P.M.H. Dummer

Challenges with studies investigating longevity of dental restorations—a critique of a systematic review

OBJECTIVES A systematic review is a method of evaluating the published and unpublished literature relating to a specific area or topic. The objectives of this paper are to identify and discuss problems encountered in synthesising the available literature; and to make recommendations for the future conduct and reporting of clinical trials that aim to determine the longevity of dental restorations. DATA SOURCES Studies were identified by a wide search of published and unpublished material in any language using a large number of general and specialist data bases, hand searching of key dental journals and searching of abstracts from conference proceedings. STUDY SELECTION Pre-defined inclusion criteria based on objective outcome measures of restoration longevity and study designs were applied to determine study selection. CONCLUSIONS A review of the longevity of dental restorations completed recently encountered substantial problems in designing an appropriate protocol to address this issue. The review found that many of the factors reported previously as affecting restoration longevity could not be confirmed using the agreed systematic review protocol that incorporated an objective study design. Further, the multiplicity of study designs, and reporting methods found in the literature made meta-analyses impossible. A proforma is proposed in order to aid the design of future research into the longevity of restorations.

Comparison of laterally condensed and low-temperature thermoplasticized gutta-percha root fillings.

The aim of this study was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta-percha or low-temperature thermoplasticized gutta-percha (Ultrafil). One hundred freshly extracted human, mature single-rooted teeth were divided into four identical groups of 25 teeth on the basis of root canal shape. The root canals of two groups were prepared in such a way to produce a relatively parallel shape with little or no flare toward the coronal orifice. The root canals of the other two groups were prepared in such a way as to produce a canal shape that was deliberately more flared to ensure that they were wider at the orifice than at the end point of the preparation. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one flared group and one parallel group were obturated using cold lateral condensation, and the canals of the other two groups were obturated using low-temperature thermoplasticized gutta-percha. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a 4-point scale. Canals filled with thermoplasticized gutta-percha had significantly less apical dye penetration than those obturated by lateral condensation (p

The effect of social class on the prevalence of caries, plaque, gingivitis and pocketing in 11–12-year-old children in South Wales

Abstract The effect of social class on the dental disease status of a group of 11–12-year-old schoolchildren in South Wales is presented. There were a number of differences between the social classes for the DMFT, DMFS and DFS indices, with social class I having significantly less caries experience than the others. These differences, however, were largely confined to the boys. There appeared to be no significant difference in reported toothbrushing frequency between the social classes but the children from the lower social classes admitted spending significantly more on sweets per week. The plaque and gingival bleeding scores showed an overall trend to increase from social class I through to social class V. The girls, in particular, showed progressively increasing and significantly different mean plaque and gingivitis scores.

Changes in the distribution of decayed and filled tooth surfaces and the progression of approximal caries in children between the ages of 11-12 years and 15-16 years

Changes in the distribution of decayed and filled tooth surfaces and the progression of approximal caries in children between the ages of 11-12 years and 15-16 years

Factors influencing the initiation of carious lesions in specific tooth surfaces over a 4-year period in children betweem the ages of 11–12 years and 15–16 years

An analysis of factors influencing the initiation of carious lesions on specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years is presented. Approximately 1000 children, resident in the County of South Glamorgan, Wales, were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. On both occasions, the children completed detailed questionnaires on dental health-related topics. Surfaces which were sound when the children were 11-12 years were identified and subsequently awarded a score of zero if they remained sound at 15-16 years or a score of one if they had developed carious lesions or had been filled. For each child, a mean mouth caries initiation score was computed for specific groups of surfaces, namely pit and fissure surfaces in posterior teeth, approximal surfaces in posterior teeth, buccal and lingual smooth surfaces of all teeth and approximal surfaces of anterior teeth. One-way analysis of variance and multiple regression techniques revealed that a number of factors had a significant influence on the initiation of caries. The factors and their level of significance varied between the surfaces. However, relatively little (less than 6 per cent) of the total variance in caries initiation score could be explained by the identified factors. Overall, more lesions developed in pit and fissure surfaces in posterior teeth than in the other surfaces included in the analyses.

