Shunsuke Minakuchi

Tokyo Medical and Dental University | TMDU · Department of Prosthodontics

The concept of oral frailty was first proposed in Japan in 2014 by the “Joint Working Committee on Oral Frailty,” consisting of three academic societies—the Japan Geriatrics Society, the Japanese Society of Gerodontology, and the Japanese Association on Sarcopenia and Frailty—to enhance public understanding of oral frailty. Oral frailty is a state...

Background Treating oral problems with dentist intervention during hospitalisation may improve patients' food intake status. Objectives This study aimed to clarify whether convalescent rehabilitation ward inpatients in a hospital with hospital dentistry (HHD) had a better diet at discharge than those in a hospital without hospital dentistry (HNHD)...

Purpose: This in vitro study investigated the effect of build orientation on the wear resistance and hardness of denture teeth fabricated using digital light processing (DLP) compared to other denture tooth materials. Methods: Disc-shaped specimens were prepared using denture tooth monomers and DLP devices in three build orientations: 0°, 45°, and...

Background Differences in the effects of cream‐type denture adhesives and home liners remain unclear. Objective This cross‐sectional study aimed to clarify the differences in the oral‐hygiene status and masticatory performance between participants using cream‐type denture adhesives and those using home liners. Methods Masticatory performance with...

Introduction Oral hypofunction comprises seven aspects of oral condition, including oral hygiene, oral dryness, bite strength, tongue‐lip motor function, tongue pressure, masticatory function, and swallowing function. Each of these seven has a single diagnostic criterion; however, the use of a single indicator without consideration of sex, age, or...

Highly polished 3, 4, and 5 mol% yttria-stabilized zirconia and CAD/CAM composite resin samples were prepared, and the influence of surface roughness (Ra and Sa, 21 areas/group), wettability (contact angle and surface energy, 3 samples/group), and surface chemical composition (2 samples/group) on single-strain bacterial adhesion models (Porphyromon...

Background The association between oral food intake and oral function during the subacute stage of stroke is not well known. Objective To investigate (1) oral function changes in subacute stroke patients and (2) association between oral function and oral intake status at several time points. Methods In a prospective study involving 324 stroke pat...

Purpose: Color-changeable chewing gums are used to evaluate masticatory performance, as measured by a colorimeter or visually based on a color scale. Although anyone can use a color scale, the evaluation accuracy depends on the evaluator. We develop an application that can determine the degree of color change in chewing gum using smartphone images,...

This study aimed to clarify the effects of multiple firings on the translucency, crystal structure, and mechanical strength of highly translucent zirconia. Four types of highly translucent zirconia (LAVA Esthetic, LAVA Plus, KATANA Zirconia STML, and KATANA Zirconia HTML) were fired three times at three different temperatures, and the translucency,...

Aim This cross‐sectional study had two aims: to assess the prevalence of oral frailty (OF), according to the Oral Frailty 5‐Item Checklist (OF‐5), among community‐dwelling older adults; and to examine the associations among oral frailty, dietary variety, social engagement, and physical frailty. Methods We pooled data from two population‐based stud...

In this study, we investigated the effects of surface treatment on the fracture strength of porcelain-veneered zirconia. Highly translucent 4 mol% yttria-stabilized zirconia disks (KATANA HT, Kuraray Noritake Dental) were divided into three surface-treatment groups: 1)as-sintered, 2) alumina sandblasted, and 3) ground. Crystallographic and surface-...

Objective As the participation of dental professionals in multidisciplinary care is often limited, instructions on oral health management provided by dental professionals to other professionals are important to achieve transdisciplinary oral health management; however, the effectiveness of such instructions remains unclear. In this longitudinal stu...

Objectives To investigate factors influencing postoperative bleeding occurrence after dental extraction in older patients receiving anticoagulation therapy. Materials and methods This retrospective study included patients aged ≥ 65 years receiving one of the following anticoagulants: apixaban, edoxaban, rivaroxaban, and warfarin. Patients who unde...

Milling machines have made denture fabrication possible with high accuracy in a short time. However, the relationship between the milling conditions, accuracy, and milling duration has not been clarified. This study aimed to clarify the effects of milling conditions on surface roughness and milling duration. The specimen was designed using CAD soft...

PURPOSE This study aimed to predict the positional coordinates of incisor points from the scan data of conventional complete dentures and verify their accuracy. MATERIALS AND METHODS The standard triangulated language (STL) data of the scanned 100 pairs of complete upper and lower dentures were imported into the computer-aided design software from...

The older adult population in Japan is expected to increase. Therefore, long-term care and frailty prevention are important. However, the relationship between masticatory performance, nutritional intake, and frailty remains unclear. This cross-sectional study aimed to examine energy, protein, and vitamin D intake and its association with frailty an...

