Aglarci Cahide, Yildiz Esma, Isman Eren, Kazak Mine
1 Faculty of Dentistry, Department of Orthodontics, Sifa University , Izmir, Turkey .
2 Faculty of Dentistry, Department of Pediatric Dentistry, Akdeniz University , Antalya, Turkey .
Photomed Laser Surg. 2016 Mar;34(3):116-20. doi: 10.1089/pho.2015.3991. Epub 2016 Feb 22.
This study compared the shear bond strength (SBS) of conventional welding (CW) and intraoral laser welding (LW) on fixed space maintainers (SMs), and investigated the intrapulpal temperature change (ITC) during LW.
Lasers have been used for intraoral welding.
The SBS test used 26 molar bands divided into two groups, CW and LW. Stainless steel wires were welded to the middle of the buccal and lingual aspects of all the bands, using an Nd:YAG laser for the LW group and silver solder and flux soldering media for the CW group. The samples, fixed to acrylic resin blocks, were subjected to shear testing. In the ITC test, 25 exfoliated primary second molar teeth were used to adapt molar bands. J-type thermocouple wire was positioned in the pulp chamber. ITCs were determined during Nd:YAG laser welding of stainless steel wires to the bands. Mann-Whitney U test was used to determine differences in SBS between the groups. ITCs were analyzed by paired t test.
The SBS between groups showed significant differences (LW: 489.47 ± 135.70; CW: 49.71 ± 17.76; p < 0.001). The mean ITC during LW was 3.64 ± 0.79 (min: 2.4; max: 5.10). None of the samples' ITCs exceeded the critical threshold value (5.5 °C).
LW obtained a higher-strength joint than CW. ITCs during LW do not present a thermal risk to primary teeth. The intraoral use of LW for SMs in primary teeth is recommended in terms of strength and ITCs.
本研究比较了传统焊接（CW）和口腔内激光焊接（LW）在固定间隙保持器（SM）上的剪切粘结强度（SBS），并研究了激光焊接过程中的牙髓腔内温度变化（ITC）。
激光已用于口腔内焊接。
SBS测试使用26个磨牙带环，分为两组，即CW组和LW组。将不锈钢丝焊接到所有带环颊侧和舌侧的中部，LW组使用Nd:YAG激光，CW组使用银焊料和助焊剂焊接介质。将样本固定在丙烯酸树脂块上，进行剪切测试。在ITC测试中，使用25颗脱落的乳牙第一恒磨牙来适配磨牙带环。将J型热电偶丝放置在牙髓腔内。在将不锈钢丝焊接到带环上的Nd:YAG激光焊接过程中测定ITC。采用曼-惠特尼U检验确定两组之间SBS的差异。通过配对t检验分析ITC。
两组之间的SBS显示出显著差异（LW组：489.47±135.70；CW组：49.71±17.76；p<0.001）。激光焊接期间的平均ITC为3.64±0.79（最小值：2.4；最大值：5.10）。没有一个样本的ITC超过临界阈值（5.5℃）。
LW获得的接头强度高于CW。激光焊接期间的ITC对乳牙不存在热风险。就强度和ITC而言，建议在乳牙中对SM使用口腔内激光焊接。
