Twenty-three maxillary first molars with three independent root canals were included in this study. The mesiobuccal (MB), distobuccal (DB), and palatal (P) root canals were prepared at sizes of #10/.02, #25/.02, and #25/.06, respectively. After being incubated with a bacterial suspension for 4 weeks, the specimen were irrigated with 2% NaOCl activated by conventional needle irrigation (CNI) (n = 10) or PIPS (n = 10). Three specimen were not treated (control group). Before and after irrigation, the presence of bacteria was assessed with an adenosine 5\'-triphosphate (ATP) assay kit and biofilms were assessed using confocal laser scanning microscopy and scanning electron microscopy.
In specimen prepared using PIPS irrigation, the ATP was reduced by more than 98%. When the root canal taper was 0.02, the size #25 root canals had a higher percentage of dead bacteria than the size #10 root canals in all regions (P < 0.05) in the PIPS group. When the root canal width was #25, the 0.02 taper group had a higher percentage of dead bacteria than the 0.06 taper group in the apical region (P < 0.05), except coronal and middle regions (P > 0.05). PIPS irrigation results in a greater percentage of dead bacteria and reduction of ATP in size #10/.02 root canals than CNI in size #25/.06 root canals in three regions (P < 0.05).
Increasing the width from #10 to #25 improves the bactericidal effect of PIPS in the root canal. Increasing the taper of the root canal from 0.02 to 0.06 at size #25 did not affect the bactericidal effects of PIPS. PIPS resulted in more dead bacteria in specimen with smaller tapers and root canal widths than CNI. PIPS can be used to clean the smear layer in the coronal region and open the dentin tubules.
Activation of irrigants with PIPS brought about significant bacterial reduction smaller tapers and width root canals compared to CNI, which was beneficial to prevent excessive loss of tooth tissue and conserve the structural integrity of teeth.
本研究包括23个具有三个独立根管的上颌第一磨牙。近颊(MB),远颊(DB),分别以#10/.02、#25/.02和#25/.06的尺寸制备腭(P)根管。用细菌悬液孵育4周后,用常规针头冲洗(CNI)(n=10)或PIPS(n=10)活化的2%NaOCl冲洗标本。三个标本未处理(对照组)。灌溉前后,使用腺苷5'-三磷酸(ATP)检测试剂盒评估细菌的存在,并使用共聚焦激光扫描显微镜和扫描电子显微镜评估生物膜.
在使用PIPS灌溉制备的样本中,ATP减少了98%以上。当根管锥度为0.02时,PIPS组中所有区域的#25根管的死亡细菌百分比均高于#10根管(P<0.05)。当根管宽度为#25时,根尖区0.02锥度组的死菌百分比高于0.06锥度组(P<0.05),除冠状区和中部区外(P>0.05)。在三个区域中,PIPS灌溉导致#10/.02根管中的死亡细菌百分比和ATP减少比#25/.06根管中的CNI更大(P<0.05)。
将宽度从#10增加到#25改善了PIPS在根管中的杀菌效果。在25号尺寸下将根管的锥度从0.02增加到0.06不会影响PIPS的杀菌作用。与CNI相比,PIPS导致标本中更多的死亡细菌,其锥度和根管宽度较小。PIPS可用于清洁冠状区域的涂抹层并打开牙本质小管。
与CNI相比,用PIPS激活灌溉剂可显著减少细菌,减少较小的锥度和宽度的根管,这有利于防止牙齿组织的过度损失和保持牙齿的结构完整性。