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The aim of this study was to evaluate 1-year stability and maintenance of peri-implant soft and hard tissues after guided bone regeneration (GBR) with L-shaped collagenated bone substitute and subepithelial connective tissue graft (CTG) in the maxillary anterior region using profilometric, volumetric, and esthetic analyses.Fourteen peri-implant defects were grafted with L-shaped collagenated bone substitute, and 5 months after implant placement with GBR, reentry surgery in combination with CTG was performed in all participants. CBCT scans and STL files were acquired at baseline (after implant surgery, T1), reentry surgery (T2), and 1-year follow-up (T3). The profilometric and volumetric changes of the peri-implant tissues were measured, and the pink esthetic score (PES) was assessed at T3.One year after GBR and CTG at the buccal aspect of the maxillary esthetic zone, the mean thickness of the hard tissue (HT) decreased (HT0: -0.87 ± 0.67 mm, HT1: -0.74 ± 0.75 mm, HT2: -0.92 ± 0.48 mm, 45-HT: -0.87 ± 0.73 mm) and the corresponding thickness of the soft tissue (ST) increased (ST0: 0.96 ± 1.06 mm, ST1: 0.85 ± 0.95 mm, ST2: 0.38 ± 0.82 mm, 45-ST: 0.12 ± 0.62 mm), and as a result, there was no statistically significant difference in the total tissue thickness between T1 and T3 (p 0.05). The mean volumetric changes of the peri-implant tissues increased after 1-year of implant surgery (T1-T2: 1.52 ± 0.83 mm, T2-T3: -0.88 ± 1.04 mm, T1-T3: 0.64 ± 0.90 mm), and a statistically significant difference was shown in all compared time periods (p 0.05). The mean PES score was 8.07 ± 1.54 at T3 (range, 6-10).Within the limitations of this 1-year follow-up study, GBR with an L-shaped collagenated bone substitute and subepithelial CTG in the maxillary esthetic zone was beneficial for stable and maintainable peri-implant hard and soft tissues.

BACKGROUND The long-term outcomes of demineralized porcine bone matrix (DPBM) in combination with enamel matrix protein derivative (EMD) for the treatment of one-wall intrabony defects have not yet been evaluated. Therefore, this study aimed to assess the clinical, radiographic, and patient-reported outcomes of regenerative therapy using DPBM with EMD (test group) in comparison with DPBM alone (control group) for the treatment of one-wall intrabony defects in the molar regions. METHODS Thirty-four patients (control group, n = 18, and test group, n = 16) were available at the 4-year follow-up assessment. Clinical (probing pocket depth and clinical attachment level [CAL]), radiographic (defect depth and width), and patient-reported (Oral Health Impact Profile [OHIP]-14) parameters were evaluated at baseline, 2 years, and 4 years after regenerative treatment. RESULTS Both treatment modalities, with and without adjunctive use of EMD, resulted in significant improvement of clinical (mean gain in CAL of 1.58 ± 1.34 mm), radiographic (mean defect width fill of 2.41 ± 0.90 mm), and oral health-related quality of life outcomes at 2 years after regenerative treatment of one-wall intrabony defects (P < 0.001), which has been sustained over a 4-year follow-up period. Particularly, OHIP-14 scores revealed a statistically significant reduction in physical pain, psychological discomfort, and physical disability (P < 0.05). CONCLUSIONS The clinical, radiographic, and patient-reported outcomes were significantly improved when DPBM was used in the regenerative treatment, but no additional benefits were observed with the adjunctive use of EMD.

