The relationship between the uptake of alveolar bone inflammation and of cervical lymph nodes on FDG-PET.

OBJECTIVES: To elucidate the relationships between the maximum standardized uptake value (SUVmax) of alveolar bone and those of lymph nodes (LNs) around the neck on 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET). METHODS: The SUVmax values of alveolar bone and of level IA, level IB, and level IIA LNs of 174 patients, including those with and without active odontogenic inflammation, on PET/computed tomography (PET/CT) performed for a health check were retrospectively evaluated. The upper and lower jaws were divided into four blocks (right maxilla, left maxilla, right mandible, and left mandible). The SUVmax values of each block and of the LNs were calculated. The differences in the SUVmax of each LN level between patients with and without odontogenic inflammation, and the relationship between the SUVmax values of alveolar bone and of the LNs were analyzed statistically. RESULTS: Significant differences in SUVmax values of bilateral level IB and IIA LNs were found between patients with and without odontogenic inflammation (Mann-Whitney U test: right level IB, p = 0.008; left level IB, p = 0.006; right level IIA, p < 0.001; left level IIA, p = 0.002), but not in bilateral level IA LNs (Mann-Whitney U test: right level IA, p = 0.432; left level IA, p = 0.549). The inflammatory site with the highest SUVmax in level IB LNs was the ipsilateral mandible (multivariate analysis: right, beta = 0.398, p < 0.001; left, beta = 0.472, p < 0.001), and the highest SUVmax in level IIA LNs was the ipsilateral maxilla (multivariate analysis: right, beta = 0.223, p = 0.002; left, beta = 0.391, p < 0.001). CONCLUSIONS: The SUVmax values of level IB and IIA LNs were associated with a tendency toward a higher SUVmax value of alveolar bone on 18F-FDG-PET.

Correlation between the presence of tonsilloliths and the bone defects by periodontitis on imaging analysis: a pilot study.

BACKGROUND: Very recently, a significant relationship between tonsilloliths and dental plaque-related pathologies was reported using digital panoramic radiographs. Their dynamics over time suggest that tonsilloliths may be in a permanently active phase that functions to remove foreign matter. The aim of the study was to evaluate the relationship between the occurrence of tonsilloliths and the extent of periodontitis. METHODS: A total of 608 patients who underwent both CT and panoramic radiographs were included in the study. Both of two imaging were retrospectively and independently assessed with respect to the presence of tonsilloliths detected on CT and panoramic radiographs, and bone defects caused by periodontitis detected on panoramic radiographs. The type of retrospective study is case-control. Then, the differences between age groups were evaluated with respect to the degree of bone resorption and its correlation with the presence of tonsilloliths. The relationships between categorical variables were assessed using Pearson's correlation coefficient or Spearman's correlation coefficient. RESULTS: There was a significant relationship between tonsilloliths on CT and the extent of the bone defect on panoramic radiographs (Spearman's correlation coefficient, r = 0.648, p = 0.043). In addition, there was a significant difference in the extent of the bone defect caused by periodontitis between subjects with and without tonsilloliths in the 60 to 69-year-old group (Mann-Whitney U test, p = 0.025), 70 to 79-year-old group (Mann-Whitney U test, p = 0.002), and 80 to 89-year-old group (Mann-Whitney U test, p = 0.022), but not in other age groups (Mann-Whitney U test: under 9-year-old group, p = 1.000; 10 to 19-year-old group, p = 1.000; 20 to 29-year-old group, p = 0.854; 30 to 39-year-old group, p = 0.191, 40 to 49-year-old group, p = 0.749; 50 to 59-year-old group, p = 0.627; ≥90-year-old group, p = 1.000). CONCLUSIONS: The presence of tonsilloliths was related to the extent of periodontitis because the structures were responding dynamically.

Imaging Characteristics of Embedded Tooth-Associated Cemento-Osseous Dysplasia by Retrospective Study.

