Influence of scanning protocol on the accuracy of complete-arch digital implant scans: An in vitro study.

OBJECTIVE: This in-vitro study assessed the influence of two intraoral scanning (IOS) protocols on the accuracy (trueness and precision) of digital scans performed in edentulous arches. METHODS: Twenty-two abutment-level master casts of edentulous arches with at least four implants were scanned repeatedly five times, each with two different scanning protocols. Protocol A (IOS-A) consisted of scanning the edentulous arch before inserting the implant scan bodies, followed by their insertion and its subsequent digital acquisition. Protocol B (IOS-B) consisted of scanning the edentulous arch with the scan bodies inserted from the outset. A reference scan from each edentulous cast was obtained using a laboratory scanner. Trueness and precision were calculated using the spatial fit analysis, cross-arch distance, and virtual Sheffield test. Statistical analysis was performed using generalized estimating equations (GEEs). Statistical significance was set at α = .05. RESULTS: In the spatial fit test, the precision of average 3D distances was 45 µm (±23 µm) with protocol IOS-A and 25 µm (±10 µm) for IOS-B (p < .001), and the trueness of average 3D distances was 44 µm (±24 µm) with protocol IOS-A and 24 µm (±7 µm) for IOS-B (p < .001). Cross-arch distance precision was 59 µm (±53 µm) for IOS-A and 41 µm (±43 µm) for IOS-B (p = .0035), and trueness was 64 µm (±47 µm) for IOS-A and 50 µm (±40 µm) for IOS-B (p = .0021). Virtual Sheffield precision was 286 µm (±198 µm) for IOS-A and 146 µm (±92 µm) for IOS-B (p < .001), and trueness was 228 µm (±171 µm) for IOS-A and 139 µm (±92 µm) for IOS-B (p < .001). CONCLUSIONS: The IOS-B protocol demonstrated significantly superior accuracy. Placement of scan bodies before scanning the edentulous arch is recommended to improve the accuracy of complete-arch intraoral scanning.

Factors influencing speech improvement following maxillary complete-arch implant-supported restorations: A retrospective study.

OBJECTIVE: This study explored factors affecting speech improvement in patients with an edentulous maxilla after the delivery of a complete-arch implant-supported fixed dental prosthesis (IFDP). MATERIALS AND METHODS: Patients who had received IFDP for edentulous maxilla were enrolled, and various potential speech improvement-related factors were considered, including patient demographics, anterior residual bone volume, preoperative facial features, preoperative acoustic parameters, and adaptation time. Acoustic analysis and perceptual ratings were used to assess three fricatives [s], [f], and [ɕ]. Correlation and regression analyses were conducted to assess the association between changes in fricatives and potential factors (α = .05). RESULTS: The study included 50 patients (18 females and 32 males, aged 50.62 ± 15.71 years, range 19-76). Significant correlations were found among the change in the center of gravity (ΔCoG) of [s] and anterior residual bone volume, zygomatic implants number and proportion (p < .05). These correlations were largely mirrored in the perceptual score (ΔPS) changes. After controlling for age, sex, preoperative acoustic parameters, and adaptation time, the ΔCoG and ΔPS of fricatives were mainly correlated with the anterior residual bone volume, preoperative acoustic parameters, and adaptation time. CONCLUSION: Speech improvements post-IFDP delivery are mainly related to preoperative speech characteristics, anterior residual bone volume, and adaptation time. The residual bone volume's impact on consonants varies with specific articulatory gestures. This study provides insights into forecasting speech outcomes following IFDP restoration and provides recommendations and methods for data collection in developing future prediction models.

Maxillary and mandibular overdentures retained by two unsplinted narrow-diameter titanium-zirconium implants - A clinical pilot study.