Purpose Due to the difficulty of the hygienic care and sanitary management of abutment teeth and subpontic areas associated with fixed dental prostheses (FDPs), intrabony defects occur and accelerate due to the accumulation of plaque and calculus. This study aimed to evaluate the efficacy of regenerative periodontal surgery for intrabony defects associated with FDPs. Methods The study inclusion criteria were met by 60 patients who underwent regenerative treatment between 2016 and 2018, involving a total of 82 intrabony defects associated with FDPs. Periodontal osseous lesions were classified as 1-, 2-, and 3-wall intrabony defects and were treated with an enamel matrix derivative in combination with bone graft material. The changes in clinical (pocket probing depth [PPD] and clinical attachment level [CAL]) and radiographic (defect depth and width) outcomes were measured at baseline and at 6, 12, and 24 months. Results Six months after regenerative treatment, a significant reduction was observed in the PPD of 1-wall (P, Graphical Abstract

The aim of this study was to investigate the risk of periodontitis according to current smoking status based on the number of cigarettes smoked per day (CPD) and the Fagerström Test for Nicotine Dependence (FTND).All enrolled patients were diagnosed and classified according to the new periodontal classification scheme, and current smoking status was investigated via a self-reported questionnaire. The correlation between smoking status (CPD and FTND) and periodontitis risk (severity of periodontitis and tooth loss due to periodontal reasons) was statistically assessed using Spearman correlation coefficients. Moreover, partial correlation analyses between smoking and periodontal status were performed after adjusting for age, sex, and diabetes mellitus.Overall, data from 74 men and 16 women (mean age: 48.1±10.8 years) were evaluated. The mean number of missing teeth, CPD, and FTND score were 3.5±5.2, 24.6±15.5, and 3.5±2, respectively. CPD and the FTND were significantly positively correlated with each other (Within the limitations of this study, both CPD and the FTND were significantly correlated with the severity of periodontitis and the number of periodontally compromised extracted teeth.

Objectives: The association between prostate cancer (PC) and chronic periodontal disease (PD) has been evaluated in previous studies, but results have been inconsistent. This study aimed to determine whether the presence of chronic PD in old age increases the risk of PC using data in the large-scale elderly cohort. Materials and Methods: This nationwide population-based cohort study examined data of 121,240 South Korean individuals aged ≥ 60 years from the National Health Insurance Service-Elderly Cohort database who completed a national program between 2002 and 2015. For a maximum 10 years' observation period, patients with incident PC with chronic PD compared with those without chronic PD were retrospectively tracked, and Cox proportional hazard ratios and 95% confidence intervals (CIs) were calculated, adjusted for potential confounding factors, including age, household income, insurance status, Charlson Comorbidity Index, hypertension, diabetes mellitus, cerebral infarction, angina pectoris, myocardial infarction, prostatitis, smoking status, daily smoking, alcohol intake habits, one-time alcohol intake, and regular exercise. Results: The overall incidence of PC with chronic PD in 10 years was 3.0% (n = 2,063). In the multivariate Cox analysis with adjustment for confounding factors, chronic PD was associated with a 24% higher risk of PC (95% CI = 1.16-1.32, P < 0.001). Conclusion: Our results suggest that chronic PD is significantly and positively associated with PC. Larger and better-controlled studies are needed to strengthen this evidence of association and explain the underlying biological mechanisms.

Purpose The purpose of this study was to utilize cone-beam computed tomography (CBCT) image analysis to obtain anatomical information related to the morphology of the incisive foramen to provide useful data regarding implant placement and clinical procedures such as anesthesia. Methods The study included 167 patients who underwent CBCT scans over 20 years. Three components were measured: 1) the anteroposterior and mediolateral diameter of the incisive foramen, 2) the horizontal bone thickness anterior to the incisive foramen, and 3) the vertical bone height coronal to the incisive foramen. All measurements were expressed as mean±standard deviation and were analyzed by a single examiner. Results The anteroposterior diameter of the incisive foramen was wider than the mediolateral diameter (P, Graphical Abstract

