Evaluation of the clinical application of personalized 3D printing and CAD/CAM resin crowns to replace stainless steel crowns in paediatric dentistry.

BACKGROUND: Children with dental caries are treated with stainless steel metal crowns (SSC), but the aesthetics and precision still need to be improved. Currently, both 3D-printed resin crowns (PRC) and computer-aided design/computer-aided manufacture (CAD/CAM) resin crowns (CRC) meet the clinical requirements for crown applications in terms of strength, production time, cost, and aesthetics. AIM: This study replaced SSC with customized resin crowns by 3D printing and CAD/CAM. DESIGN: In this study, PRC, CRC, and SSC were used for incisor and molar restorations, and 60 crowns were made with 10 for each group. The fabrication efficiency, surface characteristics, marginal fit, and stability of the two different crowns were evaluated. RESULTS: PRC and CRC show superior color and surface characteristics, though production times are longer (5.3-12.4 times and 3.3-9.1 times, respectively) than for SSC (p < .05). They, however, can be completed within 80 min. Edge gaps for PRC and CRC are significantly lower (13.0-19.2 times and 13.0-13.7 times) than for SSC (p < .05). All materials exhibit good stability. CONCLUSION: The 3D-PRCs and CAD/CAM resin crowns may replace SSCs as a potential choice for clinical child caries.

The usage of dental cone-beam computed tomography during the COVID-19 pandemic (from 2020 to 2022): A survey of a regional hospital in the northern Taiwan.

Background/purpose: In Taiwan, cone-beam computed tomography (CBCT) has already widely used in dentistry. This study explored preliminarily the usage of dental CBCT during the COVID-19 pandemic (from 2020 to 2022) through a survey of a regional hospital in the northern Taiwan. Materials and methods: This study used purposeful sampling to select a regional hospital in the northern Taiwan to survey its usage of dental CBCT during the COVID-19 pandemic. Results: In the surveyed hospital, the number of patients' visits for the usage of dental CBCT increased from 355 in 2020 to 449 in 2021 and further to 488 in 2022 with a growth rate of 37.46 %, while the growth rates compared to the previous year were 26.48 % in 2021 and 8.69 % in 2022, respectively. There were a total of 1292 patients' visits for the dental CBCT. The ages of the 1292 patients (573 males and 719 females) ranged from 4 to 89 years. The 50-59-year age group had the highest number of patients' visits (371, 28.72 %), followed in a descending order by the 60-69-year (293, 22.68 %) and 40-49-year (206, 15.94 %) age groups. The dental CBCT was used mainly for the assessment of dental implants, accounting for 1148 (78.85 %) of the total 1456 irradiations. Conclusion: During the COVID-19 pandemic, the medical services for dental care and treatments in Taiwan are still maintained normally, and the dental CBCT is also used widely and popularly by the dental patients of all ages, various dental procedures, and various dental specialties.

Sirtuin 6 ameliorates arthritis through modulating cyclic AMP-responsive element binding protein/CCN1/cyclooxygenase 2 pathway in osteoblasts.

INTRODUCTION: CCN1 is an immediate-early gene product pivotal for arthritis progression. We have previously shown that sirtuin 6 (SIRT6) inhibited hypoxia-induced CCN1 expression in osteoblasts. Herein we examined the contribution of cyclic AMP-responsive element binding protein (CREB)/CRE to this suppressive action and the influence of CCN1 on cyclooxygenase (COX) 2 synthesis. MATERIALS AND METHODS: MC3T3-E1 murine osteoblasts were cultured under normoxia (21% oxygen) or hypoxia (2% oxygen). Expressions of CCN1, phospho-CREB (Ser133), COX2 and relevant kinases were assessed by Western blot. SIRT6 was overexpressed in cultured osteoblasts and arthritic joints by a lentiviral-based technique. Activities of CCN1 gene promoter constructs were examined by luciferase reporter assay. Interaction between CREB and CCN1 promoter was assessed by chromatin immunoprecipitation (ChIP). Collagen-induced arthritis (CIA) was established in 20 rats to evaluate the effects of SIRT6 therapy on osteoblastic expressions of phospho-CREB, CCN1 and COX2. RESULTS: SIRT6 suppressed hypoxia-enhanced CCN1 expression and CREB phosphorylation. Attenuation of calcium/calmodulin-dependent protein kinase II (CaMKII) may be responsible for SIRT6-induced CREB inhibition. CRE at - 286 bp upstream of the ATG start codon was essential for CCN1 expression under hypoxia and SIRT6 reduced hypoxia-stimulated CREB/CRE interaction. Forced expression of CREB rescued SIRT6-suppressed CCN1 synthesis. CCN1 induced COX2 expression in osteoblasts. In rat CIA, the therapeutic effect of SIRT6 was accompanied by decreases in osteoblastic expressions of phospho-CREB, CCN1 and COX2. CONCLUSION: Our study indicated that the benefits of SIRT6 to inflammatory arthritis and bone resorption are at least partially derived from its modulation of CREB/CCN1/COX2 pathway in osteoblasts.

