Effectiveness of novel oral hygiene instruction avoiding inattentional blindness using an application for unique plaque control record calculation: A randomized clinical trial.

OBJECTIVE: This study was performed to estimate the effectiveness of novel oral hygiene instruction (OHI) focusing on areas with deep periodontal pockets for reduction of periodontal inflammation. BACKGROUND DATA DISCUSSING THE PRESENT STATUS OF THE FIELD: Because stained areas on the plaque chart do not always correspond to the areas with deep periodontal pockets, conventional OHI based on O'Leary's plaque control record (PCR) often provides guidance inconsistent with the target area. METHODS: This randomized clinical trial involved two groups: (1) OHI based on the PCR limited in deep pocket sites (novel OHI group) and (2) OHI based on O'Leary's PCR (conventional OHI group). The unique PCR (aggressive target for PCR [agPCR]; only counting the plaque-stained areas with PD at ≥4 mm sites) for the novel OHI was calculate by dedicated expression program. The probing depth (PD), bleeding on probing (BOP), and periodontal inflamed surface area (PISA) were obtained at the baseline and 5 to 6 months later. RESULTS: The approximation curve with PISA before and after instruction indicated that the PISA converged to a lower value after instruction in the novel OHI group. The approximation curve with the improvement rate of the PISA and agPCR showed a positive correlation in the novel OHI group but no correlation in the conventional OHI group. CONCLUSION: Control of inflammation was more effective in the novel OHI group. These results suggest that this novel OHI technique using our developed application could be used as a strategy to improve the effectiveness of brushing instruction.

Unusual imaging appearance of cemental tear in the maxillary first molar on cone-beam computed tomography: A case report.

A cemental tear (CeT) is a definitive clinical entity and its radiographic appearance is well known in single-rooted teeth. However, the imaging features of CeT in multi-rooted teeth have not been clarified. We report a case of CeT which arose in the maxillary first molar and exhibited an unusual appearance in cone-beam computed tomography images. The torn structure was verified as cementum by micro-computed tomography and histological analysis. The hypercementosis, most likely induced by occlusal force, might have been torn from the root by a stronger occlusal force caused by the mandibular implant. An unusual bridging structure was created between the two buccal roots. These features may occur in multi-rooted teeth with long-standing deep pockets and abscesses that are resistant to treatment.

Suppression of subgingival bacteria by antimicrobial photodynamic therapy using transgingival irradiation: A randomized clinical trial.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) is an effective method for eradicating bacteria in periodontal therapy. Standard aPDT requires the insertion of a laser tip into a periodontal pocket, in which the direction of irradiation is limited. Therefore, we devised an aPDT method that uses a transgingival near-infrared wavelength and indocyanine green-encapsulated and chitosan-coated nanoparticles as a photosensitizer. METHODS: Forty patients undergoing supportive periodontal therapy, who had a single root tooth with a pocket of 5 mm or deeper, were used as subjects. In the test group, aPDT was performed by laser irradiation from outside the gingiva using photosensitizer nanoparticles. In the control group, pseudo aPDT without photosensitizer was performed by transgingival irradiation. Subgingival plaque was sampled from inside the pocket before, immediately after, and 1 week after treatment, and evaluated by colony counting and real-time polymerase chain reaction. RESULTS: There were no significant differences in age, sex, periodontal pocket depth, and bleeding on probing between the test and control groups. Compared with the colony count before treatment, the count in the test group was significantly reduced immediately after treatment. The number of patients with colony reduction to ≤50% and ≤10% was significantly higher in the test group than in the control group. None of the participants reported pain, although one participant reported discomfort. CONCLUSION: As a bacterial control method for residual pockets in patients undergoing supportive periodontal therapy, transgingival aPDT is a promising treatment strategy that is not generally accompanied by pain or discomfort.

Ebi3 knockout aggravates experimental periodontitis via Th17 polarization.

