Mandibular overdenture with a single implant in the canine region (c-SIMO): a feasibility study.

OBJECTIVES: The aim of this multi-center pilot study was to assess the viability and feasibility of a novel treatment concept - the canine-positioned single implant mandibular overdenture (c-SIMO), with the single implant placed on the patient's preferred chewing side instead of the midline. MATERIALS AND METHODS: Participants received a single implant in the canine region of their preferred chewing side, based on an Asymmetry Index observed during mastication. The pre-existing mandibular denture was transformed into a c-SIMO on a spherical attachment. The primary outcome was oral health-related quality of life (OHRQoL), measured with GOHAI and OHIP-EDENT. Secondary outcomes included denture satisfaction index (DSI), chewing efficiency (CE), maximum bite force (MBF), implant survival and success, and prosthetic maintenance. Data analysis included descriptive statistics and bivariate comparison tests. RESULTS: Fifteen participants received the c-SIMO treatment (mean age: 69.9 ± 7.0). Implant success and survival rates were 100% at 1 year. Patient-reported outcome measures improved significantly compared to pre-treatment values (OHIP-EDENT: p = 0.001; DSI: p = 0.001; GOHAI: p = 0.002). Masticatory outcomes also improved significantly (CE: p = 0.001; overall MBF: p = 0.005). Post-implant, MBF was significantly higher in the ipsilateral side compared to the contralateral side at 2 weeks (p = 0.019) and 3 months (p = 0.015), but no longer at T3 (p = 0.730). Common prosthodontic events included denture base adjustments (n = 17) and matrix activation (n = 9). CONCLUSIONS: This pilot study concludes that c-SIMO is a promising treatment option, and a potential alternative to the single midline implant overdenture. CLINICAL RELEVANCE: The novel treatment concept of a canine-positioned single implant mandibular overdenture could be a viable treatment alternative to the midline positioning.

Appropriate use of antibiotics for oral/dental conditions in older adults: a narrative review.

OBJECTIVES: Considering the high rates in the use of antibiotics for oral/dental conditions in older patients and the rise in antimicrobial resistance, appropriate antibiotic prescription is important. This narrative review aimed to discuss the challenges and special considerations when prescribing antibiotics to older patients for oral/dental conditions. METHODS: PubMed/MEDLINE, Scopus, Web of Science, and articles' reference lists were searched for antibiotics use for oral conditions by older patients. Moreover, scientific and professional organisations' official websites were searched for guidelines on antibiotic use in dentistry. RESULTS: Despite several guidelines about the use of antibiotics in dentistry, specific information on their administration to older patients is missing. Relevant challenges include age-related changes in pharmacokinetics and pharmacodynamics, comorbidities and polypharmacy associated with low adherence, contraindications, adverse reactions, and drug-drug interactions. In unfit and frail older patients some antibiotics should be avoided, or doses should be adjusted, according to medical conditions or medications received. Amoxicillin, with doses adapted to renal function, is one of the safest options, while other antibiotics should be chosen with caution upon indications and individual patient characteristics. CONCLUSIONS: Healthcare providers should prescribe antibiotics to unfit and frail older adults with caution, given the multitude of comorbidities and potential interactions with medications received. Further research is needed on the safe and effective use of antibiotics in older patients.

A novel test for hyposalivation using a sugar cube.

BACKGROUND: Hyposalivation is a highly prevalent condition in old persons. OBJECTIVES: The aim of this study was to assess a novel tool for the diagnosis of hyposalivation using a sugar cube and to compare its reliability to other validated test methods. METHODS: Five tests were performed: unstimulated salivary flow test by draining method (USFT), oral moisture device Mucus® (MCS), sugar cube test (SCT), stimulated salivary flow test by chewing gum (CG) and Saxon test (SX). The sugar cube test consisted in measuring the time needed to disintegrate a standard-sized sugar cube N°4 (5.6 g) placed beneath the tongue. Bivariate correlation analyses were performed. ROC curve analysis and the Youden Index were used to determine the cut-off value. Sensitivity and specificity were calculated according to the determined cut-off point. RESULTS: A total of 121 participants were recruited, with an average age of 49.8 ± 18.2 years. The USFT was best correlated with the SCT. No correlation was found between SCT and the stimulated saliva tests (CG, SX) as well as the MCS test. According to the Youden index, 140 s is appropriate to diagnose hyposalivation. Sensitivity of .64 and specificity of .91 were found for SCT using USFT as gold standard. The mean subjective evaluation score of the SCT was 3.1 ± 1, significantly higher than USFT 2.6 ± 1.1 (p < .05). CONCLUSIONS: The sugar cube test proved to be a useful method for assessing unstimulated salivation, reducing test execution time and causing less participant discomfort than the gold standard unstimulated salivary flow test.

