Cementoblastoma Mimicking Pathology of Endodontic Origin: A Case Report.

Interdisciplinary care in the management of complex pathology is critical to ensure patients receive predictable, evidence-based treatment. The authors report the unique case of a healthy 38-year-old female patient who presented to a private endodontics practice with a radiopaque lesion associated with the root of tooth No. 20. The patient experienced mild and occasional palpation tenderness associated with the tooth. Extraoral examination and intraoral soft tissues presented without any abnormalities. Intraoral radiographs revealed a radiopacity overlying the apex of tooth No. 20. A cone-beam computed tomography scan of the region revealed a well-delineated bulbous radiopaque lesion attached to the lingual aspect of the apical third of the root of tooth No. 20. The lesion could not be distinguished from the root outline and presented with a radiolucent halo along its periphery. The differential diagnosis at the time consisted of cementoblastoma, condensing osteitis, hypercementosis, and periapical cemento-osseous dysplasia. The patient was referred to an oral and maxillofacial surgeon for evaluation and treatment. Tooth No. 20 was subsequently treated with an excisional biopsy and concurrent extraction of the tooth. Histologic examination of the lesion supported the diagnosis of cementoblastoma.

Biometric analysis of furcation area of molar teeth and its relationship with instrumentation.

The anatomy of furcation favours the bacterial retention and makes periodontal debridement as well as oral hygiene procedures difficult. Teeth that have lost attachment to a level of the furcation are said to have a furcal invasion or furcation involved.Involvement of furcation in a multi-rooted tooth poses a very different type of clinical situation in terms of establishment of diagnosis, determination of prognosis and of course planning the treatment modality.The present study was carried out on 200 selected extracted human first and second permanent molar teeth based on a predefined criteria. Teeth with prosthetic crowns, fused or fractured roots, those not fully developed, grossly carious or heavily restored at the cementoenamel junction (CEJ) were excluded from the study. The morphology of the root trunk was recorded by measuring various dimensions of the root trunk,including furcal angle and root trunk volume was calculated by using a custom made special apparatus. The furcation areas were debrided with different types of curettes in the market in order to see how best the instrument could be maneuvered in the furcation area. The data so obtained was statistically analysed using SPSS version 22. The highest root trunk volume and the longest root trunk length were found to be in the maxillary second molar. 48.60% furcations didn't allow instrument engagementof furcation area with standard area specific curettes. The proposal of inclusion of root trunk length (mm) is suggested in addition to classification of FI to have assess prognosis and appropriate treatment for of the involved tooth.

Two-year clinical and radiographic evaluation of ACTIVA BioACTIVE versus Compomer (Dyract® eXtra) in the restoration of class-2 cavities of primary molars: a non-inferior split-mouth randomised clinical trial.

OBJECTIVES: The trial aimed to compare the clinical performance and radiographic success of ACTIVA BioACTIVE versus Compomer in restoring class-II cavities of primary molars. MATERIALS AND METHODS: A non-inferior split-mouth design was considered. A pre-calculated sample size of 96 molars (48 per group) with class-2 cavities of twenty-one children whose ages ranged from 5 to 10 years were randomly included in the trial. Pre-operative Plaque Index (PI), DMFT/dmft scores and the time required to fill the cavity were recorded. Over 24 months, the teeth were clinically evaluated every six months and radiographically every 12 months by two calibrated and blinded evaluators using the United States public health service (USPHS)-Ryge criteria. The two-sided 95% confidence interval (CI) for the difference in success rate was considered to assess non-inferiority, and the margin was set at -18%. The linear mixed model and Firth's logistic regression model were used for data analysis (P < 0.05). RESULTS: After 24 months, 86 teeth (43 per group) were evaluated. The mean PI score was 1.1(± 0.9), while DMFT/dmft was 0.35 (± 0.74) and 6.55 (± 2.25) respectively. The clinical and radiographic success rate of Dyract vs. ACTIVA was 95.3% and 88.3% vs. 93% and 86%, respectively. The two-sided 95% CI for the difference in success rate (-2.3%) was - 3.2 to 1.3% and didn't reach the predetermined margin of -18% which had been anticipated as the non-inferiority margin. Clinically, ACTIVA had a significantly better colour match (P = 0.002) but worse marginal discolouration (P = 0.0143). There were no significant differences regarding other clinical or radiographic criteria (P > 0.05). ACTIVA took significantly less placement time than Dyract, with a mean difference of 2.37 (± 0.63) minutes (P < 0.001). CONCLUSION: The performance of ACTIVA was not inferior to Dyract and both materials had a comparable high clinical and radiographic performance in children with high-caries experience. ACTIVA had a significantly better colour match but more marginal discolouration. It took significantly less time to be placed in the oral cavity. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov on 4 May 2018 (#NCT03516838).