OBJECTIVES: To evaluate the survival rates and marginal bone loss of narrow-diameter titanium-zirconium implants supporting complete maxillary and mandibular overdentures up to 3 years after loading. MATERIALS AND METHODS: Ten completely edentulous patients who were dissatisfied with their complete dentures were enrolled. Two narrow-diameter implants were placed in the canine region of the maxilla and mandible. After second-stage surgery, implant-supported overdentures (palatal-free) attached by parallel alignable stud-attachments were placed. Patients were followed periodically for up to 36 months. Standardized radiographs were taken at baseline, 12 and 36 months to analyze mean marginal bone level changes around the implants. RESULTS: The Kaplan-Meier survival rates were 100% for mandibular and 68.0% (SE ± 10.9%) for maxillary implants at 36 months (p = .008). Six maxillary implants failed after loading; no mandibular implants were lost. Five implants failed due to loss of osseointegration. One implant fractured. The mean marginal bone level changes around the analyzed implants (n = 28, 9 patients) were -0.71 ± 0.82 mm in the mandible and -2.08 ± 1.52 mm in the maxilla at the 36-month follow-up. The difference in marginal bone level changes between the maxilla and mandible was significant (p = .019) at the 12- and 36-month follow-ups. CONCLUSION: Two narrow-diameter titanium-zirconium implants with stud-attachments showed a highly satisfactory outcome in the mandible. The maxillary implants showed a high failure rate and significantly more bone loss over time than the mandibular implants. The minimal concept of two implants and an overdenture should be limited to the edentulous mandible.

Maxillomandibular relationship record methods for computer-engineered complete dentures: a scoping review.

OBJECTIVES: The purpose of this scoping review was to identify different methods employed for recording the maxillomandibular relationship (MMR) for computer-aided designed and manufactured (CAD-CAM) complete dentures (CDs). MATERIALS AND METHODS: This scoping review followed the PRISMA-ScR guidelines and was developed according to Arksey and O'Malley and The Joanna Briggs Institute protocol. The methods were registered on the Open Science Framework (< osf.io/rf4xm> ). The focus question was: "What are the different techniques for recording the maxillomandibular relationship in the digital workflow used in CECDs?" Two investigators searched 3 online databases [MEDLINE (PubMed), Scopus, and Science Direct] independently. The inclusion criteria were clinical studies and reviews that assessed techniques for recording MMR using digital workflow for manufacturing of CECDs. A descriptive analysis was performed considering the study design, manufacturing system, clinical steps, and tools for the determination of MMR, and the difficulty level of procedures. RESULTS: 4779 articles were identified in the electronic search and 10 studies were included for data analysis. The review identified 4 commercially available CAD-CAM denture systems and 3 innovative methods suitable for abbreviating the number of appointments (2 to 4 visits). The trial denture is inherent to the procedure for the Baltic System and 3 innovative techniques. Three techniques (2 innovative and WholeYouNexteeth) demonstrated lower difficulty levels for performing the clinical procedures, regardless of the professional skills. CONCLUSIONS: The commercially available and innovative techniques for the recording of MMR may provide predictability of the treatment. The techniques are effective, however, rely on the learning curve and the patient's clinical condition. CLINICAL RELEVANCE: Recording of the maxillomandibular relationship is paramount for the manufacturing and functionality of complete dentures. Clinicians should be aware of the different tools and techniques described for registering the jaw relationship.

Biomechanical behavior of all-on-4 concept and alternative designs under different occlusal load configurations for completely edentulous mandible: a 3-D finite element analysis.

The aim of this study was to evaluate the effect of the All-on-4 design and 4 alternative implant-supported fixed prosthesis designs on stress distribution in implants, peri-implant bone, and prosthetic framework in the edentulous mandible under different loading conditions using three-dimensional finite element analysis (3D-FEA).Five different experimental finite element models (Model A (unsplinted 6), Model B (splinted 6), Model C (All-on-4), Model D (axial; 2 anterior, 2 posterior), and Model E (4 interforaminal)) were created. Three different loading conditions were applied (canine loading, unilateral I-loading, and unilateral II-loading). The highest minimum (Pmin) and the maximum (Pmax) principal stress values were acquired for cortical and trabecular bones; the highest von Mises (mvM) stress values were obtained for implants and metal frameworks. Model B and Model D showed the most favorable stress distribution. The All-on-4 design (Model C) also showed acceptable stress values close to those of Model B and Model D in the cortical and trabecular bones. In accordance with the stress values in the bone structure, the lowest stress values were measured in the implants and Co-Cr framework in Model B and Model D. The highest stress values in all structures were measured for unilateral loading- II, while the lowest values were found for canine loading. It was concluded that Model B and Model D experimental models showed better biomechanical performance in all structures. Furthermore, the use of a splinted framework, avoiding cantilevers, results in lower stress transmission. On the other hand, canine loading and unilateral loading-I exhibited the best loading conditions.

