A Research of Three Different Methods in the Preparation of Molar’s Curved Root Canals
|School||Central South University|
|Keywords||G-type drill Ultrasonic irrigation Curved root canals Root canal treatment|
Objective: To observe the GG drills and hand stainless steel K file joint preparatory molars severe curved root canals, and with the machine Profile nickel-titanium instruments in preparation molars severe curved root canals, simple hand stainless steel K file preparation molars severe curved root canals for comparison, research three ways to prepare curved root canal molar severe change in curvature, prepare the root time, instrument fracture, steps formed after severe reactions and other differences, provide a theoretical basis for clinical application. Methods: Patients clinic, root canal curvature at 25 ° -45 ° of pulpitis, periapical inflammation and severe cases of 497 molar root canal, the conventional open pulp, pull cord, use 15 # K filing detect root canal, pin to the apical astringent sensation when there is resistance, with ODIS-1 type of oral radiography digital imaging system to observe the file tip and apical location, according to length ratio formula derived by subtracting the length of 0.5mm as a root canal working length, measured according to Schneider root canal curvature. All cases by patients randomly divided into three treatment groups. Group A: first with 10 # -15 # K filing dredge canals, 4 # GG drill handle root canal dentin crest triangular mouth, and then the order to use 1 #, 2 #, 3 # GG drilling, processing each GG drill have put a stop to expand needle mark, GG drilling into the root canal orifices, the resistance encountered when drilling GG note the length of root canal a little force, decreasing the length of each drill 2mm for One root canal preparation, the root canal funnel-shaped crown segment, followed by hand with stainless steel K file preparatory step-back technique apical segments, will prepare the apical tip to the main file for the 30 # K filing, after each increase ONE file length decreases 1mm, until 40 # file, each file will increase with 30 # One master file back to the file in root canal tip to maintain patency and root canal wall smooth. Group B: with machine Profile nickel-titanium instruments, according to the manufacturers instructions for use with the gradual deepening of the root canal preparation method, first with Profile.OS (0.05-0.08 taper) root canal orifice; reuse Profile.06 (0.06 taper) prepare Root canal Central; followed by Profile.04 (0.04 taper) apical preparation. Group C: only hand stainless steel K file with step-back technique for root canal preparation. When you are ready to use ultrasonic treatment instrument (medium power) clean the root canal, root canals observed in each group after the root canal curvature change, time required, equipment broken, a step is formed after the reaction and so on. Results: (1) three ways to prepare molar severe curved root canal preparation before and after comparing the average curvature. Comparison between groups: Preliminary ago A group, B group, C group had no significant difference (P gt; 0.05); preparatory group A, B group the difference was not statistically significant (P gt; 0.05), C group and A group, group B, the difference was statistically significant (P lt; 0.05). Comparison group: A group, B group before and after root canal curvature average difference was statistically significant (P lt; 0.01), C group was statistically significant difference before and after preparation (P lt; 0.05). (2) three ways to prepare teeth with severe root canal the average time warp between the two groups: A group, B group used the time difference was not statistically significant (P gt; 0.05), A group and C group, B group and C group The time spent there was significant difference (P lt; 0.01), C group used more time. (3) three ways to prepare teeth with severe root canal instrument fracture comparison: A group, B group, C group instrument fracture occurs three groups was statistically significant difference between the groups (P lt; 0.05), A group had the lowest rate, B group, the highest incidence. (4) three ways to prepare curved root canal molar severe step forming, after the situation is more severe reactions. Steps form a relatively: A group, B group the difference was not statistically significant (P gt; 0.05), C group and A group, B group was significantly stepped formation (P lt; 0.05); postoperative severe reaction: C group The incidence is slightly higher, but the difference between the three groups was not statistically significant (P gt; 0.05). Instrument fracture the formation step of the cases have occurred in the root canal curvature large apical root canal stenosis segment. A set of methods use to further expand the root canal orifices, reducing root canal curvature, the broken root canal instruments were successfully removed one case each, the rest have failed, steps in addition to the formation of root canal one case in group B, C group 4 cases curved root canals can not dredge, the rest have achieved satisfactory results; cases of severe reactions occur after root canal ultrasonic irrigation and oral antibiotic therapy after the symptoms disappear, the effect is satisfactory. Conclusion: GG drill joint stainless steel K file preparation molars severe curved root canal, the root canal curvature change, root canal preparation efficiency and nickel-titanium instruments considerably; rather simple hand with stainless steel equipment preparation of the root canal curvature change is relatively small, root canals efficiency is poor. Preliminary molars severe curved root canals, the machine Profile NiTi instruments is greater than the chance of occurrence of instrument fracture stainless steel equipment; pure hand with stainless steel instruments are more prone to the formation of root canal preparation steps; After ultrasonic irrigation canals, three ways to prepare molar severe bending Root canal postoperative severe reactions no difference.