Single lateral implant for mandibular overdentures as a fallback solution or a viable treatment alternative: Four case reports.

This report of four clinical cases aims to illustrate the use of a lateral implant as a solution for implant overdentures in the mandible in different clinical situations. The first two cases describe the clinical situations of patients wearing two-implant mandibular overdentures until the failure of one of the implants, one due to implant loss and the other due to a fracture of an abutment screw, and how the conditions were managed. The third case illustrates the placement of a single implant to retain an overdenture, where a midline implant, as originally planned, was not feasible due to anatomic reasons. The final case describes the use of a lateral implant to support and retain a single-implant mandibular overdenture. The four cases demonstrate that a single lateral implant can be utilized as sole retention in cases of a failing contra-lateral implant and as an alternative to a single implant in the midline.

Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: Ten-year results from a double-blind, randomised controlled split-mouth core-trial.

The goal of this extension study was to compare the 10-year outcome of 3.3 mm diameter titanium-zirconium (TiZr) or grade IV titanium (Ti) implants in mandibular implant-overdentures. MATERIALS AND METHODS: This study is the 10-year follow-up from a randomised, controlled, double-blind, split-mouth multicentre clinical trial. Patients with edentulous mandibles had received two implants in the interforaminal region (bone-level, diameter 3.3 mm, microrough surface), one of TiZr (test) and one of Ti (control). Implant survival and success, plaque and sulcus bleeding indices, probing pocket depth, gingival margin, clinical attachment level and radiographic crestal bone levels were evaluated. RESULTS: Fifty of 91 patients with implants were available for the 10-year examination and 36 patients were valid for the intent-to-treat (ITT) analysis. The implant success rate was calculated as 94.6% and 91.9% for the TiZr implants and the Ti implants respectively. Four implants were lost (TiZr = 1; Ti = 3) in the entire study period. Kaplan-Meier survival analyses estimated 10- year implant survival rate for TiZr to 98.9% and Ti 95.8%.The mean of total and functional crestal bone loss was 1.49 mm (±1.37 mm) and 0.82 mm (±1.09 mm) in the TiZr group and 1.56 mm (±1.34 mm) and 0.85 mm (±1.16 mm) in the Ti group. CONCLUSIONS: This split-mouth design RCT on mandibular implant-overdentures evidenced, bearing in mind its follow-up time-related reduced cohort size, high 10-year implant success- and survival rates. These results confirm TiZr as well-suited implant material for realising small-diameter implants. Registered on www. CLINICALTRIALS: gov: NCT01878331.

Towards an operational definition of oral frailty: A e-Delphi study.

OBJECTIVES: Building upon our recently developed conceptual definition of oral frailty (the age-related functional decline of orofacial structures), this e-Delphi study aims to develop an operational definition of oral frailty by identifying its components. METHODS: We used a modified e-Delphi study to reach a consensus among international experts on the components of oral frailty. Twelve out of fifteen invited experts in the field of gerodontology participated. Experts responded to three rounds of an online 5-point scale questionnaire of components to be included or excluded from the operational definition of oral frailty. After each round, scores and rationales were shared with all experts, after which they could revise their position. A consensus was reached when at least 70% of the experts agreed on whether or not a component should be included in the operational definition of oral frailty. RESULTS: The experts achieved a high level of agreement (80 - 100%) on including eight components of oral frailty and excluding nineteen. The operational definition of oral frailty should include the following components: 1) difficulty eating hard or tough foods, 2) inability to chew all types of foods, 3) decreased ability to swallow solid foods, 4) decreased ability to swallow liquids, 5) overall poor swallowing function, 6) impaired tongue movement, 7) speech or phonatory disorders, and 8) hyposalivation or xerostomia. CONCLUSION: This e-Delphi study provided eight components that make up the operational definition of oral frailty. These components are the foundation for the next stage, which involves developing an oral frailty assessment tool.