AIM: To investigate the role of Ebi3-related cytokines (i.e., interleukin [IL]-35 and/or IL-27) in experimental periodontitis using Ebi3 knockout (KO) mice. MATERIALS AND METHODS: The maxillary right second molar teeth of Ebi3 KO mice and C57BL/6 mice were tied with a silk ligature to induce periodontitis. Three days after ligation, gingival tissues were collected for gene expression analyses. Five days after ligation, the maxillae were removed for haematoxylin and eosin staining and immunohistochemistry. Seven days after ligation, the maxillae were removed for micro-computed tomography. RESULTS: The ligated side of Ebi3 KO mice showed intense alveolar bone resorption, which was substantially more pronounced than in wild-type (WT) mice. IL-17A expression was significantly higher in the gingiva of the ligated side of Ebi3 KO mice compared with WT mice. IL-10 expression was significantly lower in Ebi3 KO mice than in WT mice. The ligature-induced alveolar bone resorption in Ebi3 KO mice that received recombinant IL-35 injection was significantly less compared with that in Ebi3 KO mice that received control injection. CONCLUSIONS: Together, these findings suggest that Th17 cells exacerbate experimental periodontitis in mice lacking Ebi3 and that IL-35 may play a critical role in inhibiting periodontal tissue destruction.

Increased expression of angiopoietin-like protein 4 regulates matrix metalloproteinase-13 expression in Porphyromonas gingivalis lipopolysaccharides-stimulated gingival fibroblasts and ligature-induced experimental periodontitis.

BACKGROUND: Angiopoietin-like protein 4 (ANGPTL4) is produced in chronic or acute inflammation. Although ANGPTL4 increases in the periodontal ligament fibroblasts during hypoxia, the involvement and role of ANGPTL4 in periodontitis have not been elucidated. OBJECTIVE: In this study, we investigated whether ligature-induced experimental periodontitis and/or Porphyromonas gingivalis lipopolysaccharides (Pg-LPS) would upregulate ANGPTL4 expression and whether ANGPTL4 would somehow involve in the expression of matrix metalloproteinases (MMPs) which are key molecules in the process of periodontal tissue destruction. METHODS: Experimental periodontitis was induced in 6-week-old male Sprague-Dawley rats by placing a nylon suture around the neck of the maxillary second molar. Two weeks after the induction of periodontitis, the periodontal tissue was excised and analyzed by histological/immunohistochemical staining and gene expression analyses. Human gingival fibroblasts (hGFs) were stimulated with Pg-LPS. The gene expression of ANGPTLs and receptors involved in ANGPTL4 recognition were observed. We also confirmed the changes in gene expression of MMPs upon stimulation with human ANGPTL4. Furthermore, we downregulated ANGPTL4 expression by short interfering RNA in hGFs and investigated the effect of Pg-LPS on MMP production. RESULTS: Induction of periodontitis significantly increased the expression of ANGPTL4 in the gingiva. Pg-LPS significantly increased the gene and protein expression of ANGPTL4 in hGFs but not the gene expression of other ANGPTLs or ANGPTL receptors. Recombinant human ANGPTL4 significantly increased MMP13 gene expression in hGFs. We also confirmed that MMP13 expression was increased in the gingiva during experimental periodontitis. Pg-LPS induced MMP13 gene expression in hGFs. These results suggest the pivotal role of ANGPTL4 in periodontitis. CONCLUSION: Periodontitis increases ANGPTL4 expression in the gingiva, further suggesting that increased ANGPTL4 may be a factor involved in enhancing MMP13 expression.

Porphyromonas gingivalis Fimbriae Induce Osteoclastogenesis via Toll-like Receptors in RAW264 Cells.

