Effect of reapplication on pull-out bond strength of fibre post to root dentin: An in vitro study.

Purpose: Post removal may be necessary for many reasons and is inevitable after the re-application of a dental post. The present study investigated the bond strength between root dentin and a re-applied fibre-reinforced composite (FRC) post by a pull-out test. Materials and methods: After root canal treatments of 30 extracted human maxillary canine teeth, post spaces were prepared (10 mm), and FRC posts (Hi-Rem Post; Overfibres, Imola, Italy) were luted with self-adhesive resin cement. The samples were than randomly divided into test and control groups (n = 15 in each). The FRC posts were removed in the test group, and new posts were cemented. The pull-out test (1 mm/minute speed) was used to measure the bond strength. Failure types were determined using a stereomicroscope. Mann-Whitney U, chi-square and Fisher-Freeman-Halton exact tests were used for statistical analysis. Results: The bond strength values of the test (119.5 ± 36.86 N) and control (115.55 ± 55.44 N) groups did not differ significantly (p >.05). In terms of the percentage of failure types, there was a significant difference only in the test group between the mixed failure type and the other failure types (p <.05). Conclusions: The re-application of FRC post did not seem to affect the bond strength. The distribution of failure types was similar between the control and test groups.

TNF-α, IL-1B and IL-6 affect the differentiation ability of dental pulp stem cells.

BACKGROUND: This in vitro study examined the effect of the inflammatory cytokines (tumour necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6) on osteogenic, chondrogenic, and adipogenic differentiation of dental pulp stem cells (DPSCs) which have significant relevance in future regenerative therapies. METHODS: DPSCs were isolated from the impacted third molar dental pulp and determined with flow cytometry analysis. DPSCs were divided into into 5 main groups with 3 subdivisions for each group making a total of 15 groups. Experimental groups were stimulated with TNF-α, IL-1ß, IL-6, and a combination of all three to undergo osteogenic, chondrogenic, and adipogenic differentiation protocols. Next, the differentiation of each group was examined with different staining procedures under a light microscope. Histological analysis of osteogenic, chondrogenic, and adipogenic differentiated pellets was assessed using a modified Bern score. Statistical significance determined using one-way analysis of variance, and correlations were assessed using Pearson's test (two-tailed). RESULTS: Stimulation with inflammatory cytokines significantly inhibited the osteogenic, chondrogenic and adipogenic differentiation of DPSCs in terms of matrix and cell formation resulting in weak staining than the unstimulated groups with inflammatory cytokines. On contrary, the unstimulated groups of MSCs have shown to be highly proliferative ability in terms of osteogenic, chondrogenic, and adipogenic differentiation. CONCLUSIONS: DPSCs have high osteogenic, chondrogenic, and adipogenic differentiation capabilities. Pretreatment with inflammatory cytokines decreases the differentiation ability in vitro, thus inhibiting tissue formation.

Evaluation of the relation between the pulp stones and direct restorations using cone beam computed tomography in a Turkish subpopulation.

OBJECTIVES: This study aimed to assess the presence of pulp stones through an examination of cone beam computed tomography images and correlate their prevalence with age, sex, dental arch and side, tooth type, and restoration type and depth. MATERIALS AND METHODS: Cone beam computed tomography images obtained from 673 patients and archival data on 11,494 teeth were evaluated. The associations of pulp stones with age, sex, dental arch and side, tooth type, and restoration type and depth were noted. All the measurements were subjected to a χ2 test and one sample χ2 test (p < 0.05). RESULTS: In the study group, 163 (24.2%) patients and 379 (3.3%) teeth had at least one pulp stone. The pulp stone frequency in those aged 30-39 years was significantly greater than in those aged 18-29 and ≥ 60 years, and the frequency was higher in females than in males (p < 0.05). The highest prevalence of pulp stones was found in maxillary dental arches and molar teeth (p < 0.05). Pulp stones were significantly more common in medium-depth restorations (p < 0.05). CONCLUSIONS: Maxillary molar teeth, medium-depth restorations, individuals aged 30-39 years and females had a greater percentage of pulp stones.

Evaluation of C-shaped canals in mandibular second molars of a selected patient group using cone beam computed tomography: prevalence, configuration and radicular groove types.

The aim of the present study was to examine the prevalence, symmetry and configurations of C-shaped canals and radicular groove types in mandibular second molars according to age and sex in a Turkish sub-population using cone beam computed tomography (CBCT). In total, 674 CBCT images (368 females and 306 males, aged 18-76 years) of 1348 mandibular second molars were evaluated. The symmetry, configuration of C-shaped root canals, radicular groove types with age and sex were noted. One sample chi-square test and chi-square test were used to determine statistically significant differences. The statistical significance level was set at p < 0.05. Of the 1348 mandibular second molars evaluated, 10.7% had C-shaped root canals. C-shaped root canals appeared to be significantly more common in females than in males (p < 0.05). C1 (44.4%) was the most frequent configuration in the coronal third, and C2 (44.4%), and C4 (31.9%) were the most frequent configurations in middle and apical thirds, respectively. Type 2 (45.1%) was the most common radicular groove type (p < 0.05). The frequency of C-shaped root canals in mandibular second molars in a Turkish sub-population was considerably high (10.7%). CBCT can aid the detection of C-shaped canals and their configurations. Dentists should consider the possibility of C-shaped canals in root canal treatment of mandibular second molars, as these configurations have implications for biomechanical preparation and filling methods.