Online courses for dentist continuing education: A new trend after the COVID-19 pandemic.

Background/purpose: Online courses have been widely used in all levels of education during the COVID-19 pandemic. This study explored the effectiveness of a dentist continuing education (DCE) course through the online devices in Taiwan. Materials and methods: The practicing dentists who participated in the online course of dental radiation technology for DCE offered by the Taiwan Dental Association (TWDA) in October 2022 and in March 2023 were enrolled in this study. The composition of participating dentists was confirmed by the public inquiry system and their learning effectiveness was evaluated by a questionnaire-based survey after the online DCE class. Results: All participating dentists (132 in October 2022 and 117 in March 2023) obtained consistent good learning outcomes in this online DCE course. Of these 249 dentists, there were 170 (68.27%) males and 79 (31.73%) females, 127 (51.00%) dental specialists and 122 (49.00%) general dentists, as well as 50 (20.08%) hospital dentists and 199 (79.92%) clinic dentists. The participation rates for this course of practicing dentists in non-municipalities (4.70%), counties (3.88%), eastern region (8.08%), and outlying islands (3.60%) were much higher than those in municipalities (0.79%), cities (1.16%), and the western region including the northern region (0.88%), central region (1.96%), and southern region (1.94%), respectively. Conclusion: The participating dentists express positive feedback on the online DCE courses, and the online DCE courses can reduce the urban-rural gap in dental education resources. The use of online DCE courses in dental education will be a future trend.

Fully automated film mounting in dental radiography: a deep learning model.

BACKGROUND: Dental film mounting is an essential but time-consuming task in dental radiography, with manual methods often prone to errors. This study aims to develop a deep learning (DL) model for accurate automated classification and mounting of both intraoral and extraoral dental radiography. METHOD: The present study employed a total of 22,334 intraoral images and 1,035 extraoral images to train the model. The performance of the model was tested on an independent internal dataset and two external datasets from different institutes. Images were categorized into 32 tooth areas. The VGG-16, ResNet-18, and ResNet-101 architectures were used for pretraining, with the ResNet-101 ultimately being chosen as the final trained model. The model's performance was evaluated using metrics of accuracy, precision, recall, and F1 score. Additionally, we evaluated the influence of misalignment on the model's accuracy and time efficiency. RESULTS: The ResNet-101 model outperformed VGG-16 and ResNet-18 models, achieving the highest accuracy of 0.976, precision of 0.969, recall of 0.984, and F1-score of 0.977 (p < 0.05). For intraoral images, the overall accuracy remained consistent across both internal and external datasets, ranging from 0.963 to 0.972, without significant differences (p = 0.348). For extraoral images, the accuracy consistently achieved the highest value of 1 across all institutes. The model's accuracy decreased as the tilt angle of the X-ray film increased. The model achieved the highest accuracy of 0.981 with correctly aligned films, while the lowest accuracy of 0.937 was observed for films exhibiting severe misalignment of ± 15° (p < 0.001). The average time required for the tasks of image rotation and classification for each image was 0.17 s, which was significantly faster than that of the manual process, which required 1.2 s (p < 0.001). CONCLUSION: This study demonstrated the potential of DL-based models in automating dental film mounting with high accuracy and efficiency. The proper alignment of X-ray films is crucial for accurate classification by the model.

Metformin Reduces Bone Resorption in Apical Periodontitis Through Regulation of Osteoblast and Osteoclast Differentiation.

