Postoperative pain of minimally invasive root canal treatment:a randomized clinical trial.

This randomized clinical trial compared postoperative pain between a minimally invasive (MP) and conventional root canal treatment protocol (CP). A total of 170 mature permanent teeth (either with vital or necrotic pulp), were randomly assigned into two groups. In the CP group, ProTaper Gold (Dentsply Sirona, Ballaigues, Switzerland) and a continuous wave of condensation technique were used, whereas, in the MP group, TruNatomy (Dentsply Sirona), ultrasonic-assisted irrigation (UI), calcium hydroxide, and a sealer-based obturation technique were used. Patients recorded preoperative and postoperative pain using a 0-10 numerical rating scale (NRS) at 4 h, 1, 2, 3, 4, 5, 6, and 7 days after instrumentation and 1 day after canal obturation, respectively. There were no significant differences in pain intensity at any time points assessed between the two groups (p > 0.05). The occurrence of moderate/intense pain after instrumentation was significantly associated with preoperative periapical index (PAI) (p = 0.017) and NRS scores (p < 0.001). Preoperative pulp status (p = 0.009) and NRS score (p = 0.006) were identified as significant factors in the occurrence of moderate/intense pain after obturation. Instrumentation unequivocally reduced pain severity for both groups. The post-endodontic pain associated with the use of MP, combined with UI, Ca(OH)2, and calcium-silicate cement, did not differ from that of CP. Preoperative pain score, PAI, and preoperative pulp status were determined to be prognostic factors for postoperative pain.

Biological Function and Potential Applications of Garcinol in Human Dental Pulp Stem Cells.

INTRODUCTION: The regeneration of pulp tissue is crucial for true regenerative endodontic treatment, which requires a reduction in osteogenic differentiation. Garcinol, a histone acetyltransferase inhibitor, is a natural regulator that is known to suppress the osteogenic differentiation of dental pulp stem cells. In this study, the inhibitory effect of garcinol on the osteogenic differentiation of human dental pulp stem cells (hDPSCs) was evaluated using three-dimensional culture under in vitro and in vivo conditions. METHODS: hDPSCs were obtained from caries-free third molars and cultured with 10 µM garcinol for 7 days in an ultra-low attachment plate. The cell stemness and expression of osteogenic differentiation-related genes were analyzed using reverse transcription-polymerase chain reaction and single-cell analysis. A transplantation experiment was performed in mice to investigate whether garcinol-treated hDPSCs showed restrained osteogenic differentiation. RESULTS: hDPSCs cultured in the U-shaped ultra-low attachment plate showed the highest expression of stemness-related genes. Garcinol-treated hDPSCs demonstrated downregulation of osteogenic differentiation, with lower expression of bone sialoprotein, which is related to bone formation, and higher expression of dentin sialophosphoprotein, which is related to dentin formation. However, the garcinol-treated hDPSCs did not show any alterations in their stemness. Consistent results were observed in the transplantation experiment in mice. CONCLUSIONS: Garcinol reduced the osteogenic differentiation of hDPSCs, which can contribute to true regenerative endodontic treatment.

Three-dimensional accuracy of endodontic access preparations using novel nonrestrictive static guides: A laboratory study.

This study compared the accuracy of traditional endodontic access to conservative access cavities prepared with or without novel nonrestrictive endodontic access guides by operators with different levels of clinical experience without visual aids, using a three-dimensional volumetric accuracy analysis method. The accuracy of the preparations was analysed using a novel 3D volumetric analysis by calculating the intersection and volume of the actual cavities to the planned model cavities. The experienced operator significantly outperformed the inexperienced operator in the free hand groups, while accuracy of conservative access cavities prepared using the novel guides were comparable and significantly higher than the other groups (p < 0.05). The results demonstrated clinical experience enhanced endodontic preparations accuracy and that nonrestrictive guides achieve accurate conservative access cavities which are independent of the operator skill level. Additionally, the three-dimensional volumetric analysis is a consistent and objective method to judge the accuracy of guided endodontic techniques.

Effect of thickness on the translucency of resin-based composites and glass-ceramics.

