The Shortened Dental Arch (SDA) concept and Swedish general dental practitioners : attitudes and prosthodontic decision-making

Abstract: 10ABSTRACTA Shortened Dental Arch (SDA) is defined as a dentition where most posterior teeth are missing. The SDA concept, described by Käyser and co-workers in the 1980s, was developed mainly for elderly and high risk-patients, those with poor general health and those with accumulation of dental problems. It was however, proposed as a treatment option based on individual preferences. The SDA concept suggested that a dentition comprising teeth in the anterior and premolar region might meet the requirements of a functional dentition. The aim of this thesis was to study attitudes towards the Shortened Dental Arch (SDA) concept and to explore the factors affecting prosthodontic decision-making, with a focus on the SDA concept, among Swedish General Dental Practitioners (GDPs).Two different research approaches (quantitative and qualitative) were used: a questionnaire study (Study I and II) and an interview study (Study III and IV). The base in the questionnaire study was made up of 102 responses from a random sample of 189 Swedish GDPs. The sample was taken from the membership register of the Swedish Dental Association. Besides questions about gender, age, years in profession and place of dental education, the questionnaire contained questions about factors to be considered when planning for a prosthetic treatment in an SDA. There were also questions related to risks and benefits of an SDA and various statements concerning the SDA concept. For all items the dentists were asked to mark on a Visual Analogue Scale ranging from 0 to 10 with different anchors for each section. The data was described and analyzed in contingency and frequency tables. The treatment planning statements were subjected to principal component analysis. A multiple linear regression analysis was used to study explanatory patterns regarding the assessment of importance for the variables influencing dentists’ choice of treatment in an SDA. Eleven Swedish GDPs were strategically selected for the interview study, the necessary inclusion criterion being that the participant had to have at least one year of practice to ensure experience of treating dentitions without molar support. The in-depth, semi-structured interviews dealt with treatment considerations relating to two patient cases and the participants’ opinions on pre-formulated statements about the SDA concept. Two authentic patient cases were discussed; initially with complete dental arches, and later a final treatment plan based on an SDA. The cases involved patients with compromised teeth situated mainly in the molar regions. One patient suffered from extensive caries and the other from severe periodontal disease. Qualitative Content Analysis was used to analyze the data. The participants of the questionnaire study received a short description of the SDA as an introduction and the participants of the interview study were given a brief explanation of the SDA concept after discussing the two patient cases. Attitudes towards the SDA and the SDA concept, results and conclusionsThe questionnaire study (I) showed that the Swedish GDPs had a positive attitude towards the SDA concept which they also considered carried few risks. There were small differences in attitudes between different groups of dentists (private practice dentists/dentists employed in the public dental health service and male/female dentists) but vast differences in attitudes among individual practitioners. Female practitioners envisaged a higher risk of impaired oral function, periodontitis and TMD in an SDA than male practitioners. Private practice dentists saw fewer advantages in using the SDA concept compared to Public Dental Health Service dentists in terms of reduced risk of overtreatment, better patient costs, and the patients’ ability to keep their own natural teeth as they aged. The results of the interview study (III) showed that none of the GDPs was familiar with the SDA concept of treatment although two dentists had heard the expression SDA before. Swedish GDPs showed little or no cognizance of the concept and they did not appear to apply it in their treatment planning.Prosthodontic decision-making with a focus on SDA and compromised molars, results and conclusionsThe study with a quantitative approach (II) showed that there were vast individual differences when Swedish GDPs ranked the importance of various patient-related items when planning a treatment in an SDA. The results of a factor analysis showed that dental care delivery system, place of dental education and also attitudinal factors influenced the decision-making process in relation to the SDA. The analysis also indicated that it was possible to capture common dimensions (“technical”, “comfort” and “time”) of decision-making in prosthodontics compared to other decision-making situations. The study with a qualitative approach (IV) showed that preserving a dental arch which included molars appeared to be important to Swedish GDPs. The SDA concept did not seem to have any substantial impact on prosthodontic decision-making in relation to dentitions with compromised molars. The dentist’s experience, as well as the advice of colleagues or specialists, together with etiological factors and the patient’s individual situation, influenced decision-making more than the SDA concept. There was a contradictory relevance between the patient’s age and the need for molar support when considering the SDA, mainly due to the individual patient’s need. These conflicting results in the prosthetic decision-making process require further investigation.