Root Fillings Research Articles

Radiographic Assessment of the Technical Quality and Periapical Health of Root‐Filled Teeth Performed by General Practitioners in a Turkish Subpopulation

Aim. The aim of this study was to evaluate by means of radiographs the technical quality of root fillings performed by dental practitioners. Methods and Material. Standardized periapical radiographs were made on 484 patients who received endodontic treatment in private practice. A total of 831 endodontically treated teeth with 1448 roots were evaluated for technical quality of the root canal filling and the periapical status of the teeth. Also, the apical status of each root-filled tooth was assessed according to the length, density, and taper of root fillings, and the presence of apical transportation, broken root instruments, and overfilled sealer or gutta-percha material was recorded for each root canal. Results. Of the endodontically treated teeth 26.6% had healthy periapical tissues, while technically good endodontic treatment constituted 12.8%. Based on the treatment success, there was no significant difference between the tooth groups. Statistical analysis of the data did not demonstrate statistically significant differences between the various parameters that were evaluated (P < 0.05). Conclusions. Technical quality of root fillings in a population who received treatment in private practice was poor and was consistent with a low prevalence of apical health. The probable reasons for this failure are multifactorial and may be improved if the operators improve their skills with continuing postgraduate education programs.

An innovative technique to assess the quality of root canal fillings using spiral - Computed tomography

The study is aimed to evaluate in-vitro the quality of root fillings completed by two gutta percha techniques – lateral condensation and single cone technique. Two sets of maxillary and mandibular teeth were selected (upto second molar). Root canals were prepared with Protaper instruments and then randomly divided into two groups. In group 1 canals were filled with lateral condensation technique and in group 2, canals were filled with single cone technique. AH-Plus sealer was used in all groups. After obturation the quality was assessed by subjecting the samples through spiral CT using an innovative technique having pixel frames. Percentage of root canal filled and unfilled space was calculated and compared using obturation index. Both techniques produced comparable results in terms of percentage of root canal filling. Void distribution was found to be different in both groups. External voids were found to be more common in single cone technique and internal voids were found mostly with lateral condensation technique. The Obturation Index (as proposed by the authors) may find its applications in daily clinical practise for judging the efficacy of obturation techniques, so that a technique with an aim to create voidless obturation space may be devised.

An in vitro comparison of bond strengths of Gutta-percha/AH Plus, Resilon/Epiphany self-etch and EndoREZ obturation system to intraradicular dentin using a push-out test design

Aim:To evaluate and compare the push-out bond strengths of three obturation materials; Gutta-percha/AH Plus, Resilon/Epiphany self-etch (SE) and EndoREZ obturation system to intraradicular dentin.Materials and Methods:Sixty single-canal anterior teeth were prepared and assigned to experimental groups (n = 20), designated as Group I: Gutta-percha/AH Plus, Group II: Resilon/Epiphany SE and Group III: EndoREZ sealer/EndoREZ points. After obturation, each tooth was prepared for push-out assessment with root slices of 2 mm thickness using universal testing machine.Statistical Analysis:Two way analysis of variance and Scheffe's test.Results:Gutta-percha/AH Plus root fillings showed significantly highest bond strength. Also, root segment location did not have a significant influence on bond strength.Conclusion:The adhesiveness quality to root dentin promoted by newer methacrylate resin-based obturation systems like Resilon/Epihany SE and EndoREZ is compromised even when teeth with simple anatomic features were obturated under well-monitored laboratory conditions.

Accuracy of the Dentaport ZX apex locator for working length determination when retreating molar root canals

The aim of this study was to evaluate the accuracy of the Dentaport ZX apex locator for working length determination during root canal retreatment of mandibular molars. Fifteen extracted mandibular first molars with separate mesial canals and apical foraminae and one distal canal were selected. The mesiobuccal and distal canals were investigated; the length with the file tip at the major diameter was defined as the tooth length (TL). The canals were prepared with ProTaper files to 1 mm short of this and filled with gutta-percha and AH Plus sealer. One week later, the root fillings were removed using ProTaper retreatment files. Tooth length was remeasured and recorded as the retreatment tooth length (RTL). Then electronic measurements were taken at the major (electronic apex locator (EAL) major) and minor (EAL minor) foraminae as suggested by the instrument display. These lengths were compared with RTL and measurements 0.5 and 1 mm short of this distance. For both canals, no significant difference was found between RTL and EAL major, and 0.5 mm short of RTL and EAL minor (P > 0.05). There were significant differences found between all other readings. The Dentaport ZX could not detect the minor foramen accurately but was able to indicate the major foramen in molars undergoing a root canal retreatment procedure.

