ABSTRACT
BACKGROUND: The authors conducted a study to test the hypothesis that light-curing regimens affect depth of cure of clear versus opaque sealants. METHODS: The authors light-cured samples of one clear and two opaque sealants at 20 seconds, 0 millimeters; 40 seconds, 0 mm; and 40 seconds, 2.2 mm (n = 5 each). They assessed the depth of cure with Knoop hardness at 0.5-mm increments five minutes and one hour after curing. The authors used analysis of variance. RESULTS: Curing regimens and sealant types affected the depth of cure. The clear sealant maintained a greater hardness than did the opaque sealants through a depth of 3 mm (P < .001). A 20-second duration reduced the depth of cure for all sealants (P < .001). The distance from the light source did not affect the cure depth of the clear sealant (P = .34), but it reduced the cure depth of the opaque sealants (P < .05). Sealant hardness increased significantly one hour after light curing (P < .001). CONCLUSIONS: A clear sealant cured deeper than did opaque sealants. Curing duration is crucial to achieve an adequate depth of cure. A 20-second duration may not suffice. Light source distance affected the depth of cure for the opaque sealants, but not for the clear sealant with sufficient curing duration. CLINICAL IMPLICATIONS: The authors advocate a curing duration of longer than 20 seconds to ensure thorough polymerization at the interface between the sealant and tooth. Insufficient curing could contribute to failure of the sealants, especially the opaque sealants, under clinical conditions that restrict the light tip position.
Subject(s)
Light-Curing of Dental Adhesives , Pit and Fissure Sealants/radiation effects , Resin Cements/radiation effects , Adhesiveness , Bisphenol A-Glycidyl Methacrylate , Composite Resins , Hardness , Light-Curing of Dental Adhesives/methods , Materials Testing , Optical Phenomena , Phase Transition , Time FactorsABSTRACT
Recessive Robinow syndrome (RRS) is an extremely rare short stature genetic condition with significant and characteristic oral, dental, and facial attributes that generally requires coordinated multidisciplinary dental and medical interventions. This paper describes the clinical findings and dental management over the course of 4 years of a US-born Caucasian female with recessive Robinow syndrome who presented to our dental clinic at age 11 years, 0 months and who is now age 15 years, 3 months. Of special interest was the extent to which the patient's hyperplastic gingival tissues impeded both normal tooth eruption and orthodontic tooth movement.