Efficient Production of 9,22-Dihydroxy-23,24-bisnorchol-4-ene-3-one from Phytosterols by Modifying Multiple Genes in Mycobacterium fortuitum.

C19 steroids and C22 steroids are vital intermediates for the synthesis of steroid drugs. Compared with C19 steroids, C22 steroids are more suitable for synthesizing progesterone and adrenocortical hormones, albeit less developed. 9,22-dihydroxy-23,24-bisnorchol-4-ene-3-one(9-OHBA), due to its substituents at positions C-9 and C-22, is a beneficial and innovative steroid derivative for synthesizing corticosteroids. We focused on the C22 pathway in Mycobacterium fortuitum ATCC 35855, aiming to develop a productive strain that produces 9-OHBA. We used a mutant strain, MFΔkstD, that knocked out kstds from Mycobacterium fortuitum ATCC 35855 named MFKD in this study as the original strain. Hsd4A and FadA5 are key enzymes in controlling the C19 metabolic pathway of steroids in Mycobacterium fortuitum ATCC 35855. After knocking out hsd4A, MFKDΔhsd4A accumulated 81.47% 9-OHBA compared with 4.13% 9-OHBA in the strain MFKD. The double mutant MFKDΔhsd4AΔfadA5 further improved the selectivity of 9-OHBA to 95.13%, and 9α-hydroxy-4-androstenedione (9-OHAD) decreased to 0.90% from 4.19%. In the end, we obtained 6.81 g/L 9-OHBA from 10 g/L phytosterols with a molar yield of 80.33%, which showed the best performance compared with formerly reported strains.

Trueness evaluation of three intraoral scanners for the recording of maximal intercuspal position.

OBJECTIVES: This clinical study aimed to assess the trueness of three intraoral scanners for the recor-ding of the maximal intercuspal position (MIP) to provide a reference for clinical practice. METHODS: Ten participants with good occlusal relationship and healthy temporomandibular joint were recruited. For the control group, facebow transferring procedures were performed, and bite registrations at the MIP were used to transfer maxillary and mandibular casts to a mechanical articulator, which were then scanned with a laboratory scanner to obtain digital cast data. For the experimental groups, three intraoral scanners (Trios 3, Carestream 3600, and Aoralscan 3) were used to obtain digital casts of the participants at the MIP following the scanning workflows endorsed by the corresponding manufacturers. Subsequently, measurement points were marked on the control group's digital casts at the central incisors, canines, and first molars, and corresponding distances between these points on the maxillary and mandibular casts were measured to calculate the sum of measured distances (DA). Distances between measurement points in the incisor (DI), canine (DC), and first molar (DM) regions were also calculated. The control group's maxillary and mandibular digital casts with the added measurement points were aligned with the experimental group's casts, and DA, DI, DC, and DM values of the aligned control casts were determined. Statistical analysis was performed on DA, DI, DC, and DM obtained from both the control and experimental groups to evaluate the trueness of the three intraoral scanners for the recording of MIP. RESULTS: In the control group, DA, DI, DC, and DM values were (39.58±6.40), (13.64±3.58), (14.91±2.85), and (11.03±1.56) mm. The Trios 3 group had values of (38.99±6.60), (13.42±3.66), (14.55±2.87), and (11.03±1.69) mm. The Carestream 3600 group showed values of (38.57±6.36), (13.56±3.68), (14.45±2.85), and (10.55±1.41) mm, while the Aoralscan 3 group had values of (38.16±5.69), (13.03±3.54), (14.23±2.59), and (10.90±1.54) mm. Analysis of variance revealed no statistically significant differences between the experimental and control groups for overall deviation DA (P=0.96), as well as local deviations DI (P=0.98), DC (P=0.96), and DM (P=0.89). CONCLUSIONS: With standardized scanning protocols, the three intraoral scanners demonstrated comparable trueness to traditional methods in recording MIP, fulfilling clinical requirements.