INTRODUCTION: We have previously demonstrated that auxiliary metformin therapy promotes healing of apical periodontitis. Here we aimed to investigate the effects of metformin on osteoblast differentiation and osteoclast formation in cultured cells and rat apical periodontitis. METHODS: Murine pre-osteoblasts MC3T3-E1 and macrophages RAW264.7 were cultured under hypoxia (2% oxygen) or normoxia (21% oxygen) and stimulated with receptor activator of nuclear factor-κB ligand (RANKL) when indicated. Metformin was added to the cultures to evaluate its anti-hypoxic effects. Expressions of osteoblast differentiation regulator runt-related transcription factor 2 (RUNX2), RANKL, and osteoclast marker tartrate-resistant acid phosphatase (TRAP) were assessed by Western blot. Apical periodontitis was induced in mandibular first molars of 10 Sprague-Dawley rats. Root canal therapy with or without metformin supplement was performed. Periapical bone resorption was measured by micro-computed tomography. Immunohistochemistry was used to examine RUNX2, RANKL, and TRAP expressions. RESULTS: Hypoxia suppressed RUNX2 expression and enhanced RANKL synthesis in pre-osteoblasts. TRAP production increased in macrophages after hypoxia and/or RANKL stimulation. Metformin reversed hypoxia-induced RUNX2 suppression and RANKL synthesis in pre-osteoblasts. Metformin also inhibited hypoxia and RANKL-enhanced TRAP synthesis in macrophages. Intracanal metformin diminished bone loss in rat apical periodontitis. Comparing with vehicle control, cells lining bone surfaces in metformin-treated lesions had significantly stronger expression of RUNX2 and decreased synthesis of RANKL and TRAP. CONCLUSIONS: Alleviation of bone resorption by intracanal metformin was associated with enhanced osteoblast differentiation and diminished osteoclast formation in rat apical periodontitis. Our results endorsed the role of metformin as an effective medicament for inflammatory bone diseases.

A survey of the dental radiology course designed for dentist continuing education in Taiwan.

Background/purpose: In Taiwan, dental radiology has a long history of development. However, there are very few dental radiology curricula in Taiwan's dental education system. This study explored preliminarily the dental radiology course designed for dentist continuing education in Taiwan. Materials and methods: This study used the method of dental radiology education survey by questionnaire to evaluate participating dentists' learning outcomes by assessing their perceptions of the dental radiology course. Results: In this study, 117 participating dentists filled out the questionnaires completely after the class of dentist continuing education. The results showed that most of participating dentists agreed that dental radiology courses were rare in dental school curriculum and dentist continuing education. Moreover, most of participating dentists found this course to be helpful in raising their basic knowledge and skill about dental radiology, their attitude towards dental radiology, and their interest in further learning of dental radiology. They were satisfied with the course. The degree of agreement for each question was high, and all the mean scores for each question were between 4.53 and 4.77. The numbers (rates) of respondents who answered as agree were between 105 and 113 (between 89.74% and 96.58%). Conclusion: The dental radiology course contributed to an increase in dentists' basic knowledge and skill about dental radiology and their awareness and understanding of the importance of dental radiology. Considering the effectiveness of the dental radiology course on dentists' basic knowledge/skill and attitude of dental radiology, this model shows promise for further use in dentist continuing education.

An exploration of the connotation of clinical dental radiology education for medical radiation students in Taiwan in 2022.

Background/purpose: In Taiwan, the dental radiology has a history of more than 100 years. However, medical radiation schools or teaching hospitals have not yet established a set of standard learning content for dental radiology internship. Materials and methods: We used the observational method and dental radiology teaching survey to explore the connotation of clinical dental radiology education for medical radiation students in Taiwan. Results: There were 64 dental departments of hospitals with their own independent dental radiology departments in Taiwan in 2022. Among them, 58 (90.63%) were in the teaching hospitals. Of the 58 dental radiology departments in the teaching hospitals, 40 (68.97%) had medical radiation interns in their dental radiology departments. There was a complete set of seven training items for dental radiology internship. The mean training items in the medical centers (4.94) was significantly higher than that in the regional hospital (3.9) (P < 0.05). No matter what level of hospital, it is the most common way to implement the training mode with preclinical exercises and then clinical practice. Conclusion: In Taiwan, the current status of dental radiology teachers in the teaching hospital is indeed seriously insufficient. It is necessary to establish a standard dental radiology education system, including setting one common dental radiology subject for medical radiation students, and the relevant regulations to formulate the basic requirements of the training items and training hours for dental radiology internship. Thus, medical radiation interns can acquire the operation skills related to dental X-ray machines after completing the internship training.