The effect of Mfa1 fimbriae of Porphyromonas gingivalis on the progression of bone resorption remains unclear, especially compared with another fimbriae, FimA. We investigated the effect of Mfa1 on osteoclastogenesis together with FimA. We also investigated the role of Toll-like receptors (TLRs) in Mfa1 recognition during osteoclast differentiation. Receptor activator of nuclear factor κß ligand (RANKL)-prestimulated RAW264 cells were used to examine the effects of purified Mfa1 fimbriae. The number of osteoclasts was examined by tartrate-resistant acid phosphate (TRAP) staining, osteoclast activation was investigated by bone resorption assays, and gene expression of differentiation markers was examined by quantitative real-time PCR. Transfection of Tlr2 and Tlr4 siRNAs into RAW264 cells was also employed and their role in Mfa1 recognition was investigated. Mfa1 effectively induced the formation of TRAP-positive multinucleated cells and activated osteoclasts. Mfa1 also increased gene expression of Acp5, Mmp9, and Ctsk in RANKL-prestimulated RAW264 cells compared with the control. The osteoclastogenesis induced by Mfa1 was significantly decreased in cells transfected with Tlr2 or Tlr4 siRNAs compared with control siRNA. Our results revealed the role of Mfa1 fimbriae in osteoclastogenesis that may contribute to the partial elucidation of the mechanisms of periodontal disease progression and the development of new therapeutic strategies.

Smoking Status and Risk Awareness of Heated Tobacco Product Use among General Dental Practitioners Belonging to the Aichi Dental Association, Japan.

The awareness of healthcare practitioners concerning heated tobacco product (HTP) use risks has been evaluated; however, few studies have investigated general dental practitioners' awareness regarding HTP-use risks. In this cross-sectional study, we investigated dentists' awareness of the risks of smoking, particularly HTP use. A self-administered questionnaire, including eight questions on conventional cigarette and HTP smoking/using status and both knowledge and awareness of HTP-use risks, was posted to 3883 dentists belonging to the Aichi Dental Association, Japan, in August 2019. Statistical analysis was performed using the Statistical Package for Social Sciences; statistical significance was set at p < 0.05. We analyzed the data of 1317 dentists (participation rate, 41.6%). The study group included cigarette smokers (11.5%) and HTP users (8.5%), among whom 41.1% were dual users. HTP users were more likely than never smokers/users to correctly perceive HTP-use risks (p < 0.05). This study indicates that in Japan, the proportion of HTP users is higher than that of the general population. It is important to educate not only smokers/users but also never smokers/users on the risks of smoking and using HTPs. Smoking cessation, including ceasing HTP use, and aiming to quit smoking and HTP use among dentists would contribute to appropriate smoking cessation among patients.

Study protocol for periodontal tissue regeneration with a mixture of autologous adipose-derived stem cells and platelet rich plasma: A multicenter, randomized, open-label clinical trial.

Introduction: Adipose-derived stem cells (ASCs) secrete various growth factors to promote wound healing and to regenerate various tissues, such as bone, cartilage, and fat tissue. Subcutaneous adipose tissue is a considerable cell source in clinical practice and can be collected relatively easily and safely under local anesthesia. Moreover, platelet-rich plasma (PRP), a plasma component containing many platelets purified by centrifuging the collected blood, also promotes wound healing. PRP can be easily gelled and is therefore attracting attention as a scaffolding material for transplanted cells. The usefulness of a mixture of ASCs and PRP for periodontal tissue regeneration has been in vitro demonstrated in our previous study. The aim of this study is to present the protocol of translation of tissue regeneration with ASCs and PRP into practical use, evaluating its efficacy. Methods: This study is a multicenter, randomized, open-label comparative clinical trial. Fifteen patients will be randomly assigned to the treatment with mixture of ASCs and PRP or enamel matrix derivate administration into periodontal tissue defects. Increase in height of new alveolar bone in the transplanted area will be evaluated. The evaluation will be performed using dental radiographs after 36 weeks of transplantation. Occurrence of adverse events will be evaluated as secondary outcome. Results: This clinical study was initiated after meeting the regulations to be complied with, including ethical review and regulatory notifications. Conclusions: If effective, this cell therapy using autologous mesenchymal stem cells can represent a useful medical technology for regeneration of periodontal defects.