Self-Adjusting File Cleaning-Shaping-Irrigation System Improves Root-filling Bond Strength

IntroductionThe aim of the present study was to assess the bond strength of root fillings in oval-shaped canals prepared with the self-adjusting file (SAF) system. MethodsA careful specimen selection resulted in 2 equal groups, each consisting of 12 extracted mandibular canines with oval canals that had vital pulps before extraction. One group was subjected to the SAF protocol, and the other group underwent conventional protocol, which was the ProTaper system with syringe-needle irrigation. Full-strength sodium hypochlorite was used as an irrigant for both groups. The teeth were obturated in a standardized way, filled with a lentulo spiral as the root filling, and then prepared for micropush-out assessment by using root slices of 1-mm thickness. Loading was performed on a universal testing machine at a speed of 0.5 mm/min−1. The Student's t test for pairwise comparisons was applied to assess the effect of each preparation technique on the push-out bond strength. ResultsAll specimens showed measurable adhesive properties to root dentin. In addition, no premature failure occurred. The group-by-location interaction was significant (P = .0071); thus, the group comparisons were dependent on the canal third. Overall, the push-out bond strength was the highest in the coronal third and the lowest in the apical third. SAF-prepared specimens displayed significantly higher bond strengths (P = .0012, 0.51–5.9 MPa). ConclusionsThe present study showed that SAF preparation markedly influenced root-filling push-out bond strength in oval-shaped canals. Further investigations are needed to provide a better understanding of the physicochemical modifications of the root dentin prepared with the SAF cleaning-shaping-irrigation system.

Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT

Objective. The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic gutta-percha. Furthermore, the obturation time for the two techniques was evaluated. Materials and methods. Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross-section images from Micro-computed Tomography scans. Results. All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between the two techniques was found (p < 0.001). Conclusion. The present study found no statistically significant difference in percentage of voids between two root filling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT.

3D micro‐CT analysis of the interface voids associated with Thermafil root fillings used with AH Plus or a flowable MTA sealer

To investigate nondestructively the percentage of 3D voids and marginal gaps in a pre-defined interface volume of interest (VOI) within root fillings produced by Thermafil Obturators with either a hydrophobic epoxy-resin-based sealer (AH Plus) or a hydrophilic flowable calcium-silicate sealer [mineral trioxide aggregate (MTA) Flow]. Sixteen single root canals from extracted premolar teeth were prepared with ProTaper rotary instruments, randomly allocated into two groups (n = 8) and filled with size 30 Thermafil Obturators in association with AH Plus or MTA Flow sealers. The filled roots were stored at 37 °C in 5 mL of Hank's balanced salt solution (HBSS) used to represent body fluids and scanned after 7 days and 6 months using a high-resolution micro-CT. From each root, images of 3000 sections were analysed in 3D and binarized using a high-resolution micro-CT (4-μ resolution). The 3D distribution of voids (porosity and marginal gaps) at the gutta-percha-sealer-dentine interface was detected through a threshold grey level and expressed as percentage of the 40-μ-thick pre-defined interface VOI (20 μ of interface dentine and 20 μ of gutta-percha/sealer). A method of analysis based on the root canal segmentation was used, and coronal, middle and apical thirds considered separately. The percentage of 3D void volume was compared statistically using one-way anova (significance for P < 0.05). Environmental Scanning Electron Microscope with Energy Dispersive X-ray (ESEM-EDX) analysis was performed on the surface of both sealers after soaking in HBSS. Micro-CT detected gaps at the dentine-sealer interface in both groups. Void volumes wider than 10.21 μm(3) with 1.35 μm diameter were detected. Cul-de-sac-type voids (blind pores) and through-and-through voids (continuous pores) were discriminated. The apical thirds had a significantly lower 3D void volume (P < 0.05) than the middle and coronal thirds. The 3D void volume reduced significantly (P < 0.05) over time. ESEM-EDX analysis revealed that MTA Flow sealer created a dense apatite layer after 7 days of immersion in HBSS, whilst only sparse calcium phosphate deposits were detected on AH Plus even after 28 days. Micro-CT proved to be a powerful nondestructive 3D analysis tool for visualizing the porous internal microstructure of dental/endodontic materials at the interface with dentine. The proportion of voids was least in the apical third of root canals. Voids reduced over time in the presence of simulated body fluid.

