Prosthodontic treatment can improve the ingestible food profile in Japanese adult outpatients.

PURPOSE: To investigate the effect of prosthodontic treatment on the ingestible food profile in adult Japanese outpatients, and to identify the related risk factors that can deteriorate the profile. METHODS: The participants were 277 outpatients who visited university-based specialty clinics in Japan for prosthodontic treatment. The demographic data, number of present teeth assessed via intraoral examination, and oral health-related quality of life assessed by the total Oral Health Impact Profile (OHIP-J54) scores of all participants were recorded before treatment. Ingestible food profile score (IFS) was recorded using a validated food intake questionnaire. Eligible participants who answered the questionnaire before and after treatment were categorized into five groups based on the prosthodontic treatments they received (i.e., crowns, bridges, removable partial dentures, removable complete dentures, and removable complete and partial dentures). RESULTS: Multivariate analysis of covariance revealed a statistically significant main effect of prosthodontic intervention (time course: before and after treatment) on mean IFS (P=0.035, F=4.526), even after adjusting for covariates (age, number of present teeth, and treatment modality). Multiple linear regression analysis revealed that the low number of present teeth (r=0.427, P<0.001) and a high OHIP-J54 total score (r=-0.519, P<0.001) of the patients at the baseline were significantly associated with their baseline IFSs, even after adjusting for confounding variables. CONCLUSIONS: The findings of this multicenter follow-up study indicate the importance of prosthodontic rehabilitation in improving patients' ingestible food profiles.

Impact of number of functional teeth on independence of Japanese older adults.

AIM: To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence. METHODS: Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed. RESULTS: This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan-Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168-3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant. CONCLUSIONS: The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event. Geriatr Gerontol Int 2022; 22: 1032-1039.

Effectiveness of denture space recording method in the prosthetic treatment of edentulous patients.

PURPOSE: To present a clinical rationale for the effectiveness of denture space recording methods for the prosthetic treatment of edentulous patients through a review of the literature. STUDY SELECTION: A total of 3167 studies were extracted from a search of four terms, namely denture space, neutral zone technique, flange technique, and piezography using PubMed and J-STAGE databases. A total of 57 documents that matched the inclusion and exclusion criteria were selected. RESULTS: From the extracted articles, the clinical application of denture space recording methods was found to be effective in edentulous patients with severe ridge resorption. The relationship between the labiolingual and buccolingual pressure in patients with neuromuscular problems or with mandibular or lingual defects differs from those without it, so a stable prosthesis can be easily fabricated by locating the neutral zone using denture space recording methods. CONCLUSION: The literature on denture space recording methods suggests that its application on challenging cases of edentulous patients is useful in providing prostheses with improved retention and stability.

Direct bonded fixed partial denture with an artificial denture tooth as a pontic.

Background: The present review aimed to investigate the feasibility and clinical effectiveness of a direct bonded fixed partial denture (DBFPD) based on available literature. The efficiency of a DBFPD is mainly affected by the type of artificial denture tooth, the type of luting agent, and the adhesive preparation. Methods: The parameters were reviewed based on the in vitro and in vivo studies conducted. An acrylic resin tooth or a composite resin tooth for removable dentures should be used as the artificial tooth for the pontic. Results: Considering the luting agent, a methyl methacrylate-based resin luting agent, which has low mechanical strength but is capable of plastic deformation and could sustain for a long time, should be used. Appropriate pre-adhesive treatment should be performed on both the artificial and abutment teeth. The cases in which a DBFPD can be applied are limited to one missing anterior tooth, as long as it is not overstressed. Patient cooperation in cases of occlusion seems to be another prerequisite. Conclusion: Knowledge and selection of the material and case indications are essential, and patient cooperation is pertinent in studying the long-term prognosis of a DBFPD.

Longevity of resin-bonded fixed partial dentures made of metal alloys: A review of the literature.

Purpose In this review, we evaluate the survival rate of resin-bonded fixed partial dentures (RBFPDs) made of metal alloys.Methods An electronic search of English peer-reviewed dental literature on PubMed was conducted to identify all publications reporting on RBFPDs made of metal alloys until March 2019. The searched keywords were: bridge OR fixed partial denture OR fixed prosthesis OR fixed prostheses AND resin bonded AND metal OR alloy AND survival OR longevity (RBFPD was not included). Furthermore, the "Related Articles" feature of PubMed was used to identify further references of interest during the primary search. A definitive list of articles was screened to extract qualitative data after the application of the inclusion and exclusion criteria, and the results were analyzed.Results Overall, 977 publications were found through an electronic and manual search, out of which 130 articles were selected after screening based on title and abstract. A total of 52 publications passed the second review phase after assessment for eligibility, from which 24 studies were excluded after full-text screening. Finally, a total of 28 studies were selected.Conclusions The survival rate of RBFPDs differed greatly depending on the type of metal alloy, adhesion system, and observation period assessed, e.g. the 10-year survival rate ranged from 18% to 88%. The wide range of survival rates of the RBFPDs reported indicates that though RBFPD is a reliable prosthesis, it is prone to failure if some processes are not completed.

Number of functional teeth more strongly predicts all-cause mortality than number of present teeth in Japanese older adults.

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; ••: ••-••.

Influence of experimental palatal plate on mandibular position during continuous [n] phonation and at the physiologic rest position.