Statement of problem The effect of using the custom disk method (CDM) for fabricating digital dentures on patients’ masticatory function should be studied to support its use in clinical practice. Purpose To investigate the effect of digital dentures fabricated using CDM on patients’ masticatory function. Material and methods This single-center pr...

Traditionally, simulation studies in dentistry have relied on the finite element method (FEM). However, the smoothed particle hydrodynamics (SPH) method, which represents objects as particle collections without the use of meshes, has gained recent attention. Despite its application in dentistry, there is currently a lack of comprehensive literature...

Milling machines have made denture fabrication possible with high accuracy in a short time. However, the relationship between the milling conditions, accuracy, and milling duration has not been clarified. This study aimed to clarify the effects of milling conditions on surface roughness and milling duration. The specimen was designed using a CAD so...

Background/purpose Appropriate oral health assessment and management can improve the oral health and nutritional status of hospitalized patients. The active participation of dental professionals in the nutritional support team (NST) can help achieve this outcome. However, the participation of dental professionals in NSTs is often limited, indicatin...

Comprehensive, long-term studies on patient-reported outcomes for two-implant overdentures with magnetic attachments using immediate or conventional loading methods are lacking. This study aimed to provide 5-year follow-up data comparing patient-reported outcomes for mandibular overdentures supported by two implants with magnetic attachments under...

No specific methods have been officially proposed for the prevention and improvement of oral hypofunction. Therefore, in this randomized controlled trial, we aimed to develop a gum-chewing training program and determine its effects in older adults. A total of 218 older adults, aged 65–85 years, were randomly allocated to the intervention or control...

Zirconia restorations are increasingly popular in dental treatment. Yttria-stabilized zirconia (YSZ) needs to be sintered for clinical applications and novel speed-sintering protocols are being developed for chairside treatments. Whether the properties of speed-sintered YSZ meet clinical requirements, however, remains unclear. Therefore, we conduct...

Background/purpose Impaired masticatory performance results in nutritional deficiencies in older adults. This systematic review aims to investigate the following clinical question (CQ): Do occlusal supports impact nutritional intake or nutritional status in older individuals? Materials and methods An extensive systematic literature search was perf...

Background: Oral health management involving dental professionals in a multidisciplinary Nutritional Support Team (NST) is effective collaborative care. However, the indicators for the triage of oral health management requirements and selection of oral healthcare providers remain unclear. Objective: This cross-sectional study included inpatients...

Aim To enable easy assessment of oral frailty; that is, an overlapping slight decline in multifaceted oral function, in any setting, we developed the oral frailty five‐item checklist (OF‐5), and examined its predictive validity for increased risks of physical frailty, physical disability and mortality among community‐dwelling older adults. Methods...

Mild cognitive impairment (MCI), including memory loss, has been attracting attention in Japan. This study assessed the effect of new complete dentures provision alone and with dietary intervention on cognitive functions assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). A randomized controlled trial was conducted wi...

Background/purpose Gum chewing has been found to improve oral function. Nevertheless, few randomized controlled trials have investigated the effects of gum-chewing exercises on oral function in older adults. This study aimed to examine the effect of gum-chewing exercises on oral function in older adults. Materials and methods This was a single-bli...

Objective: To investigate the occurrence of mild cognitive impairment in edentulous patients up to 3 years after they received single-implant overdentures (1-IODs). Methods: This was a follow-up study for a crossover randomized controlled trial comparing 1-IODs and conventional complete dentures, with patient satisfaction as the primary outcome....

This 1-year multicenter prospective cohort study aimed to determine the association between observable eating and swallowing function factors and outcomes (death/hospitalization or survival) among elderly persons in long-term care insurance facilities in Japan. Baseline assessments of factors, such as language, drooling, halitosis, hypersalivation,...

Purpose: The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan. Methods: The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to under...

Background: Coordination between the trunk and head is considered important for walking stability. Recent studies have reported that wearing complete dentures could improve trunk stability during walking; however, its effect on the head has not been clarified. Objective: This study aimed to clarify the effect of complete dentures on head stabili...

In Japan, the demand for home-visit dental treatment is increasing because of a super-aging society. Since home-visit dental treatments mainly provide dental care to medically compromised older adult patients, it is necessary to understand appropriate knowledge about systemic diseases. In this paper, we will present actual cases of home-visit denta...

Purpose: We evaluated the effects of build orientation and bar addition between lingual flanges on the accuracy of mandibular denture bases fabricated using a digital light processing (DLP) device. Methods: Mandibular denture bases with and without a bar at the lingual flanges were virtually designed and assigned to eight build orientations. Six de...

Purpose: Additive manufacturing has revolutionized the fabrication of complete dentures. However, this process involves support structure, which is a construction part that holds the specimen during printing, and may prove to be disadvantageous. Therefore, this in vitro study compared the effect of support structure reduction on various volume and...