A retrospective study on iRoot BP Plus full pulpotomy for primary molars with partial irreversible pulpitis.

OBJECTIVES: This study aimed to observe the outcomes of iRoot BP Plus full pulpotomy in primary molars with partial irreversible pulpitis retrospectively. METHODS: Collect 102 cases of primary molars with partial irreversible pulpitis undergoing iRoot BP Plus full pulpotomy from January 2019 to August 2023, with a follow-up period of 24-47 months. Based on the presence of irreversible pulpitis symptoms before surgery, the included cases will be divided into asymptomatic group (n=53) and symptomatic group (n=49). Observe the clinical and imaging success rates of both groups. RESULTS: Clinical success rates were 96.2% and 97.9% in asymptomatic and symptomatic groups, and radiographic success rates were 96.2% and 93.9% respectively. CONCLUSIONS: iRoot BP Plus full pulpotomy can be used for the treatment of primary molars with partial irreversible pulpitis under an enhanced pulpotomy protocol.

Site selection of micro-implant anchorages in the infrazygomatic crest in adult orthodontic patients.

OBJECTIVES: To determine the optimal placement of miniscrews, this study compared adult male and female patients in terms of cortical bone density, cortical bone thickness, and available bone width in the infrazygomatic crest region. METHODS: The cone beam computed tomography imaging data of 200 patients (20-30 years old; 100 males and 100 females) were collected. The right maxillary posterior teeth in the sagittal plane were divided into six levels from proximal to distal, and three measurement sites were positioned at vertical distances of 8, 10, and 12 mm from the cementum. Cortical bone density, cortical bone thickness, and available bone width were measured in 18 measurement sites in the infrazygomatic crest and analyzed statistically. RESULTS: The highest cortical bone density, cortical bone thickness, and available bone width in the infrazygomatic crest in adult male and female patients were at the level of the interradicular space between the maxillary second premolar and maxillary first molar. The bone cortical density and thickness increased with vertical height, whereas the available bone width decreased with increasing vertical height. Differences were observed in cortical bone density, cortical bone thickness, and available bone width between adult male and female patients. CONCLUSIONS: The optimal implantation sites of the micro-implant anchorages in the infrazygomatic crest were at the level of the interradicular space between the maxillary second premolar and the maxillary first molar, and the vertical height of the optimal implantation site in males was appropriately higher than that in females.

Fully automated deep learning approach to dental development assessment in panoramic radiographs.

BACKGROUND: Dental development assessment is an important factor in dental age estimation and dental maturity evaluation. This study aimed to develop and evaluate the performance of an automated dental development staging system based on Demirjian's method using deep learning. METHODS: The study included 5133 anonymous panoramic radiographs obtained from the Department of Pediatric Dentistry database at Seoul National University Dental Hospital between 2020 and 2021. The proposed methodology involves a three-step procedure for dental staging: detection, segmentation, and classification. The panoramic data were randomly divided into training and validating sets (8:2), and YOLOv5, U-Net, and EfficientNet were trained and employed for each stage. The models' performance, along with the Grad-CAM analysis of EfficientNet, was evaluated. RESULTS: The mean average precision (mAP) was 0.995 for detection, and the segmentation achieved an accuracy of 0.978. The classification performance showed F1 scores of 69.23, 80.67, 84.97, and 90.81 for the Incisor, Canine, Premolar, and Molar models, respectively. In the Grad-CAM analysis, the classification model focused on the apical portion of the developing tooth, a crucial feature for staging according to Demirjian's method. CONCLUSIONS: These results indicate that the proposed deep learning approach for automated dental staging can serve as a supportive tool for dentists, facilitating rapid and objective dental age estimation and dental maturity evaluation.

[Evaluation of the effect of MTF-S on the removal of impacted mandibular wisdom teeth with complete or partial crown impaction].

