Replacements of Amalgam Restorations - a Study (original) (raw)
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Journal of dental research, dental clinics, dental prospects, 2010
The present study evaluated the most common reasons for replacing amalgam restorations in a university clinic. A total of 217 restorations which needed to be replaced were clinically and radiographically evaluated in a period of 4 months. The frequencies of reasons for replacing amalgam restorations were calculated: The assessed items included recurrent caries, tooth structure fracture (functional or non-functional cusps), amalgam bulk fracture, amalgam marginal fracture, proximal overhangs, and esthetics. Data were analyzed using Fischer's exact test. Both in vital teeth and teeth which had undergone root canal therapy, the most common reason for amalgam replacement was cusp fracture, with the fracture of non-functional cusps being statistically significant. Recurrent caries was the second most common reason for amalgam replacement. In Class I restorations, the most common reasons were recurrent caries and esthetics, with no statistical significance. The most frequent problem i...
The use and repair of dental amalgam restorations as practised in South Africa
Introduction: Research has confirmed that the replacement of defective restorations is the most commonly performed procedure in general practice. Any defect or sign of secondary caries often led to the complete replacement of a dental restoration. The repair or refurbishment of defective dental amalgam restorations is now considered best practice over replacements. aims and objectives: To investigate the use and repair of dental amalgam restorations as practised in South Africa. Methods: Three hundred and twenty-four dentists participated in an electronic cross sectional survey to gather biological data and information on the management of defective amalgam restorations. Analyses included Analysis of Variance (Anova) tests, Chi-square tests, paired t tests and Friedman's test (p-value of <0.05) (SAS Institute Inc., Cary, NC, USA). results: Most dentists (n=62%) reported almost never using dental amalgam and an almost equal number (n=63%) repaired defective amalgam restorations. Resin composite was the most popular material for the repair (n=62%) and replacement (n=78%) of defective amalgam restorations. Dentists in this study relied on their clinical experience to derive their repair techniques. conclusions: Dental amalgam was no longer a preferred material for the restoration of posterior teeth in South Africa. Resin composite was the most widely used to repair or replace defective amalgam restorations. Dentists practised the repair of defective restorations.
Analyses of long-term clinical behavior of class-II amalgam restorations
Acta Odontologica Scandinavica, 1991
Jokstad A, Mjor IA. Analyses of long-term clinical behavior of class-I1 amalgam restorations. Acta Odontol Scand 1991;49:47-63. Oslo. ISSN 0001-6357. The purpose of the study was to estimate the influence of different clinical variables on the replacement rate of class-I1 amalgam restorations in permanent teeth. The study included 210 patients who had 468 restorations placed by 7 Scandinavian dentists. The observation periods varied between 7 and 10 years. At the time of the last recording 188 restorations remained intact in 88 patients, whereas 68 restorations in 53 patients had been replaced. Eighty-six patients with 212 restorations had dropped out of the study. The most prevalent criteria for replacement were secondary caries ( n = 30) and restoration bulk fractures ( n = 24). Chisquare analyses of the relationship between the prevalence of replacements and the clinical variables indicated effects of the operator and the patients' age and caries activity ( p < 0.001).
Long-term Survival of Extensive Amalgam Restorations
Journal of Dental Research, 1998
In cost-effectiveness analysis and contemporary treatment planning strategies, the postponement of placement of cast crowns plays an important role. Extensive amalgam restorations that involve the rebuilding of cusps and the provision of auxiliary retention are thought to make this postponement possible. This study reports the longterm survival (100 months) of extensive amalgam restorations in a randomized, controlled clinical trial. The operational hypothesis was that the type of retention and the operator have a long-term influence on the survival and clinical functioning of extensive amalgam restorations. Three hundred extensive amalgam restorations were placed by three operators in molar teeth in which one or more cusps were reconstructed. Five different auxiliary retention methods were used for retention of these restorations. Since the purpose of extensive amalgam restorations is considered to be twofold (to restore a broken-down molar to function acceptably as an independent restoration and to create a substructure for subsequent crown construction), survival was assessed at different levels. The survival rate of extensive amalgam restorations as an independent restoration was 88 ±-2%. The functional survival rate (as an independent restoration or as a substructure) was 92 + 2%. The influence of experimental variables ('retention method' and 'operator') and background variables ('tooth type', 'extension of extensive amalgam restorations', and 'age of patient') on the survival was analyzed by Log Rank and Breslow tests. The analyses revealed that there were no statistically significant influences on the survival rates except for the variable 'age of patient' (p < 0.05). Extensive amalgam restorations were more prone to failure in the group of older patients than in the group of younger ones. It is concluded that the clinical survival of extensive amalgam restorations is independent from several clinical variables in the study.
