Journal of the korean academy of Pediatric Dentistry (대한소아치과학회지)

Korean Academy of Pediatric Dentistry (대한소아치과학회)
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Evaluation of the Changes in Polymerization of TheraCal LC with Various Light-curing Time and Distance

광중합 시간과 거리의 변화에 따른 TheraCal LC의 중합도 평가

  • Bae, Sangyong (Department of Pediatric Dentistry, College of Dentistry, Wonkwang University) ;
  • Lee, Jewoo (Department of Pediatric Dentistry and Research Institute of Dental Education, College of Dentistry, Wonkwang University) ;
  • Ra, Jiyoung (Department of Pediatric Dentistry and Research Institute of Dental Education, College of Dentistry, Wonkwang University)
  • 배상용 (원광대학교 치과대학 소아치과학교실) ;
  • 이제우 (원광대학교 치과대학 소아치과학교실 및 치의학교육연구센터) ;
  • 라지영 (원광대학교 치과대학 소아치과학교실 및 치의학교육연구센터)
  • Received : 2019.07.01
  • Accepted : 2019.08.22
  • Published : 2019.11.30
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Abstract

The purpose of this study was to evaluate polymerization of TheraCal LC, one of the tricalcium silicate cements. To measure the Vickers hardness number (VHN), the specimens were cured at different light curing time and distance. As a result, the VHN of the upper surface was significantly higher than the lower surface's in all groups (p < 0.05). The VHN of the lower surface was increased significantly with the increase of the light curing time in all distance (p < 0.05). When the distance was more than 4.0 mm at all light curing time, the VHN of lower surface was significantly decreased (p < 0.05). When the specimen was light cured for 20 seconds, the VHN of the lower surface did not exceed 2, which corresponds to 10% of the upper surface's. These results suggested that the 20 second light curing time was not sufficient to polymerize the lower surface under specific conditions and that light-curing time should be increased.

이 연구의 목적은 tricalcium silicate cement 중 하나인 TheraCal LC의 광중합 시간과 거리에 따른 중합도를 평가하는 것이었다. 금속주형을 이용해 시편을 제작하여 Vickers hardness number (VHN)를 측정하였으며, 중합시간과 조사시간에 따른 시편의 미세경도 값을 비교 분석하였다. 그 결과, 모든 군에서 상면의 VHN이 하면의 VHN보다 유의성 있게 컸다(p < 0.05). 하면의 VHN은 모든 중합거리에서 중합시간이 증가함에 따라 유의하게 증가하였고(p < 0.05), 중합시간이 일정하고 중합거리가 4.0 mm 이상이 되었을 때 유의하게 감소하였다(p < 0.05). 또한 시편을 20초간 중합한 경우 하면의 VHN은 2를 넘지 못했으며 이는 상면의 10%에 해당하였다. 이 연구 결과에 의하면, 모든 중합거리에서 TheraCal LC 시편의 하면까지 중합하기에 20초의 광중합 시간은 충분하지 않았으며, 중합도를 높이기 위해서 중합시간의 증가와 도포 두께의 감소를 고려해볼 필요가 있다.