BACKGROUND: Since there are many differential diagnoses for cemento-osseous dysplasia (COD), it is very difficult for dentists to avoid misdiagnosis. In particular, if COD is related to an embedded tooth, differential diagnosis is difficult. However, there have been no reports on the characteristics of the imaging findings of COD associated with embedded teeth. The aim of the present study was to investigate the occurrence and imaging characteristics of cemento-osseous dysplasia (COD) associated with embedded teeth, in order to appropriately diagnose COD with embedded teeth. METHODS: The radiographs with or without histological findings of 225 patients with COD were retrospectively analyzed. A retrospective search through the picture archiving and communication system (PACS) of the Division of Oral and Maxillofacial Radiology of Kyushu Dental University Hospital was performed to identify patients with COD between 2011 and 2022. RESULTS: Fifteen COD-associated embedded mandibular third molars were identified in 13 patients. All 13 patients were asymptomatic. On imaging, COD associated with embedded mandibular third molars appeared as masses that included calcifications around the apex of the tooth. On panoramic tomography, COD showed inconspicuous internal calcification similar to that of odontogenic cysts or simple bone cysts, especially in patients with COD only around the mandibular third molar region. Those with prominent calcification resembled cemento-ossifying fibroma, calcifying epithelial odontogenic tumor, calcifying odontogenic cyst, adenomatoid odontogenic tumor, and so on, as categories of masses that include calcifications on panoramic tomography and computed tomography. CONCLUSIONS: The current investigation is the first to report and analyze the imaging characteristics of COD associated with embedded teeth. It is important to consider the differences between COD and other cystic lesions on panoramic tomography, and the differences between COD and masses that include calcifications on CT.

Imaging characteristics of gubernaculum tracts in patients with cleidocranial dysplasia: a computed tomography study.

OBJECTIVES: To elucidate the imaging characteristics of the gubernaculum tract (GT) in patients with cleidocranial dysplasia (CCD) as visualized with computed tomography (CT). STUDY DESIGN: This was a retrospective analysis of the presence and shape of GTs of unerupted permanent teeth and supernumerary teeth on CT in 9 patients with CCD. RESULTS: The overall GT detection rate for unerupted permanent teeth was 83.5% (81/97), with no significant difference between permanent teeth without and with adjacent supernumerary teeth (P = .414). The overall GT detection rate for unerupted supernumerary teeth was 83.1% (49/59). Of the 156 total unerupted teeth analyzed, 83.3% (130/156) were judged to have GTs. No significant difference in detection rate of GTs was found between permanent and supernumerary teeth (P > 0.999). A composite morphology consisted of a single GT for a permanent unerupted tooth with 1 or 2 supernumerary teeth in which the dental follicles of the permanent and supernumerary teeth were confluent. In total, 44 groups consisted of 1 permanent and 1 or 2 supernumerary teeth; 79.5% (35/44) had GTs. CONCLUSIONS: A specific composite structure of GTs and dental follicles may signify that 2 or 3 teeth are derived from a single dental lamina in patients with CCD. In such cases, tooth eruption may fail due to the presence of only 1 GT for multiple teeth.

Influence of New Sleeve Composite on Fracture Behavior of Anterior Teeth with Flared Root Canals.

We evaluated the fracture strength and failure mode of non-ferrule teeth with flared root canals that were restored using new experimental sleeve composites. Fifty endodontically treated anterior teeth with flared root canals were restored with direct restorations utilizing different techniques. Group A had teeth (non-ferrule) restored using commercialized MI glass fiber post + Gradia Core as core build-up. Group B had teeth (non-ferrule) restored with commercialized i-TFC glass fiber post + sleeve system. In Group C, the teeth (non-ferrule) were restored with an experimental sleeve composite with commercialized MI glass fiber post and Gradia Core. Group D, teeth (non-ferrule), were restored using custom-made tapered E-glass filling post and Gradia Core. Group E, teeth (with ferrule), were restored with commercialized MI glass fiber post + Gradia Core. After core construction, all specimens underwent direct composite crown restoration and were loaded until fracture using a universal testing machine. Average fracture loads were compared, and the failure modes were observed. Group C exhibited significantly greater fracture strength than other groups (p < 0.05). Favorable fracture teeth ratio of group C was more than that of the other groups. Thus, the new experimental sleeve composite could be clinically useful for core construction of non-ferrule teeth.