This study was aimed to evaluate the effect of thickness (1, 2, 3, and 4 mm) on the translucency of resin-based composites (RBCs) and glass-ceramics, and compare the influence of the thickness of those materials on the translucency parameter (TP) value. The materials were divided into two groups, eight RBCs in Group 1 and five glass-ceramics in Group 2 and TP, ΔL*, Δa*, and Δb* were compared. Statistically significant differences were present in the 2, 3, and 4 mm in the TP, in the 2 and 4 mm in ΔL*, and in all thicknesses in Δa* and Δb* betweent the two groups. The TP of RBCs and glass-ceramics decreased as thickness increased, especially from 1 mm to 2 mm. The TP values of the RBCs were more significantly decreased as the thickness of the material increased from 2 mm to 4 mm than those of the glass-ceramics.

Deep learning for early dental caries detection in bitewing radiographs.

The early detection of initial dental caries enables preventive treatment, and bitewing radiography is a good diagnostic tool for posterior initial caries. In medical imaging, the utilization of deep learning with convolutional neural networks (CNNs) to process various types of images has been actively researched, with promising performance. In this study, we developed a CNN model using a U-shaped deep CNN (U-Net) for caries detection on bitewing radiographs and investigated whether this model can improve clinicians' performance. The research complied with relevant ethical regulations. In total, 304 bitewing radiographs were used to train the CNN model and 50 radiographs for performance evaluation. The diagnostic performance of the CNN model on the total test dataset was as follows: precision, 63.29%; recall, 65.02%; and F1-score, 64.14%, showing quite accurate performance. When three dentists detected caries using the results of the CNN model as reference data, the overall diagnostic performance of all three clinicians significantly improved, as shown by an increased sensitivity ratio (D1, 85.34%; D1', 92.15%; D2, 85.86%; D2', 93.72%; D3, 69.11%; D3', 79.06%; p < 0.05). These increases were especially significant (p < 0.05) in the initial and moderate caries subgroups. The deep learning model may help clinicians to diagnose dental caries more accurately.

A One-Year Radiographic Healing Assessment after Endodontic Microsurgery Using Cone-Beam Computed Tomographic Scans.

This study aimed to evaluate one-year radiographic healing after endodontic microsurgery using CBCT with modified PENN 3D criteria and to compare the outcome with results evaluated using Molven's criteria. A total of 107 teeth from 96 patients were evaluated one year after endodontic microsurgery by using CBCT scans with modified PENN 3D criteria and periapical radiographs with Molven's criteria. Both preoperative and postoperative lesion volumes were calculated using ITK-SNAP (free software). Radiographic healing assessment using periapical radiographs and CBCT images, and preoperative and postoperative lesion volume measurements were performed independently by two examiners. The assessment using Molven's criteria resulted in 75 complete healings, 18 incomplete healings, eight uncertain healings, and six unsatisfactory healings. Based on modified PENN 3D criteria, 64 teeth were categorized as complete healing, 29 teeth as limited healing, six teeth as uncertain healing, and eight teeth as unsatisfactory healing. With the one-year follow-up, CBCT scans showed a lower healing tendency than did periapical radiography. The volumes of apical radiolucency after the surgery were reduced by 77.7% on average at one-year follow up.

Topographic Analysis of the Isthmus in Mesiobuccal and Mesial Roots of First Molars in a South Korean Population.

The purpose of this study was to evaluate the incidence and microscopic anatomy of the isthmus to provide more precise anatomical information about the mesiobuccal (MB) roots of the maxillary first molars and the mesial (M) roots of the mandibular first molars. Twenty-eight maxillary and 31 mandibular first molars were embedded, sectioned, stained, and observed at 30× magnification to evaluate the incidence and microscopic anatomy of the isthmus. The incidence of an isthmus 3 mm from the apex was 89.3% and 100% in the MB roots of the maxillary first molars and in the M roots of the mandibular first molars, respectively. The mean dentin thickness between the isthmus and the distal root surface was <1 mm at a distance of 3 mm from the apex in both types of roots. In this study, whenever two main canals were located in the MB roots of the maxillary first molars and in the M roots of the mandibular first molars, the likelihood of the presence of an isthmus increased. Therefore, clinicians should be aware of the thinnest dimensions in the distal surface of the MB roots of the maxillary first molars and the M roots of the mandibular first molars during nonsurgical and surgical root canal treatment.

Dentists' clinical decision-making about teeth with apical periodontitis using a variable-controlled survey model in South Korea.