Three tests to determine a preferred chewing side in partially edentulous patients: A pilot study.

STATEMENT OF PROBLEM: Determining the preferred chewing side may be an important factor in prosthetic treatment planning, especially where additional support for a removable dental prosthesis can be provided by implants. PURPOSE: The purpose of this clinical study was to investigate the validity and reproducibility of 3 different tests to determine the preferred chewing side. MATERIAL AND METHODS: A total of 82 partial denture wearers, with an average age of 70 years, were enrolled in this study. The first test (CG) evaluated the left or right position of a piece of chewing gum after spontaneous mouth opening during mastication. A second test (ASI) videotaped 30 seconds of mastication and analyzed the distribution of masticatory cycles by means of an asymmetry index. For the third test (VAS), participants were asked to mark their subjective perception of their preferred chewing side on a visual analog scale representing the right and left sides. All the tests were performed and repeated in a randomized sequence. The reproducibility of the tests was first evaluated. The mean values of the ASI and VAS tests were calculated, and the results were compared with the second series of the CG test. The Pearson correlation test was used to associate ASI and VAS, and the Cohen kappa agreement was used for the inter-reliability of CG (α=.01). RESULTS: The results indicated fair to almost perfect reproducibility for the 3 tests. Kappa values were.37 (P<.01) for the CG,.47 (P<.01) for the ASI and.91 (P<.01) for the VAS. Correlation coefficients resulted in rho=.86 (P<.01) for the ASI and rho=.97 (P<.01) for the VAS. The correlation between ASI and VAS was excellent, with rho=.85 (P<.010). CG and ASI (test kappa=.36, P<.010) and CG and VAS (test kappa=.39, P<.010) showed fair agreement. CONCLUSIONS: ASI and VAS seem more reliable than CG to determine a patient's preferred chewing side and might be helpful within the context of prosthetic treatment planning, where additional support may improve denture function.

Oral function in completely edentulous patients rehabilitated with implant-supported dental prostheses: A systematic review and meta-analysis.

OBJECTIVES: This review evaluated the effects of rehabilitation with implant-supported prostheses on the oral function of completely edentulous adults. MATERIALS AND METHODS: Systematic literature searches were performed to identify records reporting on oral function in completely edentulous adults rehabilitated with implant-supported prostheses. Meta-analyses were performed on various outcomes including bite force, masticatory performance, muscle activity, mandibular movement/chewing pattern, and salivary flow. RESULTS: 5507 records were identified. Thirty studies qualified for data extraction and analysis. The kappa (𝛋) for the search and identification strategy ranged between 0.50 and 1.00. Meta-analysis was performed grouping the studies by outcomes and split by time points of 6-12 months, 12-36 months, and >36 months after implant therapy. The meta-analyses revealed a significant improvement in oral function of completely edentulous adults after rehabilitation with implant-supported prostheses at 6-12 months (Z = -4.895, p < .001; 95% CI: -0.703, -0.301; τ2 = .609; Q = 114.953, df = 17, p < .001; I2 = 85.2%), at 12-36 months (Z = -4.886, p < .001; 95% CI: -0.580, -0.248; τ2 = .908; Q = 280.611, df = 35, p < .001; I2 = 87.5%) and at more than 36 months (Z = -9.108, p < .001; 95% CI: -1.472, -0.951; τ2 = .019; Q = 7.918, df = 7, p = .340; I2 = 11.6%). The included studies demonstrated a low to moderate risk of bias. CONCLUSIONS: This systematic review concluded that the oral function of completely edentate adults significantly improved with implant-supported/retained prostheses, even when only one jaw received implant therapy. Therefore, implant therapy should be promoted for edentulous adults to alleviate the shortcomings of conventional complete removable dental prostheses.

A novel prosthesis presentation test to screen for cognitive and functional decline.