Background The purpose of this study was to evaluate the potential advantages of adjunctive use of enamel matrix protein derivative (EMD) in combination with demineralized porcine bone matrix (DPBM) for the treatment of one‐wall intrabony defects in the molar regions, in comparison with the use of DPBM alone, through a randomized controlled clinical trial. Methods Forty‐two participants were randomly assigned to two groups: one where DPBM with the adjunctive use of EMD (test group, n = 20) was applied and the other without EMD (control group, n = 22). Changes in the clinical and radiographic parameters from baseline at 6, 12, and 24 months were measured (probing pocket depth, clinical attachment loss, defect depth, and defect width). Postoperative discomfort (severity/duration of pain and swelling) and early soft tissue wound healing (dehiscence/fenestration, persistent swelling, spontaneous bleeding, and ulceration) were also assessed. Results Both treatment modalities, with and without EMD, resulted in significant improvement of clinical and radiographic outcomes without any severe adverse events. However, no statistically significant differences in any of the measured parameters were found when the two groups were compared. Early wound healing outcomes and the severity of swelling did not differ between the groups, but the severity of pain (P = 0.046), duration (P = 0.033), and swelling (P = 0.022) were significantly lower in the test group. Conclusions DPBM has been verified for biocompatibility and can be used as a scaffold to enhance the clinical and radiographic outcomes of periodontal regeneration of one‐wall intrabony defects. In particular, the adjunctive use of EMD significantly reduced the postoperative discomfort.

Block bone substitutes have better augmentation stability for guided bone regeneration (GBR) than particulate bone substitutes. This study sought to determine whether GBR with an L-shaped porcine block bone (DPBM-C) differs from GBR with an L-shaped bovine block bone (DBBM-C) based on clinical, radiographic, and volumetric outcomes for peri-implant dehiscence defects. A total of 42 peri-implant defects were grafted with 20 L-shaped DPBM-C and 22 DBBM-C groups. The horizontal and vertical thicknesses of the augmented hard tissue were measured using sagittal cone-beam computed tomography, and the volumetric tissue change was evaluated by stereolithography image superimposition. Postoperative discomfort, early wound healing outcomes, and implant stability were also assessed. Among the clinical (subjective pain and swelling, wound dehiscence, membrane exposure, and periotest values), radiographic (changes in horizontal and vertical hard tissue thickness), and volumetric parameters of the L-shaped DPBM-C and DBBM-C groups during the healing period, only the periotest values showed a statistically significant difference (0.67 ± 1.19, p = 0.042). Within the limitations of this study, an L-shaped DPBM-C is not inferior to an L-shaped DBBM-C based on their clinical, radiographic, and volumetric outcomes for GBR of peri-implant dehiscence defects.

The aim of this study was to evaluate and compare the accuracy performance of dental professionals in the classification of different types of dental implant systems (DISs) using panoramic radiographic images with and without the assistance of a deep learning (DL) algorithm.Using a self-reported questionnaire, the classification accuracy of dental professionals (including 5 board-certified periodontists, 8 periodontology residents, and 31 dentists not specialized in implantology working at 3 dental hospitals) with and without the assistance of an automated DL algorithm were determined and compared. The accuracy, sensitivity, specificity, confusion matrix, receiver operating characteristic (ROC) curves, and area under the ROC curves were calculated to evaluate the classification performance of the DL algorithm and dental professionals.Using the DL algorithm led to a statistically significant improvement in the average classification accuracy of DISs (mean accuracy: 78.88%) compared to that without the assistance of the DL algorithm (mean accuracy: 63.13%,The automated DL algorithm classified DISs with accuracy and performance comparable to those of board-certified periodontists, and it may be useful for dental professionals for the classification of various types of DISs encountered in clinical practice.

OBJECTIVES To retrospectively evaluate whether guided bone regeneration (GBR) with L- and I-shaped demineralized bovine bone mineral with 10% collagen (DBBM-C) differs from GBR with DBBM in terms of augmentation stability and early wound healing outcomes in peri-implant dehiscence defects. METHODS A total of 91 peri-implant defects were grafted with 24 L- (GBR-L), 22 I (GBR-I)-shaped DBBM-C, and 45 DBBM (GBR-P). Cone-beam computed tomography images were obtained after surgery and at 5 months follow-up. The horizontal thickness (HT0, HT2, HT4), vertical thickness (VT), and VT at 45° angle (45-VT) of the augmented hard tissue were measured. Early postoperative discomfort and wound healing outcomes were assessed 2 weeks after surgery, and periotest values were also measured at 5 months in all groups. RESULTS At 5 months follow-up, the change at HT0 and VT of the GBR-L (HT0: -0.63 ± 0.55 mm, VT: -0.77 ± 0.60 mm) and GBR-I (HT0: -0.68 ± 0.53 mm, VT: -0.91 ± 0.73 mm) groups was significantly more stable than that of the GBR-P (HT0: -1.30 ± 0.77 mm, VT: -1.57 ± 0.67 mm) group (p

