Quality Of Root Canal Obturation Research Articles

Assessment of the quality of root canal obturation of teeth with destructive forms of periodontitis using Silpex (SEM studies)

AIM. To evaluate the effectiveness of using the material Sealpex with gutta-percha pins using the lateral condensation method for permanent obturation of the root canals of teeth with periapical pathology and pathologically destroyed apical constriction.MATERIAL AND METHODS. The root canals of 94 teeth with destructive forms of periodontitis were filled with Sealpex. Depending on the degree of apical constriction, patients were divided into three groups. Follow-up of patients was carried out for 4 years.RESULTS. Using SEM, in 80% of cases, single micro cracks were detected between the dentin of the root canal wall and the sealer. In the area of wide apical openings, the fit of the material is loose, and it is removed beyond the root apex. The material diffuses into the root dentin. Statistical studies have shown a high percentage of successful treatment of destructive forms of periodontitis with the use of Sealpex.CONCLUSIONS. Endo-sealant extended beyond the apex of the root canal does not mean dense obturation of the apical foramen. The presence of micropores and microcracks in the endosealant can be regarded as evidence of poor sealing of the channel. The use of Sealpex is especially effective when filling teeth of groups, I and II with destructive forms of periodontitis

Evaluation of radiographic quality of root canal obturation performed by undergraduate and postgraduate clinical dental students in a Nigerian hospital

Evaluation of radiographic quality of root canal obturation performed by undergraduate and postgraduate clinical dental students in a Nigerian hospital

Performance of obturation techniques in anatomical irregularities located at different thirds of the root canal system.

This study aimed to compare the quality of root canal obturation (ratio of area occupied by gutta-percha (G), sealer (S), and presence of voids (V)) in different anatomical irregularities (intercanal communications, lateral irregularities, and accessory canals) located at different thirds of the root canal system of mandibular molar replicas. Sixty-seven 3D printed replicas of an accessed mandibular molar were prepared using ProGlider and ProTaper Gold rotatory systems. Three specimens were randomly selected to be used as controls and did not receive further treatment. The rest were randomly distributed in 4 experimental groups to be obturated using either cold lateral compaction (LC), continuous wave of condensation (CW), and core-carrier obturation (ThermafilPlus (TH) or GuttaCore (GC)) (n=16 per group). AHPlus® sealer was used in all groups. The three controls and a specimen from each experimental group were scanned using micro-computed tomography. The rest of the replicas were sectioned at the sites of anatomical irregularities and examined at 30× magnification. The G, S, and V ratios were calculated dividing the area occupied with each element by the total root canal area and then compared among groups using the Kruskal-Wallis test. Voids were present in all obturation techniques with ratios from 0.01 to 0.15. CW obtained a significantly higher G ratio in the irregularity located in the coronal third (0.882) than LC (0.681), TH (0.773), and GC (0.801) (p<0.05). TH and GC achieved significantly higher G ratios in those located in the apical third (p<0.05). The worst quality of obturation was observed in the loop accessory canal with all obturation techniques. Whitin the limitations of this study, it can be concluded that CW and core-carrier obturation are respectively the most effective techniques for obturating anatomical irregularities located in the coronal and the apical third.

Effect of orthodontic treatment on the periapical radiolucency of endodontically treated teeth: a CBCT analysis

