Subjects. From an epidemiological oral health survey carried out among 2134 children in grades 3 through 5 in the Ilala district of Tanzania, 152 subjects were selected who needed 2 or more occlusal restorations because of carious dentin. Teeth restored in the study showed no evidence of pulpal involvement. Subjects were divided into 3 treatment groups using a random permuted block method. The study was initiated in 1992, and restorations were placed by a single dental therapist in a period of 4.5 months after completion of the epidemiological survey. Caries lesions were detected using natural light in a field situation by 2 calibrated examiners (dentists) according to WHO criteria. Therapy. Adental therapist used 3 types of restorative approaches and 2 different restorative materials to treat occlusal lesions involving carious dentin. A split-mouth design was used, with dental amalgam used in one restoration and a glass-ionomer used in the other; teeth to receive specific restorative materials were randomized. Treatment groups were as follows: c-group (50 subjects, 139 restorations) - In the conventional group, a fully equipped dental clinic of the Faculty of Dentistry of the University of Dar es Salaam, Tanzania, was used. Dentin lesions were treated using the principles of minimal intervention; infected dentin was removed with a low-speed dental handpiece and excavators. Local anesthesia was used in only 3 of the 50 subjects in this group. mc-group (49 subjects, 135 restorations) - In the modified-conventional group, portable dental equipment was used in a field setting, with subjects treated in a shaded open-air area, lying on a portable bed. A car battery supplied electricity; moisture control was with cotton rolls and an air (chip blower) syringe. Dentin lesions were treated as in the c-group. No local anesthesia was used. u-group (53 subjects, 156 restorations) - In the ultraconservative group, the ART approach, in combination with a claimed caries removal system (Caridex) was used in a field setting with moisture control provided as in the mc-group. No local anesthesia was used. A calcium hydroxide compound was applied when dentinal lesions were deep. The amalgam (ANA 200, Nordiska Dental, Sweden) was a non-gamma-2 product and the glass-ionomer material used was Fuji II (GC International, Japan). The authors reported that the effectiveness of the chemical caries-removal system used is in doubt, and the product was removed from the market in the early 1990s. Main outcome measure. The same 2 evaluators who conducted the original survey to obtain subjects also carried out the assessment of quality of restorations at year 6. They used modified USHPS (Ryge) criteria for marginal integrity, anatomic form, surface roughness, and secondary caries, and restorations were rated as perfect, satisfactory, or failed. Each restoration was examined by each examiner; in case of disagreement, the subject was reexamined and a consensus reached. Main results. At the 6-year recall, a total of 114 subjects and 341 restorations (79.3% overall recall rate) were available for evaluation. The 6-year success rate for all restorations was 72.4%. The 6-year success rates for restorations by group and material were as follows: c-group (73.4% recall rate; 50 amalgam & 52 GI restorations evaluated) 74.5% overall success rate (95% CI = 65 - 82%); 74.0% success rate for amalgam; 75.0% success rate for glass-ionomer. mc group (73.3% recall rate; 50 amalgam & 49 GI restorations evaluated) 75.8% overall success rate (95% CI = 67 - 83%); 74.0% success rate for amalgam; 77.6% success rate for glass ionomer. u-group (89.7% recall rate; 64 amalgam & 76 GI restorations evaluated) 68.6% overall success rate (95% CI = 61 - 76%); 70.3% success rate for amalgam; 68.9% success rate for glass ionomer. There was no statistically significant difference in success rates among the three restorative approaches (P = .17). There was no significant difference in the success rates of amalgam and glass-ionomer within any of the 3 groups. For anatomic form and secondary caries rates there were statistically significant differences between amalgam and glass ionomer. For failure caused by loss of material (change in anatomic form) glass-ionomer performed significantly worse (P = .003). For secondary caries, amalgam performed significantly worse (P = .001). Conclusions. The investigators concluded that, for treating occlusal caries lesions involving dentin in children in Tanzania, ART restorations with glass-ionomer placed in a field situation performed as well in a 6-year period as conventional amalgam restorations placed in a university clinic.
ASJC Scopus subject areas