Influence of denture-bearing conditions on masticatory function and patient-reported outcomes measures.

PURPOSE: To investigate the influence of different denture-bearing conditions on the masticatory function and patient-reported outcome measures (PROMs) of complete denture wearers. METHODS: Sixty edentulous patients were selected and allocated into two groups according to the American College of Prosthodontics' (ACP) classification: non-atrophic (NAT) (Classes I and II) (n = 24) and atrophic (AT) (Classes III and IV) (n = 36). All patients received new complete dentures (CDs). The objective variables (masticatory performance and swallowing threshold) were assessed as well as the PROMs (oral health-related quality of life (OHIP-EDENT), patient satisfaction) and quality of the prosthesis, at baseline (using the old CD) and after 4 months new prostheses use. Data were analyzed by Mann-Whitney test followed by the Generalized Equations Estimation (GEE), linear regression and Chi-square test. RESULTS: Higher masticatory performance was observed in the NAT group (p < .05) for both time points, baseline and after 4 months. However, compared to baseline, both groups showed significant masticatory improvement after 4 months (p < .05). Satisfaction and overall quality of life improved after 4 months with no difference between groups (p > .05). Regarding the quality of the CD, baseline results were significantly (p < .05) lower in the AT group, but after 4 months, no significant differences were found between groups and in intragroup analysis (p > .05). CONCLUSIONS: The denture-bearing conditions seems to impact masticatory function, but the PROMs are barely affected.

Changes in masticatory performance and bite force after treatment with mandibular overdentures retained by four titanium-zirconium mini implants: One-year randomised clinical trial.

OBJECTIVE: This prospective study is part of a randomised clinical trial and reports the changes in masticatory performance (MP) and bite force, and explores their influential factors, 1 year after the provision of mandibular overdentures retained by four titanium-zirconium mini implants. METHODS: Edentulous patients received conventional complete dentures, followed by placement of four mini implants (Straumann® Mini Implant System) in the anterior mandible and converting the conventional prosthesis into a mandibular overdenture. Treatment protocols were randomised using a 2×2 factorial design combining different surgical (flapped vs. flapless) and loading (immediate vs. delayed) protocols. MP was assessed using a two-colour mixing ability test and a colorimetric analysis to measure the level of colour mixing (Variance of Hue-VoH). Maximum voluntary bite force (MBF) was measured by a digital gnathodynamometer in the posterior and anterior regions. Sex, age, surgical and loading protocols and ridge morphology were tested as independent variables. MP and MBF tests were performed at baseline (pre-treatment) and the 3-, 6- and 12-month after implant loading. Descriptive statistics, independent t-test, and linear mixed-effect model (LMM) regression were used for data analysis. RESULTS: Seventy-four participants were assessed and 73 completed the 1-year follow-up. Statistically significant improvements in functional parameters were observed in all follow-up periods compared to baseline (p < .001). The flapless protocol was associated with higher improvement in MP at the 3-month follow-up (p = .004), while less resorbed ridges were associated with better MP (p = .038) and higher MBF (p < .001). CONCLUSION: The mandibular overdenture protocol using four titanium-zirconium mini implants was effective in improving MP and MBF of edentulous patients, compared to pre-treatment values. The findings also suggest that improvements in chewing function and bite force are impacted by clinical factors since better outcomes were observed for flapless surgeries and less resorbed edentulous ridges. CLINICAL TRIAL REGISTRATION: ClinicalTrials.Gov ID NCT04760457.

Masticatory performance, self-perception of oral health, oral health-related quality of life and nutritional status of completely edentulous elderly patients submitted to different rehabilitation treatments: A cross-sectional study.