BackgroundThis study aimed to evaluate periapical radiolucency of endodontically treated teeth before and after orthodontic treatment using cone-beam computed tomography (CBCT).MethodsPatients who underwent orthodontic treatment at Wonkwang University Daejeon Dental Hospital between January 2009 and June 2022 were included based on the following criteria: root canal treatment, and availability of CBCT images taken before and after orthodontic treatment with an interval of > 1 year between both scans. Patients with primary teeth or orthodontic tooth extractions were excluded. The size of the periapical radiolucency (SPR) of the endodontically treated tooth was evaluated using CBCT. Pre-orthodontic treatment CBCT images and the latest post-orthodontic treatment CBCT images were analyzed. The selected teeth were further categorized based on the orthodontic duration, CBCT interval, the patient sex and age, the tooth type and position (maxilla or mandible), and quality of root canal obturation. Statistical analyses were performed to evaluate changes in SPR using the paired t-test and multiple regression analysis.ResultsIn total, 115 teeth (37 anterior teeth, 22 premolars and 56 molars) from 61 patients (age, 14–54 years) were included, with 39 teeth from male patients and 76 teeth from female patients. The age was ranged between 14 and 54 years old, and mean age was 25.87 years old. The mean CBCT interval and orthodontic treatment period were 43.32 months and 36.84 months, respectively. Seventy-five teeth showed good obturation quality, 80 were not used as anchors during orthodontic treatment, and 71 were maxillary. The SPR size increased after orthodontic treatment for 56 teeth and decreased for 59 cases. The average change in SPR was -0.102 mm and the difference was not significant. Significant decrease of SPR were observed between female patients (p = 0.036) and maxillary teeth (p = 0.040).ConclusionOrthodontic treatment had no significant impact on the changes in the SPR in endodontically treated teeth in most categories. However, there was a significant difference among females and the maxillary teeth. In both categories, the size of radiolucency decreased significantly.

Laboratory study of the quality of root canal obturation in the application of various techniques of medical treatment

Laboratory study of the quality of root canal obturation in the application of various techniques of medical treatment

Assessment of Modality and Accuracy of Single Root Canal Treatment Performed by Undergraduate Students in Saudi Arabia: A Retrospective Study.

Aim To assess the radiographic quality of root canal treatment (RCT) performed on single-rooted anterior teeth by undergraduate dental students of Imam Abdulrahman Bin Faisal University (IAU). Moreover, the study also aimed to assess the types of procedural errors encountered during root canal treatment and to compare the results between male and female students. Methodology The record of patients who visited the endodontic clinics at IAU between the years 2018 and 2021 was obtained from the medical records department. The inclusion criteria for the study involved: i) RCT performed on anterior teeth with a single root; ii) RCT performed by fourth, fifth, and sixth-year undergraduate dental students; and iii) availability of pre-operative and post-operative peri-apical radiographs. After the inclusion criteria, a total of 278 records were selected. The radiographs were accessed by two calibrated examiners for the length of the obturation, homogeneity, and taper. In addition, procedural errors such as the presence of a ledge, perforation, or fractured instruments were also observed. Analysis was done using the Chi-square test. Results A total of 139 teeth (50%) were found to have an adequate quality root canal treatment. Regarding the length of the obturation, 85.6% were considered acceptable, while 65.1% of the obturations had acceptable radiographic homogeneity. The acceptable taper was found in 71.9% of the obturations. Dental students who participated in this study demonstrated a low rate of procedural errors, with 4.7% ledge formation and 1% perforation. A statistically significant difference was found in the quality of root canal obturation (P=<0.001) performed by fourth, fifth, and sixth-year students. Moreover, a significant difference was also observed between maxillary and mandibular teeth (P= 0.032). Conclusion The quality of RCT performed by undergraduate dental students demonstrated that improvements are required. The teaching methods used in the endodontic courses need to be developed and improved to ensure the best possible learning and treatment outcomes.

Clinical Testing of Walking Bleach, In-Office, and Combined Bleaching of Endodontically Treated Teeth.

Objective. The causes of internal posteruptive discoloration of teeth are bleeding, necroses, infections, and endodontic filling materials. The aim of this study was to establish the results of bleaching endodontically treated teeth using walking bleach, in-office, and combined techniques, using 30% carbamide peroxide and 35% hydrogen peroxide, as well as the effect of etiological factors, and the time elapsed after endodontic treatment on the success of bleaching. Materials and Methods. The research involved 30 endodontically treated teeth in healthy patients. Retroalveolar X-rays were taken to check the quality of root canal obturation. Endodontic treatment and obturation were carried out on the discolored non-vital teeth without any previous endodontic treatment. Before bleaching, two millimeters of the filling were removed from the root canal and the very entry into the canal was protected with glass ionomer cement. The teeth were divided into three groups, depending on the bleaching technique: walking bleach technique (10 patients), in-office technique (10 patients), and combined technique (10 patients). The teeth were bleached with 30% carbamide peroxide and 35% hydrogen peroxide. The bleaching procedure was repeated in all the patients three times. The color of all teeth was determined based on the Vita Classic guide before and after bleaching. The Χ2 square and Kruskal−Wallis tests were used to identify differences in teeth bleaching results. Results. A statistically significant difference (p < 0.05) was established between bleaching success and the time elapsed after endodontic treatment. There were no statistically significant differences observed between the bleaching success and etiological factors, bleaching techniques, or bleaching agents. Conclusions. The effectiveness of non-vital tooth bleaching is affected by the time elapsed after endodontic treatment.