Keywords

References

  1. Hilton TJ : Keys to clinical success with pulp capping: a review of the literature. Oper Dent , 34:615-625, 2009. https://doi.org/10.2341/09-132-0
  2. Andersen M, Lund A, Andreasen JO, Andreasen FM, et al.: In vitro solubility of human pulp tissue in calcium hydroxide and sodium hypochlorite. Endod Dent Traumatol , 8:104-108, 1992. https://doi.org/10.1111/j.1600-9657.1992.tb00445.x
  3. Cox CF, Subay RK, Suzuki SH, et al.: Tunnel defects in dentin bridge: their formation following direct pulp capping. Oper Dent , 21:4-11, 1996.
  4. Andreasen JO, Farik B, Munksgaard EC : Long-term calcium hydroxide as a root canal dressing may increase risk of root fracture. Dent Traumatol, 18:134-137, 2002. https://doi.org/10.1034/j.1600-9657.2002.00097.x
  5. Tray MJ : Pulp protection under restorations-do you need a liner? Austra Endod J , 24:104-108, 1998. https://doi.org/10.1111/j.1747-4477.1998.tb00029.x
  6. Dammaschke T, Gerth HU, Zuchner H, Schafer E : Chemical and physical surface and bulk material characterization of white ProRoot MTA and two Portland cements. Dent Mater , 21:731-738, 2005. https://doi.org/10.1016/j.dental.2005.01.019
  7. Torabinejad M, Hong CU, McDonald F, Pitt Ford TR : Physical and chemical properties of a new root-end filling material. J Endod , 21:349-353, 1995. https://doi.org/10.1016/S0099-2399(06)80967-2
  8. Camilleri J : Color stabillity of white mineral trioxide aggregate in contact with hypochlorite solution. J Endod , 40:436-440, 2014. https://doi.org/10.1016/j.joen.2013.09.040
  9. Gandolfi MG, Siboni F, Prati C : Chemical-physical properties of TheraCal, a novel light-curable MTA-like material for pulp capping. Int Endod J , 45:571-579, 2012. https://doi.org/10.1111/j.1365-2591.2012.02013.x
  10. Lee H, Shin Y, Song JS, et al.: Comparative study of pulpal response to pulpotomy with ProRoot MTA, Retro MTA, and TheraCal in dog's teeth. J Endod , 41:1317-1324, 2015. https://doi.org/10.1016/j.joen.2015.04.007
  11. Bortoluzzi EA, Niu LN, Tay FR, et al.: Cytotoxicity and osteogenic potential of silicate calcium cements as potential protective materials for pulpal revascularization. Dent Mater , 31:1510-1522, 2015. https://doi.org/10.1016/j.dental.2015.09.020
  12. Bakhtiar H, Nekoofar MH, About I, et al.: Human pulp responses to partial pulpotomy treatment with TheraCal as compared with Biodentine and ProRoot MTA: a clinical trial. J Endod , 43:1786-1791, 2017. https://doi.org/10.1016/j.joen.2017.06.025
  13. Gopika GJ, Ramarao S, Vezhavendhan N, et al.: Histological evaluation of human pulp capped with light-cured calcium based cements: a randomized controlled clinical trial. Int J Sci Rep , 3:120-127, 2017. https://doi.org/10.18203/issn.2454-2156.IntJSciRep20171926
  14. Fujisawa S, Kadoma Y, Komoda Y : Changes in 1H-NMR chemical shifts of Bis-GMA and its related methacrylates induced by their interaction with phosphatidylcholine/cholesterol liposomes. Dent Mater J , 10:121-127, 1991. https://doi.org/10.4012/dmj.10.121
  15. Gerzian TM, Hume WR : Diffusion of monomers from bonding resin-resin composite combinations through dentine in vitro. J Dent , 24:125-128, 1996. https://doi.org/10.1016/0300-5712(95)00036-4
  16. Deutsch AS, Musikant BL : Morphological measurements of anatomic landmarks in human maxillary and mandibular molar pulp chambers. J Endod , 30:388-390, 2004. https://doi.org/10.1097/00004770-200406000-00003
  17. Khojastepour L, Rahimizadeh N, Khayat A : Morphologic measurments of anatomic landmarks in pulp chambers of human first molars: a study of bitewing radiographs. Iran Endod J , 2:147-151, 2008.
  18. Bouschlicher MR, Rueggeberg FA, Wilson BM : Correlation of bottom-to-top surface microhardness and conversion ratios for a variety of resin composite compositions. Oper Dent , 29:689-704, 2004.
  19. Phillips RW : Skinner's science of dental materials, 8th ed. Philadelphia, Saunders, 230, 1982.
  20. Rueggeberg FA, Jordan DM : Effect of light-tip distance on polymerization of resin composite. Int J Prosthodont, 6:364-370, 1993.
  21. Shimokawa CAK, Turbino ML, Price RB, et al.: Effect of light curing units on the polymerization of bulk fill resin-based composite. Dent Mater , 34:1211-1221, 2018. https://doi.org/10.1016/j.dental.2018.05.002
  22. Tate WH, Porter KH, Dosch RO : Successful photocuring: don't restore without it. Oper Dent , 24:109-114, 1999.
  23. Uhl A, Mills RW, Jandt KD : Photoinitiator dependent composite depth of cure and Knoop hardness with halogen and LED light curing units. Biomaterials , 24:1787-1795, 2003. https://doi.org/10.1016/S0142-9612(02)00532-X
  24. Ota K, Kopel HM, Thanos CE, et al.: Effect of light exposure time on the depth of curing in various composite resin system. Pediatr Dent , 7:19-22, 1985.
  25. Atmadja G, Bryant RW : Some factors influencing the depth of cure of visible light-activated composite resins. Aust Dent J , 35:213-218, 1990. https://doi.org/10.1111/j.1834-7819.1990.tb05394.x
  26. Shimokawa CA, Turbino ML, Price RB, et al.: Light output from six battery operated dental curing lights. Mater Sci Eng C Mater Biol Appl , 69:1036-1042, 2016. https://doi.org/10.1016/j.msec.2016.07.033
  27. Diamanti E, Mathieu S, About I, et al.: Endoplasmic reticulum stress and mineralization inhibition mechanism by the resinous monomer HEMA. Int Endod J , 46:160-168, 2013. https://doi.org/10.1111/j.1365-2591.2012.02103.x
  28. Mahant RH, Chokshi S, Mahant P, et al.: Comparison of the amount of temperature rise in the pulp chamber of teeth with QTH, second and third generation LED light curign units: an in vitro study. J Lasers Med Sci , 7:184-191, 2016. https://doi.org/10.15171/jlms.2016.32
  29. Torno V, Soares P, Veira S, et al.: Effects of irradiance, wavelength, and thermal emission of different light curing units on the Knoop and Vickers hardness of a composite resin. J Biomed Mater Res B Appl Biomater , 85:166-171, 2008. https://doi.org/10.1002/jbm.b.30929
  30. Kurachi C, Tuboy AM, Magalhaes DV, Bagnato VS : Hardness evaluation of a dental composite polymerized with experimental LED-based devies. Dent Mater , 17:309-315, 2001. https://doi.org/10.1016/S0109-5641(00)00088-9
  31. International Organization for Standardization. ISO 4049: 2009 (E) Polymer-based restorative materials: depth of cure, class 2.
  32. AlShaafi MM, AlQussier A, AlQahtani MQ, Price RB : Effect of mold type and diameter on the depth of cure of three resin-based composites. Oper Dent , 43:520-529, 2018. https://doi.org/10.2341/17-122-L