), with a mean difference of 34.3° for the right side and 34.7° for the left side. The difference between Bonwill's method and the facebow method was significant (P < 0.005), with a mean difference of 21.5° for the right side and 22° for the left side.

CONCLUSION

The condylar guidance values obtained by clinical methods (Bonwill's and Facebow) were significantly lesser (P < 0.005) compared to the values obtained by radiographic method.

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.

3D printed, subtractive, and conventional acrylic resins: Evaluation of monotonic versus fatigue behavior and surface characteristics

This study assessed the mechanical properties and surface characteristics of dental prosthetic acrylic resin fabricated by 3D printing, comparing it with subtractive, pressing, and molding techniques. Bar-shaped specimens (N= 90; 65 × 10 × 3.3 mm; ISO:207951) were prepared and assigned into six groups: PRINT (3D printing vis stereolithography with PriZma 3D Bio Denture, Makertech Labs); SUB (subtractive manufacturing with Vipiblock Trilux, Vipi); PRESS Base (pressing using muffle with Thermo Vipi Wave, Vipi for base); PRESS Tooth (pressing with Onda-cryl, Clássico for tooth); MOLD Base (molding using addition silicone with Vipi Flash, Vipi for base); and MOLD Tooth (molding with Dencor, Clássico for tooth). Monotonic flexural strength (FS) and elastic modulus (E) were measured using a three-point bending approach (n= 5) on a universal testing machine at a crosshead speed of 5 mm/min. Fatigue testing (n= 10) followed similar geometry and settings, with a frequency of 2 Hz, initial stress level at 20 MPa, and stress increments of 5 MPa every 2,500 cycles. Surface roughness (n= 10) was assessed through profilometry, and fractographic and topographic analyses were conducted. Statistical analyses included One-Way ANOVA for monotonic FS, roughness, and E, along with Kaplan-Meier with Mantel-Cox post-hoc and Weibull analysis for fatigue strength. PRINT showed lower monotonic FS than the SUB and PRESS Tooth but comparable fatigue strength to these groups and superior to PRESS Base and MOLD (Base and Tooth) groups. All groups had similar Weibull moduli. Surface roughness of the PRINT group was comparable to most techniques but higher than the PRESS Tooth group. Fractographic analysis revealed fractures originating from surface defects under tensile stress, with SEM showing scratch patterns in all groups except PRINT, which had a more uniform surface. Despite its lower monotonic strength, 3D printed resin demonstrated comparable fatigue strength to subtractive and pressing methods and similar surface roughness to most methods, indicating its potential as a viable option for dental prosthesis.

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

OBJECTIVE

To describe the clinical procedures of complete denture set fabrication in three appointments.

BACKGROUND

Simplified approaches have proven not to be inferior to conventional ones in terms of quality, patient satisfaction and masticatory ability.

MATERIALS AND METHODS

The patient was a 77-year-old edentulous adult with mobility impairment seeking dental rehabilitation in a small number of appointments due to commuting difficulties.

RESULTS

A set of complete dentures was delivered within three appointments. The second appointment was dedicated to set-up trial due to the patient's aesthetic demands.

CONCLUSION

Under certain circumstances and after a thorough study of each case, dental clinicians may propose the fabrication of complete dentures in a three-appointment protocol incorporating a set-up trial session.

3D printing vs traditional workflow for the fabrication of mandibular implant overdentures: study protocol for a mixed-methods cross-over RCT

BACKGROUND

Complete tooth loss is a significant global oral health issue, particularly impacting older individuals with lower socioeconomic status. Computer-assisted technologies enhance oral healthcare access by the elderly. Despite promising in vitro reports on digital denture materials, evidence from randomized clinical trials (RCTs) is lacking to verify their performance. This cross-over RCT will investigate whether 3D-printed implant-retained mandibular overdentures (IMO) are more satisfactory for edentulous seniors than those made through traditional methods.

METHODS/DESIGN

We will recruit 26 completely edentulous participants (any sex/gender) based on the following eligibility criteria: age ≥ 60 years, no tooth extraction in the past 12 months, two implants in the lower jaw, and need for new dentures in both jaws. Each participant will receive two denture pairs, either manufactured by 3D printing or traditionally, to be worn in a random order. A timeline of 3 months with each denture pair will be considered for outcome assessment (total: 6 months). Patient satisfaction with dentures will be measured by the McGill Denture Satisfaction Questionnaire. We will evaluate other patient-reported outcomes (including oral health-related quality of life) as well as clinician-assessed quality and cost. At the end of the trial, participants will choose which denture pair they wish to keep and interviewed about their experiences with the 3D-printed IMO. The quantitative and qualitative data will be incorporated through an explanatory mixed-methods strategy. A final quantitative assessment will happen after 12 months with the preferred IMO to assess the long-term performance and maintenance needs.

DISCUSSION

This mixed-methods RCT will explore patient experiences with 3D-printed IMOs, aiming to assess the potential for altering clinical practice and dental public health policies. Our results will inform policies by showing whether 3D printing offers comparable outcomes at lower costs, facilitating greater access to oral care for the elderly.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT06155630, Registered on 04 December 2023. https://classic.

CLINICALTRIALS

gov/ct2/show/NCT06155630.

Evaluation of the influence of different build angles on the surface characteristics, accuracy, and dimensional stability of the complete denture base printed by digital light processing

Purpose

This study aims to investigate the influence of the build angle on the surface characteristics, accuracy, and dimensional stability of digital light processing (DLP) printed resin bases.

Material and methods

Rectangular and complete denture base samples were fabricated at 0, 45, and 90-degree angles (n = 5 for rectangular samples; n = 10 for maxillary and mandibular denture base samples) using a DLP printer. Surface morphology and roughness were assessed using a profilometer, followed by measuring hydrophilicity with a contact angle meter. Accuracy (trueness and precision) and dimensional stability were evaluated at intervals of 1, 3, 7, 14, 28, and 42 days after base printing using best-fit-alignment and deviation analysis in 3D software. Statistical analysis was performed using one-way ANOVA for surface characteristics (α = 0.05), multi-way ANOVA for accuracy and dimensional stability data, and Tukey's test for post-hoc comparisons.

Results

The 0-degree group exhibited significantly lower mean roughness (1.27 ± 0.19 μm) and contact angle (80.50 ± 3.71°) (P < 0.001) compared to the 90-degree and 45-degree groups. The 0-degree build angle led to superior trueness (maxilla: 77.80 ± 9.35 μm, mandible: 61.67 ± 10.32 μm) and precision (maxilla: 27.51 ± 7.43 μm, mandible: 53.50 ± 15.16 μm) compared to other groups (P < 0.001). Maxillary base precision was superior to mandibular base precision (P < 0.001). The maxillary base exhibited less dimensional deviation than the mandibular base. The 90-degree group showed the highest deviation compared to the other two groups, and all groups' deviations increased over time (P < 0.001).

Conclusions

The build angle significantly influences the surface characteristics, accuracy, and dimensional stability of DLP-printed denture bases. A 0-degree build angle provides the most favorable performance. The maxillary base displayed superior precision and dimensional stability than the mandibular base.

Simplified versus conventional complete dentures: A randomized crossover clinical trial

STATEMENT OF PROBLEM

A simplified approach to complete denture treatment, omitting the border molding and definitive impression appointment, was suggested as an alternative to the conventional approach. However, comparison clinical trials are lacking.

PURPOSE

The purpose of this randomized crossover clinical trial was to assess the satisfaction of edentulous patients and their oral health impact profile when provided with complete dentures fabricated through the simplified or the conventional approach.

MATERIAL AND METHODS

Forty completely edentulous patients seeking complete dentures were randomly divided into 2 groups (n=20). Each group received 2 sets of dentures. The first group received conventionally fabricated complete dentures, and the second group received complete dentures fabricated through the simplified approach. After 2 months, participants rated their overall satisfaction and their satisfaction regarding comfort, retention, stability, and efficiency of mastication and speech on a 100-mm visual analog scale (VAS). Participants also filled out the oral health impact profile for edentulous patients (OHIP-EDENT) questionnaire. Each group was then given the alternate set of dentures and reviewed again after 2 months. The results were analyzed by using the Mann-Whitney U and Wilcoxon-signed rank tests (α=.05).