Effect of a 980-nm diode laser on post-operative pain after endodontic treatment in teeth with apical periodontitis: a randomized clinical trial.

BACKGROUND: This study aimed to assess the effect of a 980-nm diode laser following chemomechanical root canal preparation on the severity of post-operative pain (PP) after root canal treatment (RCT). METHODS: This study included asymptomatic, single-rooted teeth with a periapical index (PAI) score of 3 or 4. All the patients received RCT, including dressing with calcium hydroxide (Ca(OH)2), during two visits. The patients were randomly divided into two groups (n:30): a control group, in which the final irrigation was performed using 5 ml of 2.5% sodium hypochlorite (NaOCI), followed by 5 ml of 17% and ethylenediaminetetraacetic acid (EDTA) and 5 ml of distilled water, and a laser group, in which the root canals were irradiated using a 980-nm diode laser after the final irrigation at both visits. The pain levels after both visits were evaluated using a visual analogue scale (VAS) after 8 h, 24 h, 48 h and 7 d. In addition, the time intervals to medication intake were recorded. The collected data were statistically analysed using the chi-square and Mann-Whitney U test (p < 0.05). RESULTS: The average pain level in the control group 24 h after the first visit was significantly higher than that in the laser group (p < 0.05). The average pain level 24 h and 48 h after the second visit was significantly higher in the control group (p < 0.05). The levels of PP 24 h after the first visit were higher than those after the second visit only in the control group (p < 0.05). After the first visit, analgesic use in the control group was significantly higher after 8 h (40%) and 24 h (23%) as compared with that in the laser group (p < 0.05). CONCLUSIONS: Root canal irradiation with a diode laser may reduce PP after RCT in single-rooted teeth with a PAI score of 3 or 4. TRIAL REGISTRATION: Effect of the Diode Laser on Post-operative Pain After Endodontic Treatment in Teeth with Apical Periodontitis: NCT04486196. Registered 24 July 2020-Retrospectively registered, http://clinicaltrials.gov/ct2/show/NCT04486196.

Apical periodontitis in relation to radiographic quality of endodontic treatment in a selected adult Turkish population: a cross-sectional study / Periodontite apical em relação à qualidade radiográfica do tratamento endodôntico em uma amostra da população adulta turca: um estudo transversal

Objective: The aim of this study was to examine the quality of root canal fillings and their relationship with apical periodontitis (AP) in a selected Turkish population. Material and Methods: The cases in this study was formed of patients attending routine dental treatment at the Faculty of Dentistry, University of Birun. 1024 patients were examined with panoramic radiographs and 1780 endodontically treated teeth with present periapical radiographs. Endodontic treatment quality was evaluated by obturation length, density, taper quality and iatrogenic errors. Presence of AP was analysed according to Ørstavik's periapical index (PAI). The chi-square test was used for statistical analyses. Results: Statistically significant relationship was found between both the tooth type and location with obturation quality (p: 0.000; p < 0.05). Obturation quality of maxillary and mandibular molars are significantly less than the other tooth types in the same location. Apical periodontitis were noticed in 740 teeth (41.6%). Inadequate obturation quality was found to be significantly effective on the periapical status of tooth types both in maxilla and mandible (p < 0.05). Conclusion: The frequency of inadequate root canal obturations of endodontically treated teeth of the selected Turkish population was high, especially in molar teeth and women. Even though radiographic obturation quality is not the only success criteria in endodontic treatment, it is still one of the most important criteria regarding the positive correlation of "inadequate" obturations with AP(AU)

Objetivo: O objetivo deste estudo foi examinar a qualidade dos preenchimentos do canal radicular e sua relação com a periodontite apical (PA) em uma amostra da população turca. Material e Métodos: Os casos deste estudo foram formados por pacientes em tratamento odontológico de rotina na Faculdade de Odontologia da Universidade de Birun. Mil e vinte e quatro pacientes foram examinados com radiografias panorâmicas e 1780 dentes tratados endodonticamente com radiografias periapicais presentes. A qualidade do tratamento endodôntico foi avaliada pelo comprimento da obturação, densidade, qualidade do cone e erros iatrogênicos. A presença de PA foi analisada de acordo com o índice periapical de Ørstavik (IPA). O teste do qui-quadrado foi utilizado para análises estatísticas. Resultados: Foi encontrada relação estatisticamente significante entre o tipo e a localização do dente com a qualidade da obturação (p: 0,000; p < 0,05). A qualidade da obturação dos molares superiores e inferiores é significativamente menor que os outros tipos de dentes no mesmo local. Periodontite apical foi observada em 740 dentes (41,6%). A qualidade inadequada da obturação mostrou ser significativamente eficaz no estado periapical dos tipos de dentes, tanto na maxila quanto na mandíbula (p < 0,05). Conclusão: A frequência de obturação inadequada do canal radicular de dentes tratados endodonticamente na população turca selecionada foi alta, principalmente em dentes molares e mulheres. Embora a qualidade da obturação radiográfica não seja o único critério de sucesso no tratamento endodôntico, ainda é um dos critérios mais importantes em relação à correlação positiva das obturações "inadequadas" com a PA.(AU)