Improving the accuracy of a fluid transport method

To compare the sealing ability of the same root fillings when measured by a conventional fluid transport method that uses water or by a modified fluid transport method that uses a wetting fluid as tracer. The amount of fluid transport along the same root fillings (AH26, cold lateral compaction of gutta-percha) was measured in a cross-over design in fluid transport set-ups using either water or a wetting fluid as tracer. A Wilcoxon signed-rank test revealed a significant difference in the amount of fluid transport measured along the same root fillings by the two fluid transport methods (P = 0.013). The fluid transport method using wetting fluid detected a significantly higher percentage of root fillings with fluid transport (P = 0.021). Fluid transport using a wetting fluid as a tracer was more sensitive in the assessment of sealing ability of root fillings than the conventional fluid transport method using water.

Efficacy of ProTaper Universal Rotary Retreatment System for Gutta-percha Removal from Oval Root Canals: A Micro–Computed Tomography Study

IntroductionThe aim of this study was to use micro–computed tomography to evaluate the amount of remaining root filling material in oval canals filled by using 2 obturation techniques after retreatment with the ProTaper Universal Retreatment with or without solvent. MethodsForty mandibular incisor teeth with oval canals were prepared to the ProTaper Universal F3 and filled with gutta-percha and iRoot SP sealer by using continuous wave of condensation or cold lateral condensation techniques. The root fillings were removed with the ProTaper Universal Retreatment system, and the canals were prepared further with ProTaper F4. The operating time was measured. Preoperative and postoperative micro–computed tomography imaging was used to assess the percentage of volume of residual filling material in the canals. ResultsRemaining filling material was observed in all specimens. The mean volume of remaining material was higher in the continuous wave of condensation groups than in the cold lateral condensation groups, especially in the apical portions of the root canals (P < .05). The time required to reach a working length was significantly less in the solvent groups than in the nonsolvent groups (P < .05). However, in the nonsolvent groups, less time was required to achieve satisfactory gutta-percha removal and root canal refinement than in the solvent groups (P < .05). ConclusionsNone of the retreatment techniques were able to completely remove all gutta-percha/sealer from the oval canals. More root filling material was left in the root canals filled by using the continuous wave condensation technique than those filled by using the cold lateral condensation technique after retreatment. In the nonsolvent groups, less time was needed to achieve satisfactory gutta-percha removal and root canal refinement than in the solvent groups.

Evaluation of reasons for extraction of crowned teeth: A prospective study at a university clinic

Objective. The aim of this study was to determine and classify the major reasons for extraction of teeth with full crowns belonging to patients admitted to a university clinic within a specific time frame. Methods. Two hundred and eight extracted teeth with full crown belonging to 75 patients were included. Apart from demographic information, reasons for presenting to the hospital, the major reason for extraction, the type of the crown (single crown, bridge abutment, abutment for removable prosthesis), presence of posts, age of restorations, presence of an endodontic treatment and quality were recorded. Comparable data were statistically analyzed using the chi-square test. Results. Forty-three (57.3%) of the patients were females, whereas 32 (42.7%) were males with an average age of 63.21 ± 13.56. A statistically significant relationship was determined between age groups and rate of extractions, with the lowest extractions detected in the 35–44 years age group and the highest in the 55–64 years age group (p = 0.001). Tooth mobility was the predominant reason for patients' initial presentation (52.9%). The most encountered reason for extraction was periodontal reasons with a prevalence of 59.1%, followed by caries (26.9%) and periapical lesions (12%); 35.6% of extracted teeth had endodontic treatment. Sixty teeth (81.1%) had incomplete root fillings. There was a significant relationship between extractions and incomplete root fillings (p = 0.001). Conclusion. Studies comprising other faculty clinics as well as general practices will be complementary in making more generalized statements regarding the etiology of extractions of crowned teeth.