RESULTS

The simplified complete dentures had significantly higher VAS scores for general satisfaction with maxillary dentures (P=.036), satisfaction with retention of maxillary dentures (P=.002), satisfaction with stability of maxillary dentures (P=.003), and satisfaction with speaking (P=.002). No statistically significant differences were found between the 2 groups regarding the other VAS items or OHIP-EDENT scores (P>.05).

CONCLUSIONS

The simplified denture fabrication approach required fewer appointments and resulted in higher patient satisfaction and similar OHIP-EDENT scores compared with the conventional approach. The simplified approach can be recommended over the conventional approach.

Single-Implant Overdentures Retained by a Novel Attachment: A Mixed Methods Crossover Randomized Clinical Trial

INTRODUCTION

Single-implant mandibular overdentures (SIMOs) are one of the least invasive implant treatments for edentulism. The new Novaloc attachment system can improve the clinical performance of implant-retained overdentures but has not been tested for SIMOs.

OBJECTIVES

To compare Novaloc and a gold standard system (Locator) for SIMOs in an edentate elderly population in terms of patient-reported outcomes and device- and treatment-related complications.

METHODS

In this single-center crossover randomized clinical trial (RCT), 10 edentulous participants received an implant in the lower midline and had their lower complete dentures converted to SIMOs. The participants received each attachment system for 3 mo in a randomized order, followed by measurement of patient satisfaction and oral health-related quality of life via the McGill Denture Satisfaction Questionnaire and the Oral Health Impact Profile for Edentulous People questionnaire, respectively. Complications were registered throughout the RCT. Patients were interviewed for their experiences with SIMOs and preference for one of the attachment systems. Quantitative analysis employed mixed linear models and chi-square tests (α = 0.05), whereas interview data underwent thematic analysis and, in turn, integration into quantitative data (mixed methods explanatory design).

RESULTS

All 10 randomized participants completed the trial. Mean ± SD general satisfaction was 92% ± 8% with Novaloc versus 85% ± 13% with Locator (mean difference, 9%; 95% CI, 1% to 17%). For specific McGill Denture Satisfaction Questionnaire items, only denture stability was significantly increased for Novaloc. Seven participants preferred Novaloc over Locator at the end of the RCT (chi-square, P = 0.045). No difference was found between the attachments in terms of oral health-related quality of life based on the Oral Health Impact Profile for Edentulous People and complications. Thematic analysis revealed high patient satisfaction with SIMOs, with denture stability the main criterion for their satisfaction and attachment preference.

CONCLUSION

Among elderly edentulous patients wearing SIMOs, Novaloc led to increased patient satisfaction and preference. Better patient-perceived denture stability may explain this result. The attachment systems exhibited similar short-term maintenance needs.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03126942 (first registered on April 13, 2017). Secondary identifiers: A03-M07-17A (McGill University, Institutional Review Board) and 2018-3873 (McGill University Health Centre, Research Ethics Board).

KNOWLEDGE TRANSFER STATEMENT

The results of this mixed methods study can be used by clinicians when choosing which attachment system to use for SIMOs. Results suggest that edentulous patients prefer attachments with a better-defined seating position, such as that of the Novaloc system, as opposed to the nylon matrix on metallic abutment of the Locator system.

Performance of complete dentures fabricated with the simplified and the traditional technique: A randomized clinical trial

STATEMENT OF PROBLEM

The simplified technique has been recommended for the fabrication of removable complete dentures. However, a consensus regarding the performance of the simplified and the traditional techniques is lacking.

PURPOSE

The purpose of this randomized clinical trial was to compare the performance of prostheses fabricated with the simplified and the traditional techniques.

MATERIAL AND METHODS

Sixty participants were recruited and randomized into 2 groups: traditional technique (control group) and simplified technique (experimental group). The assessments were performed before treatment (baseline) and 2 and 4 months after adaptation to the new complete dentures. The variables evaluated were satisfaction, oral health-related quality of life (OHRQoL) by using the Brazilian version of the OHIP-EDENT, the quality of the prostheses, and, for the functional assessment, the masticatory performance and swallowing threshold. The data were analyzed by the Fisher exact test, the Mann-Whitney test, and the generalized equations estimating (GEE) method.

RESULTS

At baseline, the mean ±standard deviation quality of the prostheses was 5.3 ±2.3 for the traditional technique and 4.9 ±2.3 for the simplified technique, and at 4 months, it was 9.3 ±0.9 and 9.1 ±0.9, respectively. For masticatory performance, the mean ±standard deviation X50 at baseline was 5.7 ±1.4 for the traditional technique and 5.7 ±0.9 for the simplified technique, and at 4 months, it was 3.8 ±1.2 and 3.7 ±0.9, respectively. The mean ±standard deviation OHRQoL at baseline was 14.1 ±8.6 for the traditional technique and 12.5 ±9.4 for the simplified technique, and at 4 months, it was 3.2 ±4.3 and 2.6 ±5.1, respectively. The mean ±standard deviation satisfaction at baseline was 9.5 ±3.9 for the traditional technique and 9.3 ±4.2 for the simplified technique; after 4 months, it was 14.8 ±2.0 for both techniques. There was a significant improvement (P<.05) for all variables in the study when comparing them at the baseline to those at the evaluation after provision of new complete dentures. There was no significant difference in all analyzed variables (P>.05) between the 2 techniques for prosthesis fabrication.

CONCLUSIONS

The simplified technique appears to be a suitable alternative to the traditional technique for the fabrication of complete dentures, with similar performance.

Workflow for complete dentures fabrication in three appointments: A dental technique

This technical report describes a novel workflow for complete denture fabrication designed to abbreviate the necessary steps for dental prostheses delivery by using a 3-appointment protocol in which preliminary impressions are made in the first session together with the registration of maxillary lip support, occlusal plane, and reference lines for tooth arrangement. A trial denture is fabricated with conventional or computer-aided design and computer-aided manufacturing procedures and is evaluated in the second appointment for esthetics, the definitive impression, and the maxillomandibular relationship record to provide precise references for definitive denture fabrication.

Using an Attachment System with PEEK Matrices for Single-Implant Overdentures: In Vitro Retention Force

Single-implant overdentures (SIOs) represent a major biomechanical challenge in terms of prosthetic retention. The Novaloc attachment system has the potential to overcome those challenges when used for SIOs, due to the use of PEEK matrices. This study compared the retentive force of the Novaloc attachment to the traditional Locator system, before and after cyclic insertion–removal cycles. Three Novaloc matrices (white, yellow, and green, corresponding to low, medium, and high retention, respectively) and Locator (medium retention) were tested, totalling four groups. Retentive force was measured using an Imada force gauge before and after 1095 insertion–removal cycles, corresponding to a year of SIO wearing. Retention was tested with the implants angulated at 0, 10, and 20°. Data for the different groups, angles, and cycling periods were tested via linear regression analysis and two-way ANOVA (α = 0.05). Although the Locator system yielded higher retention forces in general, it lost a much higher percentage of retention with cycling. This trend was similar with the three angles, with forces being inversely proportional to the implant angulation. The authors conclude that Novaloc may provide more reliable retention for SIOs due to their higher resistance to insertion–removal cycling.

Bite Force Evaluation in Implant-Assisted Prosthetic Rehabilitation of Reconstructed Jaws Utilizing Vascularized Free Fibula Flap: A Retro-Prospective Cohort Study

Introduction

Maxillary and mandibular defects due to tumor ablation pose considerable challenges to the reconstructive surgeon and in prosthetic management. Dental implants placed in vascularized fibula free flaps are considered to be a dependable technique for prosthetic rehabilitation in head and neck cancer patients. Although, there is evidence of survival of dental implants in the reconstructed jaw bones, there is lack of information regarding the masticatory performance and prosthetic success. The maximum bite force achieved through the prosthetic appliance is a measure of the therapeutic outcome. The purpose of this study was to determine the maximum bite force achieved through implant-assisted prosthetic rehabilitation in reconstructed jaw bones utilizing vascularized free fibula flap.

Methods

The study included a total of 65 implants, from 16 patients who underwent surgical resection of jaw bones due to benign tumors followed by rehabilitation with implant-assisted fixed or removable prosthesis. The maximum bite force was determined with a transducer. Occlusal interferences were analyzed with mounted casts. The parameters were reviewed every 3 months have T 0 marked the baseline assessment, and T 3, T 6, T 9, T 12, and T 15 were subsequent review periods.

