IADR Abstract Archives
Shear bond strength of intraoral laser welding and its effect on intrapulpal temperature rise in primary teeth in vitro
Objectives: The aim of this study was to compare the shear bond strength between conventional welding (CW) and intraoral laser welding (LW) on fixed space maintainers (SMs). Secondly the present in vitro study investigated pulpal temperature rise during LW.
Methods: Procedure of shear bond strength: 26 molar bands were divided into two groups as CW and LW. 26 pieces of 5 cm length of 0.9 mm diameter stainless steel wires were welded to the middle of the buccal and lingual aspects of bands in each groups. In LW group, the Nd:YAG laser was used for welding. In CW group, Dentaurum silver solder and flux were used as soldering media which were uniformly 4mm in length. The samples were fixed to acrylic resin blocks and were submitted to shear testing. Procedure of intrapulpal temperature: Twenty five exfoliated primary second molar teeth were used to adapt molar bands. J-type thermocouple wire was positioned in the pulp chamber and temperature changes were determined while 26 pieces of 0.9mm diameter stainless steel wires was welded to the bands using Nd : YAG laser. Mann-Whitney U test was used to determine the differences of shear bond strength, between the groups. Temperature changes were analyzed by paired T-test.
Results: Shear bond strength were found significantly different between groups (LW: 489.47±135.70, CW: 49.71±17.76; p<0.001). The mean intrapulpal change during LW was 3.64±0.79(Min:2.4; Max:5.10). None of the samples intrapulpal temperature change were exceeded the critical threshold value (5.5°C).
Conclusions: The joint obtained by LW has a higher strength compared with CW has demonstrated. Changes of the intrapulpal temperature during LW do not present a thermal risk in the primary teeth. This study demonstrated that intraoral use of LW for space maintainers in primary teeth is successful in terms of strength and intrapulpal temperature changes.
Methods: Procedure of shear bond strength: 26 molar bands were divided into two groups as CW and LW. 26 pieces of 5 cm length of 0.9 mm diameter stainless steel wires were welded to the middle of the buccal and lingual aspects of bands in each groups. In LW group, the Nd:YAG laser was used for welding. In CW group, Dentaurum silver solder and flux were used as soldering media which were uniformly 4mm in length. The samples were fixed to acrylic resin blocks and were submitted to shear testing. Procedure of intrapulpal temperature: Twenty five exfoliated primary second molar teeth were used to adapt molar bands. J-type thermocouple wire was positioned in the pulp chamber and temperature changes were determined while 26 pieces of 0.9mm diameter stainless steel wires was welded to the bands using Nd : YAG laser. Mann-Whitney U test was used to determine the differences of shear bond strength, between the groups. Temperature changes were analyzed by paired T-test.
Results: Shear bond strength were found significantly different between groups (LW: 489.47±135.70, CW: 49.71±17.76; p<0.001). The mean intrapulpal change during LW was 3.64±0.79(Min:2.4; Max:5.10). None of the samples intrapulpal temperature change were exceeded the critical threshold value (5.5°C).
Conclusions: The joint obtained by LW has a higher strength compared with CW has demonstrated. Changes of the intrapulpal temperature during LW do not present a thermal risk in the primary teeth. This study demonstrated that intraoral use of LW for space maintainers in primary teeth is successful in terms of strength and intrapulpal temperature changes.