BACKGROUND: The impact of treatments on completely edentulous individuals on masticatory performance (MP), oral health-related quality of life (OHRQoL), nutritional status (NS) and socio-economic profile (SP) is unclear in the literature. OBJECTIVE: To compare the MP, OHRQoL, NS and SP of totally edentulous elderly users of bimaxillary complete dentures (CD) and users of lower implant-supported fixed complete dentures (IFCD). METHODS: Forty participants were allocated into groups according to rehabilitation treatment (n = 20): bimaxillary CD (G1) and lower IFCD, and upper CD (G2). The evaluation of MP used almonds by the method of sieves. Four questionnaires (Geriatric Oral Health Assessment Index-GOHAI and Oral Health Impact Profile Edent-OHIP-Edent, Brazilian Economic Classification Criteria-ABEP and Mini Nutritional Assessment-MNA) were applied to assess the OHRQoL, SP and NS of the elderly, respectively. After evaluating the statistical assumptions, the Mann-Whitney (α = .05) test was applied to compare the groups regarding MP, OHRQoL, NS and SP. Spearman's correlation (α = .05) was performed to verify the correlation between the MP, the OHRQoL and the NS of the participants. RESULTS: G2 showed better MP (p < .05) in all masticatory cycles, OHRQoL (p < .05) and NS than the G1. However, the participants' self-perception of oral health did not differ between groups (p < .05). A moderate negative correlation was found between MP and OHRQoL for 40 masticatory cycles (r2 = -0.513; p = .001). CONCLUSION: Individuals rehabilitated with IFCD had a higher average monthly family income and achieved superior behaviour in MP and OHRQoL, in addition to lower risks of malnutrition when compared to individuals using bimaxillary CD.

Chewing difficulties mediated association between edentulism and depressive symptoms among middle aged and older population.

BACKGROUND: Depression is a major health condition among the aging population. Previous studies indicated that edentulism was a risk factor for depression. The link between edentulism and depression has not been fully clarified. OBJECTIVES: This study aimed to estimate whether chewing difficulties play a mediating role in the association between edentulism and depression among middle-aged and older populations with national cross-sectional data. METHODS: Data were obtained from the latest fourth wave of the China Health and Retirement Longitudinal Study (CHARLS). The outcome variable was set as depression, which was measured by the Center for Epidemiologic Studies Depression Scale (CES-D-10). Independent and mediated variables were separately set as self-assessed edentulism and chewing difficulties. The nearest neighbour propensity score matching (PSM) method was used to construct a matching group to balance the basic characteristics of individuals with and without edentulism with minimised bias in the estimation. Causal mediation analysis was performed to estimate the degree of contribution of chewing difficulties to the association between edentulism and depression. Several sensitivity analyses were performed to evaluate the robustness of the primary result. RESULTS: A total of 15 853 individuals remained for analysis. After PSM, 809 individuals with edentulism and 2628 without edentulism remained for analysis. Among the matched individuals, the mean age was 66.3 ± 9.2 years, 58.5% were female, 78.8% lived in rural areas, 23.5% had edentulism, 51.1% had depressive symptoms, and 50.1% had chewing difficulties. Logistic regression results showed that a higher incidence of edentulism was associated with a higher rate of depression (OR: 1.39, 95% CI: 1.19-1.63) in the matching group. Causal mediation analysis results indicated that the average mediation effect of chewing difficulties on the association between edentulism and depression was 0.010 (95% CI: 0.005-0.015), and the average direct effect was 0.072 (95% CI: 0.036-0.11). The mediation proportion of chewing difficulties was 11.7% (95% CI: 0.079-0.21). CONCLUSION: A higher prevalence of edentulism was associated with a higher rate of depression among middle-aged and elderly populations. Chewing difficulties moderately mediated the association between edentulism and depression. Fundamental oral function should not be neglected to improve mental health among the aging population.

Influence of new complete dentures on the touch perception threshold and quality of life of edentulous patients.

OBJECTIVE: To evaluate the touch perception threshold of the alveolar mucosa and quality of life of edentulous patients before (T0) and 30 days after (T1) the insertion of new complete dentures. BACKGROUND: Touch perception is important so that edentulous patients can detect the position of complete dentures in their mouth. MATERIALS AND METHODS: This study included 32 complete denture wearers with good oral and systemic health and no temporomandibular disorders for at least 5 years. At each time point (T0 and T1), two tests were performed (touch perception threshold and quality-of-life scale). The touch perception threshold (Von Frey or Semmes-Weinstein test) was assessed using nylon monofilaments on the regions of the alveolar mucosa of the maxilla and mandible. The Oral Health Impact Profile for edentulous individuals (OHIP-EDENT) was administered to evaluate oral health-related quality of life. RESULTS: In the maxilla and mandible, the touch perception thresholds for all regions of the alveolar mucosa were significantly lower at T1 than at T0. The OHIP-EDENT mean scores showed that the overall quality of life was significantly better at T1 (3.6) than at T0 (4.7), and a significant improvement in quality of life was observed in all domains of the OHIP-EDENT at T1. For touch perception threshold, effect sizes ranged from 0.4 to 0.8; and for quality of life, effect sizes ranged from 0.4 to 1.0. CONCLUSIONS: New complete dentures reduced the touch perception threshold of the alveolar mucosa of both edentulous arches and improved individuals' quality of life.