PURPOSE: To evaluation the effect of modified triangular flap-secondary healing (MTF-S) on the treatment of mandibular impacted wisdom teeth with full or partial bone impaction. METHODS: A total of 207 patients with mandibular impacted wisdom teeth were selected in Shaoxing Stomatological Hospital from June 2022 to June 2023. Among them, 86 patients had completely impacted wisdom teeth (group A), and 121 patients had partially impacted wisdom teeth (group B). All patients had bilateral impacted wisdom teeth. One of the wisdom teeth was removed first and was sutured with triangular flap-primary healing (TF-P). The other wisdom tooth was removed two weeks later and was sutured with MTF-S. Patients in groups A and B were divided into two subgroups based on suture methods, with TF-P used for group A1 and B1, and MTF-S used for groups A2 and B2. Perioperative indicators, including surgical time, root loss rate, and completeness of extraction sockets were recorded; Postoperative complications of four groups, including pain, swelling, and limited mouth opening were compared. SPSS 22.0 software package was used for statistical analysis. RESULTS: The surgical time of group A1, A2, B1 and B2 was (17.69±3.28), (18.22±3.06), (12.37±3.72) and (12.64±4.13) minutes, respectively. The surgical time of group A1 and A2 was significantly longer than that of group B1 and B2 (P＜0.05). Seven days after surgery, the VAS scores of group A1, A2, B1 and B2 were (1.17±0.34), (0.93±0.29), (0.48±0.15) and (0.76±0.21), respectively. The VAS scores of group B1 and B2 were lower than those of group A1 and A2, and group A2 was lower than group A1 and B2 was higher than group B1 group(P＜0.05). On the 1st day, 3rd day, and 7th day after surgery, the swelling degree in group A1 was greater than that in group B1, and the swelling degree in group B1 was greater than that in group A2 and B2(P＜0.05); while the limitation of mouth opening mouth in group A2 and B2 was lower than that in group A1 and B1, and the limitation of opening mouth in group B2 was lower than that in group A2(P＜0.05). CONCLUSIONS: Compared with partially impacted wisdom teeth, the extraction of completely impacted wisdom teeth has a longer surgical time. For completely impacted wisdom teeth, MTF-S is beneficial for reducing postoperative pain, swelling and mouth opening limitations. For partially impacted wisdom teeth, MTF-S is beneficial for reducing postoperative swelling and mouth opening limitations, but the effect is not significant in reducing patient pain.

Comparative evaluation of clinical success of Stainless Steel and Bioflx crowns in primary molar - A 12 month split mouth prospective randomized clinical trial.

PURPOSE: The purpose of this clinical trial was to assess and compare the clinical outcomes of Bioflx crowns (BFCs) with stainless steel crowns (SSCs) in primary molars (PMs). MATERIALS AND METHODS: This prospective split-mouth randomized controlled clinical trial was conducted between March 2022 and June 2023. Thirty-eight patients (17 females and 21 males) with a mean age of 5.21 years participated in this study. Each child (n = 38) received both SSC and BFC. Clinical and radiographic follow-up was performed at baseline, 3, 6, and 12 months using the modified United States Public Health System scoring criteria to evaluate various parameters. RESULTS: At the 3 and 6 months' follow-up, no significant difference was observed between the two groups. However, at 1-year follow-up, a statistically significant difference (P < 0.05) was evident in the frequency between the two groups for the criteria of crown retention after cementation and anatomic form of the crown, indicating a preference for SSC over prototype 1 BFC. CONCLUSION: The 12-month results indicate that BFC performed similarly to the established SSC for the restoration of PMs providing better esthetics.

Influence of Different Glide Path Techniques on Microcrack Formation after Two Different Root Canal Preparation Treatments: Micro Computed Tomography Analysis.

