Cost-effectiveness of silicone and alginate impressions for complete dentures.

OBJECTIVE: The aim of this study was to assess the cost effectiveness of silicone and alginate impressions for complete dentures. METHODS: Cost effectiveness analyses were undertaken alongside a UK single centre, double blind, controlled, crossover clinical trial. Taking the perspective of the healthcare sector, effectiveness is measured using the EuroQol (EQ-5D-3L) which provides a single index value for health status that may be combined with time to produce quality adjusted life years (QALYs); and Oral Health Impact Profile (OHIP-EDENT). Incremental cost effectiveness ratios are presented representing the additional cost per one unit gained. RESULTS: Mean cost was higher in the silicone impression group (£388.57 vs. £363.18). Negligible between-group differences were observed in QALY gains; the silicone group had greater mean OHIP-EDENT gains. The additional cost using silicone was £3.41 per change of one point in the OHIP-EDENT. CONCLUSIONS: The silicone group was more costly, driven by the cost of materials. Changes in the EQ-5D and QALY gains over time and between arms were not statistically significant. Change in OHIP-EDENT score showed greater improvement in the silicone group and the difference between arms was statistically significant. Given negligible QALY gains and low level of resource use, results must be treated with caution. It is difficult to make robust claims about the comparative cost-effectiveness. CLINICAL SIGNIFICANCE: Silicone impressions for complete dentures improve patients' quality of life (OHIP-EDENT score). The extra cost of silicone impressions is £30 per patient. Dentists, patients and health care funders need to consider the clinical and financial value of silicone impressions. Different patients, different dentists, different health funders will have individual perceptions and judgements. ISRCTN01528038. NIHR-RfPB grant PB-PG-0408-16300. This article forms part of a project for which the author (TPH) won the Senior Clinical Unilever Hatton Award of the International Assocation for Dental Research, Capetown, South Africa, June 2014.

IMPROVDENT: improving dentures for patient benefit. A crossover randomised clinical trial comparing impression materials for complete dentures.

BACKGROUND: According to the UK Adult Dental Health Survey (2009) 15% of adults aged 65-74, 30% aged 75-84 and 47% aged >85 years are edentulous and require complete dentures. Patients' quality of life and nutrition status are affected by poor dentures. The quality of the dental impression is the most important issue for improving the fit and comfort of new dentures. There is paucity of RCT evidence for which impression material is best for complete dentures construction. This study aims to compare two impression materials for effectiveness and cost effectiveness. METHODS/DESIGN: IMPROVDENT is a double-blind crossover trial comparing the use of alginate and silicone, two commonly used denture impression materials, in terms of patient preference and cost-effectiveness. Eighty five edentulous patients will be recruited and provided with two sets of dentures, similar in all aspects except for the impression material used (alginate or silicone). Patients will try both sets of dentures for a two-week period, unadjusted, to become accustomed to the feel of the new dentures (habituation period). Patients will then wear each set of dentures for a period of 8 weeks (in random order) during which time the dentures will be adjusted for optimum comfort. Finally, patients will be given both sets of dentures for a further two weeks to wear whichever denture they prefer (confirmation period).Patients will be asked about quality of life and to rate dentures on function and comfort at the end of each trial period and asked which set they prefer at the end of the habituation period (unadjusted denture preference) and confirmation period (adjusted denture preference). A health economic evaluation will estimate incremental cost-effectiveness ratios of producing dentures from the two materials. A qualitative study will investigate the impact of dentures on behaviour and quality of life. FUNDING: IMPROVDENT is funded by NIHR RfPB (PB-PG-0408-16300). DISCUSSION: This trial aims to provide evidence on the costs and quality of dentures cast from two different commonly used impression materials; the intention is to significantly impact on the quality of denture production within NHS dentistry. TRIAL REGISTRATION: ISRCTN Register: ISRCTN01528038 UKCRN Portfolio ID: 8305.

A comparison of the cost effectiveness of pressure-indicating materials and their ability to detect pressure areas in complete dentures.

Pressure areas on the fitting surfaces of dentures can cause great discomfort and pain to denture wearers if not detected and removed. Pressure-indicating materials are commonly used to detect these areas, and several commercial varieties are available, but these tend to be expensive. The cost effectiveness of these materials has not been investigated, nor has this been linked to their efficacy and ease of use. The aim of this study therefore, was to compare the different pressure-indicating materials available commercially with that of a home-made paste. An assumption of efficacy was made by the number and size of pressure areas revealed, by taking standardised photographs and analysing the images. User friendliness was determined by the time taken to mix, apply and remove the material. Cost was determined by a cost per unit calculation based on the average or minimum quantity required for each material. The results indicated that a home-made paste made of equal quantities of hand lanolin (BP) and zinc oxide powder was not only the most effective, but was also the cheapest, being only 3% of the cost of the most expensive of the materials.

Wastage of a silicone impression material in a general practice setting: a comparison between hand and automixing methods.

A practice-based, randomised, controlled trial has been undertaken to investigate the wastage of impression material when recording full arch one-stage, polyvinyl siloxane impressions using four techniques: putty and automix light viscosity material, putty and automix regular viscosity material, putty and tubed light viscosity material, and putty and tubed regular viscosity material. A total of 100 maxillary impressions, comprising 25 recorded using each of the four techniques, were obtained according to a predetermined scheme for randomisation. All material wasted in dispensing, mixing and applying each impression was determined by repeated weighing. Statistical comparisons of the mean weights of material wasted for each type of impression revealed that significantly (P < 0.01) less wastage occurred with the automix techniques. It is concluded that automix impression techniques may, in more extensive studies, be found to be more cost effective than tubed impression material techniques when recording impressions of the type investigated.

[The reliability of class A alginate impressions]. / Fiabilité des empreintes à l'alginate de classe A.

The class A alginates present very good properties of dimensional precision and reproduction of details, comparable to those of the reversible hydrocolloïdes and certain elastomeres used for the realization of secondary prints of precision in fixed prosthesis and in removable prosthesis. Besides, their application is easier and they are costless. The valorization of these print materials could certainly contribute to reduce the cost of comes back of prostheses in countries under developed where the weak power economic populations constitute a brake to the access to cares of health. To exploit qualities of these print biomaterials well, it agrees to manage correctly the parameters of their application. To this effect, the present survey puts in evidence that the maximum delay of stream that guarantees the good dimensional stability of these class A alginates is of 45 minutes in the hot and humid climatic tropical country conditions.