Effect of COVID-19 on dental telemedicine in Japan.

BACKGROUND/PURPOSE: In Japan, medical and dental care is provided by the universal health insurance system. The Ministry of Health, Labour, and Welfare (MHLW) in Japan sets the rules for health care services provided by health insurance. The MHLW issued a notice in 2020 permitting telemedicine and dental telemedicine for the first visit and for follow-up visits to prevent the spread of COVID-19 infection. We conducted this study to clarify the status of dental telemedicine during 2020. MATERIALS AND METHODS: We used data from lists obtained on the MHLW website in the analysis. We investigated the number of dental institutions conducing dental telemedicine for the first visit and for follow-up visits by prefecture. RESULTS: In each prefecture, fewer dental institutions conducted telemedicine for the first visit than for follow-up visits. Regions with large metropolitan areas had higher numbers of dental institutions conducting dental telemedicine for the first visit and follow-up visits. Private dental clinics provided the largest proportion of dental telemedicine for the first visit, and general hospitals provided the largest proportion for follow-up visits. CONCLUSION: Our study findings indicated that many dental institutions in Japan made efforts to provide dental services via dental telemedicine using the telephone or online with video to help prevent the spread of COVID-19 infection. Dental telemedicine can help patients to access dental services and dental care, thereby expanding the potential of dental telemedicine in Japan.

Concordance study between regular face-to-face dental diagnosis and dental telediagnosis using fluorescence.

BACKGROUND: Teledentistry consultations are an effective way to increase access to care. Whether it be for a screening, referral or even an adapted treatment plan for a certain number of patients whose access to care is complicated, demonstrating the reliability of remote consultations is essential in allowing the technique to become generalised. AIM: This study aimed to determine if teledentistry consultations using fluorescence are of the same quality as regular consultations in the diagnosis of caries. METHODS: Patients were seen in consultation in the dental care centre at the Montpellier University Hospital (France) and in the centre at Kyushu Dental University Hospital (Japan). The protocol was broken down into three parts: the regular consultation, the recording of videos with the Soprocare camera and the remote consultation. The regular consultation and the remote consultation were blinded and carried out by two different dentists. The recording of videos was carried out by a third dentist. The carious diagnosis was based on the International Caries Detection and Assessment System: a clinical rating system for the detection and assessment of caries. RESULTS: One hundred and ninety-five patients met the predefined inclusion criteria. Most patients had at least one surface at stage 3 or higher (73%) with a higher proportion amongst French patients (81% compared to 66%). However, they had good dental hygiene, given that dental hygiene was only deemed unsatisfactory for 10.8% (19% for French patients and 2% for Japanese patients). The odontogram (presence/absence of each tooth) seemed to be correctly identified during the remote consultation (reinterpretation). Out of the 195 patients, 168 (86.2%) were identified without error. CONCLUSIONS: Teledentistry consultations can represent acceptable diagnostic performance with regard to the detection of dental caries. The Soprocare camera enables an early diagnosis of carious lesions with optimal efficiency. Several areas still need to be improved, however, so that the use of the camera during remote consultations is as coherent and effective as possible, especially with regard to the organisational aspects of remote consultations.

Adhesive bonding of alumina air-abraded Ag-Pd-Cu-Au alloy with 10-methacryloyloxydecyl dihydrogen phosphate.