Prolonged use of old dentures: A qualitative study with Brazilian older adults.

OBJECTIVE: To explore older adults' perceptions, motivations and reasons for using and not replacing old and worn complete dentures over prolonged periods. MATERIALS AND METHODS: In-depth, semi-structured interviews were conducted with Brazilian edentulous older adults who were wearing complete dentures which were at least 20 years old. A purposive sampling method was used to recruit participants from an existing waiting list of those referred to a hospital clinic for new dentures. The interviews were video-recorded, transcribed verbatim and analysed using thematic analysis. RESULTS: Sixty-two individuals were assessed and nine were included in the study, aged from 61 to 77 years (mean = 65.4), with seven (77.8%) of them women. The reported time using their current dentures ranged from 22 to 45 years (mean = 28). Content analysis revealed three main themes: the perception of the current dentures' condition after prolonged use; reasons for the prolonged use and non-replacement; and unsuccessful attempts to replace the dentures. Overall, participants acknowledged the poor condition of their dentures and did recognise the need for replacement. Several factors had prompted them to delay or temporarily forego replacement, with financial constraints being the main barrier. Some reported failed attempts to replace the dentures in the past years or months; however, challenging adaptation to the new prostheses led to them reverting back to their old dentures as a fallback solution. CONCLUSION: Factors influencing prolonged denture use in older adults include a complex interplay of financial aspects, treatment awareness, access and personal factors. Dental professionals can play a pivotal role in promoting timely denture adjustment or replacement by addressing these factors through patient education and personalised care.

Complete denture palatal rugae design impact on satisfaction and quality of life.

OBJECTIVES: To compare the impact of three complete denture palatal rugae designs on participants' satisfaction and oral-health-related quality of life. BACKGROUND: Complete dentures palatal rugea are usually polished to a smooth finish, which can affect the patient's adaptation. Roughening or keeping an opening in the rugae area to replicate the natural sensation of the palatal rugae has been suggested but lacks clinical evidence. METHODS: This randomised crossover trial included participants with complete dentures randomly allocated to six sequences. Each sequence alternated between polished, roughened, and open rugae designs. Participants evaluated general and domain-specific satisfaction (eating, taste, speaking, phonetics, and ease of cleaning) on a 100-mm visual analogue scale. They also completed the Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT) and indicated their preferred design at the end. Repeated-measure ANOVA compared satisfaction, and one-way ANOVA with Tukey's test compared OHIP-EDENT scores. RESULTS: Forty-two participants were randomised. Seven dropped out. General satisfaction ratings were comparable for the polished (Mean = 80.2, SD = 19.7) and roughened designs (Mean = 79.5, SD = 20.2). However, the open design had a significantly lower satisfaction rating (Mean = 41.1, SD = 32.2). OHIP-EDENT scores for the open design (Mean = 44.9, SD = 17.5) were significantly worse than those for the polished (Mean = 36.1, SD = 12.7) and roughened designs (Mean = 36.2, SD = 13.3). Two-thirds of the participants chose the polished design. One-third chose the roughened design; of those, 83% were first-time denture wearers. CONCLUSIONS: Complete dentures with polished and roughened rugae designs were perceived similarly. Both designs could be recommended based on the patient's preference. However, the open design should be avoided due to negative perception.

Comparison of Implant-Retained Overdenture and Conventional Complete Denture: A Survey Study to Measure Patients' Satisfaction and Quality of Life in Dental School Clinics.