OBJECTIVE: This study aimed to evaluate the effect of WaveOne Glider (WOGG) with Waveone Gold (WOG) primary reciprocation systems on root dentine microcrack formation and to know the effect of TruNatomy Glider (TRNG) with TruNatomy (TRN) prime rotary systems on root dentine microcrack formation. METHODS: In this study, 40 extracted mandibular first molar roots were selected and divided randomly into four groups (n=10). Group MWOG: a manual glide path was performed + WOG primary. Group MTRN: manual glide path performed+TRN prime. Additionally, group WOGG: glide path preparation with WOGG+WOG primary. Finally, for group TRNG, the glide path preparation was performed with TRNG+TRN prime. Micro-CT was used for pre and post-instrumentation image analysis. Statistical analysis was performed using the Kruskal- Wallis test (p<0.05) with Two-way ANOVA. RESULTS: The Kruskal-Wallis test showed no significant differences among all groups in all thirds for pre and post-instrumentation regarding the crack formation. The Two-way ANOVA showed no significant difference or interaction between the ways of glide path preparation, whether manual or reciprocal WOGG, or between the rotary TRNG and the motion used in root canal preparation (rotary TRN or reciprocal WOG) regarding the crack formation and propagation. CONCLUSION: Microcrack formation and propagation occurred independently of using different glide path techniques (manual, rotary, or reciprocal).

Effect of low-level laser therapy in wound healing of primary molar teeth extraction.

INTRODUCTION: Tooth extraction in children requires attention to wound healing and pain management, which are influenced by patient-related factors and behavioral guidance. AIM OF THE STUDY: The study aimed to evaluate the effect of LLLT on healing sockets in pediatric patients with bilateral primary molar teeth extraction and determine its impact on pain management. METHODS: 6-10 years of age, systemically healthy, and with atraumatic extraction indications of bilateral primary molar teeth were included in the study (n = 40). In the first session, randomly selected teeth were extracted under local anesthesia. In the control group, only clot formation in the socket was observed and photographed. The other group extractions were performed 2 weeks later. The low-level laser therapy (LLLT) group was treated with a 980 nm wavelength, in a continuous emission mode, 0.5 W power, 300 J of energy, 400 µm tip, 60 s diode laser and photographed. Nonepithelialized surface measurements were performed using ImageJ. Pain assessment was performed using the Wong-Baker Pain Scale. Statistical analyses were performed using SPSS software. RESULTS: There was a statistically significant difference between the groups in the Wong-Baker values in 3rd day (p < 0.05). In soft tissue healing on the 3rd and 7th day, the nonepithelialized surface of the laser socket was smaller than that of the control group, and the measurement results were found to be statistically significant (p < 0.05). CONCLUSION: Although LLLT was not found to be very effective in reducing postoperative discomfort after extraction of primary molars, it provided better wound healing in extraction sockets.

Comparing the effectiveness of caries arrest by micro-operative treatment to operative treatment: A 2-year randomized controlled clinical trial.

OBJECTIVES: To compare the effectiveness of caries arrest by micro-operative treatment (sealing) to operative treatment (flowable resin composite restoration) through a 2-year randomized controlled clinical trial. MATERIALS AND METHODS: A prospective randomized controlled trial was conducted among 7-9-year-old children. At baseline, 630 subjects were screened and 92 children who had at least one carious lesion classified as ICDAS 3 on the pit and fissure of first permanent molar were included. Then they were randomly assigned to the sealant group (73 lesions) and the flowable resin composite group (76 lesions) to receive the corresponding intervention. Lesions status in each group was evaluated every 6 months up to 24 months. Clinical progression of dental caries and materials retention were the outcomes used for group comparisons at p-value < 0.05. RESULTS: After 24 months, three lesions (4.1%) in the sealant group clinically progressed to dentin caries. No lesion in the flowable composite group was observed a progression. The results of Life-table survival analysis show that the cumulative caries arrest rate had no statistically significant difference between the two groups (p = 0.075). However, the cumulative retention rate was 57.5% in the sealant group and 92.1% in the flowable composite group, with significant differences (p < 0.001). The multilevel mixed model showed the sealant had higher risk of retention failure than the flowable composite (OR = 8.66, p < 0.001), while tooth position did not influence material retention (p = 0.083). In addition, the results of Fisher Exact test show that dentin lesions had more retention failure than enamel lesions in the sealant group (p = 0.026). CONCLUSION: Although sealing microcavitated carious lesions of the first permanent molar achieved lower retention rate than resin composite restoration, both sealing and restoration effectively arrested caries progression for two years. CLINICAL RELEVANCE: To preserving dental structure and delaying or eliminating the need for operative procedures, microcavitated carious lesion can be arrested by sealing. TRIAL REGISTRATION: Registered at http://www.chictr.org.cn ; Feb 15th, 2020; No. ChiCTR2000029862.