Purpose: This technical procedure report explains the fabrication protocol for a newly developed 4D-printed sports mouthguard (MG) based on 4D-printing technology. Methods: An intraoral scanner was used to scan a maxillary arch model. A two-layer sports MG was designed based on the scanned model using computer-aided design software and output in a...

The environments of nursing home staff and residents have dramatically changed since the onset of the COVID-19 pandemic, with greater demand for infection control. This study aimed to clarify the changes and regional differences in the surrounding environment of nursing home residents as well as the working environment of staff, including oral heal...

Objectives: To investigate crystallography, translucency, phase content, microstructure and flexural strength of two commercial strength-gradient multilayered dental zirconia grades. Methods: Two zirconia grades, i.e., KATANA Zirconia YML (Kuraray Noritake; referred to as "YML"; composed of four layers: enamel, body 1-3) and IPS e.max ZirCAD Pri...

Purpose: This study aimed to determine the effects of denture adhesives on denture retention and occlusal force in complete denture wearers in a multicenter, randomized, parallel-group controlled trial. Methods: Two hundred edentulous patients wearing complete dentures were allocated to three groups: powder-type denture adhesive, cream-type dent...

Purpose: Although digital removable partial dentures have been previously described, there have been no reports on how to fabricate them in one piece. This study proposes a new method for fabricating patient-specific digital removable partial dentures using a custom plate. Methods: First, a gypsum model was scanned using a laboratory scanner and a...

: The type of denture adhesive, cream or home-liner, chosen by regular denture adhesive users and oral conditions contributing to this selection require elucidation. The factors associated with denture adhesive selection were investigated through a face-to-face survey on oral and denture conditions. Age, sex, oral moisture, masticatory performance,...

Zirconia ceramics have been widely used in dentistry. Herein, we assess the surface morphology, surface texture, and osteoblast response of additively manufactured zirconia and alumina-toughened zirconia (ATZ) in comparison with titanium. The surface roughness, contact angle, and surface microstructure of titanium sandblasted with large-grit alumin...

Statement of problem Studies on the movement of artificial teeth during the manufacturing of computer-aided design and computer-aided manufacturing (CAD-CAM) complete dentures using the custom disk method with milled recesses and on whether the movement is within a clinically acceptable range are lacking. Purpose The purpose of this in vitro study...

Purpose: We investigated and compared the stress distribution within one- and two-piece mini-implants for overdentures with three different attachments (ball, Locator, and magnet) and two different diameters using three-dimensional finite element (3D FE) analysis and a monotonic bending test. The goal was to identify the most beneficial implant att...

Purpose: Maintaining good masticatory function from a young age promotes lifelong health, yet limited studies have explored masticatory performance in young individuals. We investigated the relationship of sex, age, and individual oral functions with masticatory performance among junior and senior high school students and young adults. Methods: Thi...

This systematic review provides an update on the development and efficacy of direct restorative dental materials for root caries interventions from in vitro and clinical studies. PubMed, Embase, and Web of Science were searched using specific MeSH keywords. Full articles from September 1990 to October 2021 were collected. Additional articles were i...

Objectives: This prospective study aimed to compare the oral functions of removable partial dentures (RPDs) with those of implant-assisted removable partial dentures (IARPDs) with short implants and magnetic attachments in patients with mandibular Kennedy class I and II. Material and methods: Thirty participants with mandibular Kennedy class I o...

The management of postoperative bleeding is mandatory in patients receiving anticoagulants. In this case report, we introduce a fully digital workflow for surgical splint fabrication to prevent postoperative bleeding in patients receiving anticoagulants and/or at risk of inadvertent extraction of a mobile tooth during impression making. An 87-year-...

Although a surface pre-reacted glass ionomer (S-PRG) exerts a suppressive effect on Candida albicans (C. albicans) activity and growth, its influence on the expression of the lipase gene (LIP) family including LIP1–LIP10, an indicator of clinical infection, has not yet been investigated. Therefore, in this study, we evaluated the effect of S-PRG fi...

Background During restoration of poorly fitting complete dentures (CDs) in edentulous patients, liners are used to reconstruct the concave surfaces of CDs with a new base material. These relining materials are classified into resilient liners (RLs) and non-resilient liners (NRLs), but the clinical effects of these liners and their selection criteri...

Malnourished older inpatients referred to a nutrition support team (NST) usually receive multidisciplinary oral health management during NST intervention. However, the effects of multidisciplinary oral health management on the nutrition-intake method and oral health in these patients remain unclear. This longitudinal study aimed to investigate the...

Oral care involving the removal of dry sputum is effective for older patients who require nursing care or hospitalization. However, safe and efficient oral care methods for such patients remain unclear. We aimed to simulate the oral cavity of older adults with dry mouth and elucidate the differences between two moisturization agents, water and gel-...