Patient satisfaction and quality of life are integral to assessing oral health care quality. For many Americans still using conventional complete dentures (CD) or Implant Retained-Overdentures (IOD), it remains essential to consider improving their oral health outcomes and quality of life. Due to inexperienced student dentists providing dental care to dental school patients, patient grievances are generally considered a problem. Patient feedback and satisfaction have proven valuable resources for monitoring and improving patient safety. While CD and IOD are the two leading treatment options for edentulism, more comparative studies in the literature need to compare their outcomes in a school setting. The research question that guided this comparative analysis was, "Is patient satisfaction and quality of life affected by the type of prostheses and provider?" A validated questionnaire was mailed to 520 individuals selected from records of patients who had received treatment for edentulous mandible at a student prosthodontic clinic at the [redacted for peer review] from 2014 to 2016 with at least one year of follow-up time. A validated questionnaire for edentulous patients based on the Oral Health Impact Profile (OHIP-19) was used. In addition, information on patients' oral health-related quality of life, including questions related to the edentulous patients' satisfaction with their dentures, was collected. The response rate was 33% (N = 171). The study's findings confirm previous findings, suggesting that IODs may significantly impact oral health-related quality of life. Data show that 76% of the IOD group reported improvement in experience when using the implants to retain the mandibular denture. However, there were no statistically significant differences in the OHIP scores between overall CD and IOD patient groups. Males with IOD had lower physical pain, limitations, and concerns associated with a social disability and handicap domains. Comparing users who had experiences with both treatment options, this study discerned essential characteristics that contribute to increased patient satisfaction with IOD and identified significance in outcomes by gender. These findings guide prosthodontic practitioners' patient care practices and identify a continuing need to discuss CD and IOD treatment protocols within dental school curricula.

The Use of Splinted Versus Nonsplinted Prosthetic Design in Dental Implants: A Literature Review.

The choice of a splinted or nonsplinted implant-supported prosthesis should be based on solid scientific evidence that considers the conditions and needs of each patient. This review elaborates on the factors that directly influence clinical decisions between splinted or nonsplinted dental implants. Digital and manual searches of the published literature were conducted to identify studies that examined splinted prostheses (SPs) and nonsplinted prostheses (NSPs). The search terms used, alone or in combination, were "splinting prosthesis," "nonsplinting prosthesis," "prosthetic design," "stress distribution in dental implant," "implant loading," "implant occlusion," and "crestal bone resorption." Ninety-four studies were selected to compare and address the details emphasized in this study. Thirty-four reported articles were not directly related to restoration design but were reviewed to better understand the influence of mechanical risk factors, finite element analysis limits, and criteria for implant survival and treatment success. There are advantages and disadvantages of splinting implants together. NSPs are the ideal choice because they resemble natural teeth. Splinting a restored implant will cause the implant to appear as part of one unit and is indicated in more compromised situations, unfavorable conditions, or when pontic spaces and cantilevers are needed in implant prostheses.

Exploring lived experiences on the usage of removable complete dentures among edentulous patients attending Makerere University Dental Hospital, Kampala, Uganda.

BACKGROUND: Edentulism remains a major disability worldwide, especially among the elderly population, although the prevalence of complete edentulism has declined over the last decades. In Uganda, the prevalence of edentulism in people aged 20 years and above is 1.8%. The therapy for edentulous patients can be realized through the use of conventional removable complete dentures, implant-supported prostheses, and computer-aided design and computer-aided manufacturing (CADCAM), however, the provision of removable complete dentures continues to be the predominant rehabilitation for edentulous patients. However, no published study has explored the lived experiences with removable complete dentures among the Ugandan population. The aim of the present study was to explore patients' lived experiences on the usage of removable complete dentures among Ugandan edentulous patients attending Makerere University Dental Hospital. METHODS: This was a qualitative study approach using purposive sampling. Fifteen (15) respondents were selected across social demographics. Interviews were recorded and transcribed and themes were generated to draw a deeper meaning to the usage of removable complete dentures. A qualitative statistical package, Atlas Ti software was used to generate themes from the interviews followed by an interpretation of the generated data and the results were presented as text and in a table. RESULTS: The reported key positive experiences due to removable complete denture rehabilitation were the improvement in speech, eating ability, regaining good facial appearance, better oral hygiene management, self-esteem and confidence to smile in public, and a feeling of completeness. However, respondents complained of pain and discomfort due to the looseness of dentures, inability to eat certain foods, and regular cleaning of dentures. The respondents did not go through proper informed consent processes before getting removable complete dentures. CONCLUSION: The study found that patients were satisfied with their removable complete dentures rehabilitation due to the positive experiences registered, such as the ability to eat and talk well, and restoration of self-esteem, all of which improved their quality of life. However, they experience pain and discomfort due to the looseness of dentures.