Evaluation of Regenerative Efficacy of Amnion and Chorion Membrane in Treatment of Mandibular Molar Furcation Defects: A Clinico-radiographic Study.

AIM: Amnion and chorion membranes possess unique inherited biological properties that enhance wound healing and may accelerate periodontal regeneration. The present study aims to evaluate and compare the efficacy of amnion and chorion membranes in the treatment of furcation defects. MATERIALS AND METHODS: A total of 20 patients were selected and were randomly allocated to group I and group II with 10 subjects in each group. Amnion and chorion membranes are placental-derived membranes that accelerate regeneration by having natural growth factors with their antimicrobial and inflammation reduction properties. Group I was treated using bone grafting with decalcified freeze-dried bone allograft (DFDBA) and placement of amnion as a membrane for guided tissue regeneration (GTR) whereas group II was treated using bone grafting with DFDBA and placement of chorion as a membrane for GTR. The patients were followed for clinical and radiographic parameters and were evaluated between 3 and 6 months after surgery. RESULT: In intragroup comparison, a significant difference was evident in both the groups for all the clinical and radiographic parameters within the groups. (p = 0.01) This means both amnion and chorion membranes showed statistically significant regenerative efficacy. In intergroup comparison, the results show that all the clinical parameters and radiographic parameters show no significant difference between the groups. CONCLUSION: The amnion and chorion membranes had similar regenerative efficacy in combination with DFDBA in patients with buccal degree II furcation defects in mandibular molars. CLINICAL SIGNIFICANCE: The amnion and chorion membranes have shown significant improvement in clinical and radiographic parameters when used for the treatment of buccal degree II furcation defects in mandibular molars. How to cite this article: Mallapragda S, Gupta R, Gupta S, et al. Evaluation of Regenerative Efficacy of Amnion and Chorion Membrane in Treatment of Mandibular Molar Furcation Defects: A Clinico-radiographic Study. J Contemp Dent Pract 2024;25(2):160-167.

In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites.

AIM: This study aimed to evaluate the marginal microleakage and maximum occlusal fracture loads and fracture modes of two novel class II preparation designs, "infinity edge" and the "2.5 mm cusp reduction" preparations as compared to a traditional class II preparation without cuspal involvement. MATERIALS AND METHODS: Thirty extracted human mandibular molars were prepared for moderate-sized class II restorations with extensions into all occlusal grooves. Of these, ten class II preparations served as control. Ten were modified for a 2.5 mm even reduction of the cusps adjacent to the interproximal box. An additional 10 preparations were modified with an "infinity edge" bevel on the interproximal and occlusal portions. All teeth were restored utilizing a flowable bulk-fill composite in the apical portion of the interproximal box and 2-4 mm of heated bulk-fill composite in one increment for the remainder. All groups were cyclic loaded and thermocycled, then imaged with microcomputed tomography (µCT) before and after infiltration with a silver nitrate solution. Images were subtracted to obtain volumetric measurements of microleakage and reported as a percentage of the total volume from the apical extent of the proximal box. All groups were loaded to failure and fracture load and mode were recorded. RESULTS: No significant differences were found in microleakage volume as a percentage of total tooth volume; however, the "infinity edge" group had significantly greater microleakage in the proximal box compared to the traditional class II group. No significant differences were found in fracture load or mode between the groups. CONCLUSION: Traditional class II, 2.5 mm cuspal reduction, and "infinity edge" preparation designs have similar fracture loads as well as volumes of microleakage; however, an "infinity edge" preparation has a higher ratio of microleakage in the proximal box. CLINICAL SIGNIFICANCE: Clinicians should carefully consider the use of "infinity edge" margins, particularly on dentin in the apical extent of the proximal box. How to cite this article: Watson JC, Lien W, Raimondi JC, et al. In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites. J Contemp Dent Pract 2024;25(1):3-9.