The aim of this study was to evaluate and compare early postoperative discomfort and wound healing outcomes between patients who underwent periodontal surgery with and without enamel matrix derivative (EMD), using retrospective questionnaires and postoperative clinical examinations. All enrolled patients filled out the self-report questionnaire after suture removal. The severity and duration of subjective pain and swelling were evaluated using visual analog scale (VAS) scores and wound healing parameters (dehiscence/fenestration, spontaneous bleeding, persistent swelling, and ulceration). Chi-squared tests, two-tailed independent t tests, analysis of variance, and multiple logistic regression analysis were performed to identify significant differences between the two groups (surgery with EMD and surgery without EMD). The severity of pain and swelling did not differ between patients who underwent surgery with and without EMD, but the durations of pain (P

Fracture of a dental implant (DI) is a rare mechanical complication that is a critical cause of DI failure and explantation. The purpose of this study was to evaluate the reliability and validity of a three different deep convolutional neural network (DCNN) architectures (VGGNet-19, GoogLeNet Inception-v3, and automated DCNN) for the detection and classification of fractured DI using panoramic and periapical radiographic images. A total of 21,398 DIs were reviewed at two dental hospitals, and 251 intact and 194 fractured DI radiographic images were identified and included as the dataset in this study. All three DCNN architectures achieved a fractured DI detection and classification accuracy of over 0.80 AUC. In particular, automated DCNN architecture using periapical images showed the highest and most reliable detection (AUC = 0.984, 95% CI = 0.900–1.000) and classification (AUC = 0.869, 95% CI = 0.778–0.929) accuracy performance compared to fine-tuned and pre-trained VGGNet-19 and GoogLeNet Inception-v3 architectures. The three DCNN architectures showed acceptable accuracy in the detection and classification of fractured DIs, with the best accuracy performance achieved by the automated DCNN architecture using only periapical images.

BACKGROUND EMD has been considered to exert positive effects on wound healing, postoperative discomfort, and bone regeneration. PURPOSE The aim of this randomized controlled clinical trial was to investigate and compare (a) horizontal and vertical bone dimensional changes, (b) early postoperative discomfort and soft tissue wound healing outcomes, and (c) treatment modalities for implant placement, following posterior maxillary alveolar ridge preservation (ARP) with and without adjunctive use of EMD. METHODS Twenty-eight participants were randomly assigned to three groups: extraction sockets filled with bovine bone mineral and membrane with EMD (test group 1, n = 10) and without EMD (test group 2, n = 10) and spontaneous healing (control group, n = 8). Alveolar bone dimensional changes were measured using cone-beam computed tomography 5 months after ARP, and postoperative pain and wound healing outcomes were also evaluated. RESULTS There were no significant differences in horizontal or vertical bone dimensional changes between test groups 1 (horizontal width changes at 1 mm apically below the alveolar ridge crest [HW]: -1.44 ± 0.54 mm) and 2 (HW: -1.42 ± 0.26 mm), but the changes at HW (-2.36 ± 1.03 mm) in the control group were significantly greater than those in test groups 1 and 2 (P