Association of tooth loss and nutritional status in adults: an overview of systematic reviews.

BACKGROUND: Association of tooth loss and nutritional status has been widely researched with conflicting results. This overview aimed to analyse and summarize findings from systematic reviews on association of tooth loss with nutritional status, in view of their quality assessment and methodological characteristics. METHODS: Overview was conducted as per Cochrane Overviews of Reviews guidelines. 5 databases (PubMed, Dentistry and Oral Sciences Source, Scopus, Cochrane Register of Systematic Reviews, Epistemonikos.org) and one online source (Google Scholar) were searched for systematic reviews published between 2010 - July 2022, with inclusion criteria; population: participants aged 18 years or above, intervention/exposure: loss of teeth, comparison: not applicable, outcome: nutritional status, study: systematic reviews and meta-analysis. Reviews on association of prosthetic interventions with nutritional status were not included. Data were extracted for study characteristics, details of primary studies, and main findings. Narrative synthesis of data, overlap of primary studies and quality assessment of studies were done using AMSTAR 2 tool (A Measurement Tool to Assess Systematic Reviews). RESULT: Of 1525 articles found, seven systematic reviews were selected (four were systematic reviews, three were systematic reviews with meta-analysis). Five studies showed some or positive association, one found weak association and for one study the association was unclear. Overlap of primary studies was 'very slight'. Meta-analysis of two studies concluded fully or partially edentulous individuals were more likely to be malnourished or at risk of malnutrition, (RR = 1.095, 95% CI 1.007 to 1.190, p = 0.033. RR = 1.22; 95% CI 1.11 to 1.32 p < 0.01), but one found that edentulism was not associated with malnutrition. (RR = 1.072, 95% CI 0.9657-1.200). Quality assessment revealed four studies were 'high', one was 'low' and two were 'critically low.' CONCLUSION: This overview confirms the association between tooth loss and nutritional status specially in elderly. It is evident that tooth loss increases the likelihood of poor nutritional status. Overall, studies show high heterogeneity in the methodology and quality assessment reveals low confidence in the available evidence. Future studies should use standard assessment tools for tooth loss and nutritional status.

Evaluation of open-face maxillary complete denture for patients with prominent premaxilla: a crossover study.

BACKGROUND: The establishment of good facial esthetics is one of the main objectives of complete denture construction. Unfortunately, it may be the caused issue for patients having a prominent premaxilla due to excessive lip support by the labial flange of the maxillary denture. Open-face dentures (OFD) may suggest suitable prosthetic management for these patients. However, clinical evidence regarding the efficiency of OFD is scarce. METHODS: A total of 38 completely edentulous participants having prominent premaxilla and skeletal class I Angle's classification were enrolled in this study. Each participant received a mandibular complete denture and 2 opposing maxillary dentures; conventional (CD) and open-face (OFD). On the day of denture insertion, the participants were divided into 2 groups; CD-OFD and OFD-CD where CD-OFD group was instructed to use the mandibular denture and the maxillary CD for 3 months and then to use the maxillary OFD for another 3 months after a wash-out period of 2 weeks. While group OFD-CD was instructed to use the mandibular denture and the maxillary OFD for 3 months then to use the maxillary CD for another 3 months after a wash-out period of 2 weeks. The dislodging force of the maxillary dentures was evaluated using the universal testing machine and the patient perception of retention, esthetics, and comfort was evaluated using the Visual Analogue Scale (VAS). Evaluation was carried out 1 day, 1 month, and 3 months after denture insertion. The Student t-test was used to compare the 2 maxillary dentures and the intervals for each denture were compared by using the ANOVA test with repeated measures followed by a Post Hoc test (adjusted Bonferroni) for pairwise comparison. RESULTS: The significance of the obtained results was judged at the 5% level (P value). The dislodging force and patient perception of retention did not show significant differences between the 2 dentures, while the perception of esthetics showed significant differences throughout the follow-up period. Perception of comfort showed an insignificant difference only at the 3-month interval. CONCLUSIONS: Open-face maxillary dentures can be a suitable alternative for patients with prominent premaxilla to achieve satisfactory retention, aesthetics, and comfort.