Next-Generation Examination, Diagnosis, and Personalized Medicine in Periodontal Disease.

Periodontal disease, a major cause of tooth loss, is an infectious disease caused by bacteria with the additional aspect of being a noncommunicable disease closely related to lifestyle. Tissue destruction based on chronic inflammation is influenced by host and environmental factors. The treatment of periodontal disease varies according to the condition of each individual patient. Although guidelines provide standardized treatment, optimization is difficult because of the wide range of treatment options and variations in the ideas and skills of the treating practitioner. The new medical concepts of "precision medicine" and "personalized medicine" can provide more predictive treatment than conventional methods by stratifying patients in detail and prescribing treatment methods accordingly. This requires a new diagnostic system that integrates information on individual patient backgrounds (biomarkers, genetics, environment, and lifestyle) with conventional medical examination information. Currently, various biomarkers and other new examination indices are being investigated, and studies on periodontal disease-related genes and the complexity of oral bacteria are underway. This review discusses the possibilities and future challenges of precision periodontics and describes the new generation of laboratory methods and advanced periodontal disease treatment approaches as the basis for this new field.

Multiple assessment of molars with hypercementosis lost due to periodontitis using X-ray micro-computed tomography, electron microprobe analysis, and histological sections.

This article aimed to achieve a better understanding of cementum hyperplasia in the maxillary second molars lost due to periodontitis. Six maxillary second molars with hypercementosis were measured for the mineral concentration using micro-computed tomography and calcium element distributions using electron microprobe analysis. Calcium was distributed throughout the cementum, although the mineral concentration differed based on the cementum depth. The hyperplastic cementum was of the extrinsic fiber-rich cellular mixed stratified type. These results have implications for future studies aiming to diagnose hypercementosis. Further studies are needed to investigate the composition of the cementum matrix.

Evaluation of the Repolished Surface Properties of a Resin Composite Employing Structural Coloration Technology.

Resin composites employing structural coloration have recently been developed. These resins match to various tooth shades despite being a single paste. To accomplish this, the filler and base resin are tightly bonded, which is thought to provide excellent discoloration resistance. Here, we investigated the surface properties of one of these resins, including the discoloration of the repolished surface. We developed an innovative in vitro method to adjust the repolished surface, in which structural degradation is removed according to scanning electron microscopy (SEM) observation rather than by the naked eye. The resin samples (20 mm (length) × 10 mm (width) × 4 mm (depth)) were manufactured using this resin material. After accelerated aging of the resin by alkaline degradation, the resin was repolished and the discoloration (ΔE*ab), surface roughness (the arithmetic mean roughness (Ra)), and glossiness (the 60° specular) were measured. SEM observation showed that the appearance of the bond between the organic composite filler and base resin on the repolished surface was different from that on the mirror-polished surface. This revealed that according to our in vitro method it was difficult to make the repolished surface structurally identical to the mirror-polished surface. Among the properties of the repolished surface, the degree of discoloration did not change despite the rougher and less glossy surface. It can be concluded that the factors that induce discoloration in this resin composite are independent of the surface roughness and glossiness.

Porphyromonas gingivalis Components/Secretions Synergistically Enhance Pneumonia Caused by Streptococcus pneumoniae in Mice.