Influence of the Quality of Endodontic Treatment and Coronal Restorations on the Prevalence of Apical Periodontitis in a Turkish Cypriot Population

Objectives: The aim of this study was to assess the prevalence of periapical lesions in root canal-treated teeth in a Turkish Cypriote population and to investigate the influence of the quality of root canal fillings and coronal restorations on the prevalence of periapical lesions. Subjects and Methods: The sample for this cross-sectional study consisted of 1,006 adult patients seeking routine dental care. Patients who had received dental care in the last 2 years were excluded. Radiographs of 2,200 root canal-treated teeth were evaluated. The teeth were grouped according to the radiographic quality of the root canal filling and the coronal restoration. Periapical status was assessed using periapical index (PAI) scores. Results: Of the 2,200 root canal-treated teeth, 1,364 (62%) had apical periodontitis as compared with 1,364 (5.5%) of the total sample. Root-filled teeth classified as adequately treated had apical periodontitis in 223 (26.6%) cases compared with 1,192 (87.7%) in teeth classified as inadequately root filled. PAI 1 scores of adequate root canal treatment were significantly higher than in inadequate root canal treatment, regardless of the quality or presence of coronal restorations (p < 0.01). Conclusion: Our findings showed a high prevalence of periapical pathology with or without endodontic treatment and poor technical standard of both root fillings and coronal restorations of root-treated teeth. Hence, we suggest the need for better education for dental health providers so that they can perform better root canal treatments and coronal restorations.

Self-Adjusting Files in Retreatment: A High-resolution Micro–Computed Tomography Study

IntroductionRotary instruments that are used for retreatment are very effective, but most of them leave root filling residue in the canal. The aim of this study was to evaluate the efficacy of removing gutta-percha–based root fillings with ProTaper retreatment files (Dentsply Maillefer, Ballaigues, Switzerland) followed by F1 and F2 ProTaper instruments and to compare these results with those obtained with a #25 .06 ProFile instrument (Dentsply Maillefer) followed by the Self- Adjusting File (SAF; ReDent, Ra’anana, Israel) using high resolution micro–computed tomography (CT) scanning. MethodsTwenty-eight mandibular molar teeth with oval distal root canals were divided into 2 equal groups of 14 teeth each. The distal root canals were instrumented with ProTaper files up to an F2 instrument, the roots were subsequently filled, and the root filling was allowed to set fully. Removal of the root canal filling was performed with D1-D3 ProTaper retreatment files followed by F1 and F2 ProTaper instruments or with a #25 .06 ProFile followed by SAFs. Chloroform was used in both groups to assist in the removal of the root filling material. High-resolution micro-CT scans were used to measure the residual quantities of the root filling material after completion of the procedures. Statistical analysis was performed using the Wilcoxon test and the Student t test. ResultsThe median root filling residue in the ProTaper group was 5.39% (interquartile range [IQR] = 4.71) of the original volume of the root canal filling. In the ProFile and SAF group, the median residue was 0.41% (IQR = 1.64, P < .001). An arbitrarily selected threshold of less than 0.5% residue was defined as “effectively cleaned,” and 57% of the teeth treated with the ProFile and the SAF met this threshold, whereas none of the cases in the ProTaper group did. The ProFile and SAF procedure required less time than the ProTaper protocol. ConclusionsNone of the retreatment methods rendered all of the canals completely free of all root filling residue. Under the conditions of this study, the ProFile and SAF procedure was more effective than the ProTaper procedure and left significantly less root filling residue in the root canal.

