Observational 16-year Study of Posterior Tooth Fracture in Dental Practice

Objectives: An observational study of an approach to manage posterior tooth fracture up to 16 years in primary dental care.

Methods: Posterior Tooth Fractures (PTF) were observed up to 16 years in all patients attending a dental practice in London, using a previously established recording system; Class I enamel only fracture, Class II enamel and dentine fracture, Class III enamel and dentine fracture coronal to the amelo-gingival margin, Class IV enamel and dentine fracture below the amelo-gingival margin. Teeth were in occlusion with natural tooth antagonists. Whether a fracture occurred in a Functional (F) or Non-Functional (NF) cusp was recorded. The material/s used to restore fractures were also recorded. All teeth were followed up annually up to 16 years. One skilled operator undertook all procedures.
Results: At 16 years, 5273 patients of average age 74 years were observed. Most patients were caucasian (99.5%) female (68%). The total PTF recorded was 7% (n=4,473) in 63,900 posterior teeth. The proportions of PTF in these teeth were Class I 3%, Class II 37%, Class III 55%, Class IV 5%. Restorations placed following fracture included Glass Ionomer Cement (GIC) 70% (placed out of occlusion in exposed dentine fractures), Composite 15%, Amalgam 11% and full Crowns 4%. Restorations survived up to 16 years. Significantly more fractures occurred in NF cusps compared with F cusps in mandibular second premolars, and mandibular first and second molars (p=0.04). There were no significant differences in fracture between maxillary NF and F cusps.
Conclusions: Limited posterior tooth fractures and low restoration maintenance are possible long-term in an ageing dentition with good annual recall. GIC was commonly used for restoration of PTFs in dentine and survived out of occlusion. Non-functional posterior cusps in the mandible had significantly more fractures and thus occlusion should be planned carefully to reduce fracture risk.