OBJECTIVES AND BACKGROUND: To validate a novel screening test for cognitive and functional decline in older patients rehabilitated with complete removable dental prostheses (CRDPs). MATERIALS AND METHODS: Edentate old in-patients rehabilitated with CRDPs were included in this study. Participants were requested to remove their prostheses before their intraoral examinations. The prostheses were then presented in an inverted orientation. Participants had to correct the orientation of the prostheses and insert them in the appropriate jaws. The test was repeated after the intraoral exam. Appropriate statistical models were used (⍺ = .05) to associate the test results with the participants' mini-mental state examination (MMSE) score, functional independence measure (FIM), age and sex. RESULTS: Among the 86 participants (mean-age: 85.4 ± 6.4 years; mean MMSE: 19.8 ± 5.5; mean FIM: 77.9 ± 20.8), 21 (24.4%) failed to correctly insert the prosthesis. The prosthesis presentation test (PPT) was associated with the FIM but not the MMSE. Regression models further confirmed an association with age (P = .043), but not sex. Additional analyses revealed the PPT test is associated with the FIM's cognitive sub-sets of memory, problem solving and social interaction. CONCLUSION: The PPT is a novel, simple and quick screening tool that can help detect functional difficulties in older people. It can easily be performed during an oral examination. Future studies are needed to determine whether the PPT can be used to detect deficits in executive function, as a complement to the MMSE and also as a first assessment of a patient's ability to manage dentures independently.

The Impact of Xerostomia on Food Choices-A Review with Clinical Recommendations.

Xerostomia and hyposalivation are highly prevalent conditions in old age, particularly among multimorbid elders, and are often attributed to the use of multiple medications. These conditions negatively affect oral functions, such as chewing, swallowing, speech, and taste. Additionally, the lack of lubrication of the oral mucosa frequently leads to super-infections with candida. Denture retention and comfort may also be compromised. The risk of dental caries and erosion of natural teeth increases since saliva, which is essential for repairing initial lesions in tooth structures, is insufficient. The dry sensation in the mouth also impacts the emotional and social well-being of elderly individuals. Patients experiencing xerostomia often avoid certain foods that are uncomfortable or difficult to consume. However, some foods may alleviate the symptoms or even stimulate salivation. This review discusses the limited available evidence on nutritional advice for patients with xerostomia and aims to provide insight into the patient's perspective while offering clinical recommendations. Future studies should focus on investigating the nutritional intake of individuals suffering from xerostomia or hyposalivation in order to ensure oral health comfort, prevent malnutrition, and minimize the impact on their quality of life.

Exploring preferences of older adults for dental services: A pilot multi-national discrete choice experiment.

OBJECTIVES: To pilot an exploration of older adults' future preferences using discrete choice experiments to understand who should provide dental examinations and treatment, where these services should be provided, and participants' willingness to pay and willingness to travel. BACKGROUND: The proportion of older adults in the general population is increasing and is recognised as a pressing public health challenge. MATERIALS AND METHODS: Older people aged 65 years and over were recruited into this study from the UK, Switzerland and Greece. Drawing on earlier stakeholder engagement, a set of choice experiments are developed to explore the future preferences of older people for dental examinations and dental treatment, as they anticipated losing their independence. These were presented to the participants using a range of platforms, because of the COVID pandemic. Data were analysed in STATA using a random-effects logit model. RESULTS: Two hundred and forty-six participants (median age 70 years) completed the pilot study. There was a strong preference across all countries for a dentist to undertake a dental examination (Greece: ß = 0.944, Switzerland: ß = 0.260, UK ß = 0.791), rather than a medical doctor (Greece: ß = -0.556, Switzerland: ß = -0.4690, UK: ß = -0.468). Participants in Switzerland and the UK preferred these examinations to be undertaken in a dental practice (Switzerland: ß = 0.220, UK: ß = 0.580) while participants in Greece preferred the dental examination to be undertaken in their homes (ß = 1.172). Greek participants preferred dental treatment to be undertaken by a specialist (ß = 0.365) in their home (ß = 0.862), while participants from the UK and Switzerland preferred to avoid any dental treatment at home (Switzerland: ß = -0.387; UK: ß = -0.444). Willingness to pay analyses highlighted that participants in Switzerland and the UK were willing to pay more to ensure the continuity of future service provision at a family dental practice (Switzerland: ß = 0.454, UK: ß = 0.695). CONCLUSION: Discrete choice experiments are valuable for exploring older people's preferences for dental service provision in different countries. Future larger studies should be conducted to further explore the potential of this approach, given the pressing need to design services that are fit for purpose for older people. Continuity of dental service provision is considered as important by most older people, as they anticipate losing their dependence.