Clinical variables affecting the marginal degradation of amalgam restorations
Acta Odontologica Scandinavica, 1990
Jokstad A, Mjor IA. Clinical variables affecting the marginal degradation of arnalg3rn restorations. Acta Odontol Scand 1990;48:37%387. Oslo. ISSN 0001-6357. The influence of different clinical variables on the marginal degradation of amalgam restorations was studied in a clinical trial of class-I1 amalgam restorations. Seven Scandinavian dentists using 5 different alloys placed 468 restorations in 210 patients. The marginal degradation was scored on impressions of the restored teeth by using a six-point ordinal rating scale and was transformed to ridit values. After 5 years 126 patients with 296 restorations remained in the trial. Ridit analysis and paired comparison tests utilizing the Bonferroni correction factor at each yearly interval indicated that the extent of degradation of the restoration margins was influenced by the location in the mouth, the position on the tooth, the type of alloy, and the operator. The results demonstrate that features of the cavity preparation and the handling of the material by the operator are more important for the degradation of the restoration margins than other clinical variables. 0 Amalgam degradation; clinicaZ study; dental materials; iatrogenic effects; operative dentistry Asbjorn Jokstad,
The Internet Journal of Dental Science, 2009
The study investigated the usage of restorative materials in Nigeria, the reasons for the usage and the longevity of the used materials. A cross sectional study on 370 odd numbered attendees aged 18 years and above referred to the Restoration clinic for placement or replacement of 450 restorations was done by two experienced dentists over 9 months. While class II cavity was prepared most often, primary and secondary caries were responsible most often for placement and replacement, respectively. Furthermore, replacements due to secondary caries occurred most often in class II cavities, while amalgam was both the most durable and the most often used material. Public campaign against primary and secondary caries, with attention to the risk group is recommended.
Journal of Dental Research, 1997
Data from 14 independent controlled clinical trials on the oral behavior of Classes 1 and 2 amalgam restorations, with a follow-up between five and 15 years, were re-evaluated by secondary analysis for the influence of alloy composition on the survival of amalgam restorations. For the analysis, 3119 restorations were available, which were made from 24 different alloys by a group of seven operators. The alloys were divided into four groups according to their zinc content (zinc-containing and zincfree) and their copper content (conventional and highcopper). During the follow-up of the trials, the restorations were annually assessed for failures, which were classified as to (1) restoration-, (2) restorative process-, and (3) patientrelated reasons. With the restoration-related failures, survival functions of the restorations were estimated by alloy and alloy group. The total number of failed restorations was 481, of which 77% were restoration-related and 14% process-related. Eighty percent of the restorationrelated failures were due to some form of fracture of the amalgam. Restorations of conventional zinc-free alloys had the shortest survival. After 13 years, only 25% survived. Zinc and a high copper content had an equally favorable influence on the survival rate, which was 70% after 13 years when either was present. The highest survival rates were of restorations of zinc-containing high-copper alloys: 85% after 13 years. The zinc and copper contents of the alloy contributed to the corrosion resistance of the amalgams, which in turn influenced the survival of the restoration. The current ISO Standard 1559 on alloys for dental amalgam should be modified to account for these factors that influence the survival of amalgam restorations.