Journal of Oral Science Research ›› 2020, Vol. 36 ›› Issue (3): 276-279.DOI: 10.13701/j.cnki.kqyxyj.2020.03.021

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Micro CT Evaluation of Microleakage in Composites Resin Cured by Various Light Curing Modes

ZHAO Yan1, JIN Chenxin2*   

  1. 1. Department of Pediatric Dentistry, Stomatological Hospital of Tianjin Medical University, Tianjin 300070, China;
    2. Department of Periodontology, Stomatological Hospital of Tianjin Medical University, Tianjin 300070, China
  • Received:2019-05-05 Online:2020-05-15 Published:2020-05-15

Abstract: Objective: To evaluate the effects of different light modes on microleakage of composite resin filling by Micro CT. Methods: Twenty-four freshly extracted maxillary premolars were collected. Circular cavity(diameter 1mm, depth 1mm) were prepared on the buccal surface of the crown. The cavity was filled with composite resin (3M Z250) and cured by light curing. According to the light curing mode, they were randomly divided into three groups: conventional model group (group A), soft-start light group (group B), and intermittent light group (group C). After thermal cycling and 50% ammoniacal silver nitratesolution staining, the volume of silver deposit at the tooth-restoration interface were scanned by micro CT, and the degree of microleakage was evaluated quantitatively. Results: The microleakage in the conventional light group was significantly higher than that in the soft-start light group and the intermittent light group (P<0.05), but there was no statistical differences between the soft-start light group and the intermittent light group (P<0.05). Conclusion: The soft-start light mode and intermittent light mode can reduce the microleakage of composite resin (3M Z250) more effective than the conventional light mode.

Key words: composite resins, microleakage, photoactivation mode, micro CT, three-dimensional reconstruction