Overview of dental radiology education for medical radiology students in Taiwan.

Background/purpose: In Taiwan, the formal education for cultivating medical radiation technologists began in 1965. However, there are very few dental radiology curricula in Taiwan's medical radiology schools. We investigated mainly the appearance of dental radiology education for medical radiology students in Taiwan. Materials and methods: We used documentary analysis, a survey of dental radiology education, and secondary data analysis in this study to find the appearance of Taiwan's dental radiology education for medical radiology students. Results: There were currently ten medical radiology schools. Among them, five offered independent curricula in their subject schedules and another five had dental radiology education included in their general medical radiology curricula. Of the 53 dental radiology teaching hospitals, 21 (39.62%) were medical centers and 25 (47.17%) were regional hospitals, and these large hospitals were concentrated in the northern region of Taiwan. These large dental radiology teaching hospitals offered more training hours of dental radiology internship for medical radiology students and had a higher availability for the medical radiology students. Conclusion: In Taiwan, the current status of dental radiology curricula in the medical radiology schools is indeed seriously insufficient. A dental radiology education system should be established in the future, including the innovative dental radiology curricula developed for medical radiology students and more dental radiology curricula designed for dental students. This in turn can create new career options for medical radiology students and new practice directions for medical radiation technologists, and then expand their potential involvement in dental radiology.

Radiographic characteristics of odontomas in patients in the National Taiwan University Children's Hospital.

Background/purpose: Odontoma is the most common odontogenic tumor. A literature review revealed limited data for odontomas in Taiwan. This study evaluated the radiographic characteristics of odontomas in 1280 patients in the National Taiwan University Children's Hospital (NTUCH). Materials and methods: This retrospective study analyzed the odontomas based on examination of mainly panoramic radiographs and related radiographs of 1280 patients in the NTUCH. Chi-square test was used for trend analysis. Results: Among 1280 patients (710 boys and 570 girls), a total of 16 patients with odontomas (10 boys and 6 girls) were identified. There were 14 compound and 2 complex odontomas. The mean age of the patients was 10.38 years with the majority of odontomas occurring in the first (37.5%) and second decade (62.5%) of life. Odontomas had a marked predilection for the mandible (56.25%) and for the anterior region of the jaws (75%), particularly for the anterior maxilla (43.75%). Ten odontomas (62.5%) were associated with the impacted corresponding permanent teeth. The sagittal position of odontomas and vertical relation of odontomas to the corresponding permanent teeth were significantly correlated with the eruption rate of corresponding permanent teeth (P < 0.05). Conclusion: The odontomas occur most commonly in male patients with a male to female ratio of 1.67:1. The incidence of odontomas in our 1280 patients is 1.25%. The age range of patients with odontomas is 6-17 years. The most frequent location of odontomas is the anterior maxillary region. Odontoma is frequently associated with an impacted corresponding permanent tooth.

Occupational radiation exposure for various medical radiation workers, especially the dental radiation workers, in Taiwan from 2013 to 2020.

Background/purpose: The development of dental radiology in Taiwan has been over a century. This study explored mainly the profile of dental radiation workers and their occupational radiation exposure in Taiwan from 2013 to 2020. Materials and methods: This study used the secondary data analysis to survey mainly the changes of manpower of the dental radiation workers and their occupational radiation exposure in Taiwan from 2013 to 2020. Results: The number of monitored dental radiation workers increased from 678 in 2013 to 770 in 2020. However, the proportion of monitored dental radiation workers to the total monitored medical radiation workers decreased from 4.29% in 2013 to 3.67% in 2020. Although the number of monitored dental radiation workers increased, the number of the measurably exposed dental radiation workers decreased from 2013 to 2020. The annual collective exposure dose fluctuated from 5.21 man-Sv to 15.47 man-Sv, but it showed a decreasing trend. Furthermore, the mean annual effective exposure dose of total monitored dental radiation workers (0.01-0.02 mSv) and that of the measurably exposed dental radiation workers (0.15-1.11 mSv) were relatively low among various medical radiation workers. In overall, the proportion of medical radiation technologists to dentists varied from 0.41 to 0.45. Conclusion: Although the number of monitored dental radiation workers increase, the number of the measurably exposed dental radiation workers, the proportion of the measurably exposed dental radiation workers to the total monitored dental radiation workers, and the annual collective exposure dose for monitored dental radiation workers decrease from 2013 to 2020.