BACKGROUND: This study, by using a variable-controlled survey model, sought to compare clinical decisions made by dentists with different clinical backgrounds in South Korea regarding teeth with apical periodontitis and to identify factors that influenced decision-making. METHODS: A questionnaire with 36 questions about identical patient information, clinical signs, and symptoms was filled out by participants. Each question referred to a radiograph that had been manipulated using computer software in order to control tooth-related factors. Participants were instructed to record their demographic information and choose the ideal treatment option related to each radiograph. Simple and multivariable logistic regression analyses (p < .05) were used to investigate factors related to the decision to extract the tooth. We divided factors into dentist-related factors (gender, years of experience, and professional registration) and tooth-related factors (tooth position, coronal status, root canal filling status, and size of the periapical radiolucency). Dentists were categorized into three groups, based on professional registration: general dental practitioners (GDPs), endodontists, and other specialists. Simple logistic regression analysis (p < .05) was used to evaluate the tooth-related factors influencing extraction, depending on the dentists' specialty. RESULTS: Participants mostly preferred saving the teeth over extraction. This preference was highest among the endodontists, followed by other specialists and GDPs. Extractions were significantly preferred for molars, teeth with previous root canal fillings, and those with apical lesions greater than 5 mm. CONCLUSIONS: This study suggests that dentists' decision-making regarding teeth with apical periodontitis was associated with their work experience and specialty and influenced by tooth position, root canal filling status, and size of the apical lesion. CLINICAL RELEVANCE: This survey revealed that clinical decision-making related to teeth with apical periodontitis was affected by dentists' specialty and work experience and by tooth-related factors, such as tooth position, root canal filling status, and size of the apical lesion.

Qualitative analysis on crystal growth of synthetic hydroxyapatite influenced by fluoride concentration.

OBJECTIVE: This study was designed to analyze the crystal growth of synthetic hydroxyapatite (HA) particles in pH 7.0 supersaturated solutions with different fluoride concentrations by FE-SEM, FE-TEM, X-ray diffraction (XRD), and FTIR. DESIGN: Eight groups of pH 7.0 calcium phosphate supersaturated solutions were prepared with different fluoride concentrations (0, 1, 2, 4, 8, 16, 32, and 64 ppm). Each solution was introduced into the reactive column containing the synthetic HA for 48 h. The resulting products were prepared for FE-SEM, FE-TEM, XRD, and FTIR. RESULTS: The FE-SEM examination revealed various morphological changes of the crystals, with additional, less-ordered crystallites in experimental solutions containing more than 8 ppm of fluoride. FE-TEM examination showed an additional amorphous layer on the surface of the crystals with the presence of fluoride, whereas definite lattice structures completely reached the surface of the crystals without fluorides. XRD data showed that all crystals had the same patterns as the unreacted synthetic HA, regardless of fluoride concentration. With FTIR results, the intensity of the OH-libration mode decreased when adding fluoride, compared to that of pristine HA. The resulting crystals were considered to be partially fluoridated HA under room temperature and pH 7.0 supersaturated solutions. CONCLUSION: Under the experimental conditions in this study, fluorides mainly react with the surface of the seed HA and have an impact on the growth of HA in a less effective manner as the concentration of fluoride increases.

Scanning electron microscopic examination of resected root apices obtained from endodontic microsurgery.

This study was designed to examine the morphological features of the resected root apices obtained from endodontic microsurgery using a scanning electron microscope (SEM) as well as their anatomical effect on the clinical outcome of the surgical treatment. One-hundred-six resected root apices from 91 patients/surgeries were obtained by endodontic microsurgery, and fixed immediately for storage. The resected apices were prepared for SEM to examine their morphological features, such as the number and size of the apical foramina. The patients were periodically checked up at least 1 year and the clinical outcome of the microsurgery was judged as a success or failure according to the Molven's criteria. The SEM findings and the clinical outcome of apical surgery were evaluated to see any potential correlation between them. The SEM examination revealed that 60.4% of specimens had more than two portals of exit on the resected root apices and the size of the major foramen was at least 386 micrometer and 334 micrometer from maxillary and mandibular molar, respectively. With a recall rate of 72.9%, 91.9% of the surgical cases were decided to have successful outcomes. Based on this SEM study, a relatively high frequency of multiple portals of exit was existed and the sizes of major foramina were bigger than that were reported in previous reports. The clinical outcomes of endodontic microsurgery were not correlated with the anatomical features of resected apical root apices. SCANNING 38:455-461, 2016. © 2016 Wiley Periodicals, Inc.