Endodontic interappointment emergencies (EIAE) are pain or discomfort of varying degrees in the affected area of the tooth during root canal treatment, and in severe cases, localized swelling or even acute cellulitis may occur, mostly after root canal preparation. Currently, it is recognized that microbial infection is the main cause of EIAE, therefore, infection control has become a very important part of the root canal treatment process. In order to control infection and prevent EIAE, the surgeon's operations need to be performed in a sterile environment, while removing as much infected material remaining in the root canal as possible. Rubber-barrier hygromancy provides complete isolation of the affected tooth from the oral cavity and is the most thorough hygromancy method available for root canal treatment. Among the commonly used rinsing solutions, sodium hypochlorite is one of the most effective root canal rinsing solutions with its antibacterial and dissolving effects on necrotic pulpal tissues. In this study, we investigated whether the use of sodium hypochlorite rinsing combined with rubber-barrier wet isolation in root canal therapy could have the clinical effect of reducing the incidence of emergencies during root canal therapy.

1 Data and Methods

1.1 Clinical data

The stomatology department of the hospital affiliated to the Armed Police Logistics College collected 287 patients (287 teeth) diagnosed with pulpitis, pulp necrosis, chronic apical periodontitis requiring root canal treatment from September 2014 to September 2015, with the age of the patients ranging from 18 to 60 years old, with an average age of 36.5 years old, and a male-to-female ratio of about 1.1:1. Patients included in the experiment were asked to participate in the experiment under the principle of informed and voluntary participation and to The patients were asked to participate in the trial on an informed, voluntary basis and to sign an informed consent form.

In this study, patients were randomly divided into 3 groups according to the order of consultation, rubber-barrier sodium hypochlorite group (experimental group), rubber-barrier hydrogen peroxide group (control group 1) and hydrogen peroxide group (control group 2) according to the different ways of humidity insulation and flushing drugs.The general conditions of the patients in the 3 groups were equal in terms of age, gender, and condition, and there was no significant difference (P＞0.05), and the samples were comparable. Inclusion criteria: (1) patients aged ≥18 years; (2) healthy, without immune system diseases and diabetes mellitus; (3) diagnosed with pulpitis, pulp necrosis, chronic apical periodontitis according to the diagnostic criteria of the Ministry of Health planning textbook, Endodontics, 3rd edition; (4) X-ray examination did not find calcification of the root canals of the affected teeth, perforation at the base of the pulp chambers, lateral perforation of the root canals, incomplete development of apical foramen, and destruction of the apical stenosis area; (5) no root canal calcification, pulp chamber bottom perforation, root canal side penetration, incomplete development of apical foramen, and destruction of the apical (5) No antibiotics were used within 1 week prior to the consultation.

Exclusion criteria: (1) cases with obvious percussion pain in the affected tooth, redness, swelling, pressure and pain in the apical region and other symptoms of acute apical periodontitis; (3) cases with severe periodontal disease and may interfere with the assessment of pain level; (3) cases that cannot be followed up on time.

1.2 Equipment and Methods

1.2.1 Rubber barrier system (Swiss Contour Dental Group)

Includes rubber barriers, rubber barrier holders, rubber barrier clips, perforators, rubber barrier clamps, and other auxiliary materials (e.g., lubricants, fixation bands, dental floss, sealants, etc.).

1.2.2 Treatment method

Test group and control group 1 before treatment on the rubber baffle, first clean the tooth surface, according to the tooth position to select the appropriate rubber baffle clamp, referring to the rubber baffle punch template to punch the holes; the selected rubber baffle clamp into the holes of the rubber baffle, with both sides of the rubber baffle clamp wings support the rubber baffle holes, rubber baffle pliers placed in the holes of rubber baffle clamps; rubber baffle pliers to place rubber baffles and rubber baffle clamps on the treated teeth, to ensure that not to clip to the soft tissues, with a Finger to guide the rubber baffle clamp in place; rubber baffle clamp completely in place, remove the rubber baffle pliers, and finally the rubber baffle from the rubber baffle clamp wing down, set into the neck of the tooth, with dental floss will be adjacent to the gap on the rubber baffle pressed into the gap at the tooth, and then the rubber baffle will be fixed in the rubber baffle frame, rubber baffle installation is complete. In all groups of cases, the affected teeth were routinely opened and extracted, the root canals were unblocked, and the working length of the root canals was determined, and the root canals were prepared with Protaper root canal preparation using the step-by-step deepening method machine. Root canals were rinsed alternately with 5.25% sodium hypochlorite + 0.9% sodium chloride in the test group; and with 3% hydrogen peroxide + 0.9% sodium chloride in both control 1 and control 2 groups. The amount of rinsing solution per canal was 1 ml in each group. After rinsing, the root canals were drained with a paper tip, and a screw conveyor was used to introduce calcium hydroxide paste, and zinc oxide and clove oil mucoadhesive powder were used to temporarily close the fossa. The patients were followed up by telephone within 24 h after the operation to record the symptomatic changes in detail, and those who had EIAE during the sealing period were instructed to have a timely follow-up. All cases were followed up 1 week later, and the patients were asked about their condition, clinical examination was performed and recorded. The above treatment and follow-up were completed by the same physician.

1.3 Evaluation criteria

The occurrence of EIAE was determined according to the pain criteria proposed by Sulong et al: Grade 0: no pain; Grade I: only mild pain or discomfort, no need for emergency treatment; Grade II: the occurrence of pain can be relieved by medication or lowering of occlusion; Grade III: severe pain accompanied by local or facial swelling. Among them, grade II and III were judged as EIAE.

1.4 Statistical analysis

Using SPSS18.0 statistical software, the χ2 test was applied to compare the incidence of EIAE in the three groups of cases, and the difference was considered statistically significant at P<0.05.