Purpose Maintenance of oral feeding is important in terms of maintaining and improving the quality of life in terminal cancer patients receiving palliative care. Although adequate oral health status is essential for oral feeding in hospitalized patients, the relationship between oral health and oral feeding in patients receiving palliative care rem...

Background During restoration of poorly fitting complete dentures (CDs) in edentulous patients, liners are used to reconstruct the concave surfaces of CDs with a new base material. These relining materials are classified as resilient liners (RLs) or non-resilient liners (NRLs), but the clinical effects of and selection criteria for these liners rem...

All-ceramic restorations have become increasingly popular in dentistry. Toward ensuring that these restorations adhere to the tooth structure, this study determines the optimal femtosecond laser (FL) treatment parameters for lithium disilicate glass-ceramics and highly translucent zirconia ceramics with respect to surface morphology. For both the c...

Zirconia ceramics are now widely used in dentistry as one of the golden standards of restorative materials. More recently, highly translucent zirconia ceramics and multi-layered zirconia have enabled us to apply monolithic zirconia restorations in both anterior and posterior regions. Several new zirconia materials, as well as different fabrication...

Statement of problem The custom disk is a novel method of complete denture fabrication; however, patient-reported outcomes and fabrication costs are unknown. Purpose The purpose of this retrospective study was to evaluate general patient satisfaction with complete dentures fabricated through the custom disk method. In addition, a comparative cost-...

Background/purpose Implant assisted removable partial dentures (IARPDs) improved biomechanical behavior of removable partial dentures (RPDs), but information of the effect of attachment type and implant position is limited. This study aimed to investigate the effect of implant position and attachment type on the stress distribution of IARPDs. Mate...

Photopolymer resins are widely used in the production of dental prostheses, but their mechanical properties require improvement. We evaluated the effects of different zirconia filler contents and printing directions on the mechanical properties of photopolymer resin. Three-dimensional (3D) printing was used to fabricate specimens using composite ph...

Purpose Patients with terminal cancer undergoing multidisciplinary palliative care often have oral health problems, but these details are still unclear. This cross-sectional study aimed to elucidate the oral health of patients with terminal-stage cancer who are inpatient recipients of acute-phase palliative care, and to unveil the factors affecting...

Purpose: This in vitro study investigates the effect of different post-rinsing times and methods on the trueness and precision of denture base resin manufactured through stereolithography. Materials and methods: Ninety clear photopolymer resin specimens were fabricated and divided into nine groups (n = 10) based on rinsing times and methods. All...

Introduction: Jaw-opening force (JOF) can be a potential screening tool for dysphagia. However, confounding variables such as comorbidities or physical and oral functions that are associated with the physiology of swallowing have not previously been examined. Adjusting for these variables could reveal the relationship between JOF and dysphagia and...

Background: Previous research indicates that patients with mild cognitive impairment (MCI) are more likely to have poor oral health and impairments in oral functions, which may be due to few remaining teeth and impaired tongue and lip motor function. However, the oral health of those patients following comprehensive cognitive assessment by a demen...

Background The appropriate loading protocol to improve masticatory performance (MP) is still unclear in elderly patients and two-implant overdentures (2-IODs) wearers. This study aimed to compare the long-term MP and maximum occlusal force of immediate loading (IL) and conventional loading (CL) of 2-IODs retained by magnetic attachments. Nineteen e...

Objective: Patient satisfaction with single-implant overdentures (1-IODs) is unclear. This randomized crossover trial aimed to compare the general satisfaction, oral health-related quality of life, and patients’ self-assessment between mandibular 1-IODs and experimental removable complete dentures (eRCDs). Methods: New mandibular RCDs were fabricat...

Objectives Impacts of high-speed sintering on the optical and mechanical properties, microstructure, crystallography, and low-temperature degradation of commercial yttria-partially stabilized zirconia (Y-PSZ) were investigated. Methods Five commercial Y-PSZ products (KATANA HT, KATANA STML, KATANA UTML, Zpex 4, and Zpex Smile) were investigated. S...

This study aimed to evaluate the role of the general condition and oral health status in determining the primary nutritional route and suitable food form for oral ingestion among malnourished inpatients. This cross-sectional study included 255 inpatients referred to a nutrition support team (NST), which included dental professionals, at an acute ca...

We aimed to evaluate the properties of a novel tissue conditioner containing a surface pre-reacted glass-ionomer (S-PRG) nanofiller. Tissue conditioners containing 0 (control), 2.5, 5, 10, 20, or 30 wt% S-PRG nanofiller or 10 or 20 wt% S-PRG microfiller were prepared. The S-PRG nanofillers and microfillers were observed using scanning electron micr...