Overview of dental radiation technologists in Taiwan.

Background/purpose: In Taiwan, there is no independent licensing system for dental radiation technologists. A licensed medical radiation technologist who engages in dental radiology is the so-called dental radiation technologist. This study explored mainly the profile of dental radiation technologists in Taiwan. Materials and methods: This study used the methods of documentary analysis, dental radiation manpower survey, and the secondary data analysis to find the profile of dental radiation technologists in Taiwan. Results: There were currently 59 dental radiology departments and 101 dental radiation technologists (29 males and 72 females) in 57 hospitals and their branches. Of the 101 dental radiation technologists, 56 worked in the medical centers, 28 in the regional hospitals, and 17 in the district hospitals. More than half of the dental radiation technologists were concentrated in the medical centers (55.45%, 56/101) or the northern region of Taiwan (57.43%, 58/101), especially in the northern medical centers (30.69%, 31/101). Conclusion: In Taiwan, the manpower of dental radiation technologists is insufficient, and dental radiation technologists usually work in the dental departments of the hospitals. A large number of clinic dentists lack dental radiation technologists to assist in dental radiology works and the clinic dentists have to perform the dental radiology works by themselves. Therefore, a dental radiology education system should be established to design innovative dental radiology courses for radiological technology students. This in turn can provide a new practice direction for medical radiation technologists and expand their potential participation in the field of dental radiology.

Nonsyndromic supernumerary teeth in patients in National Taiwan University Children's hospital.

Background/purpose: A literature review reveals limited data for supernumerary teeth in Taiwan. This study aimed to analyze the characteristics of nonsyndromic supernumerary teeth in patients in the National Taiwan University Children's Hospital. Materials and methods: This retrospective study analyzed the nonsyndromic supernumerary teeth in 1280 patients (710 boys and 570 girls) based on examination of mainly panoramic radiographs and related radiographs. Chi-square test was used for trend analysis. Results: The incidence of nonsyndromic supernumerary teeth was 11.25% (179 supernumerary teeth in 144 of the 1280 patients). There was a male predominance (4.33: 1, P < 0.0001) for our 144 patients. Most supernumerary teeth were single (63.69%), conical-shaped (78.77%), and unerupted (77.09%). Supernumerary teeth also tended to be located in the premaxilla (93.85%), fully developed (51.40%), invertedly oriented (45.25%), sagittally located in a palatal/lingual position (67.60%), and adjacent to the root and root apex of permanent teeth (70.39%). The supernumerary teeth with a normal orientation (64.52%) had a high potential to erupt into the oral cavity, but the majority of the supernumerary teeth with a transverse orientation (97.22%) or an inverted orientation (100%) were unerupted. Conclusion: The nonsyndromic supernumerary teeth occur most commonly in male patients with a male to female ratio of 4.33: 1. The incidence of nonsyndromic supernumerary teeth in our 1280 patients is 11.25%, and the most frequent location of supernumerary teeth is the anterior maxillary region. More than three quarters of supernumerary teeth are conical-shaped or unerupted. Inverted supernumerary teeth are all embedded in the jawbones.

Differences of condylar changes after orthognathic surgery among Class II and Class III patients.

BACKGROUND/PURPOSE: The nature of susceptibility to condylar resorption after orthognathic surgery can be different between skeletal Class II and Class III populations, which was addressed by few in the past. The aim of the present study was to use cone-beam computed tomographic (CBCT) images to investigate the displacement and morphological changes of temporomandibular joints (TMJs) in patients received orthodontic treatment combined with orthognathic surgery. METHODS: Both Class III (n = 34) and Class II (n = 17) patients were compared through overall and regional superimpositions of the initial and posttreatment CBCTs. Two-sample t-test was used to identify significance between group differences. Pearson's correlation coefficient was used to address changes of TMJ and the amount of setback or advancement. RESULTS: The axial ramal angle increased significantly in Class III group and decreased in Class II groups after orthognathic surgery (p < FDR_p). For condylar dimensions, significant widths and lengths reductions were noted only in Class II group. However, no significant difference was found after comparing subgroup differences according to one-jaw and two-jaw options, nor any significant correlation found between the condylar changes and the amount of surgical movements. CONCLUSION: The nature of condylar susceptibility could result more from different skeletal patterns than the amount of surgical movements. However, the direction of mandibular surgery may contribute to different changes of condylar angle in axial section.