Difficulties in performing root canal treatment among dental students in Sudan

BackgroundThe technical quality of root fillings performed by undergraduate students indicated unsatisfactory results. AimThe aim of the present study was to investigate the difficulties and amount of time encountered by final year dental students during performing conventional root canal treatment for a molar tooth. MethodsA questionnaire was distributed to 325 students in four different Dental Faculties in Sudan. The levels of difficulties during performing access cavity preparation, instrumentation, isolation and obturation of the root canals of a molar tooth. Also information regarding the time spent on procedures were recorded based on categorized groups. ResultsResults showed that 64.9% had difficulty in maintaining an aseptic field. Moderate difficulty was recorded in both locating the canal orifices (48.3%) and mechanical preparation of the root canal (45.0%). Obturating the root canal was the most time demanding procedure among all other procedures according to 49.2% of the students. ConclusionIn conclusion, results seem to signify noticeable obstacles among undergraduate students to maintain an aseptic field. Also obturating the root canal appeared to be the most time demanding procedure.

Assessment of Root Canal Treatment Outcomes Performed by Turkish Dental Students: Results After Two Years

The aim of this study was to evaluate radiographically the periapical status and technical standard of root canal therapies performed by a group of undergraduate dental students in Turkey two years following completion of the treatments. A random sample of 264 patients who received root canal treatment from undergraduate students at the Yeditepe University Faculty of Dentistry in 2009 were recalled after two years. The study sample consisted of 319 root-filled teeth in 158 dental patients (females=97, males=61) who presented to the student clinics during that time frame. For each root-filled tooth, two periapical radiographs were examined to identify the periapical status, one showing pre-treatment and the other showing post-treatment status. The quality of endodontic treatment was examined according to the distance between the end of root filling and radiographic apex and the density of the obturation according to presence of voids within the root filling material. This examination found that 54.2 percent of roots had fillings of acceptable length, while 37.3 percent were short, 7.8 percent were overfilled, and 0.6 percent was unfilled; 2.5 percent of the teeth were observed with broken root canal instruments. After two years, PAI scores of teeth with acceptable length of root canal filling (0-2 mm from the radiographic apex) were found to be lower than those of the overfilling and short filling cases (>2mm) (p<0.01). Moreover, voids were detected in the root canal fillings of 52.7 percent of endodontically treated teeth. The PAI scores of root fillings with inadequate density were significantly higher than adequate ones (p<0.01). Although endodontic treatments performed by undergraduate students do not appear to be unqualified compared to those performed by general practitioners, more emphasis must be placed on the technical quality of endodontic treatment to obtain better results.

Evaluation of three imaging techniques for the detection of vertical root fractures in the absence and presence of gutta‐percha root fillings

To compare the accuracy of digital radiography (DR), multidetector computed tomography (MDCT) and cone beam computed tomography (CBCT) in detecting vertical root fractures (VRF) in the absence and presence of gutta-percha root filling. The root canals of 100 extracted human single-rooted teeth were prepared and randomly divided into four groups: two experimental groups with artificially fractured root and two intact groups as controls. In one experimental and one control group, a size 40, 0.04 taper gutta-percha cone was inserted in the root canals. Then DR, MDCT and CBCT were performed and the images evaluated. Statistical analyses of sensitivity, specificity and accuracy of each imaging technique in the presence and absence of gutta-percha were calculated and compared. In the absence of gutta-percha, the specificity of DR, MDCT and CBCT was similar. CBCT was the most accurate and sensitive imaging technique (P < 0 .05). In the presence of gutta-percha, the accuracy of MDCT was higher than the other imaging techniques (P < 0.05). The sensitivity of CBCT and MDCT was significantly higher than that of DR (P < 0.05), whereas CBCT was the least specific technique. Under the conditions of this ex vivo study, CBCT was the most sensitive imaging technique in detecting vertical root fracture. The presence of gutta-percha reduced the accuracy, sensitivity and specificity of CBCT but not MDCT. The sensitivity of DR was reduced in the presence of gutta-percha. The use of MDCT as an alternative technique may be recommended when VRF are suspected in root filled teeth. However, as the radiation dose of MDCT is higher than CBCT, the technique could be considered at variance with the principles of ALARA.

