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

Photoelastic analysis of mandibular full-arch implant-supported fixed dentures made with different bar materials and manufacturing techniques

PURPOSE

To compare the stress distribution of mandibular full dentures supported with implants according to the bar materials and manufacturing techniques using a qualitative photoelastic analysis.

MATERIAL AND METHODS

An acrylic master model simulating the mandibular arch was fabricated with four Morse taper implant analogs of 4.5×6mm. Four different bars were manufactured according to different material and techniques: fiber-reinforced resin (G1, Trinia, CAD/CAM), commercially pure titanium (G2, cpTi, CAD/CAM), cobalt‑chromium (G3, Co-Cr, CAD/CAM) and cobalt‑chromium (G4, Co-Cr, conventional cast). Standard clinical and laboratory procedures were used by an experienced dental technician to fabricate 4 mandibular implant-supported dentures. The photoelastic model was created based on the acrylic master model. A load simulation (150N) was performed in total occlusion against the antagonist.

RESULTS

Dentures with fiber-reinforced resin bar (G1) exhibited better stress distribution. Dentures with machined Co-Cr bar (G3) exhibited the worst standard of stress distribution, with an overload on the distal part of the posteriors implants, followed by dentures with cast Co-Cr bar (G4) and machined cpTi bar (G2).

CONCLUSION

The fiber-reinforced resin bar exhibited an adequate stress distribution and can serve as a viable alternative for oral rehabilitation with mandibular full dentures supported with implants. Moreover, the use of the G1 group offered advantages including reduced weight and less possible overload to the implants components, leading to the preservation of the support structure.

Does a face-bow lead to better occlusion in complete dentures? A randomized controlled trial: part I

OBJECTIVES

In a double-blinded randomized controlled clinical trial, the impact of face-bow registration for remounting complete dentures (CDs) on the occlusal parameters (part I) was evaluated.

MATERIALS AND METHODS

New CDs of 32 patients were duplicated and mounted after intraoral pin registration according to mean settings (group 1) and (group 2) using a face-bow (arbitrary hinge axis). The vertical dimension was reduced to the first occlusal contact point, and a bite record was fabricated in the articulator. The number of contacts and the number of teeth in contact were evaluated by a computer program (laboratory result). After randomization, half of the CDs were adjusted according to protocol of group 1 and group 2 and delivered to the patients. After 3 days (T1) and 84 days (T2), clinical static contact points and teeth in contact were counted. Contact points and teeth in contact of both groups (laboratory results) and at different moments (clinical results) were analyzed statistically with the F test and bootstrapping.

RESULTS

Laboratory: No. 2 (face-bow) showed more occlusal contact points than no. 1 (mean setting), p > 0.05. The number of teeth with at least one occlusal contact was significantly higher in no. 2 (p = 0.027). Clinic: The mean number of teeth with at least one clinical contact point was significantly higher in no. 1 (no. 1 = 7.13, no. 2 = 5.31; p = 0.042). Extent of the vertical shift poorly correlated with number of laboratory occlusal contact points (R ² = 0.017).

CONCLUSIONS

Considering the complex multistep study design, a limited number of participants, and referring to one specific arbitrary face-bow, the following conclusion could be drawn: no substantial difference by the use of the arbitrary face-bow compared to a mean setting could be determined, when changing the vertical dimension in the articulator within a remounting procedure of complete dentures.

CLINICAL RELEVANCE

Further research is necessary to determine the effects of different arbitrary face-bows on the fabrication and adaptation of removable dentures.

