Application Of Minimally Invasive Instrument Combined With Single Tip Method In Root Canal Treatment Of Patients With Restricted Mouth Opening

Objective:Pulpitis and apicitis are oral diseases that account for a large proportion in clinical reception.The continuous or intermittent pain caused by them has adverse effects on the patient’s spirit and body.Root canal therapy（RCT）technology is the most widely used and effective scheme.However,for the dental pulp diseases of patients with limited mouth opening,due to the insufficient flexibility of RCT instruments,the narrow operation space and the short tolerance time of patients,the low feasibility and poor long-term efficacy of traditional instruments and methods,there is no effective method.Over the years,the concept of minimally invasive has been gradually popularized,and the performance of the new control memory nitinol preparation instrument has been optimized.It has excellent properties such as pre bending,flexibility,minimally invasive and strong bending resistance^[1].These properties may effectively reduce the operation space required for RCT,so that the root canal treatment of special patients with limited mouth opening can be carried out smoothly;Moreover,the single tip integrated filling procedure combined with bioceramic sealer is relatively simplified^[2],which can improve the operation efficiency of RCT.Due to the excellent performance of sealer,it can lay a foundation for long-term good curative effect and improve the therapeutic effectiveness.We plan to apply M3 pre bendable minimally invasive nitinol instrument and i Root SP single tip method to patients with mouth opening restriction,evaluate its clinical effect in RCT of molar pulp diseases,provide effective and feasible RCT methods for patients with mouth opening restriction,and ensure the success rate of RCT and long-term tooth retention rate.Method:From January to August 2020,among the patients diagnosed and treated in Hefei stomatological hospital,a total of 90 cases were selected as the first molar pulp disease with mild to moderate mouth opening restriction.For each patient,the selected cases could not be treated with conventional complete root canal treatment,such as the proximal buccal root canal of maxillary teeth or the proximal middle root canal of mandibular teeth.It was difficult to carry out root canal treatment under the condition of limited mouth opening.The cases were divided into two groups according to the order of treatment and the rules of the random number table generated by the computer.There were 22 males and 23 females in the experimental group,aged between 36 and 57 years,21 maxillary and 24 mandibular;In the control group,there were 20 males and 25females,aged between 33 and 55 years,20 maxillary and 25 mandibular;There were no significant differences in gender,age and jaw position between the two groups（P>0.05）.These differences can be ignored when comparing the two groups.The experimental group was prepared with M3 minimally invasive nickel titanium instrument combined with single point filling,and the control group was prepared with Pro Taper gold combined with hot dental glue vertical compression filling.The feasibility ratio,root canal treatment time,root canal filling rate,pain incidence and1-year treatment success rate of the two groups were recorded respectively.The measurement data were expressed in（（?）±s）and analyzed byttest;The counting data is expressed by the rate[n（%）]and^X~2test is adopted for data analysis.Results:（1）The feasibility rate of root canal therapy in the experimental group was86.44%,which was higher than 68.89%in the control group,but there was no significant difference in the feasibility rate between the two groups（P>0.05）.（2）The root canal preparation time and root canal filling time in the experimental group were shorter than those in the control group,and there was significant difference between the two groups（P<0.05）.（3）With the increase of curvature,the root canal preparation and filling time increased,and there was significant difference between the times of different curvature（P<0.05）,but there was no difference between the filling time of the control group（P>0.05）.There was no significant difference in preparation time between the two groups（P>0.05）,but there was significant difference in root canal filling time（P<0.05）.（4）The success rate of the experimental group was 86.84%,while the control group was90.32%.There was no significant difference between the two groups（P>0.05）.（5）There was no significant difference between the two groups in the filling rate and the incidence of pain（P>0.05）.Conclusion:M3 minimally invasive nickel-titanium instrument preparation combined with single-point filling and Protaper Gold preparation combined with hot gutta-percha vertical pressure filling can both provide effective preparation for patients with limited mouth opening who cannot fully undergo root canal treatment.The M3 minimally invasive instrument preparation combined with single-point filling has a higher feasibility rate and a shorter filling time,and is a practical method for effectively treating pulp diseases in patients with limited mouth opening.