GEE analysis showed that smoking was a risk factor for early implant failure, and several risk factors were identified for late implant failure.

Aim Previous studies on the association between intraoral conditions and mortality in community‐dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community‐dwelling Japanese older adults. Methods This study was a retrospective, observational and population‐based follow‐up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow‐up period was 1697.0 ± 774.5 days. The primary outcome was all‐cause mortality at follow‐up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Results Kaplan–Meier analysis, followed by a log‐rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089). Conclusions Current results suggest that the number of FT more strongly predicts all‐cause mortality than the number of PT among community‐dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status. Geriatr Gerontol Int 2020; ••: ••–••.

Keratinized mucosa is of fundamental importance to maintain healthy gingival tissue, and understanding the mechanisms of oral mucosa keratinization is crucial to successfully manage healthy gingiva. Previous studies have shown a strong involvement of the basement membrane in the proliferation and differentiation of epithelial cells. Therefore, first, to identify the keratinized mucosa-specific basement membrane components, immunohistochemical analysis for the six alpha chains of type IV collagen was performed in 8-week-old mice. No difference in the expression pattern of type IV collagen α1(IV) and α2(IV) chains was observed in the keratinized and non-keratinized mucosa. Interestingly, however, type IV collagen α5(IV) and α6(IV) chains specifically were strongly detected in the keratinized mucosa. To analyze the functional roles of the type IV collagen isoform α6(IV) in oral mucosa keratinization, we analyzed Col4a6-knockout mice. Epithelial developmental delay and low levels of KRT10 were observed in new-born Col4a6-knockout mice. Additionally, in vitro experiments with loss-of function analysis using human gingival epithelial cells confirmed the important role of α6(IV) chain in epithelial keratinization. These findings indicate that α112:α556 (IV) network, which is the only network that includes the α6(IV) chain, is one regulator of KRT10 expression in keratinization of oral mucosal epithelium.

Medication-related osteonecrosis of the jaw (MRONJ) is a severe pathological condition associated mainly with the long-term administration of bone resorption inhibitors, which are known to induce suppression of osteoclast activity and bone remodeling. Bone Morphogenetic Protein (BMP)-2 is known to be a strong inducer of bone remodeling, by directly regulating osteoblast differentiation and osteoclast activity. This study aimed to evaluate the effects of BMP-2 adsorbed onto beta-tricalcium phosphate (β-TCP), which is an osteoinductive bioceramic material and allows space retention, on the prevention and treatment of MRONJ in mice. Tooth extraction was performed after 3 weeks of zoledronate (ZA) and cyclophosphamide (CY) administration. For prevention studies, BMP-2/β-TCP was transplanted immediately after tooth extraction, and the mice were administered ZA and CY for an additional 4 weeks. The results showed that while the tooth extraction socket was mainly filled with a sparse tissue in the control group, bone formation was observed at the apex of the tooth extraction socket and was filled with a dense connective tissue rich in cellular components in the BMP-2/β-TCP transplanted group. For treatment studies, BMP-2/β-TCP was transplanted 2 weeks after tooth extraction, and bone formation was followed up for the subsequent 4 weeks under ZA and CY suspension. The results showed that although the tooth extraction socket was mainly filled with soft tissue in the control group, transplantation of BMP-2/β-TCP could significantly accelerate bone formation, as shown by immunohistochemical analysis for osteopontin, and reduce the bone necrosis in tooth extraction sockets. These data suggest that the combination of BMP-2/β-TCP could become a suitable therapy for the management of MRONJ.