Design and fabrication of complete dentures using CAD/CAM technology

The aim of the study was to test the feasibility of using commercially available computer-aided design and computer-aided manufacturing (CAD/CAM) technology including 3Shape Dental System 2013 trial version, WIELAND V2.0.049 and WIELAND ZENOTEC T1 milling machine to design and fabricate complete dentures.The modeling process of full denture available in the trial version of 3Shape Dental System 2013 was used to design virtual complete dentures on the basis of 3-dimensional (3D) digital edentulous models generated from the physical models. The virtual complete dentures designed were exported to CAM software of WIELAND V2.0.049. A WIELAND ZENOTEC T1 milling machine controlled by the CAM software was used to fabricate physical dentitions and baseplates by milling acrylic resin composite plates. The physical dentitions were bonded to the corresponding baseplates to form the maxillary and mandibular complete dentures.Virtual complete dentures were successfully designed using the software through several steps including generation of 3D digital edentulous models, model analysis, arrangement of artificial teeth, trimming relief area, and occlusal adjustment. Physical dentitions and baseplates were successfully fabricated according to the designed virtual complete dentures using milling machine controlled by a CAM software. Bonding physical dentitions to the corresponding baseplates generated the final physical complete dentures.Our study demonstrated that complete dentures could be successfully designed and fabricated by using CAD/CAM.

The importance of a two-step impression procedure for complete denture fabrication: a systematic review of the literature

The literature has questioned the real need for some clinical and laboratory procedures considered essential for achieving better results for complete denture fabrication. The aim of this study was to review the current literature concerning the relevance of a two-step impression procedure to achieve better clinical results in fabricating conventional complete dentures. Through an electronic search strategy of the PubMed/MEDLINE database, randomised controlled clinical trials which compared complete denture fabrication in adults in which one or two steps of impressions occurred were identified. The selections were made by three independent reviewers. Among the 540 titles initially identified, four studies (seven published papers) reporting on 257 patients evaluating aspects such as oral health-related quality of life, patient satisfaction with dentures in use, masticatory performance and chewing ability, denture quality, direct and indirect costs were considered eligible. The quality of included studies was assessed according to the Cochrane guidelines. The clinical studies considered for this review suggest that a two-step impression procedure may not be mandatory for the success of conventional complete denture fabrication regarding a variety of clinical aspects of denture quality and patients' perceptions of the treatment.

Simplified Complete Denture: A Systematic Review of the Literature

PURPOSE

Many procedures are used to construct traditional (T) complete dentures; however, a simplified (S) method requiring fewer steps and less time is available. This systematic review intends to summarize the modeling of simplified methods for complete dentures and evaluate the differences between the T method and S method. With this review, we hope to lay the foundation for proposing a standardized fabrication method for "simplified dentures."

METHODS

The MEDLINE (via PubMed) and EMBASE databases were searched for articles on simplified complete dentures published in English before April 2014. Eleven articles were included. One was about one-step complete dentures, two were about SET (simplified treatment of edentulous patients), and the others were about the normal simplified method, which includes impression, occlusal registration, and try-in. Seven were randomized controlled clinical trials (RCTs). The time, cost, patient satisfaction, clinical effects, masticatory performance, masticatory ability, and professional evaluation reported in these studies were compared.

RESULTS

We summarized the different techniques of fabricating complete dentures and discussed the RCTs of the normal complete technique. None of the RCTs identified significant differences between the S and T groups in terms of patient ratings for general satisfaction, OHIP-edentulous scale, denture quality, or masticatory ability. At the same time, the T method was significantly more expensive and required more time to complete than the S method.

CONCLUSIONS

Current scientific evidence suggests that the S method can replace or partly replace the T method. Moreover, specific rules should be devised to restrict the simplified construction, and detailed research should be conducted.

A randomized controlled trial of the different impression methods for the complete denture fabrication: Patient reported outcomes

OBJECTIVES

To compare the effect of conventional complete dentures (CD) fabricated using two different impression methods on patient-reported outcomes in a randomized controlled trial (RCT).