Streptococcus pneumoniae is an important causative organism of respiratory tract infections. Although periodontal bacteria have been shown to influence respiratory infections such as aspiration pneumonia, the synergistic effect of S. pneumoniae and Porphyromonas gingivalis, a periodontopathic bacterium, on pneumococcal infections is unclear. To investigate whether P. gingivalis accelerates pneumococcal infections, we tested the effects of inoculating P. gingivalis culture supernatant (PgSup) into S. pneumoniae-infected mice. Mice were intratracheally injected with S. pneumoniae and PgSup to induce pneumonia, and lung histopathological sections and the absolute number and frequency of neutrophils and macrophages in the lung were analyzed. Proinflammatory cytokine/chemokine expression was examined by qPCR and ELISA. Inflammatory cell infiltration was observed in S. pneumoniae-infected mice and S. pnemoniae and PgSup mixed-infected mice, and mixed-infected mice showed more pronounced inflammation in lung. The ratios of monocytes/macrophages and neutrophils were not significantly different between the lungs of S. pneumoniae-infected mice and those of mixed-infected mice. PgSup synergistically increased TNF-α expression/production and IL-17 production compared with S. pneumoniae infection alone. We demonstrated that PgSup enhanced inflammation in pneumonia caused by S. pneumoniae, suggesting that virulence factors produced by P. gingivalis are involved in the exacerbation of respiratory tract infections such as aspiration pneumonia.

Sustainable Effects of Human Dental Pulp Stem Cell Transplantation on Diabetic Polyneuropathy in Streptozotocine-Induced Type 1 Diabetes Model Mice.

Dental pulp stem cells (DPSCs) are suitable for use in regenerative medicine. Cryopreserved human DPSCs (hDPSCs) ameliorate diabetic polyneuropathy, and the effects of hDPSC transplantation are related to VEGF and NGF secretion. This study evaluated the long-term effects of a single transplantation of hDPSCs on diabetic polyneuropathy. hDPSCs were obtained from human third molars extracted for orthodontic treatment, which were then transplanted into the unilateral hindlimb skeletal muscles 8 weeks after streptozotocin injection in nude mice. The effects of hDPSC transplantation were analyzed at 16 weeks post-transplantation. DPSC transplantation significantly improved delayed nerve conduction velocity, decreased blood flow, and increased sensory perception thresholds. Furthermore, the hDPSC-conditioned medium promoted the neurite outgrowth of dorsal root ganglion neurons. In conclusion, the therapeutic effects of hDPSC transplantation with a single injection last for prolonged periods and may be beneficial in treating long-term diabetic polyneuropathy.

Photodynamic Inactivation of an Endodontic Bacteria Using Diode Laser and Indocyanine Green-Loaded Nanosphere.

Apical periodontitis, an inflammatory lesion causing bone resorption around the apex of teeth, is treated by eradicating infectious bacteria from the root canal. However, it has a high recurrence rate and often requires retreatment. We investigated the bactericidal effect of antimicrobial photodynamic therapy (aPDT)/photodynamic antimicrobial chemotherapy (PACT) using indocyanine green (ICG)-loaded nanospheres coated with chitosan and a diode laser on a biofilm of Enterococcus faecalis, a pathogen of refractory apical periodontitis. Biofilm of E. faecalis was cultured in a porcine infected root canal model. ICG solution was injected into the root canal, which was then irradiated with a laser (810 nm wavelength) from outside the root canal. The bactericidal effect was evaluated by colony counts and scanning electron microscopy. The result of the colony counts showed a maximum 1.89 log reduction after irradiation at 2.1 W for 5 min. The temperature rise during aPDT/PACT was confirmed to be within a safe range. Furthermore, the light energy transmittance through the root was at a peak approximately 1 min after the start of irradiation, indicating that most of the ICG in the root canal was consumed. This study shows that aPDT/PACT can suppress E. faecalis in infected root canals with high efficiency.

Gelatin Methacryloyl-Riboflavin (GelMA-RF) Hydrogels for Bone Regeneration.