The purpose of this study was to clarify the influence of an experimental palatal plate on the mandibular position during continuous [n] phonation and at the physiologic rest position. Twenty healthy dentulous volunteers (10 males and 10 females, mean age of 24.4 years) were investigated. Three kinds of experimental plate with a thickness of 3 mm, 5 mm, and 8 mm were fabricated and used for each subject. The mandibular position was recorded by a K7 kinesiograph during continuous [n] phonation and at the physiologic rest position under normal conditions and when the three kinds of plate with different thickness were worn separately. The results showed that the mean interocclusal dimensions during continuous [n] phonation were 0.5 mm vertically and 0.4 mm anteroposteriorly under the normal condition. After insertion of an experimental plate, the interocclusal distance increased a little, but the difference was not statistically significant between the normal condition and any of the three experimental conditions. No significant difference was found between the male and female groups. Furthermore, no significant difference in the interocclusal distance at the physiologic rest position was found between the above comparisons. Within the limitations of this study, we concluded that the mandibular position during continuous [n] phonation and at the physiologic rest position was not significantly influenced by the experimental plates.

Influence of experimental palatal plate on mandibular position during continuous phonation of [n].

PURPOSE: This study aimed to determine the influence of the thickness of a palatal plate on the mandibular position during continuous phonation of the sound [n]. METHODS: Eleven healthy volunteers (10 males and 1 female; 24-36 years of age, mean age 26.4 years) were recruited from dental students. They were instructed to pronounce [n] continuously under six conditions: wearing a palatal plate with a thickness of 0.3, 1.5, 3.0, 5.0, and 10.0mm, and without a plate (control). Mandibular movement during pronunciation was simultaneously recorded by a K-7 mandibular kinesiograph. Their mandibular positions in the physiologic rest position were also recorded. The distance between the incisal edge of maxillary and mandibular anterior teeth both in vertical and antero-posterior directions during continuous phonation of [n] (interocclusal distance) under all six conditions were measured and compared. RESULTS: Interocclusal distance tended to increase in both vertical and antero-posterior directions as the thickness of the palatal plates increased. There were statistically significant differences in the mandibular position both in vertical and antero-posterior directions during continuous phonation of [n] between the control condition and those wearing a palatal plate with a thickness of 10.0mm. CONCLUSION: The mandibular position determined by the phonetic method employing continuous [n] as a test pronunciation was affected by the thickness of the palatal plates inserted into the mouth. However, its influence was not significant when the thickness of the palatal plates was 5mm or less.

Three-dimensional finite element analysis of stress distribution in composite resin cores with fiber posts of varying diameters.

Using three-dimensional finite element analysis (3D-FEA), stress distributions in the remaining radicular tooth structure were investigated under the condition of varying diameters of fiber post for fiber post-reinforced composite resin cores (fiber post and core) in maxillary central incisors. Four 3D-FEA models were constructed: (1) fiber post (ø1.2, ø1.4, and ø1.6 mm) and composite resin core; and (2) gold-cast post and core. Maximum stresses in the tooth structure for fiber post and core were higher than that for gold-cast post and core. In the former models, stresses in the tooth structure as well as in the composite resin were slightly reduced with increase in fiber post diameter. These results thus suggested that to reduce stress in the remaining radicular tooth with a large coronal defect, it is recommended to accompany a composite resin core with a fiber post of a large diameter.

Modulation of branching morphogenesis of fetal mouse submandibular gland by sodium ascorbate and epigallocatechin gallate.

As an initial step to study the effect of antioxidants on the oral environment, we here investigated how sodium ascorbate and (-)-epigallocatechin 3-O-gallate (EGCG) affect the branching morphogenesis of the fetal mouse submandibular gland (SMG). When mouse SMG was prepared from the embryo at 13-day post prenatal stage and cultured, gradual development of branching morphogenesis was observed. Addition of sodium ascorbate affected this morphological change in a bimodal fashion. At lower concentrations of sodium ascorbate (0.25 approximately 2.27 mM), the branching morphogenesis was slightly but significantly (about 60%) enhanced, whereas at higher concentrations of sodium ascorbate (6.82 approximately 10.1 mM), the branching morphogenesis was inhibited. The addition of EGCG failed to stimulate, but inhibited the branching morphogenesis in a dose-dependent manner. These data support that the addition of a lower concentration of sodium ascorbate is essential to stimulate the growth of SMG, and that sodium ascorbate, but not all antioxidants, induces hormesis (beneficial action at lower concentration) in the present SMG system.

Inhibition of branching morphogenesis of mouse fetal submandibular gland by sodium fluoride--protection by epidermal growth factor.

As an initial step to study the effect of sodium fluoride on the oral environment, we investigated how sodium fluoride (NaF) affects the branching morphogenesis of fetal mouse submandibular gland (SMG). When mouse SMG was prepared from the embryo at 13 days post prenatal stage and cultured, gradual development of branching morphogenesis was observed. Addition of NaF affected this morphological change in bimodal fashions. At a lower concentration of NaF (< 2 microM), the branching morphogenesis was slightly enhanced, whereas at a higher concentration of NaF (4 - 8 microM), it was almost completely inhibited. The inhibitory effect of NaF at the higher concentration was abrogated by stimultaneous addition of epidermal growth factor (EGF), but not by 5alpha-dihydrotestosterone (DHT) or insulin-like growth factor (IGF). These data demonstrate that EGF can effectively reduce the cytotoxic activity of NaF at micromolar concentration.

Septic pulmonary embolism associated with periodontal disease: reports of two cases and review of the literature.

We report two cases of septic pulmonary embolism associated with periodontitis. Chest CT revealed multiple nodular shadows with features characteristic of septic pulmonary embolism in both patients. Both patients had toothache, fever, and chest pain, and showed findings of periodontitis at initial presentation. Antimicrobial agents combined with dental surgery were successful in treatment. While septic pulmonary embolism from the lesions of periodontitis appears to be rare, periodontitis remains important in the differential diagnosis of septic pulmonary embolism.