2010 Volume 53 Issue 2 Pages 106-114
We previously showed that in clinical practice minimal intervention (MI) is used less frequently for non-vital teeth than for vital teeth. We also showed that MI recognition did not result in an increase in the clinical use of MI restorations (restorations based on MI) for non-vital teeth, but did so for vital ones. However, there were also dentists who did not necessarily select MI restorations, even though they knew of MI and intended to use MI restorations. This study aimed to clarify factors limiting the increased clinical use of MI restorations. We surveyed 133 dentists working at Kyushu University Dental Hospital about MI. The questionnaire included colour illustrations of two carious cavities: a small distal carious cavity in a mandibular second premolar (Case 1, an example of a vital tooth) and a large mesio-occlusal-distal cavity in a mandibular first molar (Case 2, an example of a non-vital tooth after root canal filling). The questionnaire was designed to obtain data regarding the dentists' attitudes toward and use of MI: MI recognition, intention to use MI restorations, selection of restorations for Cases 1 and 2, and reasons for the selection. We performed discriminant analysis to determine which reasons for selection discriminated between MI restorations and conventional restorations (restorations based on GV Black's concept for vital teeth, and a full coverage crown for non-vital teeth), which revealed the characteristics of respondents who selected conventional restorations. Compared with respondents having a strong preference toward MI restorations, respondents who selected conventional restorations more often indicated prevention of recurrent caries, acquiring retention force for vital teeth, prevention of tooth fracture and acquiring retention force for non-vital teeth as reasons for their selection. These results indicated that the factors limiting the clinical use of MI included concerns about the adhesive properties of adhesive materials and their influence on the recurrence of caries in vital teeth or tooth fractures in non-vital ones. The discriminant analysis also revealed that the reason, "preservation of the remaining tooth structure," alone discriminated MI and conventional restorations for non-vital teeth, with very few respondents who selected conventional restorations indicating this reason, while most respondents who selected MI restorations did. Therefore, it will be necessary to accumulate evidence about the applicability and usefulness of MI restorations with adhesive materials, along with data about the importance of preserving the remaining tooth structure for tooth longevity.