The purpose of this study was to compare the microbial composition of 3 types of oral samples through 16S metagenomic sequencing to determine how to resolve some sampling issues that occur during the collection of sub-gingival plaque samples.In total, 20 subjects were recruited. In both the healthy and periodontitis groups, samples of saliva and supra-gingival plaque were collected. Additionally, in the periodontitis group, sub-gingival plaque samples were collected from the deepest periodontal pocket. After DNA extraction from each sample, polymerase chain reaction amplification was performed on the V3-V4 hypervariable region on the 16S rRNA gene, followed by metagenomic sequencing and a bioinformatics analysis.When comparing the healthy and periodontitis groups in terms of alpha-diversity, the saliva samples demonstrated much more substantial differences in bacterial diversity than the supra-gingival plaque samples. Moreover, in a comparison between the samples in the case group, the diversity score of the saliva samples was higher than that of the supra-gingival plaque samples, and it was similar to that of the sub-gingival plaque samples. In the beta-diversity analysis, the sub-gingival plaque samples exhibited a clustering pattern similar to that of the periodontitis group. Bacterial relative abundance analysis at the species level indicated lower relative frequencies of bacteria in the healthy group than in the periodontitis group. A statistically significant difference in frequency was observed in the saliva samples for specific pathogenic species (In this 16S oral microbiome study, we confirmed that saliva samples had a microbial composition that was more similar to that of sub-gingival plaque samples than to that of supra-gingival plaque samples within the periodontitis group.

OBJECTIVES This study aimed to identify patients with the highest risk of periodontal disease (PD), and to provide recommendations for the effective use and application of data mining (DM) techniques when establishing evidence-based dental-care policies for vulnerable groups at a high risk of PD. METHODS This study used the SEMMA (Sample, Explore, Modify, Model, and Assess) methodology to construct DM models based on data acquired from the fifth and sixth Korea National Health and Nutrition Examination Surveys (2000-2015). We analyzed the sociodemographic and comorbidity variables that influence PD by applying the popular DM techniques of decision-tree, neural-network, and regression models, and also attempted to improve the predictive power and reliability by comparing the results obtained by these three models. RESULTS Our comparisons of the three DM algorithms confirmed that the average squared error, misclassification rate, receiver operating characteristic index, Gini coefficient, and Kolmogorov-Smirnov test results were the most appropriate for the decision-tree model. The analysis of the decision-tree model revealed that age and smoking status exert major effects on the risk of PD, and that stress and education level exert effects in rural areas, whereas education level, sex, hyperlipidemia, and alcohol intake exert effects in urban areas. CONCLUSIONS We demonstrated that the decision-tree model is an effective DM technique for identifying the complex risk factors for PD. These results are expected to be helpful in improving the equality and efficacy of dental-care policies for vulnerable groups at a high risk of PD.

BACKGROUND Currently, there is incomplete understanding of the fracture patterns in the implant and their association with clinical factors. PURPOSE The aim of this study was to investigate the incidence and pattern of implant fracture (IF) by using 9-year, long-term multicenter follow-up data. MATERIALS AND METHODS The association of the incidence and differences in fracture patterns with clinical factors (based on patient variables and implant variables) was assessed for statistical significance using the Chi-square and Fisher exact test, as appropriate. RESULTS Among a total of 19 087 implants in 8501 patients (7838 male and 663 female) placed over 9 years, fractures were observed in 70 implants (0.4%) in 57 patients (50 male and 7 female). Cases with less than 50% bone loss had a higher incidence of horizontal and vertical IFs limited to the crest module, which are defined as Type I fractures (n = 13, 18.6%). In contrast, cases with ≥50% severe bone loss exhibited a higher incidence of Type II vertical fractures (n = 22, 31.4%), extending beyond the crestal portion (P = .001). Type III fractures (n = 5, 7.1%), defined as a horizontal fracture beyond the crestal module, were also observed. CONCLUSION Peri-implantitis-induced marginal and vertical bone loss and manufacturing-induced defects were considered to be major factors in IF. Therefore, using clinically verified implant systems and striving to minimize bone loss by preventing and actively treating peri-implantitis is essential to reduce IFs.