Results

The mean occlusal force was increased in most of the patients through 15 months (P < 0.01). The maximum bite force measured in the reconstructed mandible and maxilla were 225.63 N and 176.51 N, respectively. Occlusal interferences were absent in 68.8% of the study population.

Conclusion

The bite force measured in reconstructed maxilla and mandible is comparable to the masticatory force measured with conventional implant supported prosthesis in native mandible and maxilla.

Digital versus Conventional Dentures: A Prospective, Randomized Cross-Over Study on Clinical Efficiency and Patient Satisfaction

Digital technology facilitates the manufacturing of complete dentures; however, clinical and patient-reported outcomes are underreported. This prospective, randomized, single-blind cross-over study reports the clinical and patient-related outcomes of 10 edentulous patients receiving digital dentures prepared with the Vita Vionic System and conventional dentures produced from heat-polymerized polymethylmethacrylate resin. Clinical efficiency was stated based on the Sato score for quantitative assessment of complete denture quality. Patient satisfaction was evaluated with the oral health-related quality of life questionnaire (OHIP-20). We report here that the Sato score was slightly higher in patients receiving digital versus conventional dentures with a mean of 73.2 ± 12.3 and 67.4 ± 11.8, respectively (p = 0.16). Moreover, upper and lower stability was superior in digital dentures (p = 0.03 and p = 0.10, respectively), while denture polish was better in conventional dentures (p = 0.03). Quality of life was slightly higher in patients receiving conventional compared to digital dentures with an OHIP-20 of 101.7 ± 12.0 and 95.6 ± 24.2, respectively (p = 0.33). Taken together and when considering the low power of the study, our findings suggest a trend towards better clinical efficiency of digital compared to conventional dentures, while patient satisfaction remained unaffected by the type of manufacturing.

Multiresin Additive Manufacturing Process for Printing a Complete Denture and an Analysis of Accuracy

A complete denture, consisting of teeth and a gum base, is a standard device used to restore masticatory and esthetic functions in patients with complete edentulism. The different colors and mechanical properties for teeth and the gum base mean a complete denture is manufactured using two materials with different mechanical properties. This study proposes a method to make a complete denture using a laboratory-developed, multiresin additive manufacturing (MRAM) system with two resins and different mechanical properties. A tenon joint is used to create the bottom of the teeth that fit into the gum base, ensuring automatic alignment and higher bending strength. The mechanical properties, material waste, fabrication time, and effect of the tenon joint on the bending strength of a complete denture printed using the MRAM system are compared with the values for a computer-aided design and computer-aided manufacturing (CAD/CAM) system. Experimental results show that the printed denture is manufactured 3 times faster and produces 14 times less material waste, but is 35.08% less inaccurate than one produced using a CAD/CAM system. The proposed tenon joint increases the bending strength by 31.94%. The MRAM system is applicable for printing a complete denture.

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.

Current educational concepts and techniques related to impression making of removable complete dentures

The purpose of the present study is to gain an understanding of the current state of pre-clinical education for procedures of impression making. In 2019, a survey questionnaire was emailed to the senior professors and department heads of 29 Japanese dental colleges. The response rate was 100%. This cross-sectional survey clarified the impression making for removable complete denture fabrication in Japanese dental schools' education.

3D-Printed vs. Heat-Polymerizing and Autopolymerizing Denture Base Acrylic Resins

The aim of this work was to investigate the effect of two post-curing methods on the mechanical properties of a 3D-printed denture base material. Additionally, to compare the mechanical properties of that 3D-printed material with those of conventional autopolymerizing and a heat-cured denture base material. A resin for 3D-printing denture base (Imprimo^®), a heat-polymerizing acrylic resin (Paladon^® 65), and an autopolymerizing acrylic resin (Palapress^®) were investigated. Flexural strength, elastic modulus, fracture toughness, work of fracture, water sorption, and water solubility were evaluated. The 3D-printed test specimens were post-cured using two different units (Imprimo Cure^® and Form Cure^®). The tests were carried out after both dry and 30 days water storage. Data were collected and statistically analyzed. Resin type had a significant effect on the flexural strength, elastic modulus, fracture toughness, and work of fracture (p < 0.001). The flexural strength and elastic modulus for the heat-cured polymer were significantly the highest among all investigated groups regardless of the storage condition (p < 0.001). The fracture toughness and work of fracture of the 3D-printed material were significantly the lowest (p < 0.001). The heat-cured polymer had the lowest significant water solubility (p < 0.001). The post-curing method had an impact on the flexural strength of the investigated 3D-printed denture base material. The flexural strength, elastic modulus, fracture toughness, work of fracture of the 3D-printed material were inferior to those of the heat-cured one. Increased post-curing temperature may enhance the flexural properties of resin monomers used for 3D-printing dental appliances.

The Effect of Alteration of Vertical Dimension of Occlusion on Brain Activity in Complete Denture Wearers

BACKGROUND: The establishment of appropriate vertical dimension of occlusion (VDO) is paramount for successful and functioning complete dentures (CDs). AIM: The aim of this study was to assess the effect of alteration of VDO on the brain activity in CD wearers. MATERIALS AND METHODS: Ten completely edentulous patients participated in this study. Each patient received three sets of CDs: one control set and two duplicates’ CDs. The control CDs was designed with appropriate VDO (control - VDO), while the duplicate CDs were designated as followed: one with VDO lowered by –3 mm (low - VDO) the other one VDO was increased by +5 mm (high - VDO). The effect of alteration of VDO on brain activity was assessed by measuring alpha waves changes using electroencephalogram (EEG) before and after chewing gum. Statistical analysis was carried out using one-way ANOVA and dependent t-test. The significance level was set at p < 0.05. RESULTS: There was a significant increase in the alpha waves mean values after chewing (p < 0.05) gum compared to before except for low - VDO CDs (p > 0.05). The control-VDO revealed a statistically significant higher mean values compared to the duplicate dentures. CDs with high - VDO showed higher mean value than low - VDO dentures, however, it was statistically insignificant (p > 0.05). CONCLUSION: Appropriate determination of VDO is not only important for the success of CDs but also for the functional augmentation of brain activity.

Digital Workflow for a Scleroderma Patient with Microstomia: A Clinical Report

Making impressions in patients with microstomia is often rather problematic due to their restricted mouth opening. Herein, this report describes a novel digital workflow for making impressions with computer-aided design and computer-aided manufacturing (CAD/CAM) custom sectional trays for a 58-year-old female patient with scleroderma and microstomia. CAD/CAM custom sectional trays were made based on digital dentition models from another case with similar arch scale. After the sectional impressions were obtained, the sectional casts were scanned and digitally aligned to form the final dentition models. The removable partial dentures were designed on the final digital models and printed using a 3D printer. This procedure was executed with a successful prosthetic outcome that included good fit and acceptable esthetics. The patient also reported a high level of satisfaction.

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

STATEMENT OF PROBLEM

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Mandibular residual ridge morphology in relation to complete dentures and implant overdentures-Part II: Predictors for effectiveness of implant overdenture therapy

BACKGROUND

The significance of mandibular residual ridge height and satisfaction with conventional complete dentures (CCD) as predictors for the added value of implant-overdenture (IOD) therapy is unknown.

PURPOSE

To investigate the predictive value of thresholds for (1) residual ridge height at premolar location (PRH), and (2) satisfaction with CCD-stability for the added value of two intraforaminal implants supporting the mandibular CCD.

METHODS

Thirty CCD wearing patients (67.9 ± 7.0 years) for whom a new CCD was advised, received a new CCD. Mandibular gypsum models were digitally measured. After 3 months free of complaints (T1), perceived CCD-stability was evaluated, and participants received two intraforaminal implants. At T1 and T2 (3 months free of complaints after IOD therapy) participants completed OHIP14-CN, and denture satisfaction (VAS) questionnaires, and performed mixing ability tests. Participants were grouped according to PRH of ≥6.15 mm versus < 6.15 mm, and perceived CCD-stability satisfied vs. dissatisfied. Scores at T2 were compared to T1 (paired t-tests). Predictive values of PRH and CCD-stability were analyzed with logistic multivariate regression models.