Indicators for root caries in Danish persons with recently diagnosed Alzheimer’s disease

To identify indicators of root caries among persons with newly diagnosed Alzheimer's disease (AD). Few studies have investigated dental caries in older adults with AD. Previously we found that persons with AD had significantly more root caries compared to persons with dementia other than AD. Participants were recruited from two university hospital clinics in Copenhagen, Denmark. A team of neurologists/geriatricians carried out the diagnostic screening. The study included an interview, oral examination and medical records. We evaluated potential indicators of root decay across subjects with 3+ decayed surfaces vs. <3 decayed surfaces. Variables associated with increased odds of root caries were age over 80 years, 2+ decayed coronal surfaces and 5+ filled root surfaces. Among the social variables, living with someone was associated with a nearly 70% reduction in the odds of having 3+ surfaces of untreated caries. Root caries is highly prevalent among individuals with new AD and there is still a strong need for active assessment of and attention to oral problems in persons with AD. Our findings document that recently diagnosed AD cases with multiple coronal caries lesions are at elevated risk of having more root caries. Also persons 81+ years and those with multiple root fillings are more likely to have numerous untreated root lesions.

Interference of partial visual analysis of root filling quality and apical status on retreatment decisions

Objective The presence of periapical radiolucency has been used as a criterion for endodontic treatment failure. However, in addition to the inherent limitations of radiographic examinations, radiographic interpretations are extremely subjective. Thus, this study investigated the effect of partial analysis of root filling quality and periapical status on retreatment decisions by general dentists. Material and Methods Twelve digitalized periapical radiographs were analyzed by 10 observers. The study was conducted at three time points at 1-week intervals. Radiographs edited with the Adobe Photoshop CS4 software were analyzed at three time points: first, only root filling quality was analyzed; second, only the periapical areas of the teeth under study were visualized; finally, observers analyzed the unedited radiographic image. Spearman's coefficient was used to analyze the correlations between the scores assigned when the periapical area was not visible and when the unedited radiograph was analyzed, as well as between the scores assigned when root fillings where not visible and when the unedited radiograph was analyzed. Sensitivity, specificity, positive and negative predictive values between partial images and unedited radiographs were also used to analyze retreatment decisions. The level of significance was set at 5%. Results The visualization of the root filling on the unedited radiograph affected the interpretation of the periapical status and the technical quality of the fillings has a greater influence on the general dentist's decision to prescribe endodontic retreatment than the periapical condition. Conclusion In order to make endodontic diagnosis, radiographic interpretation process should not only emphasize technical aspects, but also consider biological factors.

Ten‐year follow‐up observations of periapical and endodontic status in a Danish population

To describe changes in periapical and endodontic status in a general adult Danish population examined in 1997, 2003 and 2008. The study provides longitudinal, observational information on endodontic status for 327 individuals who participated in three consecutive full-mouth radiographic examinations performed with an approximately 5-year interval. The collected data allow changes to be investigated within and between age-cohorts. The median number of teeth declined slightly, but the number of individuals with apical periodontitis (AP) and with root filled teeth increased. The number of teeth with AP and of teeth with root fillings increased, whereas the number of root filled teeth with AP was almost stable. The proportion of individuals who had no AP and the proportion of individuals who had no root fillings decreased during the 10-year observation period. The proportion of teeth with AP/individual increased steadily with age, unaffected by the different time periods. Differences were found between the age groups for the proportion of root filled teeth/individual where the younger age-cohorts had root fillings performed later in life and at a slower rate. In the old age-cohort, the proportion of lost teeth/individual was much larger and showed a stronger increase with age, than in the younger age-cohorts. The younger age-cohorts will probably never reach the proportion of root fillings or lost teeth seen in the oldest age-cohort. However, it is disturbing that the proportion of teeth with AP/individual increased steadily with age, completely unaffected by the different time periods.

