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.

Implant survival/success and peri-implant outcomes of titanium-zirconium mini implants for mandibular overdentures: Results from a 1-year randomized clinical trial.

OBJECTIVE: To report the 1-year implant survival/success and peri-implant outcomes of mandibular overdentures retained by four titanium-zirconium mini implants (Straumann® Mini Implant System), and to assess how surgery and loading protocols influence these outcomes. MATERIALS AND METHODS: A 2 × 2 factorial randomized clinical trial (RCT) tested the combined effects of two loading protocols (immediate or delayed) and two surgical approaches (flapless or flapped) on the success/survival of the mini implants, and peri-implant parameters (plaque, bleeding, sulcus depth, gingival position, and marginal bone loss). Outcomes were assessed up to 1-year after loading, and generalized estimating equations (GEEs) were used to analyze longitudinal and within-patient clustered data. RESULTS: Two hundred and ninety-six implants were placed in 74 patients. The implant survival/success rates after 1 year were 100%, and no major biological complications were observed. After 1-year, descriptive data suggest no noticeable changes in plaque scores, whilst a reduction in bleeding scores at the 6-month and 1-year follow-ups compared to baseline. Good longitudinal stability was observed for the probing depth and gingival margin height measures. Overall mean marginal bone loss was 0.68 (±0.68) mm after 3 months and 0.89 (±0.75) mm after 1-year. The flapless protocol showed better results on soft tissue stability and health but a slightly higher risk for marginal bone loss. CONCLUSION: The results of this RCT suggest that mandibular overdentures retained by this novel mini implant system represent a safe and predictable treatment option as confirmed by implant survival/success and peri-implant outcomes, even when flapless surgery and immediate loading protocols are adopted.

Willingness to accept or refuse mandibular implant overdenture treatment: A prospective study on edentulous enrolled in a clinical trial.

BACKGROUND: Several complete denture wearers have major complaints and may be benefitted from implant treatment. However, the factors that shape the demand for and utilization of implants need further investigation. OBJECTIVE: The aim was to evaluate edentulous patient's willingness to accept or refuse the offer and provision of implant-retained treatment. METHODS: As part of a clinical trial, edentulous subjects were offered a mandibular overdenture retained by four mini-implants opposing a conventional maxillary denture. Treatment was offered without any financial costs for the patients. Patients' level of interest in receiving treatment was assessed using a 5-point Likert scale, and they were asked to respond to a list of reasons that led to their decision to accept or refuse implants. Those who refused implants received conventional prosthodontic interventions as required, and those who accepted implant treatment underwent surgical planning and implant placement. RESULTS: Of 175 eligible subjects, 147 accepted the offer of treatment and were invited to take part in the study (69.4% women, mean age 67.4 ± 10.0 years). Overall, 111 patients (75.5%) expressed a positive intention to undergo implant treatment at the initial contact. Implant treatment was performed for 56.3% (9/16) of those who answered 'probably yes' about their level of interest in implant treatment on the Likert scale, and 69.6% (64/92) of 'certainly yes' (p < .001). Older subjects were less likely to receive implants (OR = 0.93; p = .036), whilst those with a positive intention towards implants (OR = 3.15; p = .001), those previously treated by the dental team (OR = 7.89; p < .001), and who actively demanded implants (OR = 18.1; p < .001) were more likely to accept treatment. Improved chewing was the most common reason for accepting implants, whilst fear of surgery was the most reported reason for refusal. CONCLUSION: Refusal of implants was high among edentate patients even when financial costs were removed. Patients' initial attitude towards acceptance is a key factor in the demand for and uptake of implant therapy.

Mandibular bone characteristics, drilling protocols, and final insertion torque for titanium-zirconium mini-implants for overdentures: A cross-sectional analysis.

OBJECTIVE: The aim of this study was to assess the final insertion torque values achieved using site-specific drilling protocols for a novel mini implant system for removable complete overdentures. Anatomical and technical factors influencing final insertion torque were recorded and analyzed. MATERIAL AND METHODS: Participants were randomized to two surgical protocol groups (flapped or flapless) and all received four mini implants (Straumann® mini implant system; Straumann AG) in the anterior mandible, using a 1.6 mm needle drill and a 2.2 mm pilot drill for the implant bed site preparation. The final insertion torque was recorded as the main outcome variable during surgery. Bone type, radiographical bone density, ridge form, implant length, and the drilling protocol were considered as independent variables. Descriptive statistics, generalized estimating equations (GEE) regression, and heatmap charts were used for data analyses. RESULTS: A total of 296 mini implants were placed in 74 patients (mean age = 64.1 ± 8.0; 64.9% female) using flapless (n = 37) or flapped (n = 37) surgeries. Mean final insertion torque was 55.8 ± 18.4 Ncm (10.5% > 35 Ncm, 48.9% between 35 and 65 Ncm, and 40.6% > 65 Ncm). The needle drill was used in only 43.9% of the implant bed sites. Higher final torque values were observed for higher bone densities (bone type I > II > III, and D1-D2 > D3-D4), highly resorbed ridge forms (5-6 > 3-4), flapped surgeries, and male patients. However, regression models showed that the likelihood of achieving optimal insertion torque (≥35 and ≤65 Ncm) was higher for females (OR = 2.14; 95%CI = 1.14-4.01; p = 0.018), ridge forms 3-4 (OR = 2.87; 95%CI = 1.05-7.85; p = 0.040), and flapless surgeries (OR = 1.96; 95%CI = 1.09-3.51; p = 0.024). CONCLUSIONS: Sufficient primary stability for immediate loading was achieved for the majority of the mini implants placed. Surgical implant bed preparation should be site-specific to achieve optimal primary stability for immediate loading while avoiding excessive insertion torque.