Effect of different dentin moisture on the push-out strength of bioceramic root canal sealer

Background/purposeDifferent moisture condition may affect the adhesion between obturation materials and root canal walls, thus further affect the quality of root canal obturation. The aim of this study was to evaluate the influence of dentin moisture conditions after different root canal drying protocols on the push-out strength of bioceramic root canal sealer. Materials and methodsTwenty root canals from extracted human decoronated premolars were prepared in vitro to #30/0.09 taper and assigned to 4 moisture condition groups after using different root canal drying protocols: normal moisture (paper point) group: the canals were blot dried with paper points until the last one appeared dry. Ethanol dry group: the canals were dried with paper points followed by dehydration with 95% ethanol. Isopropanol dry group: the canals were dried with paper points followed by dehydration with 70% isopropanol. Complete dry group: the canals were dried in an air-blowing thermostatic oven for at least 6 h until there was no change in weight at an interval of 1 h. After drying, the canals were obturated with bioceramic sealer iRoot SP. Then, each root was sectioned into eight slices with 1-mm-thick using a diamond saw (40 slices each group). The push-out strength was tested for each slice between the sealer and dentin wall using a universal testing machine at a crosshead speed of 0.5 mm/min, and failure modes were recorded. Two-way analysis of variance and Tukey test were used to analyze the push-out strength. Logarithmic linear regression analysis was used to compare the failure modes. ResultsPush-out strength was statistically different in different moisture groups (P < 0.05). After drying using paper point, iRoot SP specimens showed the highest push-out strength (2.04 ± 0.03 MPa), followed by 95% ethanol, 70% isopropanol. The lowest push-out strength (0.68 ± 0.04 MPa) was observed under complete dry. For the failure modes, the majority were cohesive failures in the coronal and middle thirds of the root; while in the apical third, mixed failure was common. ConclusionDifferent drying protocols influenced the push-out strength between bioceramic sealer and canal wall.

The effect of the quality of removal of temporary sealers from anatomically limited volumes of the root canal system on the quality of root canal obturation

The success of endodontic treatment depends on many factors. One of the most important is the proper root canal obturation. In the treatment of apical periodontitis, temporary sealers are used to improve healing process of the infected periodontium, which contain calcium hydroxide on different bases: hydrophilic and hydrophobic. If there are remnants of temporary sealants, the doctor cannot guarantee the good root canal obturation. Complete removal of temporary sealers from the root canal system and dentine tubules is ensured by the use of special irrigants. The aim. Evaluate the application of adhesion of epoxy resin sealant after temporary root canal filling.Materials and methods. Samples of 60 intact molars were randomly distributed into six groups. In the samples of the 1st group, a sealant based on epoxy resins was used; In the 2nd group, before applying the sealer, dentin samples were additionally treated with liquid for drying and degreasing the hard tissues of the tooth. In the samples of teeth in the 3rd and 4th group, a paste with calcium hydroxide on a hydrophilic basis with calcium hydroxide was applied to the dentin section. Then epoxy sealer was used for permanent obturation. In the samples of teeth in the 4th group, dentin was applied liquid for drying and degreasing the hard tissues of the tooth before the use of epoxy sealer. In the samples of teeth in the 5th and 6th groups, a hydrophobic paste containing calcium hydroxide and silicone-based iodoforms was applied to the dentin section before the application of epoxy sealer. In the samples in the 6th group, dentin was pretreated with liquid for drying and degreasing the hard tissues of the tooth. In the samples of all groups, the adhesive shear strength was determined on the test machine «SYNTHEZ 5» (France). After the tests, the samples were studied by scanning electron microscopy (SEM).The resultsof the study showed adhesive shear strength in the 1st group of (9,1±1,2) MPa, in the 2nd group – (11,4±1,1) MPa, in the 3rd group – (8,0±1,1) MPa, in the 4th group – (10,5±1,1) MPa, in the 5th and 6th groups – (7,6±1,3) MPa and (10,3±1,1) MPa, respectively. Samples treated with a liquid for drying and degreasing the hard tissues of the tooth under SEM showed the penetration of epoxy sealer into the dentin tubules.Conclusion. The adhesive strength of the epoxy resin-based sealant after the application of pastes for temporary filling of root canals ranges from (9,1±1,2) МРа до (11,4±1,1) MРa. Residual fragments of pastes on hydrophilic and hydrophobic bases reduce the strength of adhesion of the root sealаnt to dentin.The use of liquid for drying and degreasing the hard tissues of the tooth allows to remove the remnants of the paste from the root canal as much as possible and increases the strength of adhesion of the root sealant to the dentin.