Role of αENaC in root resorption of adjacent teeth due to entirely impacted mandibular third molars.

BACKGROUND: Entirely impacted mandibular third molar (EIM3M) concerns the pathological external root resorption (ERR) of the adjacent mandibular second molar (M2M) and formation of granulation tissue between two molars. The study aimed to clarify the effect of αENaC, a mechano-sensitive molecule, to explore the mechanical mechanism in this scenario. METHODS: The force EIM3M exerted on M2M was proved by finite element analysis. αENaC expressions were tested by real-time polymerase chain reaction (PCR), immunoblotting and immunofluorescence. Inflammatory and epithelial-mesenchymal transition (EMT)-related molecules expressions were also detected by real-time PCR. The correlation was analyzed by Spearman's correlation analysis, and receiver-operator characteristic (ROC) curve was further exhibited. RESULTS: The force was concentrated in the ERR area. αENaC was upregulated, positively correlated with ERR degree and localized to the fibroblasts in ERR granulation tissues. Moreover, αENaC was respectively and positively associated with elevated TNF-α and N-cadherin in ERR granulation tissues. More importantly, ROC analysis verified αENaC as a novel indication of the incidence of this disease. CONCLUSIONS: Our finding revealed the force from EIM3M causing ERR of M2M, and elucidated the expression and localization of αENaC and its positive correlation with inflammation, EMT and disease severity, suggesting a novel indication in this disease.

Micro-computed tomographic evaluation of the shaping ability of three nickel-titanium rotary systems in the middle mesial canal of mandibular first molars: an ex vivo study based on 3D printed tooth replicas.

BACKGROUND: The preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The purpose of this study was to evaluate the ex vivo shaping ability of 3 nickel-titanium (NiTi) rotary systems in the MM canal using 3D printed resin tooth replicas. METHODS: A permanent mandibular first molar with a MM canal was acquired from a pool of extracted teeth and reproduced by a 3D printer. The resin tooth replicas (n = 18) were equally assigned to 3 groups for the evaluation of the shaping abilities of 3 NiTi rotary systems (OneShape [OS], Twisted Files [TF], and ProTaper Gold [PTG]) according to the manufacturer's recommendations. The tooth replicas were scanned by micro-computed tomography (micro-CT) twice before and after instrumentation of the mesiobuccal (MB), mesiolingual (ML), and MM root canals. After 3D reconstruction, the canal straightening, change of root canal volume and surface area, the mesial and distal canal wall thickness and canal transportation at the levels of 1, 2, and 3 mm below furcation were assessed. One-way variance analysis and Turkey's post hoc test were used for comparisons of the means among different groups, and paired-t test was used to compare the mesial and distal sides of the mesial roots. RESULTS: As compared with OS and TF, the use of PTG in preparation of MM canals resulted in significantly more straightening of canal curvature (p < 0.05), greater post-instrumentation canal volume and surface area, and thinner mesial and distal remaining canal wall thickness at 1, 2 and 3 mm below furcation (all p < 0.05). Regarding the root canal transportation in the mesiodistal direction, there was no significant difference among the 3 instruments (all p > 0.05) after the preparation of the MB and ML canals. However, in the MM canal, more pronounced transportation was detected in the PTG group at 2 mm below furcation, and in the TF group at 3 mm below furcation as compared with the other 2 systems (both p < 0.05). CONCLUSIONS: 3D printed tooth replicas have the advantages of consistency and can be an ideal model to evaluate the shaping ability of different instruments in the MM canal. OS and TF files performed similarly and both are appropriate for shaping the MM canal, while PTG may cause excessive and uneven resin removal, especially near the furcation, and may lead to root fragility and procedural errors.

Clinical and electromyographic signals analysis about the effect of space-adjustment splint on overerupted maxillary molars.