Masticatory performance in oral function assessment: Alternative methods.

BACKGROUND: Masticatory function declines with age or disease, implicating a poor chewing efficiency and an often-unconscious change for a less healthy, yet easy to chew diet. Timely screening of masticatory function may foster an early-onset diagnosis and potential treatment. The aim of this study was to compare alternative diagnostic tools for masticatory function to a Jelly-scan test. MATERIALS AND METHODS: Patients aged 70 years and older who were hospitalised for rehabilitation were recruited for this study. A total of four different tests for masticatory function were administered. The Japanese Society of Gerodontology glucose extraction test (Jelly-scan) was used as reference to compare a colour-changing gum test (Gum1-colour) as well as a mixing ability test with a visual (Gum2-visual) and opto-electronical (Gum2-digital) analyses. Receiver operating characteristic (ROC) curves were used to establish the discriminative value, kappa-values were used to estimate individual agreements and correlations were verified using Spearman's tests. RESULTS: Sixty-one patients (Men n = 23, Women n = 38) aged 82.4 ± 6.8 years participated in the experiments. The average number of natural teeth was 16.5 ± 10.5, 34.4% of the participants wore removable dentures. For all tests, the sum of sensitivity and specificity was >150%. All test correlated with Jelly-scan (absolute Rho >0.5). With Jelly-scan 51 participants (83.6%) were diagnosed with "masticatory hypofunction". After reducing the cut-off value of the test from 100 mg/dL to 65 mg/dL, only 33 participants (54%) fulfilled the diagnosis. This post-hoc analysis increased the sensitivity of the Gum2-tests and the agreement to kappa >0.5 for all three tests. CONCLUSION: All three tests can be considered useful screening alternatives. In its original version, Jelly-scan may tend to over-diagnose masticatory hypofunction, hence a novel cut-off with better agreement between tests is suggested.

Fit and retention of complete denture bases: Part II - conventional impressions versus digital scans: A clinical controlled crossover study.

STATEMENT OF PROBLEM: Although the intraoral scanning of edentulous ridges is feasible, clinical evidence that the resulting denture retention is equivalent to that achieved with conventional impressions is lacking. PURPOSE: The purpose of this clinical study was to determine the retention of complete denture bases fabricated from digital intraoral scans versus conventional impressions by using border molding and posterior palatal seal compression. MATERIAL AND METHODS: Twenty volunteers with an edentulous maxilla were recruited. An intraoral scan of the maxilla and a conventionally border-molded impression with a custom tray were made. The conventional impression was poured; the definitive cast was scanned. Three-dimensionally (3D) printed (PB1) and milled bases (MB1) were fabricated based on the scan of the definitive cast. Based on the intraoral scan, a 3D-printed (PB2) and a milled base (MB2) were fabricated. On each base, a platform with a hook consisting of a central notch orienting the force against the post dam (PD) and 2 lateral notches orienting the forces against the left (LT) and right (RT) tuberosities was set in the center of the outer surface of the base. A traction dynamometer was inserted in the hook and oriented into the corresponding notch by applying force until dislodgement. All bases were subsequently stored in artificial saliva for 2 weeks and scanned. Retention testing was repeated by using the same procedure. To evaluate trueness and to visualize the differences on a color map, the scan of the definitive cast and the intraoral scans were matched and compared in 3 dimensions. The Wilcoxon tests were used to compare the retention of the different bases (95% confidence interval, α=.05). RESULTS: Nineteen participants with a mean ±standard deviation age of 64.1 ±14.7 years completed the 4 study sessions. The retention of printed bases (PD: 16.08 ±15.28 N; LT: 14.98 ±14.72 N; RT: 11.28 ±9.57 N) and milled bases (PD:14.52 ±17.07 N; RT: 11.99 ±12.10 N; LT: 13.55 ±15.53 N) fabricated from conventional impressions presented significantly higher retentive forces than those printed (PD: 6.21 ±4.72 N; RT:5.12 ±2.78 N; LT: 4.45 ±2.77 N) and milled (PD: 6.58 ±4.92 N; RT: 4.65 ±2.63 N; LT: 5.02 ±3.58 N) from the intraoral scans (P<.05). The differences were significant in all directions of dislodgement, as well as after storage in artificial saliva for 2 weeks. Comparison of the 3D distances between the intraoral scan and the definitive cast revealed a mean deviation of 0.45 ±0.11 mm. CONCLUSIONS: Conventional impressions of the edentulous maxilla, including the clinical steps of border molding and posterior palatal seal compression, provide better retention than digital intraoral scans with both milled and 3D-printed denture bases.

