Various measurement methods have been described for the determination of dimensional accuracy and stability of denture base materials. This investigation introduces a computerised coordinate measuring machine (CCMM) and compares it with two methods routinely used for assessment of the accuracy of fit of denture base materials. The results demonstrate that the three methods (digital calipers, optical comparator, and CCMM) are acceptable for linear measurement. The CCMM was also used in its scanning mode to define and to quantify the contour changes of the resin bases. The advantages of the CCMM become apparent when two-dimensional changes require assessment.

Acrylic Resins↗

PubMedDate not supplied

Finite element analysis of the stress-concentrating effect of fraenal notches in complete dentures.

Based on clinical experience and empiricism, it was postulated that fraenal notches and midline diastemas lead to fracture of complete dentures. This study used finite element stress analysis to investigate the stress-concentrating effect of a fraenal notch with and without a midline diastema. It was found that a large fraenal notch resulted in high stress levels and that these stresses were augmented more by a narrow median diastema than its wider counterpart.

Dental Stress Analysis↗

PubMedDate not supplied

Soft lining materials in prosthetic dentistry: a review.

Although soft lining materials are widely used in prosthetic dentistry, their properties are far from ideal. This paper presents a review of these materials, including their historical development, clinical indications, ideal properties, and limitations. Examples of the three basic types are given together with their typical compositions. It is evident that further research and development is necessary to achieve a material with optimum properties.

Denture Liners↗

PubMedDate not supplied

Computer-aided learning in prosthodontics.

Interactive video is computer-aided learning illustrated by still or moving video pictures. First introduced for the study of pathology, its application and potential in prosthodontics is reported in this article. Partial denture design was chosen as the first subject, since the systematic approach concept could easily be established by dividing the subject into five units that could individually be expanded and tested. Students are generally enthusiastic about computer-aided learning and there is considerable potential to further develop this type of learning process.

Audiovisual Aids↗

PubMedDate not supplied

Some effects of varying denture base resin polymer/monomer ratios.

Variations in the polymer/monomer mixing ratios from 1.5:1 to 4.5:1 vol/vol have been evaluated to determine the effect on dimensional accuracy and impact resistance of a PMMA homopolymer. Two polymerisation cycles were used. It was shown that a wide variation in mixing ratios (1.5:1 to 4:1) had no effect on dimensional accuracy or impact resistance and that a polymerisation cycle that includes a final boiling period is preferred. It was further found that notched impact resistance was almost an order of magnitude below unnotched impact resistance, emphasising the weakening effect of sharp contours on the impact resistance of denture resins.

Acrylic Resins↗

PubMedDate not supplied

A comparison of some properties of denture base acrylic resins polymerized by dry and wet curing systems.

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Absorption↗

PubMedDate not supplied

The effect of variations in the polymer/monomer mixing ratios on residual monomer levels and flexural properties of denture base materials.

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Chemical Phenomena↗

PubMedDate not supplied

The effects of various disinfectant solutions on the surface hardness of an acrylic resin denture base material.

There is an increasing awareness of the importance of cross-infection control in dental clinics and laboratories. This study evaluates the effects of various disinfecting solutions on the surface hardness of an acrylic resin denture base material. Hardness was measured as resistance to indentation following the method specified by the British Standards Institute. The results demonstrated that immersion of denture base acrylic resin in disinfecting solution for up to 24 hours resulted in no significant effect on hardness values.

Acrylic Resins↗