METHODS

A cross-over RCT was performed with edentulous patients, required maxillomandibular CDs. Mandibular CDs were fabricated using two different methods. The conventional method used a custom tray border moulded with impression compound and a silicone. The simplified used a stock tray and an alginate. Participants were randomly divided into two groups. The C-S group had the conventional method used first, followed by the simplified. The S-C group was in the reverse order. Adjustment was performed four times. A wash out period was set for 1 month. The primary outcome was general patient satisfaction, measured using visual analogue scales, and the secondary outcome was oral health-related quality of life, measured using the Japanese version of the Oral Health Impact Profile for edentulous (OHIP-EDENT-J) questionnaire scores.

RESULTS

Twenty-four participants completed the trial. With regard to general patient satisfaction, the conventional method was significantly more acceptable than the simplified. No significant differences were observed between the two methods in the OHIP-EDENT-J scores.

CONCLUSIONS

This study showed CDs fabricated with a conventional method were significantly more highly rated for general patient satisfaction than a simplified.

CLINICAL SIGNIFICANCE

CDs, fabricated with the conventional method that included a preliminary impression made using alginate in a stock tray and subsequently a final impression made using silicone in a border moulded custom tray resulted in higher general patient satisfaction.

TRIAL REGISTRATION

UMIN000009875.

Simplified versus traditional techniques for complete denture fabrication: a systematic review

STATEMENT OF PROBLEM

A number of methods have been described for the fabrication of complete dentures. There are 2 common ways to make conventional complete dentures: a traditional method and a simplified method.

PURPOSE

The purpose of this study was to conduct a systematic review to compare the efficiency of simplified and traditional methods for the fabrication of complete dentures.

MATERIAL AND METHODS

The review was conducted by 3 independent reviewers and included articles published up to December 2013. Three electronic databases were searched: MEDLINE-PubMed, The Cochrane Library, and ISI Web of Science. A manual search also was performed to identify clinical trials of simplified versus traditional fabrication of complete dentures.

RESULTS

Six articles were classified as randomized controlled clinical trials and were included in this review. The majority of the selected articles analyzed general satisfaction, denture stability, chewing ability and function, comfort, hygiene, esthetics, speech function, quality of life, cost, and fabrication time.

CONCLUSIONS

Although the studies reviewed demonstrate some advantages of simplified over traditional prostheses, such as lower cost and clinical time, good chewing efficiency, and a positive effect on the quality of life, the reports related the use of different simplified methods for the fabrication of complete dentures. Additional randomized controlled trials that used similar simplified techniques for the fabrication of complete dentures should be performed with larger sample sizes and longer follow-up periods.

Método simplificado versus convencional de confecção de próteses totais: práticas adotadas pelos Cirurgiões-Dentistas

Introdução: A fim de reduzir custos e tempo clínico envolvidos com o tratamento, Dentistas têm utilizado métodos simplificados, omitindo ou abreviando partes da técnica de confecção das próteses totais. Objetivo: Levantar as práticas utilizadas pelos Cirurgiões-Dentistas para a confecção de próteses totais. Material e método: Os dados foram levantados por meio de um formulário eletrônico contendo perguntas relativas ao perfil e aos procedimentos clínicos utilizados, a fim de quantificar o uso de métodos simplificados e convencionais, bem como para determinar a relação com o perfil desses profissionais. Os resultados foram analisados por meio de análise de Aglomerados. Resultado: As respostas foram dadas, em sua maioria, por homens, tendo a prática clínica como sua principal fonte de renda e clínica privada ou conveniada como ambiente principal de trabalho (n=119). Grande parte dos entrevistados relatou realizar duas moldagens por arcada, utilização de articulador semiajustável com arco facial, determinação de plano oclusal por meio de guias anatômicos, utilização de meios métricos para análise da dimensão vertical de oclusão e determinação direta da relação cêntrica. O próprio Cirurgião-Dentista relatou ser o responsável na fase de seleção de dentes. A estatística identificou dois Aglomerados, com base nas características demográficas e na prática clínica, sendo um grupo formado por generalistas adeptos de perfis mais simplificados e outro formado por profissionais mais especializados em prótese que realizam técnicas convencionais. Conclusão: A adoção de técnicas simplificadas é associada àqueles Dentistas com perfil mais generalista, enquanto protesistas tendem a trabalhar mais de acordo com a Academia.