Determination of correlation between the quality of obturation and postoperative pain following root canal preparation with rotary and manual file systems in the primary molars-A comparative randomized clinical trial

To determine the correlation between the quality of root canal obturation and postoperative pain following root canal preparation with rotary and manual file systems in the primary molars. A total of 150 primary molars requiring pulpectomy were selected from children aged 4–7 years. The selected teeth were divided into three groups: Kedo-S (KS), HERO Shapers (HS) and Manual Files (MF)-of 50 teeth each. In groups KS, HS, and MF, root canal instrumentation was carried out with Kedo-S pediatric rotary files, HERO Shaper rotary files, and manual NiTi K-files, respectively. Root canal obturation was carried out with zinc oxide eugenol cement using an engine-driven Lentulo spiral. The quality of the root filling was radiographically assessed immediately after obturation. The postoperative pain was evaluated at time intervals of 6, 12, 24, 48, 72 h, and 1 week. The quality of obturation was superior in the root canals instrumented with rotary file systems compared to manual files. There was decreased postoperative pain with the use of rotary file systems as compared to manual files. In all three groups, postoperative pain decreased over time. The use of rotary file systems resulted in a higher percentage of optimal root canal filling with lesser postoperative pain than the manual file system. The overfilled root canals were not associated with significant postoperative pain.

Evaluating the Quality of Root Canal Obturation Performed by Undergraduate Dental Students: A Retrospective Clinical Study

Evaluating the Quality of Root Canal Obturation Performed by Undergraduate Dental Students: A Retrospective Clinical Study

Technical Quality Assessment of Root Canal Treatment on ETP by Pre-Clinical Students at Fatima Jinnah Dental College

Background: Students at pre clinical level at Fatima Jinnah Dental College are taught root canal treatment on endodontic typodonts. Technical quality of the root canal treatments performed by these students was assessed to determine success of teaching methodology and reinforcement of tooth morphology concepts. Methodology: In this cross-sectional study, obturation quality of 20 anterior and 30 posterior endodontic typodonts were evaluated on the parameters of length, density and taper. The collected data was evaluated using SPSS software, version 20.0. Chi square analysis was applied to compare the quality of root canal obturation between types of tooth. Kappa statistics was used for inter examiner reliability. Results: After assessing the three variables, adequate length control was observed in (92.9%), while 7.1% of under filling was seen in both groups. Percentage of teeth showed homogeneity in obturation density that is 30%, 60% teeth showed acceptable, whereas 10% showed unacceptable obturation homogeneity. 55.6% teeth showed perfect obturation taper and 4% showed acceptable. Conclusion: The obtained results showed root canal treatment quality done by Fatima Jinnah Dental College undergraduate dental students to be adequate on anterior endodontic typodont teeth as compared to posterior endodontic teeth. This will guide us in utilizing further demonstration hours and more practice time on posterior endodontic teeth. Our study also displayed the need of incorporating hands on practice of root canal treatments on extracted teeth before students are allowed to work on patients. Keywords: Root Canal Treatment, Endodontic Typodont, Obturation, Preclinical.