The aim of this paper is to study changes in the Ag-Pd-Cu-Au alloy surfaces by alumina air-abrasion process and effect of those changes on the adhesive bonding characteristic. Surface roughness, surface composition and chemical state of the alumina air-abraded alloys were analyzed by a confocal laser scanning microscope, an energy dispersive X-ray spectroscopy and an X-ray photoelectron spectroscopy. The results showed that the alumina air-abrasion changed the alloy surface by mechanical roughening, alumina remain and copper oxidation. Effect of the changes in the alloy surface on the adhesive bonding characteristic was examined by using a methyl methacrylate/tri-n-butylborane derivative (MMA/TBB) resin cement with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer. The shear bond strength test results indicated that the surface oxidation by the abrasion is the main contributor that improved the adhesive bonding rather than other effects such as mechanical roughening or alumina remain.

Effect of Bioactive Glass-Based Root Canal Sealer on the Incidence of Postoperative Pain after Root Canal Obturation.

The purpose of this study is to evaluate the effect of a bioactive glass-based root canal sealer, Nishika Canal Sealer BG (CS-BG), on the incidence of postoperative pain (PP) after root canal obturation (RCO). Eleven dentists performed pulpectomy or infected root canal treatments for 555 teeth. During RCO, CS-BG was used. After RCO, the rate of PP and the factors affecting PP (pain during RCO and pain immediately after RCO) were analyzed. PP was observed in eight teeth (1.5%), and within 7 days after RCO, there were no teeth with pain. In these teeth with PP, there was a significant difference in the occurrence of pain during RCO, but not in the occurrence of pain immediately after RCO, when compared with pulpectomy and infected root canal treatment. These clinical results show that CS-BG has an excellent biocompatibility, and can suppress the distress of patients during RCO.

Bioactive Glass-Based Endodontic Sealer as a Promising Root Canal Filling Material without Semisolid Core Materials.

Endodontic treatment for a tooth with damaged dental pulp aims to both prevent and cure apical periodontitis. If the tooth is re-infected as a result of a poorly obturated root canal, periapical periodontitis may set-in due to invading bacteria. To both avoid any re-infection and improve the success rate of endodontic retreatment, a treated root canal should be three-dimensionally obturated with a biocompatible filling material. Recently, bioactive glass, one of the bioceramics, is focused on the research area of biocompatible biomaterials for endodontics. Root canal sealers derived from bioactive glass-based have been developed and applied in clinical endodontic treatments. However, at present, there is little evidence about the patient outcomes, sealing mechanism, sealing ability, and removability of the sealers. Herein, we have developed a bioactive glass-based root canal sealer and provided evidence concerning its physicochemical properties, biocompatibility, sealing ability, and removability. We also review the classification of bioceramics and characteristics of bioactive glass. Additionally, we describe the application of bioactive glass to facilitate the development of a new root canal sealer. Furthermore, this review shows the potential application of bioactive glass-based cement as a root canal filling material in the absence of semisolid core material.

Chemical alteration of Ag-Pd-Cu-Au alloy surface by alumina air-abrasion and its effect on bonding to resin cement.

The goal of this study was to investigate the chemical alteration of a dental alloy surface by alumina air-abrasion and its effect on bonding to resin cement. Alumina air-abrasion was carried out on an Ag-Pd-Cu-Au alloy. The surface morphology and chemical state of the abraded alloy were characterized. The effect of the air-abrasion on the shear bond strength between the alloy and a methyl methacrylate/tri-n-butyl borane (MMA/TBB) resin cement with some primers was evaluated. The surface characterization revealed that the alumina air-abrasion mechanically roughened and chemically altered the surface. The chemical alterations had two effects: (1) abraded alumina particles remained on the alloy surface and (2) copper ions were oxidized in the alloy surface. As the result, the shear bond strength test indicated that 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer worked with the abraded alloy surface, whereas it did not work with the non-abraded alloy surface.