Purpose To retrospectively evaluate the relationship between the vertical position of the implant-abutment interface and marginal bone loss over 3 years using radiological analysis. Methods In total, 286 implant surfaces of 143 implants from 61 patients were analyzed. Panoramic radiographic images were taken immediately after implant installation and at 6, 12, and 36 months after loading. The implants were classified into 3 groups based on the vertical position of the implant-abutment interface: group A (above bone level), group B (at bone level), and group C (below bone level). The radiographs were analyzed by a single examiner. Results Changes in marginal bone levels of 0.99±1.45, 1.13±0.91, and 1.76±0.78 mm were observed at 36 months after loading in groups A, B, and C, respectively, and bone loss was significantly greater in group C than in groups A and B. Conclusions The vertical position of the implant-abutment interface may affect marginal bone level change. Marginal bone loss was significantly greater in cases where the implant-abutment interface was positioned below the marginal bone. Further long-term study is required to validate our results., Graphical Abstract

Objectives The aim of the current study was to evaluate the detection and diagnosis of three types of odontogenic cystic lesions (OCLs)-odontogenic keratocysts, dentigerous cysts, and periapical cysts-using dental panoramic radiography and cone beam computed tomographic (CBCT) images based on a deep convolutional neural network (CNN). Methods The GoogLeNet Inception-v3 architecture was used to enhance the overall performance of the detection and diagnosis of OCLs based on transfer learning. Diagnostic indices (area under the ROC curve [AUC], sensitivity, specificity, and confusion matrix with and without normalization) were calculated and compared between pretrained models using panoramic and CBCT images. Results The pretrained model using CBCT images showed good diagnostic performance (AUC = 0.914, sensitivity = 96.1%, specificity = 77.1%), which was significantly greater than that achieved by other models using panoramic images (AUC = 0.847, sensitivity = 88.2%, specificity = 77.0%) (p = .014). Conclusions This study demonstrated that panoramic and CBCT image datasets, comprising three types of odontogenic OCLs, are effectively detected and diagnosed based on the deep CNN architecture. In particular, we found that the deep CNN architecture trained with CBCT images achieved higher diagnostic performance than that trained with panoramic images.

Objectives The aim of this randomized, controlled, parallel-arm study was to evaluate the (a) radiographic bone dimensional changes, (b) postoperative discomfort, and (c) early soft tissue wound healing outcomes, following extraction of maxillary anterior teeth (central and lateral incisors) and treatment with alveolar ridge preservation (ARP) with and without the adjunctive use of enamel matrix derivative (EMD). Methods Thirty extraction sockets were randomly assigned to two groups: deproteinized bovine bone mineral with 10% collagen covered with collagen membrane with the adjunctive use of EMD (test group) and without EMD (control group). Bone dimensional changes were measured using cone beam computed tomography at 3 and 5 months after ARP. The severity and duration of pain and swelling were evaluated using self-reported questionnaires, and soft tissue wound healing outcomes were assessed clinically. Chi-square tests and t tests were conducted to compare differences between the two groups. Results Radiographic and clinical analyses showed no significant differences in horizontal and vertical bone dimensional changes and soft tissue wound healing outcomes (including spontaneous bleeding, persistent swelling, and ulceration) between the two groups. There were no significant differences in the severity of pain and swelling between the two groups, but the durations of pain (difference [df] = 1.20, 95% CI = 0.33-2.06; p = .008) and swelling (df = 1.06, 95% CI = 0.11-2.01; p = .029) were significantly reduced in the test group. Conclusion Alveolar ridge preservation with the adjunctive use of EMD reduced the durations of postoperative pain and swelling following maxillary anterior teeth extraction.

