Clinical success of stainless steel crowns placed under general anaesthesia in primary molars: an observational follow up study.

AIM: Quality assessment of stainless steel crowns (SSCs) placed in primary molars of high caries risk children after 1, 3 and 5 years of service time.

MATERIAL AND METHODS: Out of 1149 SSCs placed 1, 3 or 5 years before the evaluation period in 558 children, 428 (37.2%) SSCs were clinically evaluated in 171 (30.6%) children aged between 1.1 and 8.6 years. Marginal adaptation, extension and proximal contacts of SSCs, plaque and gingival bleeding at SSC were assessed. Caries experience was recorded by WHO standards.

RESULTS: Caries experience was 7.8 dmft/18.4 dmfs before treatment. The overall success rate of SSCs was 97.2%, regardless of the extent of carious lesions or pulp treatment of the tooth. Loss of SSCs (1.9%), pathological tooth mobility (0.7%) and perforation of the crown (0.2%) were scored as clinical failures. The majority of SSCs had sealed margins and the marginal extension reached sub-gingival level. Open proximal contacts occurred mesially and distally (21.7%, 20%). All qualitative defects increased with service time. Secondary caries was not diagnosed. Of the SSCs, 46.4% were free of dental plaque. Gingival bleeding after probing was observed in 72.1% of all SSCs. Gingivitis was significantly associated with increased dmft-values (OR=1.108, 95%CI: 1.03-1.19) and plaque at SSCs (OR=0.29, 95%CI: 0.18-0.47). Children with migration background exhibited significantly more often insufficient oral hygiene and higher rates of gingival bleeding and caries experience than did German children.

CONCLUSIONS: SSCs are clinically successful restorations in primary molars of high caries risk children. High caries prevalence and insufficient oral hygiene were greater determining factors for the occurrence of gingivitis than the quality of the SSCs.