RESULTS

At T2, only participants with PRH of <6.15 mm or dissatisfied with CCD-stability had significant lower OHIP-total and domain scores for 'physical pain' and 'physical disability' and significantly higher VAS scores for perceived chewing function, denture retention and oral comfort. Regression analyses showed that participants with PRH of <6.15 mm, or dissatisfied with CCD-stability had significantly higher chance for lower OHIP-total and domain scores 'physical pain' and 'physical disability', and for higher VAS scores for perceived chewing function, denture retention and oral comfort at T2. Masticatory performance improved significantly after IOD therapy, but independent of PRH and CCD-stability.

CONCLUSION

PRH and satisfaction with CCD-stability were adequate prognostic indicators for improvement of oral health-related quality of life and denture satisfaction by mandibular IOD therapy.

Use of Facebow device in prosthodontics: A systematic review on randomized control trials

Aim

Recording the maxillomandibular relationship is important in various prosthodontic treatments. Evidence of face-bow transfer resulting in improved outcome is conflicting. Hence the objective of this study is to determine the use of face-bow transfer in prosthodontics.

Settings and Design

: Systematic review based on PRISMA guidelines.">.

Materials and Methods

A protocol was developed prior, which covered all aspects of the review. The databases explored were MEDLINE database, ScienceDirect, and Cochrane collaboration library. The PICO model included participants who received a complete denture/partial denture prosthesis. Intervention was the use of the face-bow device. Comparator was prosthesis made with a simple procedure of not using a face-bow device for prosthodontic rehabilitation. Outcomes were patient satisfaction with dentures, the stability of the dentures, esthetics, and time taken for clinical and laboratory procedures. Only randomized clinical trials were included in this study. The methodological quality of the studies was assessed according to the Cochrane risk of bias tool.

Statistical Analysis Used

Qualitative analysis.

Results

A total of 144 articles were identified. On excluding 4 duplicates and screening the title and abstracts of the rest of the records based on exclusion criteria only 15 studies were selected for review.

Conclusions

The use of the face-bow did not yield superior results for the quality of the prosthesis. Therefore, there is no evidence for the utility of face-bow transfer in complete denture treatment. However, no inference could be drawn for its utility in partial denture prosthodontics as there was no study to draw an inference.

Utility versus futility of facebow in the fabrication of complete dentures: A systematic review

Aim:

The aim of this review was to investigate utility or futility of facebow for fabrication of complete denture prosthesis to maximise clinical efficiency and acceptability of complete dentures.

Settings and Design:

Systematic review following PRISMA guidelines.

Materials and Methods:

A study question was designed based on PICOT model which was used to evaluate whether facebow transfer is required or not for fabrication of complete denture prosthesis. An extensive search was carried out manually and using electronic databases such as PubMed-Medline, Cochrane, Google Scholar, and Clinicaltrials.gov. Parameters under review included patient satisfaction, masticatory efficiency, occlusal adjustments, clinician time, stability and retention. Boolean operators, MeSH terms and limiters were applied to develop the search and reach to conclusive studies pertaining to study design. Literature dated between 1950 and 2019 were selected. The data extraction and assessment of the studies was done by two independent investigators.

Statistical Analysis Used:

No meta-analysis was conducted due to heterogeneity of data obtained.

Results:

13690 studies were shortlisted, 13672 were excluded based on title and abstract. By the end of search phase, 07 RCTs were considered relevant. 04 studies concluded comparable/ no differences in outcome with and without use of facebow for fabrication of complete denture prostheses, whereas 03 studies concluded better results without the use of facebow.

Conclusion:

The use of facebow results in fabrication of complete denture prostheses with similar results in terms of clinical efficiency and patient acceptability as compared to simplified techniques using anatomical landmarks. Variations in assessment criteria, non uniform distribution of sample size amongst different clinical trials and subjective questionnaire based criteria are the weaker links in the review. Extensive research and long term standardised studies with objective criteria for assessment are required for comprehensive and conclusive results to establish the need for change in clinical practice.

A Comprehensive Systematic Review In Search Of Evidence for Pragmatic Altercations in Simplified Denture

Aim:

To explore the evidence available to evaluate if simplified dentures could be as effective as the conventional complete dentures.

Materials and Methods:

A total of 1,482 articles were obtained using keywords in a Boolean search operator in the PubMed search engine, Google Scholar and Cochrane Library. Duplicates were removed and the remaining articles were subjected to a title analysis which yielded a total of 20. Further analysis of the article abstracts led to an exclusion of four articles. The remaining 16 articles were subjected to full text analysis which finally yielded a total of 11 articles.

Results:

The cumulative results of the meta-analysis for oral health-related quality of life, patient satisfaction and professional quality of denture show no significant difference ( P > .05) between conventional and simplified dentures.

Conclusion:

Based on the available evidence adjusted for the potential literature/geographic bias, we conclude that the conventional procedures in complete denture fabrication such as facebow and gothic arch tracing do not improve the quality of the denture outcome from patients’ perspective and simplified dentures are equally effective as conventional complete dentures.

Influence of the height of the mandibular ridge on the masticatory function during the functional adaptation with new complete dentures

BACKGROUND

The period of functional adaptation to a new conventional complete denture embraces many transitory issues, and this period is directly related to the rehabilitation success.

OBJECTIVE

This clinical trial evaluated the influence of the height of mandibular ridge on the masticatory function of complete denture (CD) wearers during the adaptation period.

METHODOLOGY

A total of 28 individuals wearing new CDs (NR, n=14, normal mandibular ridges, 64±12.5 years, 9 female; RR, n=14, resorbed mandibular ridges, 69±6.8 years, 9 female) were assessed at 24 hours, 30 days, three months and six months after the insertion of the CDs for masticatory performance (MP, sieves method), satisfaction with CDs (questionnaire) and maximum occlusal bite force (MOBF) (gnatodynamometer). The classification of the mandibular ridges followed the Kapur index. Data of MP and MOBF were analyzed by two-way ANOVA and satisfaction with CDs was analyzed by Generalized Estimating Equations (GEE), α=.05.

RESULTS

Participants with NR presented better masticatory performance (p=.000 - NR 30.25±9.93%, RR 12.41±7.17%), general satisfaction (p=.047), retention of mandibular denture (p=.001), chewing ability (p=.037), and comfort of wearing a mandibular denture (p=.000). Regardless of the mandibular ridge, MP (p=.000) was higher at three (21.26±12.07%) and six months (24.25±12.26%) in comparison to 24 hours (18.09±10.89%), the MOBF (p=.000) was higher at three months (78.50±6.49 N) compared to 24 hours (57.34±5.55 N) and 30 days (62.72±5.97 N), and the comfort of wearing a mandibular denture (p=.002) at three months (1.61 ± 0.07) was greater than 24 hours (1.29±0.10) and 30 days (1.36±10).

CONCLUSIONS

The study suggests that the participants with NR have higher MP and satisfaction with their CD, regardless of the follow-up period after the insertion of the new CD. After subjects received the CD, a period of 3 months was necessary for achieving better achievement MOBF, MP, and self-perceived comfort with the mandibular denture, regardless of the height of the mandibular ridge.

Efficiency of simplified versus traditional denture fabrication methods: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Conventional techniques (CTs) for complete denture fabrication involve a series of clinical and laboratory steps. A simplification of this process has been advocated, but whether simplified techniques result in acceptable treatment outcomes is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the efficiency of simplified denture fabrication techniques in comparison with CTs.

MATERIAL AND METHODS

The standard methodological procedures prescribed by the Cochrane Collaboration for systematic review and meta-analysis were used. An electronic search (MEDLINE through PubMed, Cochrane trial registry, and Scopus) and a manual search up to February 2020 were made to identify studies. Only randomized controlled trials involving edentulous adults requiring complete denture treatment were included.

RESULTS

Nineteen studies met the inclusion criteria. The pooled estimate of the included studies for patient satisfaction at 6 months marginally favored the simplified method of denture fabrication (standardized mean difference=0.02 [95% confidence interval {CI} -0.22 to 0.27]). The pooled estimate of the included studies for clinical time and cost of fabrication favored the simplified method (mean difference=-77.34 [95% CI -122.45 to -32.24] and mean difference=-85.89 [95% CI -170.02 to -1.77] respectively).