Purpose This study investigated the association between health status and tooth loss based on data from the National Health Insurance Service-Health Examinee Cohort in 2002–2015. Methods Multivariate Cox proportional hazards regression analyses were applied to a longitudinal retrospective database, which was updated and newly released in 2018, to assess the association between health status and tooth loss while adjusting for potential confounders among sociodemographic and economic factors (sex, age, household income, insurance, and presence of disability), general and oral health status (body mass index [BMI], smoking and drinking status, periodic dental visits and scaling, and brushing before sleep), and comorbid disease (hypertension, diabetes mellitus [DM], and Charlson comorbidity index [CCI]). Results Among 514,866 participants from a South Korean population, 234,247 (45.5%) participants satisfying the inclusion criteria were analyzed. In the adjusted multivariate analysis, sex, age, household income, insurance, presence of disability, BMI, smoking and drinking status, periodic scaling, tooth brushing before sleep, DM, and CCI showed statistically significant associations with the loss of at least 1 tooth. The risk of experiencing a loss of ≥4 teeth was associated with an increase in age (in those 50–59 years of age: hazard ratio [HR], 1.98; 95% confidence interval [CI], 1.93–2.03; in those 60–69 years of age: HR, 2.93; 95% CI, 2.85–3.02; and in those 70–79 years of age: HR, 2.93; 95%, CI 2.81–3.05), smoking (HR, 1.69; 95% CI, 1.65–1.73), and DM (HR, 1.43; 95% CI, 1.38–1.48). Conclusions The results of this study showed that the risk of experiencing tooth loss was related to multiple determinants. DM and smoking were especially significantly associated with tooth loss., Graphical Abstract

Purpose The aim of this study was to evaluate and compare tooth surface characteristics in extracted human molars after cervical enamel projections (CEPs) were removed with the use of three rotating instruments. Methods We classified 60 extracted molars due to periodontal lesion with CEPs into grade I, II, or III, according to the Masters and Hoskins’ criteria. Each group contained 20 specimens. Three rotating instruments were used to remove the CEPs: a piezoelectric ultrasonic scaler, a periodontal bur, and a diamond bur. Tooth surface characteristics before and after removal of the projections were then evaluated with scanning electron microscopy (SEM). We analyzed the characteristics of the tooth surfaces with respect to roughness and whether the enamel projections had been completely removed. Results In SEM images, surfaces treated with the diamond bur were smoothest, but this instrument caused considerable harm to tooth structures near the CEPs. The piezoelectric ultrasonic scaler group produced the roughest surface but caused less harm to the tooth structure near the furcation. In general, the surfaces treated with the periodontal bur were smoother than those treated with the ultrasonic scaler, and the periodontal bur did not invade adjacent tooth structures. Conclusions For removal of grade II CEPs, the most effective instrument was the diamond bur. However, in removing grade III projections, the diamond bur can destroy both adjacent tooth structures and the periodontal apparatus. In such cases, careful use of the periodontal bur may be an appropriate substitute., Graphical Abstract

Convolutional neural networks (CNNs), a particular type of deep learning architecture, are positioned to become one of the most transformative technologies for medical applications. The aim of the current study was to evaluate the efficacy of deep CNN algorithm for the identification and classification of dental implant systems. A total of 5390 panoramic and 5380 periapical radiographic images from 3 types of dental implant systems, with similar shape and internal conical connection, were randomly divided into training and validation dataset (80%) and a test dataset (20%). We performed image preprocessing and transfer learning techniques, based on fine-tuned and pre-trained deep CNN architecture (GoogLeNet Inception-v3). The test dataset was used to assess the accuracy, sensitivity, specificity, receiver operating characteristic curve, area under the receiver operating characteristic curve (AUC), and confusion matrix compared between deep CNN and periodontal specialist. We found that the deep CNN architecture (AUC = 0.971, 95% confidence interval 0.963–0.978) and board-certified periodontist (AUC = 0.925, 95% confidence interval 0.913–0.935) showed reliable classification accuracies. This study demonstrated that deep CNN architecture is useful for the identification and classification of dental implant systems using panoramic and periapical radiographic images.

Purpose The purpose of this study was to evaluate severe periodontitis with tooth loss as a modifiable risk factor for Alzheimer dementia (AD), vascular dementia (VaD), and mixed dementia (MD) using the National Health Insurance Service-National Health Screening Retrospective Cohort database with long-term follow-up over 14 years. Methods Multivariate Cox hazards regression analysis was applied to a longitudinal retrospective database, which was updated in 2018, to evaluate the association between severe periodontitis with few remaining teeth and dementia after adjusting for potential risk factors, including sociodemographic factors and comorbid diseases. Results Among 514,866 individuals in South Korea, 237,940 (46.2%) participants satisfying the inclusion criteria were selected. A total of 10,115 age- and sex-matched participants with severe periodontitis and 10,115 periodontally healthy participants were randomly selected and evenly assigned. The results showed that the risks of AD (hazard ratio [HR], 1.08), VaD (HR, 1.24), and MD (HR, 1.16) were significantly higher in patients with severe periodontitis with 1–9 remaining teeth after adjustment for sociodemographic factors, anthropomorphic measurements, lifestyle factors, and comorbidities. Conclusions Severe periodontitis with few remaining teeth (1–9) may be considered a modifiable risk factor for the development of AD, VaD, and MD in Korean adults., Graphical Abstract