Clinical Efficacy of Sealer-based Obturation Using Calcium Silicate Sealers: A Randomized Clinical Trial

IntroductionThis randomized controlled clinical trial compared the clinical efficacy and outcome of a sealer-based obturation technique (SBO) with calcium silicate sealers and a continuous wave of condensation technique (CWC) with a resin-based sealer. MethodsRoot canals were prepared using rotary instruments and 2.5% sodium hypochlorite. At the next visit, patients were enrolled and randomly assigned into 2 groups on the basis of the obturation protocol: CWC with AH Plus sealer and SBO with Endoseal TCS. Patients were assessed for the level of postoperative pain using a numeric rating scale. The quality of root canal obturation was evaluated in terms of the sealer extrusion, root-filling voids, and level of root filling. The participants were recalled after at least 6 months. Healing of the teeth was determined as a decrease in Periapical Index score and resolution of symptoms. The results were statistically compared by using the χ2 test or Fisher exact test, followed by multivariate analysis with logistic regression. ResultsA total of 74 teeth were included in the analysis (79% recalls), and the mean follow-up period was 17 months (6–29 months). Two groups expressed identical distribution of postoperative pain (P = .973) and similar quality of root canal obturation. The total success rates were 93.2% (CWC 92.3%, SBO 94.3%) by loose criteria and 60.8% (CWC 51.3%, SBO 71.4%) by strict criteria, with no significant differences between the 2 groups. The success rate by loose criteria in teeth with sealer extrusion was significantly lower than those in teeth without sealer extrusion (P = .049). ConclusionsSBO using an Endoseal TCS could be a possible alternative to CWC using AH Plus. Sealer extrusion and postoperative pain were found to negatively impact prognosis of the endodontic treatment.

Evaluation of Quality of Root Canal Obturation, Coronal Restoration and Periapical Health in Failed Endodontically Treated Teeth

Objective: To investigate the implication of quality of obturation and coronal restoration on periapical tissue in failed endodontically treated teeth. Study Design and Setting: This cross-sectional research was performed in the Operative Department of BUMDC on 187 patients reporting with root canal failure from March 2019 to August 2019. Methodology: Patients of both genders aged between 20-60 years were considered for this study. Single and multirooted teeth indicated for repeated endodontic treatment due to under filled, overfilled obturation, voids in obturation, absence and presence of coronal restoration were included. One operator carried out clinical examination of the teeth and periapical radiograph was taken for each patient by using E-Speed film and evaluated by the same operator using an illuminated viewer box. SPSS 17 for windows software was used for data entering and chi- square test was applied for statistical calculation of the outcomes. Results: Total n=187 endodontic treated failed teeth were evaluated, out of which 52.9% were of females and 47.1% to males. The number of obturations with acceptable length were 81(43.3%), with adequate density were 107 (57.2%) and with consistent taper were 116(62%). Periapical lesion was observed in 118(63.1%) cases. Quality of obturation significantly affects the periapical health. Cross tabulation showed a significant association (p-value &lt;0.000) between inadequate coronal restoration and changes in periapical area. Conclusion: The successful prognosis of the root canal treatment relies on the good quality of obturation and adequate coronal filling.

Root Canal Filling Quality Comparison of a Premixed Calcium Silicate Endodontic Sealer and Different Carrier-Based Obturation Systems.

Background: The number of voids within the root canal obturation is a relevant parameter to describe the quality of the technique, as well as to predict long-term prognosis. The aim of this study was to evaluate the quality of root canal obturation in curved root canals filled with Thermafil, GuttaCore, GuttaFusion and lateral compaction with AH Plus and EndoSequence BC sealer, by means of percentage of gutta-percha and sealer filled area. Methods: 200 curved canals of mandibular molars were divided in five groups (n = 40). Each specimen was evaluated at 3, 6 and 9 mm from the apex. A total of 600 samples were analyzed. Obturation was performed with either Thermafil (TH), GuttaCore (GC), GuttaFusion (GF) or lateral compaction (LC), using AH Plus as sealer. In another group EndoSequence BC sealer (BC) was used. Subgroups (n = 20) were made depending on the use of sonic activation during the placement of the sealer. The percentage of total obturation material was analyzed as an indirect measurement of percentage of voids. Results: GF showed a better performance at the apical level, while GC showed the higher percentage of total obturation at the coronal area. No differences were observed for the activation of sealers in any of the groups. Statistical analysis was performed by using two-way ANOVA. Statistical significance was set at CI: 95% (p < 0.05). Conclusions: Sonic activation of sealers did not show any benefit to avoid the presence of voids within obturation of curved canals. Following the manufacturer recommendations, we found that TH did not show benefits when applied to curved canals.