CONCLUSIONS

Simplified techniques were cost effective and less time consuming than the CT, with no significant difference in patient satisfaction or oral health-related quality of life. The high risk of bias and heterogeneity among studies requires that the results be considered cautiously.

Patient satisfaction, clinical outcomes and oral health-related quality of life after treatment with traditional and modified protocols for complete dentures

Background/purpose

Conventional complete denture treatment course requires six appointments, but modified protocol only takes four appointments. This study compared the conventional and modified protocol for complete denture fabrication regarding patient satisfaction and clinical outcomes.

Materials and methods

A total of 24 patients accepted complete denture treatment. According to complete denture treatment protocol, these patients were divided into the conventional group (group C, n = 12) and the modified group (group M, n = 12). Group C used the conventional protocol and required six appointments. Group M used the one-appointment master impression and jaw relation record technique, and it took four appointments. Data of oral health impact profile-14 (OHIP-14), satisfaction scale and the number of recalls in the first year were collected for the statistical analysis.

Results

The mean OHIP-14 scores in group C and group M were 13.79 ± 3.81 and 15.33 ± 5.25, respectively. In terms of satisfaction, the mean scores in group C and group M were 8.33 ± 0.61 points and 8.66 ± 1.13 points, respectively. There were no statistically significant differences between the group C and M in terms of participant ratings for satisfaction and OHIP-14. At the same time, the results indicated that group M significantly reduced the number of postinsertion visits (P < 0.05).

Conclusion

In terms of OHIP-14 and patients’ satisfaction, the modified treatment protocol is comparable to the conventional protocol. Based on the number of recalls in the first year, the modified treatment protocol has a better clinical outcome.

The McGill Denture Satisfaction Questionnaire revisited: Exploratory factor analysis of a binational sample

OBJECTIVES

To examine the McGill Denture Satisfaction Questionnaire (MDSQ) in terms of dimensionality, item reduction and construct validity in a binational sample of complete denture wearers.

MATERIALS AND METHODS

We conducted secondary analyses of baseline data from two studies on implant-retained overdentures: a quasi-experimental study in the United States (n = 145) and a randomised trial in Brazil (n = 120). All participants wore upper/lower dentures and responded at baseline to the MDSQ items concerning their original mandibular dentures. A putative model of the MDSQ items resulted in two question subsets: (a) overall satisfaction, retention/stability, aesthetics, cleaning, speech and comfort, plus general chewing ability; (b) mastication of specific foods. Analyses focused on the internal consistency of each subset and possible item reduction, using Cronbach's alpha (Cα), inter-item correlation and exploratory factor analysis (EFA).

RESULTS

The 1st subset showed high inter-item correlation for most question combinations and no redundancy (r ≤ .8). An item on cleaning had low correlation, but its removal does not increase internal consistency (Cα ≥ .83). Results were similar for both studies, with EFA showing a single significant factor (namely "overall satisfaction, lower denture") able to explain nearly 54% of the variance. The 2nd subset also shows strong internal consistency (Cα ≥ .95) and inter-item correlation, with a single factor representing 65% of the variation.

CONCLUSIONS

This study discloses the reliability and construct validity of the MDSQ for patient-centred evaluation of complete dental prostheses in the edentulous mandible. Findings also support the use of both "overall satisfaction" and "masticatory ability" as summary scores, for improved outcome assessment.

Is a two-step impression mandatory for complete denture fabrication on the severely resorbed mandible? A randomized trial on mastication, patient satisfaction and adjustments

OBJECTIVES

To compare one- vs two-step impression procedures for the provision of conventional complete dentures (CCDs) for edentulous individuals with severe mandibular resorption, in terms of (1) masticatory performance and ability; (2) satisfaction with mandibular CCDs; and (3) post-delivery adjustments.

METHODS

Fifty-two patients requiring maxillary + mandibular CCDs were randomly divided into two parallel arms according to the impression method of the mandibular ridge: (SI) single impression with stock trays (irreversible hydrocolloid); (TI) two-step impression in custom trays, with border molding (impression compound) followed by the impression itself (polyether). Mastication performance was evaluated by a colorimetric test, whereas patients answered questions on masticatory ability and satisfaction with mandibular CCDs (100-mm visual analogue scale). The number of post-delivery sessions for adjustments were also quantified. Outcomes were assessed at 3 and 6 months after delivery.

RESULTS

The masticatory performance was similar for both groups, regardless of time (3 months, P = 0.62; 6 months, P = 0.61). No significant difference was found for patient-reported (P > 0.05), i.e. masticatory ability (general ease of chewing and quality of grinding food; ability to chew specific foods), general satisfaction with the mandibular CCD (general satisfaction, comfort, aesthetics, ability to speak and to perform correct cleaning, retention and stability). Both methods resulted in a similar number of post-delivery adjustment sessions [SI: 3.8 (1.7); TI: 3.2 (1.4); P = 0.09].

CONCLUSIONS

Compared to a traditional approach, CCDs obtained from a single impression achieve similar masticatory performance/ability and patient satisfaction, even in patients with severely reabsorbed mandibular ridge. Both methods demand the same amount of post-delivery adjustment.

CLINICAL SIGNIFICANCE

A simplified impression technique which eliminates the secondary impression can provide CCDs of good clinical quality, which influences the OHRQoL, and satisfaction in the same extent they would by a two-step procedure, even for patients with severely reabsorbed mandibular ridges (ClinicalTrials.gov: NCT02339194).

Is a two-step impression mandatory for complete denture fabrication on the severely resorbed mandible? A randomized trial on patient perception and denture quality

OBJECTIVES

To evaluate the effectiveness of CCDs produced by two impression procedures for the mandibular ridge, in patients with severe mandibular atrophy.

METHODS

Fifty-two completely edentulous patients with severely resorbed mandibles were randomly allocated into two groups according to the impression procedure of the mandibular ridge: SI - single impression (stock tray and irreversible hydrocolloid); TI - two-step impression (custom tray, border molding with compound, and polyether). Assessments of oral health related quality of life (OHRQoL, primary outcome) and denture satisfaction were performed by using validated questionnaires. Denture quality was evaluated by means of functional tests.

RESULTS

Regardless of the technique, participants reported better OHRQoL (P < 0.001) in both follow-up periods (3 and 6 months after denture delivery), and groups resulted in similar OHIP-EDENT scores in its different domains (P > 0.05). Between-group differences were insignificant for general satisfaction (3 months, P = 0.699, 6 months, P = 0.392), as well as for aspects such as esthetics, comfort, mastication, speech, and prosthesis retention (P > 0.05). Overall clinical quality of the CCDs (P = 0.383) was similar between-group, as well as in specific aspects - interocclusal distance, occlusion, articulation, retention of the maxillary denture, and stability of both maxillary and mandibular dentures (P > 0.05).

CONCLUSIONS

Mandibular CCDs based on a single impression technique showed quality levels comparable to those generated by a two-step impression, both from the patient and clinician perspective.

CLINICAL SIGNIFICANCE

A simplified impression technique which eliminates the secondary impression can provide CCDs of good clinical quality, which influences the OHRQoL, and satisfaction in the same extent they would by a two-step procedure, even for patients with severely reabsorbed mandibular ridges. (ClinicalTrials.gov: NCT02339194).

Impact of immediately loaded implant-supported maxillary full-arch dental prostheses: a systematic review

OBJECTIVE

The immediate loading of implant-assisted fixed prostheses in edentulous maxillae may achieve favorable success rates with reduced treatment time. An evidence summary of clinical trials is key to recommend loading protocols in these cases.

OBJECTIVES

To compare immediately loaded, fully implant-supported complete dentures to early and conventional/delayed loading in the edentulous maxillae of adult patients by a systematic review of controlled clinical trials (CCT).

METHODOLOGY

CCTs reports were identified up to January 17, 2019 from Cochrane Oral Health Group's Trial register, Cochrane Central Register of controlled trials (CENTRAL), MEDLINE (Ovid), BIOSIS, EMBASE, CINAHL, Web of Science, and DARE. Two independent reviewers screened titles/abstracts and confirmed inclusion using full texts. Data were extracted and quality assessed (Cochrane Risk of Bias tool) independently and in duplicate. Study heterogeneity prevented pooling by meta-analysis.