BACKGROUND: Overerupted maxillary molars is common in adults, which can lead to insufficient intermaxillary vertical space ,great difficulty in prosthetic reconstruction ,and cause occlusal interference in movements.To reconstruct occlusal function, it is necessary to prepare enough space for prostheses. The aim of the present study was to evaluate the effect of space-adjustment occlusal splint on overerupted maxillary molars by clinical and electromyographic signals analysis. METHODS: Eighteen patients with overerupted maxillary molars were selected to wear space-adjustment occlusal splint suppressing overerupted maxillary molars for three months. Satisfaction was assessed by 5-point Likert; intermaxillary vertical space and the teeth transportation distance were measured in models; clinical periodontal status were evaluated by periodontal probing depth (PPT) and bleeding index (BI); electromyographic recordings of the masseter and anterior temporal muscles were monitored by Cranio-Mandibular K7 Evaluation System. RESULTS: All the patients were satisfied with the treatment effect (Likert scale ≧ 4). The intermaxillary space in edentulous areas after treatment showed statistically significant increasing when compared with those before treatment. PPT and BI showed no significant difference. No statistically significant differences were found in electromyographic activity of anterior temporal muscles, while a reduction of muscle activity in masseter in the contralateral side were detected in post-treatment evaluations compared with pre-treatment at mandibular rest position. CONCLUSIONS: Space-adjustment occlusal splint is an efficient treatment option on overerupted maxillary molars by intruding the maxillary molar to obtain adequate intermaxillary space for prostheses.

Knowledge and perception regarding molar incisor hypomineralisation among dental students and dental hygienist students in Spain: a cross-sectional study.

BACKGROUND: Molar incisor hypomineralisation (MIH) has a high prevalence in the Spanish pediatric population and is a precursor of carious lesions in teeth in which it is present. Although this pathology is included in the curricula of the Degree in Dentistry and the Training Cycle in Oral Hygiene in our country, the contents currently taught seem to be insufficient in relation to the level of knowledge that we have today about this condition. METHODS: A digital questionnaire of 18 questions was sent to a sample of 448 students attending the 4th and 5th year of the Degree in Dentistry and 2nd year of the Training Cycle in Oral Hygiene from different universities and vocational training centers in the Valencian Community. Descriptive and multivariate statistical analysis of the data was subsequently performed. RESULTS: Of the 290 questionnaires that were obtained, 53.8% were from students attending the 2nd year of a training course in oral hygiene and 46.2% were from students pursuing a degree in dentistry. Most of the respondents had heard about MIH (75.2%), mainly through master classes. However, most students had difficulties distinguishing MIH lesions from other lesions (58.3%). The degree of knowledge about MIH was greater among dental students in all the aspects evaluated: prevalence, diagnosis, prevention, and treatment. Of all the students, 83.8% were interested in increasing their training on MIH, especially in the areas of diagnosis and treatment. CONCLUSION: The results of the present study justify the need to expand the content on MIH, both theoretical and practical, in the educational curricula of the Degree in Dentistry and Integrated Vocational Training Centers in Spain.

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OBJECTIVES: Distolingual root of the permanent mandibular first molar (PMFM-DLR) has been frequently reported, which may complicate the treatment of periodontitis. This study aimed to assess the morphological features of PMFM-DLR and investigate the correlation between the morphological features of PMFM-DLR and periodontal status in patients with Eastern Chinese ethnic background. MATERIALS AND METHODS: A total of 836 cone beam computed tomography (CBCT) images with 1497 mandibular first molars were analyzed to observe the prevalence of PMFM-DLR at the patients and tooth levels in Eastern China. Among them, complete periodontal charts were available for 69 Chinese patients with 103 teeth. Correlation and regression analyses were used to evaluate the correlation between the morphological features of DLR, bone loss, and periodontal clinical parameters, including clinical attachment loss (CAL), probing pocket depth (PPD), gingival recession (GR), and furcation involvement (FI). RESULTS: The patient-level prevalence and tooth-level prevalence of DLR in mandibular first molars were 29.4% and 26.3%, respectively. Multiple linear regression analysis suggested that bone loss at the lingual site and CAL were negatively affected by the angle of separation between distolingual and mesial roots in the transverse section, while they were significantly influenced by age and the angle of separation between distobuccal and mesial roots in the coronal section. CONCLUSIONS: The prevalence of PMFM-DLR in Eastern China was relatively high in our cohort. The morphological features of DLR were correlated with the periodontal status of mandibular first molars. This study provides critical information on the morphological features of DLR for improved diagnosis and treatment options of mandibular molars with DLR.