Fit and retention of complete denture bases: Part I - Conventional versus CAD-CAM methods: A clinical controlled crossover study.

STATEMENT OF PROBLEM: Clinical evidence is sparse on whether dentures fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) methods afford superior fit and retention when compared with those fabricated conventionally. PURPOSE: The purpose of this clinical controlled crossover study was to evaluate the peak retention force and fit of CAD-CAM manufactured (3D-printed and milled) maxillary complete denture bases and conventional heat-polymerized bases (control). MATERIAL AND METHODS: Twenty participants with edentulous maxillary arches were recruited. Impressions were made with a border-molded custom tray, and the resulting definitive cast was scanned. The conventional base was manufactured on the definitive cast with a hook and a 45-degree platform with a central notch and 2 lateral notches. The scan of the definitive cast was used for the fabrication of a milled and a printed base. The platform and hook position on the conventional base were transferred digitally to the milled and printed bases. All bases were scanned. A traction dynamometer was orientated into the notches, and retention was evaluated in the post dam and tuberosity areas. Scans were imported into a comparison software program which matched scans to their corresponding reference and performed a 3-dimensional comparison. The Friedman and Wilcoxon tests were used to compare between groups (confidence interval: 95%, α=.05). RESULTS: Nineteen participants with a mean ±standard deviation age of 64.1 ±14.7 years completed all clinical sessions. No significant difference in peak retention was measured between milled (MB1), printed (PB1), and conventional (CB) bases in the post dam (CB: 12.44 ±9.62 N, PB1: 16.08 ±15.28 N, MB1: 14.52 ±17.07 N) and right tuberosity area (CB: 8.99 ±7.82 N, PB1: 11.28 ±9.57 N, MB1: 11.99 ±12.10 N). In the left tuberosity area, peak retention was lower for CB (10.03 ±8.39 N) than PB1 (14.98 ±14.72 N) and MB1 (13.55 ±15.53 N; P=.05). Compared with the definitive cast, the fit of the conventional base (0.18 ±0.01 mm) was closer than the printed (0.21 ±0.03 mm) and milled bases (0.21 ±0.02 mm) (P<.001). CONCLUSIONS: The CD bases manufactured by CAD-CAM techniques provided retention and fit similar to that of conventionally manufactured bases and can therefore be considered suitable techniques.

Periodontitis and peri-implantitis in elderly people experiencing institutional and hospital confinement.

An increasing number of elderly people retain their natural teeth into old age and further, the prevalence of endosseous implants for supporting oral prosthesis is ever increasing. These teeth and implants now present a considerable challenge in terms of maintenance, especially when patients become dependent on care. Periodontal and peri-implant diseases are more prevalent in elderly than in younger age cohorts. There are distinct differences related to the inflammatory response between periodontal and peri-implant tissues, both in young and old age. The age-related reasons for the increase in periodontal infections may be related to poor oral hygiene because of a loss of dexterity or vision, but also to immunosenescence. This term describes the aging of the immune system and the decline of its effectiveness with age. Low-grade infections, like chronic periodontitis, may cause low-grade inflammation and subsequently increase the likelihood of developing chronic diseases. In return, treatment of periodontitis may improve general health, as demonstrated for diabetes. A second mechanism illustrating how poor oral health translates into systemic disease is the risk of developing aspiration pneumonia. The treatment options in old age should be evaluated with regard to the issues of general health and maintenance. Systematic periodontal maintenance therapy, as performed in younger age cohorts, may be difficult to implement in elderly people experiencing institutional or hospital confinement because of logistics, barriers related to patients and caregivers, or cost. The scale of periodontal disease in old age represents a public health issue.