Differences between the temporal and mandibular components of the temporomandibular joint in topographic distribution of osseous degenerative features on cone-beam computerized tomography.

BACKGROUND/PURPOSE: Temporomandibular joint osteoarthritis (TMJOA) pathology is characterized by degenerative changes of the subchondral bone. The topographic distribution of osseous degenerative changes in TMJ is not clear. This study aimed to evaluate the topographic distribution of osseous degenerative features in the TMJ by using cone-beam computerized tomography (CBCT). MATERIALS AND METHODS: The CBCT images of 26 female patients diagnosed to have TMJOA were retrieved from the database of the National Taiwan University Hospital. The images of left and right TMJs were evaluated independently by 2 examiners. The evaluated degenerative features included surface erosion, subcortical cysts, subcortical sclerosis, and osteophytes in the mandibular condyle and temporal component of the TMJ. The topographic distribution at different portions in the mandibular condyle and temporal component of the TMJ was statistically analyzed. RESULTS: Significant differences in the topographic distribution of the osseous degenerative features were observed (a) between the mandibular condyle and the temporal component and (b) between the anterior/central portion and posterior portion of the temporal component. No significant differences were observed in the topographic distribution of the TMJOA features in the condyle, except for surface erosion between the central and lateral portion of the condyle. CONCLUSION: The results suggest that the mandibular condyle and temporal component react differently in TMJ osseous degeneration, with the condyle being more vulnerable than the temporal component. Mandibular activities that require the mandibular condyle to function outside the fossa may be more destructive to the health and integrity of the TMJ.

Comparing image qualities of dental cone-beam computed tomography with different scanning parameters for detecting root canals.

BACKGROUND/PURPOSE: Cone-beam computed tomography (CBCT) is a useful device in creating 3-dimensional images in the examining area of dentistry and is one of the most common clinical methods in detecting second mesiobuccal (MB2) canals in maxillary molars. The aim of this in vitro study was to compare the image quality of the small field of view (FOV) CBCT with different rotation arcs and scanning speeds in the use of detecting root canals. METHODS: A dentate human skull was scanned in Morita 3D Accuitomo 170 with 4 × 4 cm FOV under 5 mA and 90 kVp. Two different rotation arcs (360° and 180°) and three different scanning modes (slow-speed mode, standard mode and high-speed mode) combined into six different groups. Five different levels of axial sections were selected from each group. Five endodontic specialists rated the image quality by focusing on the sharpness of the MB2 canal of the upper right first molar and the surrounding structures. RESULTS: Despite the rotation arcs, all the observers gave excellent ratings to images taken with slow-speed mode. The high-speed mode taken with 360° and 180° got the second lowest and the lowest ratings, respectively. Under the same scanning speed, the rotation arc did not have a significant difference in image quality. CONCLUSION: Slow-speed mode is inevitable in maintaining adequate image quality during taking CBCT. However, endodontists can use the half rotation mode to significantly reduce radiation dose, exposure time, and still maintain sufficient image quality for root canal anatomy assessment.

Comparison of regular- and slope-configured dental implants placed in the edentulous ridge with height discrepancy: A pilot randomized controlled trial.