Push‐out strength of root fillings with or without thermomechanical compaction

To evaluate the influence of thermomechanical compaction (Tagger's hybrid technique - THT) on the push-out strength of several root filling materials to root dentine. Root canals of eighty roots in human canines were prepared with the ProTaper system and filled with one of the following materials, using either lateral compaction (LC) (n = 40) or THT (n = 40): AH Plus/gutta-percha (GP) (n = 10), Sealer 26/GP (n = 10), Epiphany SE/Resilon (n = 10) and Epiphany SE/GP (n = 10). Three 2-mm-thick dentine slices were obtained from each third of each root. The root filling in the first slice was subjected to a push-out test to evaluate the bond strength of the materials to intraradicular dentine. Data (in MPa) were analysed using anova and post hoc Tukey's test (P < 0.05). Failure mode was determined at × 25 magnification. The other two slices were prepared for scanning electron microscopy (SEM) to examine the surface of the filling materials. Lateral compaction (1.34 ± 1.14 MPa) was associated with a significantly higher bond strength (P < 0.05) than the THT (0.97 ± 0.88 MPa). AH Plus/GP (2.23 ± 0.83 MPa) and Sealer 26/GP (1.86 ± 0.50 MPa) had significantly higher bond strengths than the other materials and differed significantly from each other (P < 0.05). There was a significant difference (P < 0.05) between the coronal (1.36 ± 1.15 MPa), middle (1.14 ± 1.05 MPa) and apical thirds (0.95 ± 0.83 MPa). Considering the technique and root filling material interaction, AH Plus/GP-LC was associated with the highest mean values (2.65 ± 0.66 MPa) (P < 0.05). Sealer 26/GP-LC (2.10 ± 0.46 MPa), AH Plus/GP-THT (1.81 ± 0.78 MPa) and Sealer 26/GP-TH (1.63 ± 0.44 MPa) had intermediate values that were not significantly different from each other (P > 0.05). Epiphany SE was associated with the lowest mean values (3.70 ± 0.86 MPa) (P < 0.05), regardless of the root filling technique and type of solid material (cone). Adhesive failures predominated in the specimens filled with Epiphany SE, whilst mixed and cohesive failures were more frequent in those filled with AH Plus and Sealer 26, regardless of the root filling technique. SEM analysis revealed that LC produced a dense and well-compacted filling whilst the use of a hybrid thermomechanical technique resulted in the solid material (GP or Resilon) intermingled within sealer to form a nonhomogenous mass. Lateral compaction was associated with higher bond strengths of the materials to intraradicular dentine than a hybrid technique using thermomechanical compaction. The greatest push-out strengths were obtained when the canals were filled with LC of AH Plus and GP cones.

Tobacco Smoking and Radiographic Periapical Status: A Retrospective Case-Control Study

IntroductionThe aim of this study was to investigate radiographically the relationship of tobacco smoking and periapical status by using a retrospective case-control study design. MethodsThe records of 79 controls and 79 age- and sex-matched cases were examined. Case was defined as a patient who has at least 1 radiographically detectable periapical lesion in a tooth. Control was defined as a patient who has no radiographically detectable periapical lesion in any teeth. Periapical status was assessed by using panoramic radiographs and the periapical index score. The history of smoking and diabetes, the number of teeth and root-filled teeth, and the quality of root fillings were recorded. Statistical analyses were conducted by using the Cohen kappa test, χ2 test, Student's t test, and logistic regression analysis. ResultsAmong the case subjects, 75% had antecedents of smoking, whereas in the control group only 13% had been smokers (odds ratio, 20.4; 95% confidence interval, 8.8–46.9; P = .0000). After multivariate logistic regression analysis adjusting for covariates (age, gender, number of teeth, root-filled teeth, root-filled teeth with a root filling technically unsatisfactory, and diabetes), a strong association was observed between the presence of at least 1 radiographically detectable periapical lesion and antecedents of smoking (odds ratio, 32.4; 95% confidence interval, 11.7–89.8; P = .0000). ConclusionsAfter adjusting for age, gender, number of teeth, endodontic status, quality of root filling, and diabetic status, tobacco smoking is strongly associated with the presence of radiographically diagnosed periapical lesions.