Gelatin methacryloyl (GelMA) is a versatile biomaterial that has been used in various biomedical fields. UV light is commonly used to photocrosslink such materials; however, its use has raised several biosafety concerns. We investigated the mechanical and biological properties of a visible-wavelength (VW)-light-crosslinked gelatin-based hydrogel to evaluate its viability as a scaffold for bone regeneration in bone-destructive disease treatment. Irgacure2959 or riboflavin was added as a photoinitiator to create GelMA solutions. GelMA solutions were poured into a mold and exposed to either UV or VW light. KUSA-A1 cell-laden GelMA hydrogels were crosslinked and then cultured. Mechanical characterization revealed that the stiffness range of GelMA-RF hydrogel was suitable for osteoblast differentiation. KUSA-A1 cells encapsulated in GelMA hydrogels photopolymerized with VW light displayed significantly higher cell viability than cells encapsulated in hydrogels photopolymerized with UV light. We also show that the expression of osteogenesis-related genes at a late stage of osteoblast differentiation in osteoblasts encapsulated in GelMA-RF hydrogel was markedly increased under osteoblast differentiation-inducing conditions. The GelMA-RF hydrogel served as an excellent scaffold for the encapsulation of osteoblasts. GelMA-RF hydrogel-encapsulated osteoblasts have the potential not only to help regenerate bone mass but also to treat complex bone defects associated with bone-destructive diseases such as periodontitis.

A large-scale observational study to investigate the current status of diabetic complications and their prevention in Japan (JDCP study 6): baseline dental and oral findings.

Japan Diabetes Complication and Prevention prospective (JDCP) study was conducted to examine the association between glycemic control and oral conditions in a large database of Japanese patients with diabetes. It included a total of 6099 patients with diabetes (range, 40-75 years) who had been treated as outpatients between 2007 and 2009. The mean number of present teeth at baseline was 19.8 and women with type 2 diabetes had fewer teeth than men with type 2 diabetes. Within the previous year, 17% of all patients had lost teeth. At baseline, 32% had experienced gingival swelling, 69% had brushed more than twice a day, 37% had used interdental cleaning aids, and 43% had undergone regular dental checkups. Multiple logistic regression analysis indicated that type 1 patients with HbA1c ≥ 7.0% were at higher risk of having fewer than 20 teeth (odds ratio [OR] 2.38; 95% confidence interval [CI] 1.25-4.78), and type 2 patients with HbA1c ≥ 8.0% also were at high risk of having fewer than 20 teeth (OR 1.16; 95% CI 1.00-1.34), after adjustment for nine possible confounding factors. In conclusion, patients with diabetes were found to be at high risk of tooth loss, and the poorer the glycemic control, the higher the risk of tooth loss in these patients.

Automatic measurement of mandibular cortical bone width on cone-beam computed tomography images.

OBJECTIVE: The computed tomography cortical index (CTCI), computed tomography mandibular index (CTMI), and computed tomography index (inferior) [CTI(I)] are indexes obtained from cone-beam computed tomography images for the assessment of the mandibular cortex quality for implant planning or osteoporosis. However, cross-sectional image reconstruction for the measurements is labor-intensive. This study aimed to develop and evaluate a method to automatically reconstruct cross-sectional images and measure the cortex width in all areas inferior to the mental foramen (MF). METHODS: Seventy-one women (mean age: 52.4 years; range: 20-78 years) were enrolled. They were divided into four age and CTCI groups, including females younger (FY) and females older (FO) than 50 years (C1: normal, C2: mild/moderate erosion, and C3: severe porosity). Automatic and manual measurements of CTMI and CTI(I) were compared, and the inter- and intraobserver agreements were assessed using the intraclass correlation coefficient (ICC). The relationships between CTMI or CTI(I) and CTCI were also assessed. RESULTS: The mean processing times for reconstruction and measurements were 31.9 s and 1.22 s, respectively. ICCs for the comparison of automatic and manual measurements were 0.932 and 0.993 in the C1 and C2/C3 groups, respectively. Significant differences in CTMI and CTI(I) were observed between the FY or the FO-C1 and FO-C3 groups (p < 0.05). CONCLUSION: The automatic and manual measurements showed a strong agreement. The new method could drastically reduce routine clinical workload. Additionally, our method enables the measurement of the cortex width in all the mandibular bones inferior to the MF.

Porphyromonas gingivalis Mfa1 Induces Chemokine and Cell Adhesion Molecules in Mouse Gingival Fibroblasts via Toll-Like Receptors.