Misfit of Complete Maxillary Dentures' Posterior Palatal Seal following Polymerisation with Four Different Autopolymerising Resins: An In Vitro Study.

BACKGROUND: The majority of complete dentures are still conventionally manufactured using a flask-and-pack technique. However, the polymerization process may introduce a distortion of the denture body. The aim of this study was to evaluate the three-dimensional fit of the posterior palatal seal of maxillary complete dentures with the original impression, and to give recommendations for scraping. METHODS: Four autopolymerising resins were used to manufacture 40 palatal plates each for high, medium and flat palates (total n = 120). The misfit was captured by taking a reline impression with a highly fluid silicone, the dimensions of which were measured with a flat-bed scanner. RESULTS: The shape of the palate had a significant impact (median p = 0.0435), but not the resin type (median p = 0.2575). It was largest for the flat palate and smallest for the high palate. The largest misfit was observed in the palatal midline area (flat-palate average median: 685 µm; high and medium palates: 620 µm) decreasing towards the lateral and anterior regions. CONCLUSIONS: The results suggest compensating for the palatal misfit that occurs with autopolymerising resins by scraping a postdam of an approximately 0.7 mm depth to the master cast, decreasing towards the anterior and lateral areas. In high and medium palates, the scraping could be less pronounced.

Assessing masticatory performance with a colour-mixing ability test using smartphone camera images.

BACKGROUND: Colour-mixing ability tests are frequently used to assess masticatory performance, but the image acquisition process may be cumbersome and technique sensitive. OBJECTIVES: To evaluate the reliability of smartphone camera images in assessing masticatory performance using a colour-mixing ability test. METHODS: Participants were recruited into three groups of dental state (n = 20 each): fully dentate, removable partial denture wearers and complete denture wearers. After performing a colour-mixing ability test, images of the gum specimens (Hue-Check Gum©) were captured with two smartphones and compared with the images obtained from a flatbed scanner by two examiners. The images were analysed with a subjective- (SA) and an opto-electronical assessment (VoH). Inter- and intra-rater reliability were tested. ANOVA models with repeated measures were used for statistical analysis (⍺ = .05). RESULTS: All three image acquisition techniques were able to distinguish masticatory performance between different dental states. For SA, inter-rater reliability was fair to substantial and intra-rater reliability was substantial to almost perfect. For VoH, inter-rater reliability with the smartphones was at times different between two examiners, but the intra-rater assessment was reliable. The opto-electronic analysis with smartphone images underestimated the masticatory performance significantly when compared to the flatbed scanner analysis. Seven-day ageing of the specimens did not significantly affect the results. CONCLUSIONS: The assessment of masticatory performance with the Hue-Check Gum© is a reliable method. The use of smartphones may occasionally underestimate masticatory performance; image acquisition with a flatbed scanner remains the gold standard. A centralised analysis of the photographed wafer may foster the reliability of the diagnosis.

Analysis of the residual monomer content in milled and 3D-printed removable CAD-CAM complete dentures: an in vitro study.