Research progress in clinical prognosis of apical overfilling of root canal obturation

Root canal obturation is conducted by using filling materials to tightly seal the root canal system after the procedure of preparation in order to control infection and promote periapical healing. The quality of root canal obturation is one of the essential factors affecting the prognosis of root canal treatment. Qualified root canal filling is defined as a homogeneous radiographic apical filling within the cemento-dentine junction with neither overfilling nor underfilling. This review elucidates the long-term outcome of root canal overfilling and its causes, the influence of apical overfilling on adjacent structures and the prevention and management of overfilling, so as to help the clinicians achieving a better outcome of root canal treatment and obtaining an optimal long-term prognosis.

Effect of Adaptive, Rotary, and Manual Root Canal Instrumentation in Primary Molars: A Triple-Armed, Randomized Controlled Clinical Trial.

Simple SummaryUntimely loss of primary molars may lead to undesirable consequences; hence, pulpectomy is considered a rational treatment approach to avoid it. Advances in root canal instrumentation by means of motorized files while treating primary teeth have reduced the chair-side time and have also exhibited better quality of obturation. This helps reduce the patient’s anxiety about pulpectomy procedures. However, root canals in primary teeth exhibit a larger perimeter and are irregular in shape, posing a challenge to currently used motorized endodontic files. Instrumenting root canals in three dimensions is the need of the hour and is vastly explored in the literature, albeit for adult dentition. The application of adaptive root canal instrumentation for pulpectomies in primary teeth is yet to be reported in the literature.This clinical trial focused on collating the instrumentation time and quality of root canal obturation in primary molars treated with three instrumentation techniques: adaptive, rotary, and manual. A triple-armed, randomized controlled clinical trial was performed on 75 primary molars requiring pulpectomy treatment, divided into three groups (n = 25 per group). The teeth in Group 1 were instrumented with an adaptive technique (XP-endo Shaper, FKG Dentaire, La Chaux-de-Fonds, Switzerland), Group 2 with pediatric rotary files (Kedo-S; D1 and E1), and Group 3 with a manual technique (hand K-files). The apical size of the final instrumentation was maintained at #30 for all groups. Instrumentation time and the grade of the root canal obturation were evaluated. Instrumentation duration was recorded, employing a digital stopwatch from the insertion of the first file until the completion of final irrigation. Obturation quality was assessed using radiographs. The criteria taken as a reference for obturation were: optimal (1 mm short of the apex), underfilled (2 mm short of the apex), or overfilled (beyond the apex). The use of an adaptive technique was associated with the lowest instrumentation time (p < 0.0001) when used for instrumenting primary molars and with the highest root canal filling quality of the three groups. The application of the new concept of adaptive instrumentation for pulpectomy of primary molars was a favorable technique, considering the significant reduction in instrumentation time and better obturation.

Filling quality of several obturation techniques in the presence of apically separated instruments: A Micro-CT study.

Separated root canal instruments may affect the quality of root canal obturation and hence the survival of endodontically treated teeth. Obturation techniques may influence filling-quality. The aim was to evaluate the obturation quality of teeth filled with different obturation techniques in the presence of apically separated instruments using micro-computed tomography (μ-CT). Notched ProTaper F2 rotary-files were separated in the apical third of 36-human mandibular incisors with single root/canal and mature apex. Samples were filled by an endodontist according to one of the following obturation techniques (n=12): cold lateral-compaction (CLC), single-cone (SC) and thermoplastic injection (TI). Samples were scanned by the Skyscan 1,274® μ-CT device after 1-week at 37°C in 100% humidity. Images of the sections were evaluated with CTan software in terms of total-volume and volume percentage of the filling materials and voids between coronal end of the separated instrument and gutta-percha/sealer filled void-free sections. Data was analyzed using Kruskal-Wallis and Mann Whitney-U tests with a significance level of 5%. Kruskal-Wallis revealed differences among groups (p < 0.05).Pairwise comparisons revealed that less volume of voids were measured in SC (0.02 ± 0.03 mm3 ) compared to CLC (0.15 ± 0.16 mm3 ) and TI (0.18 ± 0.24 mm3 ) (p < 0.05); while TI was statistically similar with CLC (p > 0.05). Percentages of volumes of voids and filling materials were as follows for SC, CLC and TI, respectively: 8.88 ± 18.52% and 24.45 ± 38.40%, 46.92 ± 33.53% and 53.07 ± 33.53%, 40.54 ± 33.85% and 42.79 ± 34.45%. The obturation technique may have a significant impact on the volume of voids in the presence of a separated file. No obturation technique produced a void-free root canal filling.