A randomized trial on simplified and conventional methods for complete denture fabrication: cost analysis

PURPOSE

This study aimed to quantify the costs of complete denture fabrication by a simplified method compared with a conventional protocol.

MATERIALS AND METHODS

A sample of edentulous patients needing conventional maxillary and mandibular complete dentures was randomly divided into group S, which received dentures fabricated by a simplified method, and group C, which received conventionally fabricated dentures. We calculated direct and indirect costs for each participant including unscheduled procedures. This study assessed 19 and 20 participants allocated into groups S and C, respectively, and comparisons between groups were conducted by the Mann-Whitney and Student's t-test (α = 0.05).

RESULTS

Complete denture fabrication demanded median time periods of 173.2 and 284.5 minutes from the operator for groups S and C respectively, and 46.6 and 61.7 minutes from the dental assistant (significant differences, p < 0.05). There was no difference between groups regarding postinsertion adjustments. Group S showed lower values for costs with materials and time spent by patients than group C during the fabrication stage, but not during adjustments.

CONCLUSIONS

The median direct cost of complete denture treatment was 34.9% lower for the simplified method. It can be concluded that the simplified method is less costly for patients and the health system when compared with a conventional protocol for the rehabilitation of edentulous patients.

Face-bow transfer in prosthodontics: a systematic review of the literature

An extensive search for randomised controlled clinical trials was accomplished to compare dental prostheses and occlusal splints constructed with or without face-bow transfer, and question whether face-bow transfer may present better clinical results than simpler approaches. Studies were identified by searching electronic databases (PubMed/MEDLINE, Latin American and Caribbean Literature on the Health Science, and Brazilian Bibliography of Dentistry). The keywords 'dental articulator', 'semi-adjustable articulator', 'face-bow', 'jaw relation record' and 'occlusal splint therapy' were used. The minimum inclusion requirements were (i) randomised controlled trials with patients of any age, (ii) comparison between dental prostheses or occlusal splints constructed with or without face-bow transfer and (iii) assessment of clinician's time, number of occlusal contacts, patient satisfaction or masticatory function. The search resulted in the identification of 8779 articles. Subsequently, 8763 articles were excluded on the basis of title and abstract. By the end of the search phase, eight randomised controlled trials were considered eligible. Current scientific evidence suggests that face-bow transfer is not imperative to achieve better clinical results in prosthodontics. Randomised clinical trials suggest that simpler approaches for the construction of complete dentures and occlusal splints may present acceptable results, while no clinical study has investigated its use in fixed and removable partial dentures.

A randomised trial of a simplified method for complete denture fabrication: patient perception and quality

Complete denture fabrication involves a series of complex technical procedures. Nevertheless, simplified methods may be as effective as conventional ones albeit the lesser use of time and resources, without disadvantage for the patient. This study compared a simplified method for complete denture fabrication to a conventional protocol in terms of oral health-related quality of life (OHRQoL), patient satisfaction and denture quality. Forty-two edentulous patients requesting treatment with complete dentures were randomly allocated into two study groups. Group S received dentures fabricated by a simplified method and Group C received conventionally fabricated dentures. Before interventions and after three and 6 months following insertion, OHRQoL and patient satisfaction were analysed by specific instruments. A prosthodontist assessed denture quality 3 months after delivery. Groups presented no difference for OHRQoL, denture quality and general satisfaction. Differences regarding patient satisfaction with some aspects of the dentures were found after 3 months (S > C), but were insignificant at 6 months. It was concluded that the simplified method is able to produce dentures of a quality comparable to those produced by the conventional method, influencing OHRQoL and patient satisfaction similarly.