BACKGROUND/PURPOSE: Edentulous ridges with height discrepancies (RHDs) could jeopardize the outcome of implant placement. This study aimed at evaluating the outcomes of placing regular- and slope-configured implants in RHDs. METHODS: Patients with >1 mm RHDs requesting implant rehabilitation were recruited and randomly assigned to regular- (control) or slope-configured (test) implant treatment using a submerged installation protocol. Thread exposure (TE) and implant stability quotient (ISQ) were evaluated during implant installation (S1) and uncovered surgery (S2), and marginal bone level (MBL) was evaluated after implant installation (T1) and uncovery (T3), and one year after implant placement (T4). Periodontal status and gingival crevicular fluid (GCF) biomarkers of adjacent teeth were evaluated before implant installation (T0), before uncovery (T2), and at T4. Peri-implant clinical status and peri-implant crevicular fluid (PICF) biomarkers of examined implants were evaluated at T4. RESULTS: Nineteen patients with 17 control and 13 test implants were included. All of the implants survived with acceptable peri-implant health, and PICF biomarkers were at equivalent levels as GCF biomarkers of the adjacent teeth at T4. Compared with the control group, the test group showed reduced TE and equivalent ISQ at S1 and S2, and the loss of MBL was reduced at T4. Regarding the adjacent teeth, all periodontal parameters and GCF biomarkers were slightly decreased from T0 to T2, and the reductions in probing pocket depth and clinical attachment level were slightly greater at T4. CONCLUSION: Slope-configured implants maintained the implant-supporting structures and minimally altered periodontal status of the adjacent teeth in RHDs.

The advantage of cone-beam computerized tomography over panoramic radiography and temporomandibular joint quadruple radiography in assessing temporomandibular joint osseous degenerative changes.

BACKGROUND/PURPOSE: The clinical diagnosis of temporomandibular joint (TMJ) degenerative joint disease (DJD) is based primarily on radiographic features of the condyle and articular eminence. The purpose of this study was to compare the reliability, sensitivity, and specificity of using plain radiography to that of cone-beam computerized tomography (CBCT) in identifying different types of osseous degenerative features in the TMJ condyle. MATERIALS AND METHODS: The panoramic radiography (PANO), TMJ quadruple radiography (TMJQR) and CBCT images of 29 patients' TMJs were retrieved from a computer database and independently evaluated by a young oral surgeon and a senior TMD specialist. The examiners diagnosed osseous degenerative features on the radiographic images. The radiologist-assisted CBCT diagnoses were used as a reference standard and the reliability, sensitivity, and specificity of using the three radiographic modalities were statistically analyzed. RESULTS: There were cases of indeterminate diagnoses using the PANO and TMJQR due to superimposition from surrounding structures, but none using CBCT. Reliability was generally poor when using PANO and TMJQR for detecting osseous degenerative features of the TMJ condyle but good to excellent when using CBCT. The sensitivity and specificity in the use of PANO and TMJQR were typically below acceptable, but the levels were generally satisfactory when using CBCT. CONCLUSION: CBCT is superior to plain radiographic modalities for diagnosing osseous degenerative features of TMJs with regard to indeterminate cases, reliability, sensitivity, and specificity. It is recommended that CBCT can be used as an effective tool in identifying TMJ osteoarthritis.

Baseline probing depth and interproximal sites predict treatment outcomes of non-surgical periodontal therapy.

BACKGROUND/PURPOSE: The efficacy of non-surgical periodontal therapy (NSPT) has been well discussed. The aim of this study was to investigate whether the baseline clinical periodontal parameters, radiographic defect angle, and interproximal site predict the treatment outcome of NSPT. MATERIALS AND METHODS: A total of 39 patients who were diagnosed with generalized chronic periodontitis and met the inclusion criteria were enrolled in this study. All patients received full-mouth periodontal examination by two well-trained periodontists. Clinical periodontal parameters, including probing depth (PD), recession (Rec), and clinical attachment level (CAL), were recorded, and vertical bitewing radiographs were taken as baseline data. Revaluation was performed after 4 weeks of non-surgical periodontal treatment. Pearson's correlation coefficient and multivariate logistic regression were performed to examine the association between favorable treatment outcome (PD reduction ≥ 3 mm) and various clinical parameters. RESULTS: A significant improvement was observed in PD reduction and CAL gain after NSPT. The radiographic defect angle was strongly correlated with baseline Rec, baseline CAL, and interproximal sites in teeth with a deeper PD. Baseline PD and interproximal sites emerged as significant prediction factors for favorable treatment outcome with a PD reduction of ≥3 mm. CONCLUSION: Our study is the first to report that distal sites show wider radiographic angles with shallow infrabony defects and that pocket reduction is more obvious at distal sites than at mesial sites. These data provide evidence that baseline PD and interproximal sites may predict the treatment outcome of NSPT.