Purpose: The concept of gingival biotype has been used as a predictor of periodontal therapy outcomes since the 1980s. In the present study, prospective and controlled experiments were performed to compare periodontal pocket depth (PPD) reduction and gingival shrinkage (GSH) after scaling and root planing (SRP) according to gingival biotype. Methods: Twenty-five patients diagnosed with chronic periodontitis participated in the present study. The PPD and GSH of the labial side of the maxillary anterior teeth (from the right canine to the left canine) were evaluated at baseline and 3 months after SRP. Changes in the PPD following SRP were classified into 4 groups according to the gingival thickness and initial PPD. Two more groups representing normal gingival crevices were added in evaluation of the GSH. The results were statistically analyzed using the independent t-test. Results: In the end, 16 patients participated in the present study. With regard to PPD reduction, there were no significant differences according to gingival biotype (P > 0.05). Likewise, sites with a PPD of over 3 mm failed to show any significant differences in the GSH (P > 0.05). However, among the sites with a PPD of under 3 mm, those with the thin gingival biotype showed more GSH (P < 0.05). Conclusions: PPD changes after SRP were not affected by gingival biotype with either shallow or deep periodontal pockets. GSH also showed equal outcomes in all the groups without normal gingival crevices. The results of SRP seem not to differ according to gingival biotype.

PURPOSE The aim of this study was to explore root shape abnormalities, to investigate the influence of root form abnormalities on periodontal attachment loss, and to gather basic data to assist in the diagnosis and treatment of aggressive periodontitis. METHODS From January 2010 to June 2012, a survey was conducted of all 3,284 periodontitis patients who visited the Department of Periodontology, Daejeon Dental Hospital, Wonkwang University School of Dentistry. Clinical parameters (probing depth, periodontal attachment loss, missing teeth) were measured and a radiographic examination was performed at the baseline. We classified the root shape abnormality of bicuspids and molars based on Meng classification. RESULTS The periodontal attachment loss was the highest at the maxillary first molar (6.03 mm). The loss of the second molar was prominent. Type V deformity was shown to be the most common in the second maxillary and mandibular molars (P

Purpose The aim of the current study was to develop a computer-assisted detection system based on a deep convolutional neural network (CNN) algorithm and to evaluate the potential usefulness and accuracy of this system for the diagnosis and prediction of periodontally compromised teeth (PCT). Methods Combining pretrained deep CNN architecture and a self-trained network, periapical radiographic images were used to determine the optimal CNN algorithm and weights. The diagnostic and predictive accuracy, sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve, area under the ROC curve, confusion matrix, and 95% confidence intervals (CIs) were calculated using our deep CNN algorithm, based on a Keras framework in Python. Results The periapical radiographic dataset was split into training (n=1,044), validation (n=348), and test (n=348) datasets. With the deep learning algorithm, the diagnostic accuracy for PCT was 81.0% for premolars and 76.7% for molars. Using 64 premolars and 64 molars that were clinically diagnosed as severe PCT, the accuracy of predicting extraction was 82.8% (95% CI, 70.1%–91.2%) for premolars and 73.4% (95% CI, 59.9%–84.0%) for molars. Conclusions We demonstrated that the deep CNN algorithm was useful for assessing the diagnosis and predictability of PCT. Therefore, with further optimization of the PCT dataset and improvements in the algorithm, a computer-aided detection system can be expected to become an effective and efficient method of diagnosing and predicting PCT., Graphical Abstract