Thermal behavior and viscoelastic properties of gutta-percha used for back-filling the root canal

Background/purposeIn clinical operations, qualitative differences in the texture and operational feeling of the regular type and soft type back-filled gutta-percha are readily discernible. This study aimed to investigate and compare the thermal behavior and physical properties of the two gutta-percha materials. Materials and methodsThe chemical compositions of regular and soft type Gutta-Percha Obturator® pellets were examined via energy dispersive X-ray spectroscopy. The thermal behaviors of the pellets during heating and cooling were evaluated using a differential scanning calorimeter. Finally, the viscoelastic properties of the two materials during cooling were assessed using a modular compact rheometer. ResultsThe soft type gutta-percha contained a greater atomic percentage of zinc than the regular type material. In addition, the soft type gutta-percha exhibited exothermic peaks during cooling, whereas the regular type gutta-percha did not. The two materials exhibited different viscoelastic behaviors under cooling. In particular, the rate of change of the loss factor for the soft type gutta-percha was more than that of the regular type gutta-percha at temperature lower than 80°C. ConclusionThe soft type gutta-percha underwent significant crystallization during cooling, and therefore exhibited pronounced volume shrinkage. Furthermore, the soft type gutta-percha underwent a greater rate of change in viscoelasticity under cooling than the regular type gutta-percha, and exhibited poorer physical stability. Consequently, in the back-packing procedure, soft type gutta-percha must be compacted more often over time than regular type gutta-percha to ensure the same quality of root canal obturation.

РЕЗУЛЬТАТЫ ВНУТРИКОРОНКОВОГО ОТБЕЛИВАНИЯ ДЕПУЛЬПИРОВАННЫХ ЗУБОВ

&#x0D; Изменение в цвете депульпированного зуба – весьма распространенное и многофакторное по этиологии явление, являющееся частой причиной обращения к стоматологу, особенно если потемневший зуб находится в линии улыбки. Цвет зубов, в свою очередь, наряду с их формой и оптическими свойствами, является важнейшим эстетическим критерием современного человека. Одним из способов исправления цвета таких зубов является внутрикоронковое отбеливание. Целью исследования было оценить эффективность внутрикоронкового отбеливания и восстановления флуоресцентных свойств депульпированных зубов в зависимости от типа используемого силлера при эндодонтическом лечении и причин депульпирования. Для изучения эффективности внутрикоронкового отбеливания депульпированных зубов провели отбеливание 194 зубов 190 пациентам, обратившихся в Клинику ВГМУ и на кафедру терапевтической стоматологии с курсом ФПК и ПК УО «ВГМУ» в период 2014–2018 гг. с жалобами на изменение в цвете зубов после эндодонтического лечения. Средний возраст пациентов составил 34,6±8,2 года. Результаты полученных данных свидетельствуют о том, что эффект отбеливания с восстановлением цвета и флуоресцентных свойств до исходных характеристик витального зуба был достигнут у 72 зубов из 194 (37,11%). У 122 зубов (62,89%) необходимого отбеливания и восстановления флуоресценции не произошло. Из них частично отбелилось 68 зубов (35,05%), не отбелилось 54 зуба (27,84%). В зубах, корневые каналы которых были обтурированы материалами на основе эвгенола, цветовые и флуоресцентные параметры восстановлены в 50% случаев. При обтурации корневых каналов депульпированных зубов силлером на основе резорцин-формалина восстановления цвета и флуоресценции не произошло ни в одном из случаев. Зависимости эффективности отбеливания депульпированных зубов от причины, вызвавшей дисколорит, не выявлено. Однако наиболее частой причиной возникновения изменения в цвете депульпированного зуба был осложненный кариес.&#x0D;