What type of filling? Best practice in dental restorations

Dental caries (tooth decay) is one of the most common diseases, with approximately 80% of the population in developed countries having experienced the condition. If decay has not been prevented cavities develop. To prevent considerable pain and tooth loss it may be necessary to remove the diseased tissues and restore the cavities (a filling). Restorations have a limited lifespan and, once a tooth is restored, the filling is likely to be replaced several times in the patient’s lifetime. Studies in the UK suggest that much of restorative dentistry is replacement of existing restorations, accounting for around 60% of all restorative work. Similar figures have been found in other parts of Europe, 4 and the USA. (Quality in Health Care 1999;8:202–207) There is a large choice of materials which can be used for fillings. Many are introduced into the market place and used on patients with limited evidence that they are more eVective or robust than existing materials. Consequently, one of the key questions is, all other things being equal, what type of filling is best? This paper summarises the results of a systematic review of the relative longevity and cost eVectiveness of routine intracoronal dental restorations, which formed the basis of a recent issue of EVective Health Care. The reasons for replacing a restoration are numerous and vary with tooth type and restorative material. Once inserted, restorations may fail at variable rates due to various “objective” factors aVecting both the failure of the filling material and further decay of the tooth around the filling. These factors include the characteristics of the filling material and eVect modifiers related to operator skill and technique, patients’ dental characteristics, and the environment around the tooth. The decision to replace a restoration is also influenced by more subjective factors such as dentists’ interpretation of the restoration’s condition and the health of the tooth, the criteria used to define failure, and patient demand. These decisions are subject to much variation. 10 A lack of standardisation exists, and no generally agreed criteria are used to decide when a restoration requires replacement. Types of restoration Tooth restorations may be classified as intracoronal, when they are placed within a cavity prepared in the crown of a tooth, or extracoronal, when they are placed around (outside) the tooth as in the case of a crown. Intracoronal restorations are usually placed directly into the tooth cavity and normally consist of a mouldable material that sets and becomes rigid; the material is retained by the surrounding walls of the remaining tooth tissue. An alternative intracoronal restoration uses an indirect technique; here an impression of the cavity is taken and a laboratory constructed inlay is produced and subsequently cemented into the prepared cavity. The materials currently used to restore intracoronal preparations are: dental amalgam, composite resins, glass ionomer cements, resin modified glass ionomer cements, compomers and cermets, cast gold, and other alloys inlays and porcelain (box 1).

Factors influencing the caries experience of a group of children at the ages of 11–12 and 15–16 years: results from an ongoing epidemiological survey

An analysis of factors influencing the caries experience of adolescents in South Wales is presented. Approximately 1000 children were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. In addition, on both occasions, the children completed detailed questionnaires on dental health-related topics. When aged 11-12 years, the observed mean DMFT, DMFS and DFS scores of the children were 4.0, 6.7 and 5.5 respectively. The corresponding scores at age 15-16 years were 6.5, 11.8 and 10.2. A preliminary analysis using conventional multiple regression techniques revealed that a number of factors had a significant influence on the caries experience of the children. The significance of the factors depended on the sex of the population subgroup, the age of the children and the particular caries index studied. However, at both ages the factors of most significance were the number of erupted teeth, total mean plaque score and the reported amount of money spent on sweets per week. A further evaluation using analysis of covariance with the number of erupted teeth and surfaces as the covariates confirmed the significant influence of the total mean plaque score and amount of money spent on sweets. In addition, both analyses indicated that toothbrushing frequency and social class had a significant influence on the caries experience of boys.

The relationship between loss of first permanent molar teeth and the prevalence of caries and restorations in adjacent teeth: a study of 15–16-year-old children

Abstract The relationship between loss of first permanent molar teeth and the prevalence of caries and restorations in the surfaces of adjacent teeth was assessed in a group of 793 children, aged 15–16 years old. The data obtained from the children was divided into two subgroups. Group 1 comprised those arches in which the first permanent molar had been retained, and Group 2 contained those arches in which the first permanent molar had been extracted before the age of 11–12 years. The disease status of the mesial and occlusal surfaces of second molars and the distal and occlusal surfaces of second premolars was examined visually and radiographically in both groups. Arches with missing first molars had significantly fewer decayed and filled approximal surfaces but significantly more decayed and filled occlusal surfaces in the adjacent second molar and premolar teeth than those arches which had not lost the first molar. The implications of these findings are discussed.