RESULTS

Out of 1,052 candidate studies, four CCTs were included. Two trials had patient satisfaction as an outcome: (1) A randomized trial compared immediately and early loaded fixed dentures and found more satisfaction with the first after 12 months; (2) A non-randomized study found better satisfaction with immediate fixed dentures compared to conventional loading after 3 months (no more at 12 months). Regarding implant success and prosthetic complications, three trials did not report significant differences comparing immediate loading to other protocols.

CONCLUSIONS

This review found weak evidence of differences between immediate load and other loading regimens, regarding patient satisfaction and maintenance events/adversities. The potential of immediate loading for favorable results in edentulous maxillae reinforces the need for well-designed RCTs, for solid clinical guidelines. Registration number CRD42018071316 (PROSPERO database).

Effectiveness of a simplified method for final impression in complete denture treatment: A pragmatic clinical trial

PURPOSE

This study aimed to compare two methods for final impression during the fabrication of complete dentures: a traditional method using custom trays (T-group) and a simplified method using the trial denture baseplate (S-group).

METHODS

A pragmatic clinical trial was conducted among edentulous individuals referred for conventional denture treatment. A consecutive sample of edentulous patients was assigned to two groups by cluster randomisation according to the final impression strategy, 30 in the T-group and 38 in the S-group. In the T-group, an auto-polymerising acrylic resin custom tray was used for impression; in the S-group, the final impression was performed using the try-in dentures. For both groups, zinc oxide eugenol paste was used as the impression material. The quality of the dentures was assessed using two rating scales (Functional Assessment of the Dentures and Kapur method). Moreover, clinical time for denture fabrication, number of post-insertion appointments for adjustments, patient satisfaction and post-treatment oral health-related quality of life impacts were also assessed.

RESULTS

There were no significant differences between groups regarding prosthodontic and patient-reported outcomes. The S-group demanded less clinical time (P = 0.002), with a 23.3% mean reduction in clinical time (P = 0.002) and lower number of appointments until the delivery of the dentures (S-group = 4.18 vs T-group = 5.0; P = 0.001).

CONCLUSIONS

This study showed that the alternative method for final impression is less time-consuming and has similar clinical outcomes when compared to the traditional final impression method. Findings suggest that this alternative may be considered when efficiency is a critical issue in healthcare services.

Masticatory performance of different impression methods for complete denture fabrication: A randomized controlled trial

OBJECTIVES

To compare the effect of conventional complete dentures fabricated using two different impression methods on masticatory performance and factors relating to masticatory performance in a randomized controlled trial.

METHODS

A crossover randomized controlled trial was performed with edentulous patients requiring maxillomandibular complete dentures. Mandibular complete dentures were fabricated using two different methods. The conventional method (C) used a custom tray border molded with an impression compound and a silicone. The simplified method (S) used a stock tray and an alginate. Participants were randomly divided into the two groups. In the C-S group, the conventional method was used first, followed by the simplified method; the order was reversed in the SC group. Adjustments were performed four times. The wash out period was 1 month. Masticatory performance as assessed by the mixing of a color-changeable chewing gum (mixing ability). Maximum occlusal force, occlusal contact area, and perceived chewing ability were assessed for each group.

RESULTS

Twenty-seven patients underwent randomization and 24 participants completed the trial. With regard to occlusal contact area, the conventional method showed significantly larger occlusal contact area than the simplified method. No significant differences were observed between the two methods regarding mixing ability, maximum occlusal force, and perceived chewing ability.

CONCLUSIONS

This study showed that complete dentures fabricated with the conventional method had a significantly larger occlusal contact area than those made using the simplified method.

CLINICAL SIGNIFICANCE

Complete dentures fabricated with the conventional method, comprising a preliminary impression using alginate in a stock tray followed by a final impression using silicone impression material in a border molded custom tray, resulted in fewer post-insertion adjustments than the simplified method, potentially contributing to earlier stability of new dentures.

Teaching Complete Denture Procedures to Dental Students by Conventional or Simplified Methods: A Randomized Clinical Trial

With populations aging around the world, the need for complete dentures is likely to increase in Brazil and other developing countries, as well among low-income populations globally, making the teaching of cost-efficient techniques to dental students essential. The aim of this study was to evaluate the effectiveness of complete dentures fabricated by the simplified method in comparison to the conventional method regarding patients' oral health-related quality of life (OHRQoL) and satisfaction, dentures' functional quality, and masticatory performance of patients who were rehabilitated by dental students. From February 2016 to April 2017, final-year dental students at the Federal University of Alfenas, Brazil, were instructed to fabricate new complete dentures for 36 edentulous patients, who were randomly divided into two groups according to denture manufacturing method: simplified method or conventional method. Patients' OHRQoL and satisfaction and the prostheses quality were evaluated at one, three, and six months. Masticatory performance was evaluated at three months. The results showed there was no significant difference between the two methods regarding OHRQoL, patient satisfaction, prostheses quality, or masticatory performance (p>0.05). All aspects evaluated also remained constant for the same group (simplified method or conventional method) in all periods of evaluation (p>0.05). The study concluded that the simplified method for complete denture fabrication was able to produce protheses with functional quality and patient satisfaction comparable to those produced with the conventional method, even when made by dental students.

The Influence of Age, Gender, Mandibular Bone Height, Previous Experience with Prostheses, and Fabrication Methods on Masticatory Performance of Complete Denture Wearers

PURPOSE

To evaluate the influence of age, gender, mandibular bone height, previous experience with prostheses, and methods for denture fabrication on masticatory performance of complete denture (CD) wearers.

MATERIALS AND METHODS

For this study, 29 individuals treated with CDs fabricated by simplified or conventional methods had their masticatory performance assessed 4 weeks after the prostheses' adjustment and control, using the sieve method and almonds as a natural food test. Experimental variables related to age, gender, and previous use of complete dentures were collected from dental records. Panoramic digital radiographs were used to determine mandibular bone height according to the criteria described by the American College of Prosthodontists. Data on masticatory performance were assessed using t-test for independent samples to make comparison between simplified and conventional methods, and a multiple linear regression analysis was performed to evaluate the influence of age, gender, previous experience with CDs, and mandibular bone height on masticatory performance using SPSS software with a significance level of 5%.

RESULTS

There was no significant influence regarding the method for CD fabrication (p = 0.92), age (p = 0.36), mandibular bone height (p = 0.37), and previous experience with prostheses (p = 0.15) on masticatory performance of CD wearers. Female patients presented lower masticatory performance than male (p = 0.04) patients did.

CONCLUSIONS

Considering the limitations of this study, it was concluded that gender might be considered a risk factor for masticatory performance of CD wearers. Female patients demonstrated reduced masticatory performance in comparison to male patients.

Clinical remounting of complete dentures: A systematic review

STATEMENT OF PROBLEM

A recent trend has been to reduce the procedural complexity of complete denture fabrication. Whether the clinical remount step is necessary is unclear.

PURPOSE

The purpose of this systematic review was to assess the relevance of the clinical remount procedure on complete denture outcomes.

MATERIAL AND METHODS

Five electronic databases were searched through to May 2018. The terms "denture*", "dental prosthes*", "equilibrat*", and "remount*" were chosen. The titles and abstracts were screened, and those which met the inclusion criteria were selected for full-text assessment. Studies that only performed the laboratory remount or were not randomized controlled studies were excluded.

RESULTS

After duplicate removal, the database search strategy resulted in a total of 226 potential studies. After the titles and abstracts had been screened and the inclusion and exclusion criteria applied, 10 studies were retrieved for full-text assessment. Four randomized controlled clinical studies were included in the systematic review. A meta-analysis could not be performed because of variation in outcome measures after the clinical remount.

CONCLUSIONS

A clinical remount for complete dentures is recommended on delivery to reduce clinically observed areas of discomfort and reduce the number of recall appointments. The development of a reliable and valid patient satisfaction questionnaire is necessary to determine conclusively whether the clinical remount also improves patient-perceived satisfaction and mastication.

Success of Complete Denture Treatment, Detailed Investigation of Construction Protocols, Occlusal Schemes and Evaluation Questionnaires

Background/Aim: The successful outcome of conventional complete denture treatment can be defined with the use of both subjective and objective criteria. Denture satisfaction determinants may include denture quality, oral tissue condition, patient-dentist relationship, patient’s attitude toward dentures, patient’s personality and socioeconomic factors. Purpose: The aim of the current review was to identify and analyze the different construction protocols and occlusal schemes that contribute to the success of complete denture rehabilitation through the use of evaluation questionnaires.