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Purpose: Dental implant therapy is a common clinical treatment for missing teeth. However, the esthetic result is not as satisfactory as expected in some cases, especially in the anterior maxillary area. Poor esthetic results are caused by inadequate preparation of the hard and soft tissues in this area before treatment. The socket shield technique may be an alternative for a desirable esthetic outcome in dental implant treatments. Study selection: In the present systematic review, PubMed-Medline, Google Scholar, and ScienceDirect were searched for clinical studies published from January 2000 to December 2018. Results: Twenty studies were included, comprising one randomized controlled trial, two cohort studies, 14 clinical human case reports, and three retrospective case series. In total, 288 patients treated with the socket shield technique with immediate implant placement and follow-up between 3-60 months after placement were included. A quality assessment showed that 12 of the 20 included studies were of good quality. Twenty-six of the 274 (9.5%) cases developed complications or adverse effects related to the socket shield technique. Most studies reported implant survival without the complications (90.5%); most of the cases that were followed up for more than 12 months after implant placement achieved a good esthetic appearance. The failure rate was low without the complications, although there were some failures due to failed implant osseointegration, socket shield mobility and infection, socket shield exposure, socket shield migration, and apical root resorption. Conclusions: The socket shield technique can be used in dental implant treatment, but it remains difficult to predict the long-term success of this technique until high-quality evidence becomes available.

Objectives To identify significant risk factors associated with incidence of mortality and pneumonia in whole‐community‐based older inpatients resident in Japanese rural region. Methods Patients older than 65 years admitted between 1 April and 15 April 2010 to a core hospital located in a rural region were exhaustively recruited, and incidence of mortality and pneumonia during the 32‐month follow‐up period were evaluated. Independent variables at baseline measurement included age, gender, body mass index, Charlson comorbidity index, functional dependency, oral self‐care ability index, number of remaining teeth, hyposalivation and nutritional status. Dependent variables were incidence of mortality and pneumonia. Survival and non‐pneumonia curves were drawn using Kaplan‐Meier analysis. Cox proportional hazards analysis was performed to identify the risk factors related to incidence of mortality and pneumonia. Results The survival rate of 46 patients (male/female: 11/35; mean age: 83.8 ± 6.8 years) was 52.1%, and the incidence of pneumonia was 60.9%. Malnutrition and gender (male) were identified as significant risk factors for mortality (odds ratio [OR]: 8.18 and 4.90; 95% confidence interval [CI]: 1.77‐37.3 and 1.50‐16.0; P < 0.01 and <0.01, respectively). Loss of oral self‐care ability and gender (male) were identified as significant risk factors for incidence of pneumonia (OR: 8.97 and 4.58; 95% CI: 1.70‐47.4 and 1.50‐14.0; P = 0.01 and <0.01, respectively). Conclusions Malnutrition and loss of oral self‐care ability were significant risk factors for incidence of mortality and pneumonia, respectively. In response, supplying nutrition with appropriate diet and personalised oral care might contribute to reduction in mortality and prevention of pneumonia.

Purpose: The purpose of the study was to compare the long-term performance of three prostheses for partial edentulism: implant-supported, fixed denture (IFD), fixed partial denture (FPD), and removable partial denture (RPD), in terms of prosthesis survival and oral health-related quality of life (OHRQoL). Methods: The 138 patients in our previous study (Kimura et al., 2012) received one of the three prosthetic treatments and answered a validated OHRQoL questionnaire before and immediately after treatment. In the present study, the patients were followed up six years after treatment using medical records and OHRQoL examinations to evaluate prosthesis survival and change in OHRQoL. The cumulative survival rates were calculated using the Kaplan-Meier analysis. The Steel-Dwass test was used to compare the median OHRQoL scores at the three time points. Results: For the 105 patients (66.8 ± 10.8 years, IFD/FPD/RPD: 58/27/20 patients) who successfully completed the follow-up assessments, the six-year estimated cumulative survival rates of the IFDs, FPDs, and RPDs were 94.7%, 77.4%, and 33.3%, respectively. The log-rank tests indicated that the survival curves were significantly different (IFDs vs. FPDs: p = 0.01; RPDs vs. IFDs, FPDs: p < 0.01). The median OHRQoL scores of the IFD group immediately after treatment and six years after treatment were significantly higher than those observed before treatment (p < 0.01). There was no significant difference in the median OHRQoL scores among the three time points in the RPD or FPD groups. Conclusions: IFDs showed significantly longer survival rates than FPDs and RPDs in partially edentulous patients. Only in the IFD patients was the OHRQoL level six years after treatment significantly higher than that before treatment.