Effect of bar designs on peri implant tissues health in implant-supported removable prostheses: a systematic review.

Different characteristics of bars (cross-sectional shape, diameter, distal extension etc.) lead to different biomechanical behavior (retention and stress) with implants and peri-implant tissues.Aim: To evaluate the impact of implant-supported removable prostheses bar designs in fully edentulous arch (in the maxilla and/or mandibula), with 4 implants or more, on the peri-implant soft and hard tissues.Two reviewers searched for observational studies, RCT and in vitro studies, published on five main databases and three from the grey literature, without restrictions on November 2023.Of the 3049 selected articles, four met the inclusion criteria. Four RCT evaluated peri-implant health tissues in full edentulous arches with 4 or 6 implants rehabilitated with implant bar overdentures. One prospective study with 5 years follow-up evaluated the success/survival rate of implants and implant bar overdentures. Overall, 261 subjects were enrolled in our systematic review with 1176 implants. Overdentures' survival rate was 100%. There was a trend that plaque indices and gingival indices were low in all of the studies, however no statistical analysis was done due to the lack of information.Due to the lack of information in the included studies, we cannot confirm if bar characteristics affect the peri-implant tissues health.

Intraoral optical impression versus conventional impression for fully edentulous maxilla: an in vivo comparative study.

AIM: The aim of the present in vivo study was to compare the clinical trueness of primary mucostatic impressions obtained either by a classical alginate or an optical intraoral scanner technique in patients with a fully edentulous maxilla. MATERIALS AND METHODS: A total of 30 patients with a fully edentulous maxilla were included in the study and underwent both conventional impressions and intraoral optical impressions (Trios 3). The conventional impressions were casted and the resulting plaster casts were digitized using a desktop scanner (Imetric D104i). These digitized impressions were superimposed over the optical impressions to compare the differences between the two data sets. Statistical analyses were performed to identify relevant deviations. RESULTS: For the 30 intraoral impressions, 80.88% of the surface areas were below the tolerance threshold of 25 µm and were thus considered similar to the areas scanned with the desktop scanner from the reference plaster cast. Interestingly, the differences (19.12% of the surface areas) were localized in depressible areas such as the vestibule, soft palate, incisive papilla, and flabby ridges. These locations were consistent with the mean of positive differences of +22.8 µm, indicating deformation or less compression with the use of the intraoral scanner. CONCLUSIONS: The digital primary impression of the fully edentulous maxilla can be considered similar to the conventional alginate impression except in the depressible areas. Considering the mucostatic objective of such a primary impression, one may consider the optical impression to be more accurate than the conventional one.

Influence of the scanning path on the accuracy of intraoral scanners in the implanted edentulous patient: an in vitro study.

AIM: The aim of this in vitro study was to investigate the influence of scan paths on the accuracy (trueness and precision) of intra-oral scanning of an implant impression on an edentulous patient. MATERIAL AND METHODS: An epoxy resin maxillary model was made with 6 bone level implants (NobelParallel Conical Connection RP, NobelBiocare®). The implants were placed at the spot of the first incisor, the canine and the first molar. The trans gingival component (Multi-unit, NobelBiocare®) was screwed onto the implants. The scanbodies (IO 2C-A, Elos Accurate®) were then screwed onto the multi-units. The model was run through a coordinate measurement machine to obtain a control cast. Then, five different scanning paths, respectively the zigzag technique (ZZT), the zigzag technique with palatal (ZZTP), the wrap technique (WT), the wrap technique with palatal (WTP), and the big zigzag technique (BZZT), were applied by a single operator. Finally, each scan was compared to the control model. Results were assessed by one-way ANOVA and linear mixed effects models at P<0.05. RESULTS: The study showed that scan paths ZZT and ZZTP had significantly lower absolute positioning errors and residual mean square errors than the others (P<0.0001). For distances between consecutive implant axes and for absolute vertical errors, their superiority was borderline (P<0.10). Overall, techniques ZZT and ZZTP were equally performant and proved to be the most accurate. CONCLUSIONS: This in vitro experimental study demonstrates that the scan path can have an influence on the accuracy of the optical impression for full arch rehabilitation on implants.