Porphyromonas gingivalis Mfa1 fimbriae are thought to act as adhesion factors and to direct periodontal tissue destruction but their immunomodulatory actions are poorly understood. Here, we investigated the effect of Mfa1 stimulation on the immune and metabolic mechanisms of gingival fibroblasts from periodontal connective tissue. We also determined the role of Toll-like receptor (TLR) 2 and TLR4 in Mfa1 recognition. Mfa1 increased the expression of genes encoding chemokine (C-X-C motif) ligand (CXCL) 1, CXCL3, intercellular adhesion molecule (ICAM) 1 and Selectin endothelium (E) in gingival fibroblasts, but did not have a significant effect on genes that regulate metabolism. Mfa1-stimulated up-regulation of genes was significantly suppressed in Tlr4 siRNA-transfected cells compared with that in control siRNA-transfected cells, which indicates that recognition by TLR4 is essential for immunomodulation by Mfa1. Additionally, suppression of Tlr2 expression partially attenuated the stimulatory effect of Mfa1. Overall, these results help explain the involvement of P. gingivalis Mfa1 fimbriae in the progression of periodontal disease.

Glucagon-Like Peptide-1 Receptor Agonist Liraglutide Ameliorates the Development of Periodontitis.

Periodontitis is one of the diabetic complications due to its high morbidity and severity in patients with diabetes. The prevention of periodontitis is especially important in diabetic patients because the relationship between diabetes and periodontitis is bidirectional. Here, we evaluated the impacts of glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide on the amelioration of periodontitis. Five-wk-old Male Sprague-Dawley (SD) rats (n = 30) were divided into 3 groups: normal, periodontitis, and periodontitis with liraglutide treatment groups. Periodontitis was induced by ligature around the maxillary second molar in SD rats. Half of the rats were administered liraglutide for 2 weeks. Periodontitis was evaluated by histological staining, gene expressions of inflammatory cytokines in gingiva, and microcomputed tomography. Periodontitis increased inflammatory cell infiltration, macrophage accumulation, and gene expressions of tumor necrosis factor-α and inducible nitric oxide synthase in the gingiva, all of which were ameliorated by liraglutide. Liraglutide decreased M1 macrophages but did not affect M2 macrophages in periodontitis. Moreover, ligature-induced alveolar bone resorption was ameliorated by liraglutide. Liraglutide treatment also reduced osteoclasts on the alveolar bone surface. These results highlight the beyond glucose-lowering effects of liraglutide on the treatment of periodontitis.

Evaluation of root morphology of maxillary and mandibular second molars lost due to periodontitis.

BACKGROUND AND OBJECTIVE: Little is known about the anatomical characteristics of root morphology in molars lost due to periodontal reason. The aim of this study was to study root morphology in maxillary and mandibular molars lost due to periodontitis by investigating the frequency of root fusion, classifying fusion types, and measuring radicular groove depth by micro-computed tomography. MATERIAL AND METHODS: Ninety-eight posterior teeth were collected from 87 Japanese patients during the study period. Of these, maxillary (N = 36) and mandibular (N = 22) second molars lost most frequently were assessed for root fusion and morphology. RESULTS: The 36 maxillary second molars included nine (25%) teeth with a single root, 14 (39%) with two roots, and 13 (36%) with three roots. Of the 23 maxillary second molars with fused (1 and 2) roots, there were 11 (48%), 2 (9%), 1 (4%), 1 (4%), 3 (13%), and 5 (22%) teeth with root types 1-6, respectively. The 22 mandibular second molars comprised 14 (64%) teeth with a single root, 7 (32%) with two roots, and one (4%) with three roots. Of the 14 mandibular second molars with a fused (1) root, 12 (86%) had a C-shaped root and two (14%) had a non-C-shaped root. CONCLUSION: We observed a higher frequency of root fusion in the present study compared with that reported by previous studies using randomly selected second molars.