Low-Diversity Microbiota in Apical Periodontitis and High Blood Pressure Are Signatures of the Severity of Apical Lesions in Humans.

(1) Background: In developed countries, the prevalence of apical periodontitis (AP) varies from 20% to 50% for reasons that could be associated with the apical periodontitis microbiota ecology. (2) Methods: We performed a clinical study in the Odontology department of Toulouse hospital in France, to sequence the 16S rRNA gene of AP microbiota and collect clinical parameters from 94 patients. Forty-four patients were characterized with a PAI (periapical index of AP severity) score lower or equal to 3, while the others had superior scores (n = 50). (3) Results: The low diversity of granuloma microbiota is associated with the highest severity (PAI = 5) of periapical lesions (Odds Ratio 4.592, IC 95% [1.6329; 14.0728]; p = 0.001; notably, a lower relative abundance of Burkholderiaceae and a higher relative abundance of Pseudomonas and Prevotella). We also identified that high blood pressure (HBP) is associated with the increase in PAI scores. (4) Conclusions: Our data show that a low diversity of bacterial ecology of the AP is associated with severe PAI scores, suggesting a causal mechanism. Furthermore, a second risk factor was blood pressure associated with the severity of apical periodontitis.

Effect of Sodium Hypochlorite Concentration on Electronic Apex Locator Reliability.

This ex vivo study aimed to measure the performance of an electronic apex locator (EAL) in the presence of sodium hypochlorite irrigants with different concentrations. Two EALs (Root ZX Mini and Locapex 6) were used to locate the apical foramen in 10 extracted single-rooted teeth in the presence of 0.5%, 2.5% and 5% sodium hypochlorite. Visual working lengths were also determined using #10 K-file under a microscope before the electronic measurements were made. The performance of both EALs was compared for the electronic working lengths determined under the different concentrations of sodium hypochlorite. A multiple-way ANOVA and PLSD Fisher's test with an α risk fixed at 5% were conducted. There were no statistical differences in the working lengths determined by both EALs between the three groups with different concentrations of sodium hypochlorite and their visual control measurements. When a ± 0.5 mm margin was applied, the Root ZX Mini and the Locapex 6 presented 88% and 83% accuracy, respectively. Sodium hypochlorite concentration in irrigants does not affect the accuracy and reliability of either the Root ZX Mini or the Locapex 6. Electronic apex locators are reliable with any concentration of sodium hypochlorite irrigants.

The XP-Endo Finisher for the removal of calcium hydroxide paste from root canals and from the apical third.

BACKGROUND: The aim was to compare the efficacy of the passive ultrasonic irrigation PUI and the Xp-endo Finisher (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland) in removing the calcium hydroxide paste from root canals and from the apical third. MATERIAL AND METHODS: Sixty-eight root canals of single-rooted teeth were shaped using the BT-Race files (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland). Ca(OH)2 was placed in all samples except for the negative control group (n=4). Remaining teeth were randomly divided into three groups: G1-Xp (n=30), G2-PUI (n=30) and the positive control group (n=4). Removal procedure consisted of three repeated one-minute-cycles. Samples were split longitudinally, photos of halves were taken at X6.4 magnification and were analyzed using the ImageJ-Software (The National Institutes of Health NIH, Bethesda, Maryland, USA) to calculate the percentage of surfaces with residual Ca(OH)2; the results were compared using the Wilcoxon-Mann Whitney test. Photos of the apical thirds were taken at X16 and X40 magnifications and were scored by two examiners from (0) to (4). Scores of the apical third were compared using the Fisher test. RESULTS: The Xp-endo Finisher removed completely the Ca(OH)2 dressing from four teeth (13.33%) whereas the PUI in one tooth (3.33%). The mean values of the remaining Ca(OH)2 were (2.1%, 3.6%) respectively and the difference was not significant (p= 0.195). Both examiners found the Xp-endo Finisher more efficient in the apical third and the difference was significant; p= (0.025, 0.047) respectively. CONCLUSIONS: The Xp-endo Finisher showed a superiority over the PUI in removing the Ca(OH)2 from the apical third after 3 minutes of activation. Key words:Calcium hydroxide removal, Passive ultrasonic irrigation, Xp-endo Finisher.

Interrelationships in the Variability of Root Canal Anatomy among the Permanent Teeth: A Full-Mouth Approach by Cone-Beam CT.

OBJECTIVES: In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The aim of this study was to assess using CBCT acquisitions regarding whether one root canal anatomy of a tooth is associated with a specific anatomy of another tooth. METHODS: A total of 106 CBCT acquisitions were obtained using a CBCT scanner with 200µm voxel size. Numbers of roots and canals of the entire dentition were described. Bivariate analyses and logistic regressions were conducted to explore root canal anatomy on one tooth according to age, gender, jaw, side and the others teeth. Multiple correspondence analysis (MCA) was performed to correlate the different numbers of canals profiles. RESULTS: A total of 2424 teeth were analyzed. Independently from the other variables, the presence of an additional root canal on a mandibular incisor increases the risk of having an additional root canal on a mandibular premolar (OR [95%] 3.7 [1.0;13.2]). The mandibular molar variability increases in women compared to men (OR [95%] 0.4 [0.1; 0.9]). MCA showed correspondence between 2-canals maxillary incisor and canines and 5-canals maxillary molars, and some correlation between additional canal on maxillary and mandibular premolars. CONCLUSIONS: Although CBCT examinations are conducted in the first intention of making a diagnosis or prognostic evaluation, medium FOV acquisitions could be used as an initial database thus furnishing preliminary evaluations and information. In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The visualization of all canals is considered essential in endodontic therapy. The use of multi-correspondence analysis for statistics in endodontic research is a new approach as a prognostic tool.