Material and Methods: A comprehensive literature search was performed through electronic databases (MEDLINE via PubMed) using the appropriate key words (complete denture construction, complete denture fabrication, complete denture occlusion and complete denture occlusal scheme). The related to the subject scientific papers were selected and evaluated for eligibility utilizing a predefined review process (English, full text articles, published from January 2000 up to April 2017).

Results: None of the analyzed studies identified significant differences between dentures constructed with simplified, CAD/CAM and traditional protocols in terms of general satisfaction and Oral Health Related Quality of Life scales. The same condition applied to the studies which compared complete dentures with bilateral balanced, lingualized, monoplane and canine guided occlusion.

Conclusions: Current scientific evidence suggested that patients could adapt comfortably to any type of bilateral balanced occlusal scheme and to complete dentures been fabricated with all types of complete denture construction protocol. Disease-specific questionnaires could be considered valuable tools and should be used to assess the outcome of any treatment modality.

Effect of mucostatic and selective pressure impression techniques on residual ridge resorption in individuals with different bone mineral densities: A prospective clinical pilot study

STATEMENT OF PROBLEM

Although different impression techniques have been advocated for complete denture prosthodontics, objective studies that predict their effect on alveolar bone resorption are lacking.

PURPOSE

The purpose of this prospective clinical pilot study was to objectively evaluate the effect of complete dentures fabricated by different impression techniques on mandibular residual ridge resorption in individuals with different bone mineral density.

MATERIAL AND METHODS

Ninety-six participants with edentulism, selected according to inclusion criteria, underwent bone mineral density assessment and were divided into normal, osteopenic, and osteoporotic groups. Half of the participants in each group were provided with dentures fabricated by selective pressure impression technique (subgroup SIT), and the other half were provided with dentures fabricated by mucostatic impression technique (subgroup MIT). Computed tomographic scans of the mandible were made at denture delivery and 1 year after prosthesis use to assess alveolar bone height and width difference at marked locations at and after denture delivery. The data obtained were analyzed with the Student t test (α=.05).

RESULTS

Significantly less reduction in mandibular ridge height and width was found in the MIT versus the SIT subgroups in both osteopenic and osteoporotic participants (P<.05). No significant subgroup difference was found for normal bone mineral density group, although resorption increased in height and width for the SIT subgroup.

CONCLUSIONS

Mandibular residual ridge resorption was reduced for dentures fabricated using the mucostatic impression technique compared with the selective pressure impression technique in individuals with diminished bone density.

Do traditional techniques produce better conventional complete dentures than simplified techniques? A 10-year follow-up of a randomized clinical trial

OBJECTIVES

The use of a simplified method (S) of fabricating complete dentures has been shown to be more cost-efficient than the traditional method (T), and there are no negative consequences that detract from the cost savings in the short term. However, it is not clear whether this remains constant over a decade. The objective of this study was to clarify patients' perspectives and determine any differences between the dentures fabricated with these two different techniques after a decade of use.

MATERIAL AND METHODS

Edentate individuals participated in a randomized controlled clinical trial and completed a 6-month follow-up from 2001 to 2003 (T group n = 50; S group n = 54). For this 10-year follow-up, they were interviewed by telephone. The assessment included whether the denture was still in use or replaced, the condition of the dentures, patient satisfaction and oral health-related quality of life (OHRQoL). Between and within-group differences and the factors that cause deterioration of oral health-related quality of life (OHRQoL) were determined.

RESULTS

Among 54 responders (25 T and 29 S), 14T and 21S kept the original dentures. Both groups were similar in ratings of satisfaction and OHRQoL (maxilla T: 80.0 S: 86.0, p = 0.36; mandibular; T: 66.1 S: 72.3, p = 0.48; OHRQoL T: 111.1 S: 108.5, p = 0.46). Irrespective of fabrication method, discomfort, chewing difficulty and esthetics were the factors that deteriorate OHRQoL (adjusted r = 0.76, p < 0.001).

CONCLUSION

The results indicate that the simplified method remains more cost-efficient than the traditional method over a 10-year period. (IRB approval: A09-E71-12 B McGill University, trial registry: ClinicalTrial.org; NCT02289443).

Single-implant overdentures retained by the Novaloc attachment system: study protocol for a mixed-methods randomized cross-over trial

BACKGROUND

Overdentures retained by a single implant in the midline have arisen as a minimal implant treatment for edentulous mandibles. The success of this treatment depends on the performance of a single stud attachment that is susceptible to wear-related retention loss. Recently developed biomaterials used in attachments may result in better performance of the overdentures, offering minimal retention loss and greater patient satisfaction. These biomaterials include resistant polymeric matrixes and amorphous diamond-like carbon applied on metallic components. The objective of this explanatory mixed-methods study is to compare Novaloc, a novel attachment system with such characteristics, to a traditional alternative for single implants in the mandible of edentate elderly patients.

METHODS/DESIGN

We will carry out a randomized cross-over clinical trial comparing Novaloc attachments to Locators for single-implant mandibular overdentures in edentate elderly individuals. Participants will be followed for three months with each attachment type; patient-based, clinical, and economic outcomes will be gathered. A sample of 26 participants is estimated to be required to detect clinically relevant differences in terms of the primary outcome (patient ratings of general satisfaction). Participants will choose which attachment they wish to keep, then be interviewed about their experiences and preferences with a single implant prosthesis and with the two attachments. Data from the quantitative and qualitative assessments will be integrated through a mixed-methods explanatory strategy. A last quantitative assessment will take place after 12 months with the preferred attachment; this latter assessment will enable measurement of the attachments' long-term wear and maintenance requirements.

DISCUSSION

Our results will lead to evidence-based recommendations regarding these systems, guiding providers and patients when making decisions on which attachment systems and implant numbers will be most appropriate for individual cases. The recommendation of a specific attachment for elderly edentulous patients may combine positive outcomes from patient perspectives with low cost, good maintenance, and minimal invasiveness.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03126942 . Registered on 13 April 2017.

Final-impression techniques and materials for making complete and removable partial dentures

BACKGROUND

Edentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures (CD) and removable partial dentures (RPD) using different techniques and materials. Applying the correct impression technique and material, based on an individual's oral condition, improves the quality of the prosthesis, which may improve quality of life.

OBJECTIVES

To assess the effects of different final-impression techniques and materials used to make complete dentures, for retention, stability, comfort, and quality of life in completely edentulous people.To assess the effects of different final-impression techniques and materials used to make removable partial dentures, for stability, comfort, overextension, and quality of life in partially edentulous people.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 22 November 2017), MEDLINE Ovid (1946 to 22 November 2017), and Embase Ovid (21 December 2015 to 22 November 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases, however the search of Embase was restricted by date due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different final-impression techniques and materials for treating people with complete dentures (CD) and removable partial dentures (RPD). For CD, we included trials that compared different materials or different techniques or both. In RPD for tooth-supported conditions, we included trials comparing the same material and different techniques, or different materials and the same technique. In tooth- and tissue-supported RPD, we included trials comparing the same material and different dual-impression techniques, and different materials with different dual-impression techniques.

DATA COLLECTION AND ANALYSIS

Two review authors independently, and in duplicate, screened studies for eligibility, extracted data, and assessed the risk of bias for each included trial. We expressed results as risk ratios (RR) for dichotomous outcomes, and as mean differences (MD) or standardised mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CI), using the random-effects model. We constructed 'Summary of findings' tables for the main comparisons and outcomes (participant-reported oral health-related quality of life, quality of the denture, and denture border adjustments).