Flapped versus flapless surgery and delayed versus immediate loading for a four mini implant mandibular overdenture: A RCT on post-surgical symptoms and short-term clinical outcomes.

OBJECTIVE: This factorial randomized clinical trial (RCT) tested the effects of the surgical approach (flapped-FPS vs. flapless-FLS surgery) and loading protocol (delayed-DL vs. immediate-IL) for treatment with a four mini implant mandibular overdenture. MATERIAL AND METHODS: A total of 296 one-piece titanium-zirconium mini-implants were inserted in 74 patients (IL/FLS = 17; IL/FPS = 18; DL/FLS = 20; and DL/FPS = 19). Outcomes included patient's perceived surgical burdens, clinical time, implant survival, and post-surgical symptoms and complications, assessed immediately after surgery, in the 7-day and 6-week follow-ups. RESULTS: Perceived surgical burdens were relatively low, higher for females, and no difference was found between FPS and FLS surgery. Surgical time was lower for FLS surgery. Overall symptoms were mild after 24 h, and higher for females. Less symptoms were recorded for the FLS surgery compared to the FPS for the delayed loading patients, and FLS surgery was associated with a lower risk of bleeding. No early implant failure was observed until the 6-week follow-up. Delayed was associated with discontinuous use of the prosthesis and poor function. Lower complaint rates were observed for immediate loading regardless of the surgery protocol. CONCLUSIONS: Mini implants for mandibular overdenture are a feasible option regardless of surgical access and loading protocol, with high safety and predictable survival rates, and low incidence of post-insertion complications. FLS surgery requires less clinical time and results in easier intraoral prosthetic incorporation of attachments compared to FPS surgeries. Immediate loading did not increase the risk of early implant failure when satisfactory primary stability was achieved.

The Potential Role of Dental Patient-Reported Outcomes (dPROs) in Evidence-Based Prosthodontics and Clinical Care: A Narrative Review.

Oral health problems are associated with poor quality of life, with the potential to cause functional, aesthetic, nutritional, and psychological difficulties, in addition to pain and suffering. Traditionally, dental treatment outcomes are measured using purely clinical parameters; however, this may be ineffective as these parameters cannot adequately capture the full impact of poor oral health on the patient, or their respective coping strategies. From this perspective, there are significant benefits when the patient's perception of their care is considered, and included in treatment planning and delivery. The impacts perceived by the patient on their treatment outcomes can be measured using patient-reported outcomes (PROS), or more specifically with dPROS, focused on dental patient-reported outcomes. Although there are some instruments available for measuring these outcomes in clinical trials, very little information is available for explaining the context in which these outcomes are considered, and also how to capture this information using appropriate instruments, specially in evidence-based dental practice. This article aims to review the literature, seeking to describe what has been considered about assessing patient's outcomes, as well as how to measure them, and explore the potential benefits of using dPROS in evidence-based prosthodontics and clinical care of partially and fully edentulous patients.

Immediately loaded single-implant mandibular overdentures compared to conventional complete dentures: A cost-effectiveness analysis.

BACKGROUND: In recent years, the single-implant mandibular overdenture (SIMO) has been proposed as an alternative to more complex overdenture designs as a simplified implant intervention for edentulous patients. OBJECTIVE: The aim of this study was to run a cost-effectiveness analysis alongside a randomized clinical trial comparing the SIMO and the conventional complete denture (CCD) treatment. Imediately loaded external hexagon implant and ball attachment were used for the overdenture goup. Direct costs related to therapies were identified and valuated throughout a 1-year period after delivery, in Brazilian currency (R$) and converted into international dollars (I$) using purchase power parity exchange rates. Treatment effectiveness was measured using the OHIP-Edent and satisfaction scores for calculation of incremental cost-effectiveness ratios (ICER). RESULTS: Outcomes were assessed at the 1-year follow-up for 65 patients (CCD=34; SIMO=31). Overall OHIP-Edent and satisfaction scores improved significantly in the SIMO group, while remained unchanged in the CCD group. The mean overall costs were R$1,179.04 (I$590.99) for the CCD group and R$2,127.91 (I$1,068.20) for the SIMO group - 80.7% incremental cost for SIMO. The ICER calculation for SIMO treatment showed a mean cost of I$48.20 for 1-point reduction in OHIP-Edent scores, and I$12.56 for 1-point increase in satisfaction score. CONCLUSIONS: Findings support the effectiveness of this simplified and low-cost implant intervention for edentulous patients. SIMO also seems a cost-effective alternative to the CCD and the relatively low incremental cost may potentially increase the utilization of dental implants among older subjects, especially those with limited financial resources. CLINICAL SIGNIFICANCE: The immediately loaded single-implant mandibular overdenture was superior to the conventional complete denture in terms of patient-reported outcome measures at a low incremental cost.