Prevalence of Apical Bone Defects and Evaluation of Associated Factors Detected with Cone-beam Computed Tomographic Images.

INTRODUCTION: Cone-beam computed tomographic (CBCT) imaging has been shown to be accurate for detecting apical bone defects (ABDs). Medium field of view CBCT imaging may provide apical images of the whole oral cavity at a resolution that is sufficient to allow ABDs to be located and measured. The aim of the work presented was to calculate the prevalence of ABDs from CBCT images as well as to assess some associated factors and their measurement. METHODS: One hundred CBCT data sets with a voxel size of 0.2 mm were analyzed by 2 evaluators according to a standardized reading protocol. The number of maxillary and mandibular teeth, the presence of endodontic treatment, and the presence of ABDs associated with endodontic treatment were identified, and the presence of intraradicular posts was documented. The size of ABDs detected was measured, and they were classified according to the Cone Beam Computed Tomography Periapical Index. RESULTS: A total of 2368 teeth and 100 subjects were analyzed. The prevalence of ABDs in subjects was 78%; in 8.6% of the sample teeth, ABDs were present, and 38.2% of endodontically treated maxillary molars were affected by it. Endodontic treatment was significantly associated with an increased risk for the presence of an ABD (P = .0001); 40.8% of endodontically treated teeth were associated with an ABD. This rate increased to 85.9% in endodontically treated maxillary molars. Placement of a post was significantly associated with the presence of an ABD (P = .003). The most frequent lesions were those with diameters between 2 and 4 mm (39.2%). CONCLUSIONS: There are only few studies on the prevalence of ABDs using CBCT analysis. This study in a French population shows a high prevalence of ABDs, especially on endodontically treated molars. The most effective way to exhaustively detect such defects is with CBCT imaging. Moreover, CBCT images show details of the extent of bone loss, thus providing information valuable for the therapeutic decision and details that could help with the prognosis.

Effect of fixed orthodontic appliances on salivary microbial parameters at 6 months: a controlled observational study.

OBJECTIVE: The aim of this study was to assess the microbial changes in children with fixed orthodontic appliances compared with a control group of children without orthodontic treatment. MATERIAL AND METHODS: Ninety-five children, aged between 12 and 16 years, participated in this study. Forty-eight subjects were fitted with fixed orthodontic appliances and forty-seven were free of any such appliances. The follow-up was 6 months for all children. The association between orthodontic appliances and high levels of Streptococcus mutans and Lactobacillus spp was assessed with logistic regression models, taking age, sex, pH and buffer capacity into account. RESULTS: Differences at baseline between the two groups were not statistically significant. We found that wearing a fixed orthodontic appliance was associated with high levels of Streptococcus mutans and Lactobacillus spp (adjusted OR: 6.65, 95% CI [1.98-22.37]; 9.49, 95% CI [2.57-35.07], respectively), independently of other variables. CONCLUSION: The originality of the present epidemiological study was to evaluate the evolution of salivary microbial parameters in a population of children with fixed orthodontic appliances. Our results show an increase of Streptococcus mutans and Lactobacillus spp values during the follow-up. The whole dental workforce should be aware that preventive measures are of paramount importance during orthodontic treatment.

Surgical and nonsurgical endodontic treatment-induced stress.

This observational study compared physiologic and psychological indicators of stress between two groups of 30 healthy patients undergoing either surgical or nonsurgical endodontic treatments. Heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure were monitored during care sessions. The patients were asked to score their anxiety before treatment and to report pain, stress, and/or discomfort experienced during care. Variations in HR and SBP were significantly dependent on treatment group (HR: F = 6, p < 0.001; SBP: F = 4, p = 0.05). Intergroup differences increased during the active steps of the treatment, such as local anesthesia, rotary instrumentation, periradicular curettage, root filling, and field removal. Moreover, the level of stress experienced during the care procedure was correlated to the level of anticipated anxiety in both groups. This study raises questions on the indications for anxiolysis or sedation in endodontic patients as a means of preventing the neurophysiologic consequences of stress.

Effect of fixed orthodontic appliances on salivary microbial parameters at 6 months: a controlled observational study

Objective: The aim of this study was to assess the microbial changes in children with fixed orthodontic appliances compared with a control group of children without orthodontic treatment. Material and Methods: Ninety-five children, aged between 12 and 16 years, participated in this study. Forty-eight subjects were fitted with fixed orthodontic appliances and forty-seven were free of any such appliances. The follow-up was 6 months for all children. The association between orthodontic appliances and high levels of Streptococcus mutans and Lactobacillus spp was assessed with logistic regression models, taking age, sex, pH and buffer capacity into account. Results: Differences at baseline between the two groups were not statistically significant. We found that wearing a fixed orthodontic appliance was associated with high levels of Streptococcus mutans and Lactobacillus spp (adjusted OR: 6.65, 95% CI [1.98-22.37]; 9.49, 95% CI [2.57-35.07], respectively), independently of other variables. Conclusion: The originality of the present epidemiological study was to evaluate the evolution of salivary microbial parameters in a population of children with fixed orthodontic appliances. Our results show an increase of Streptococcus mutans and Lactobacillus spp values during the follow-up. The whole dental workforce should be aware that preventive measures are of paramount importance during orthodontic treatment. .