MAIN RESULTS

We included nine studies in this review. Eight studies involved 485 participants with CD. We assessed six of the studies to be at high risk of bias, and two to be at low risk of bias. We judged one study on RPD with 72 randomised participants to be at high risk of bias.Overall, the quality of the evidence for each comparison and outcome was either low or very low, therefore, results should be interpreted with caution, as future research is likely to change the findings.Complete denturesTwo studies compared the same material and different techniques (one study contributed data to a secondary outcome only); two studies compared the same technique and different materials; and four studies compared different materials and techniques.One study (10 participants) evaluated two stage-two step, Biofunctional Prosthetic system (BPS) using additional silicone elastomer compared to conventional methods, and found no evidence of a clear difference for oral health-related quality of life, or quality of the dentures (denture satisfaction). The study reported that BPS required fewer adjustments. We assessed the quality of the evidence as very low.One study (27 participants) compared selective pressure final-impression technique using wax versus polysulfide elastomeric (rubber) material. The study did not measure quality of life or dentures, and found no evidence of a clear difference between interventions in the need for adjustments (RR 0.81, 95% CI 0.38 to 1.70). We assessed the quality of the evidence as very low.One study compared two stage-two step final impression with alginate versus silicone elastomer. Oral health-related quality of life measured by the OHIP-EDENT seemed to be better with silicone (MD 7.20, 95% CI 2.71 to 11.69; 144 participants). The study found no clear differences in participant-reported quality of the denture (comfort) after a two-week 'confirmation' period, but reported that silicone was better for stability and chewing efficiency. We assessed the quality of the evidence as low.Three studies compared single-stage impressions with alginate versus two stage-two step with elastomer (silicone, polysulfide, or polyether) impressions. There was no evidence of a clear difference in the OHIP-EDENT at one month (MD 0.05, 95% CI -2.37 to 2.47; two studies, 98 participants). There was no evidence of a clear difference in participant-rated general satisfaction with dentures at six months (MD 0.00, 95% CI -8.23 to 8.23; one study, 105 participants). We assessed the quality of the evidence as very low.One study compared single-stage alginate versus two stage-two step using zinc-oxide eugenol, and found no evidence of a clear difference in OHIP-EDENT (MD 0.50, 95% CI -2.67 to 3.67; 39 participants), or general satisfaction (RR 3.15, 95% CI 0.14 to 72.88; 39 participants) at six months. We assessed the quality of the evidence as very low.Removable partial denturesOne study randomised 72 participants and compared altered-cast technique versus one-piece cast technique. The study did not measure quality of life, but reported that most participants were satisfied with the dentures and there was no evidence of any clear difference between groups for general satisfaction at one-year follow-up (low-quality evidence). There was no evidence of a clear difference in number of intaglio adjustments at one year (RR 1.43, 95% CI 0.61 to 3.34) (very low-quality evidence).

AUTHORS' CONCLUSIONS

We conclude that there is no clear evidence that one technique or material has a substantial advantage over another for making complete dentures and removable partial dentures. Available evidence for the relative benefits of different denture fabrication techniques and final-impression materials is limited and is of low or very low quality. More high-quality RCTs are required.

Learning effects of different training models for border molding from the perspective of dental students

BACKGROUND

The aim of this study was to investigate the effects of different practical training models on the comprehension and evaluation of practical training among dental students.

METHODS

The study subjects were all sixth-year dental students at our institute, and the study took place over three consecutive years (n = 58, 63, and 65, respectively). In practical training, all students learned border molding, and practical models were modified each year from plaster models to silicone models and then to silicone models mounted in mannequins. Immediately after completing clinical training, all students were asked to complete questionnaires consisting of 21 items regarding their overall practical training and their clinical comprehension of border molding. All items were rated on a five-point Likert scale, and in order to reduce the large number of interrelated questions, exploratory factor analysis was carried out using maximum likelihood estimation with promax rotation (κ = 4) and Kaiser normalization. The number of factors was chosen using the Kaiser-Guttman rule, which states that the eigenvalue should be larger than 1, and the scree plot criteria. Items that scored less than 0.25 in communality and exhibited factor loading greater than 0.35 for more than one item were excluded. The defined factors were analyzed for the plaster models, the silicone models alone, and the silicone models with mannequins using the Kruskal-Wallis test and follow-up tests using Bonferroni-corrected Mann-Whitney U tests. The significance level was set at p < 0.05.

RESULTS

Exploratory factor analysis identified the following three factors: "knowledge of border molding"; "contents of practical training"; and "personal learning attitude". The students who used silicone models and mannequins gave significantly better evaluations on the "knowledge of border molding" (p < 0.001, both) and "contents of practical training" (p = 0.046, p < 0.001, respectively) subscales than those who used plaster models. No significant differences were observed between those who used silicone models and those who used mannequins. Moreover, no significant differences were found on the "personal learning attitude" subscale among students for any model.

CONCLUSIONS

The change in practical training models from plaster to silicone improved student evaluations of border molding training.

Mini-Implants for Mandibular Overdentures: Cost-Effectiveness Analysis alongside a Randomized Trial

Mandibular overdentures retained by 2 conventional implants have been considered the standard of care for complete edentulism, according to the McGill and York consensuses. However, many patients refuse this treatment modality due to the associated costs and postsurgical discomfort. Mini-implants have the chance to overcome these limitations due to their potentially lower costs and a relatively uncomplicated surgical technique. This study compared treatment costs and incremental cost-effectiveness following the insertion of mini-implants (2 or 4) or 2 standard-size implants for the retention of mandibular overdentures, by means of a randomized clinical trial. In total, 120 edentulous participants (mean age 59.5 ± 8.5 y) were randomly allocated into 3 groups according to treatment received: 4 mini-implants (group 1), 2 mini-implants (group 2), or 2 standard implants (group 3). Treatment costs and outcomes (Oral Health Impact Profile for Edentulous [OHIP-EDENT] and satisfaction with the dentures) were evaluated after 6 mo. Incremental cost-effectiveness ratios (ICERs) were calculated for each intervention in terms of cost per 1-point change in patient outcomes. A 1-way sensitivity analysis was performed considering a 95% confidence interval variation in cost and outcome parameters, represented in tornado diagrams. Overall treatment cost was the lowest for group 2 (average cost: US$318.08), followed by group 1 (US$510.75) and group 3 (US$566.13). Groups did not differ in terms of the length of unscheduled appointments and time spent by participants. In summary, our findings indicate that mandibular overdentures retained by 2 or 4 mini-implants are less costly compared to 2-implant overdentures. Despite the lower costs of overdentures retained by 2 mini-implants, those retained by 4 mini-implants showed further improvement in patient-reported outcomes and reduced costs compared to standard implants ( ClinicalTrials.gov NCT01411683).

Knowledge Transfer Statement: This report shows that mini-implant retained overdentures are less costly than overdenture treatment on 2 standard-sized implants. Treatment with 2 mini-implants is an effective procedure to substantially save resources, whereas treatment with 4 mini-implants provides better results from a patient perspective combined with slightly reduced costs compared to the treatment with 2 standard implants. Therefore, mini-implant overdentures may be effective and more accessible than overdentures on 2 standard-size implants for those with limited incomes.

Cost-effectiveness analysis of two impression methods for the fabrication of mandibular complete dentures

OBJECTIVES

To compare the cost and to evaluate cost-effectiveness of fabricating mandibular complete dentures (CDs) using two different impression methods.

METHODS

A crossover randomized controlled trial including 27 edentulous participants was performed. Mandibular CDs were fabricated using two different impression methods, as follows: (i) conventional method using a custom tray border moulded with impression compound and silicone and (ii) simplified method using a stock tray and alginate. Cost analysis was performed from a clinical practitioner's perspective. The total cost included labor cost, which was calculated using the time spent by dentists and technicians in fabricating CDs and their hourly wages, and the material costs, which were calculated using purchase prices. To evaluate cost-effectiveness, we used general patient satisfaction as an indicator of effectiveness and calculated the incremental cost effectiveness ratio (ICER). ICER represents the cost per one unit of effectiveness.

RESULTS

The trial was completed by 24 participants. The total cost was 43,904 Japanese Yen (JPY) (330.91 EUR / 395.78 USD) for the conventional method and 39,792 JPY (299.93 EUR / 358.70 USD) for the simplified method, and this difference was statistically significant (p<0.001). The ICER showed a cost of 633 JPY (4.77 EUR / 5.70 USD) for every one point change in general patient satisfaction.

CONCLUSIONS

The results indicated that the total cost of the conventional method was significantly higher than that of the simplified method (p<0.001).

CLINICAL SIGNIFICANCE

The conventional impression method for fabricating mandibular CDs, which took additional 633 JPY (4.77 EUR / 5.70 USD) for improvement of general satisfaction, is supposed to be clinically meaningful¹.