OBJECTIVE: The study aimed to quantitatively evaluate the elution of methylmethacrylate from CAD-CAM manufactured removable complete dentures (RCDs) using high performance liquid chromatography (HPLC). METHODS: Thirty-two RCDs were manufactured following either the CNC-milling (Milled: n=8) or the 3D-printing (n=24) protocols. The 3D-printed dentures were further categorized into three groups based on their post-production rinsing cycles [Extended wash cycle (EWC), Standard wash cycle (SWC), and SWC with an additional Durécon coating (SWC2)]. HPLC was used to evaluate the methylmethacrylate concentrations (MMCs) eluted from the dentures in each group for different time periods (1, 2, 4, 8, and 24 hours). Mean and standard deviations were calculated for the MMCs; data was verified for normal distribution, ANOVA and post hoc tests were applied for statistical analyses (⍺=0.05). RESULTS: The HPLC revealed that all the denture groups recorded some amounts of MMCs, with significant differences [F (3, 31) = 23.646, p<0.0001]. The milled denture group had the highest MMCs at 24 hours when compared to the EWC (p<0.0001), SWC (p=0.001), and SWC2 (p<0.0001) denture groups. SWC had a higher MMC than EWC (p=0.032) and SWC2 (p=0.015). No differences were found in MMCs when comparing EWC and SWC2 (p=0.989). CONCLUSION: Methylmethacrylate concentrations were significantly lower in 3D-printed RCDs than in milled RCDs when using the resins employed in this study. Furthermore, the MMCs can be further decreased in 3D-printed RCDs when coated with an additional thin protective layer (Durécon) by following the manufacturer-recommended rinsing protocol or when an extended isopropanol wash cycle is adopted.

Effects of overnight storage conditions on conventional complete removable prostheses.

PURPOSE: To evaluate the effects of overnight storage conditions on the dimensional stability and retention of prostheses, as well as the participant's subjective perception of these interventions. MATERIALS AND METHODS: Subjects with maxillary complete prostheses (CRPs) were randomly assigned to receive two interventions in a crossover design: storing the CRPs overnight in a dry or wet environment with a cleansing tablet. The denture intaglio surface was scanned, and outcome measures were collected before each intervention (BLN), post ntervention (PIS), and after immersion in water for 15 minutes after the intervention (WOC). Dimensional changes were analyzed for the total surface, anterior flange, palate, and tuberosities. Retention force was measured using a dynamometer, and the participants' subjective assessment of comfort, fit, and retention of their CRPs were collected. After verifying normal distribution, paired t and Wilcoxon signed-rank tests were used to check for any statistical significance (α = .05). RESULTS: Ten participants (mean age: 76.5 ± 5.9 y) were recruited in this study. Between BLN and PIS, the dimensional changes after dry intervention were significantly less than when stored wet for total surface (P = .009), anterior flange (P = .028), and the palate (P = .005). No difference was found between the effects of storage or washout interventions on objectively measured CRP retention. However, after WOC following dry storage, participants perceived a lower retention (P = .021), and a more comfortable palate after WOC following the wet intervention (P = .018). CONCLUSION: For dimensional stability, dry overnight storage of removable prostheses can safely be recommended when indicated. Immersion in water for 15 minutes does not seem to add advantages.

Oral function and nutritional status in non-acute hospitalised elders.

INTRODUCTION: Malnutrition and risk of malnutrition continues to be a common finding in elders, yet its association with oral function in hospitalised patients remains unclear. MATERIAL AND METHODS: Patients aged 70 years or over who had been hospitalised for non-acute rehabilitation were recruited. Nutritional risk was screened using the Mini-Nutritional Assessment Short Form (MNA-SF) and Nutritional Risk Screening (NRS) scores. Malnutrition was assessed according to the Global Leadership Initiative on Malnutrition (GLIM) criteria. All participants underwent the oral hypofunction test battery, evaluating oral hygiene, oral dryness, occlusal force, tongue-lip motor function, tongue pressure, masticatory and swallowing function. Statistical analyses comprised Mann-Whitney or Kruskal-Wallis tests. Bivariate associations between categorical variables were tested using the Pearson chi-square test; for continuous variables, the Spearman correlation was calculated. A P-value < .05 was considered statistically significant. RESULTS: Sixty patients aged a mean 82.5 ± 7.0 years participated. Some 88.3% were diagnosed with oral hypofunction, and this was more common in older patients (P = .020). Analysing the 7 oral hypofunction tests as an interval variable (NiOF) revealed additional correlations with number of teeth (ρ = 0.477) as well as the nutritional risk, evaluated by the MNA-SF (ρ = -0.284) and NRS (ρ = 0.317) scores. NiOF scores were higher among denture wearers (P = .003). GLIM did not confirm the correlation with NiOF. Biomarkers such as serum albumin and CRP were not associated with the NiOF score. CONCLUSION: In this sample, the association between oral function and nutritional state is more obvious in nutritional risk scores than in the malnutrition diagnosis by GLIM.