Endoscopic System Based on Intraoral Camera and Image Processing.

OBJECTIVE: In dentistry, dentists perform many treatments with a few visually magnified information. About deep area of root canals, it commonly relies on exploration carried out with the fingers of the dentist, because the root canal entrance is very small to be observed. In clinical practice, the intraoral camera and endoscopic systems are separate devices, and there are no sensors to capture both pictures of the whole tooth and those inside the root canal. Objective of this research is to combine the intraoral camera and endoscopic system facilitating to use clinical practice. METHODS: We propose an endoscopic system based on the thin image fiber, SOPROLIFE intraoral camera as an image sensor, and a new adaptor to connect the two parts. We observed resolution charts with 50, 25, 10, and 5 line pairs (LP)/mm patterns. The acquired images are processed to both remove fixed-pattern noise using robust principal component analysis and enhance contrast. RESULTS: The acquired images containing all LP/mm patterns were clear and showed higher contrast after processing. Visibility of the processed images is 1.7, 1.6, 2.2, and 1.9 times higher than that of the raw images for 50, 25, 10, and 5 LP/mm patterns, respectively. CONCLUSION: Our fabricated endoscopic system based on the SOPROLIFE intraoral camera could observe 50, 25, 10, and 5 LP/mm patterns. After image processing, the noise was reduced, and high-contrast images were obtained. SIGNIFICANCE: This system can be considered as a further step toward facilitating noninvasive and contactless systems in clinical practice.

In Vitro Evaluation of a Novel Root Canal Endoscope for Visualizing the Apex of Curved Root Canal Models and an Extracted Tooth.

INTRODUCTION: In straight root canals, intraradicular structures around the root canal orifice and apical foramen can be visualized with a dental operating microscope and commercially available root canal endoscopes. However, the root apex area, including the apical foramen, in a curved root canal cannot be visualized using these devices. In the present study, the potential of a newly developed root canal endoscope implementing an image fiber was examined in 3 types of root canal models and extracted teeth. METHODS: A straight and 2 curved (10° and 30°) resin block models were prepared. A resolution chart was set at the outer surface of the apical foramen in each model. Using the microscope and the endoscope, the resolution chart was observed, and the captured images were analyzed quantitatively. Additionally, fracture lines in 20 extracted teeth were observed with both devices. RESULTS: With the dental operating microscope, a resolution chart line was clearly observed in the straight canal model with 18.0 line pairs/mm resolution and an observing capability of 0.16 at 40 × magnification but not in the curved root canal models. With the root canal endoscope, resolution charts in all types of root canal models were visualized, and the resolution and observing capability were 16.0 line pairs/mm and 0.053, respectively. Fracture lines and the apical foramen of the extracted teeth were observed more clearly with the endoscope than the microscope. CONCLUSIONS: The newly developed root canal endoscope using an image fiber is useful for accurate visualization of the apex area of curved root canals.

Two-year clinical comparison of a flowable-type nano-hybrid composite and a paste-type composite in posterior restoration.

AIM: The purpose of the present study was to compare the clinical efficacy between a flowable-type nano-hybrid composite and a paste-type composite for posterior restoration. METHODS: Of 62 posterior teeth in 33 patients (mean age: 34.1 years), 31 were filled with a paste-type composite (Heliomolar [HM] group), and another 31 with a flowable nano-hybrid composite (MI FIL [MI] group). Clinical efficacy was evaluated at 2 years after the restoration. RESULTS: There were no differences for retention, surface texture deterioration, anatomical form change, deterioration of marginal adaptation, and secondary caries, while a statistical difference was found for marginal discoloration, which was significantly greater in the HM group (P < 0.05). Furthermore, color matching in the MI group was superior to that in the HM group immediately after the restoration throughout the study period. CONCLUSIONS: The present 2-year clinical evaluation of different composites showed that the flowable nano-hybrid composite could be an effective esthetic material for posterior restoration.