Mandibular overdenture retained by four one-piece titanium-zirconium mini implants: A 2-year RCT on patient-reported outcomes

AIM

The positive impact of implant interventions on dental patient-reported outcomes is an essential parameter of treatment effectiveness. This study assessed the 2-year changes in patient satisfaction and oral health-related quality of life (OHRQoL) of edentulous patients treated with a four mini implant mandibular overdenture (IOD) METHODS: The study was planned as a 2 × 2 factorial randomized clinical trial that tested two surgical approaches (flapped or flapless) and two loading protocols (immediate and delayed) using a titanium-zirconium mini implant (Straumann Mini Implant System®) and a PEEK retentive system (Straumann® Optiloc® Retentive System). Outcome measures (OHIP-Edent scores and the McGill Denture Satisfaction questionnaire) were assessed before treatment and at the 3-, 6-, 12-, and 24-month follow-ups. The Friedman test and multiple regression using Generalized Estimating Equations (GEE) were used for data analysis, considering the per-protocol (PP) and intention-to-treat (ITT) approaches RESULTS: Seventy-four patients were randomized to the study groups. No implant failure occurred during the study period. Marked improvement in all post-treatment periods compared to baseline were observed for the two outcomes. No significant effect of patient's gender, age, and surgical protocol on the study outcomes. The effect of treatment provision was significant for the two outcomes in the PP and ITT approaches (p < 0.001). A barely significant positive effect of the immediate loading was observed for OHIP-Edent in the PP approach (p = 0.020) CONCLUSION: IOD treatment significantly improved patient-reported outcomes measures, with sustained benefits over the two years of overdenture use, and can be considered a promising treatment option in for the edentulous mandible.

Group 4 ITI Consensus Report: Patient benefits following implant treatment in partially and fully edentulous patients

OBJECTIVES

The aim of Working Group 4 was to address patient benefits associated with implant dentistry. Focused questions on (a) dental patient-reported outcomes (dPROs), (b) improvement in orofacial function, and (c) preservation of orofacial tissues in partially and fully edentulous patients following provision of implant-retained/supported dental prostheses were addressed.

MATERIALS AND METHODS

Three systematic reviews formed the basis for discussion. Participants developed statements and recommendations determined by group consensus based on the findings of the systematic reviews. These were then presented and accepted following further discussion and modifications as required by the plenary of the 7th ITI Consensus Conference, taking place in 2023 in Lisbon, Portugal.

RESULTS

Edentulous patients wearing complete dentures (CD) experience substantial improvements in overall dPROs and orofacial function following treatment with either complete implant-supported fixed dental prostheses (CIFDP) or implant overdentures (IODs). With respect to dPROs, mandibular IODs retained by two implants are superior to IODs retained by one implant. However, increasing the number of implants beyond two, does not further improve dPROs. In fully edentulous patients, rehabilitation with CIFDP or IOD is recommended to benefit the preservation of alveolar bone and masseter muscle thickness.

CONCLUSIONS

Completely edentulous patients benefit substantially when at least the mandible is restored using an CIFDP or an IOD compared to CD. In fully edentulous patients, implant prostheses are the best option for tooth replacement. The availability of this treatment modality should be actively promoted in all edentulous communities, including those with limited access and means.

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.

Treatment effect of implant-supported fixed complete dentures and implant overdentures on patient-reported outcomes: A systematic review and meta-analysis

OBJECTIVES

To analyze the effect of implant treatment in edentulous patients rehabilitated with implant-supported fixed complete dentures (IFCDs) or implant overdentures (IODs) on dental patient-reported outcomes (dPROs).

MATERIALS AND METHODS

In January 2022, Medline, Embase, CINAHL, Cochrane Library, PubMed Central, Web of Science, and ClinicalTrials.gov were screened for prospective clinical studies on completely edentulous patients treated with IFCDs and/or IODs, reporting pre-treatment and follow-up dPROs. Hedges' g effect sizes (ES) with corresponding 95% confidence intervals (CI) were calculated. Afterward, meta-analyses were conducted using random effect models.

RESULTS

A total number of 1608 records was initially identified. Of those, 28 studies reporting dPROs from 1457 patients were finally included. The applied dental patient-reported outcome measures (dPROMs) included several versions of the Oral Health Impact Profile (OHIP) or specific items assessing satisfaction with Visual Analogue Scales (VAS). The overall ES was large for rehabilitation with IFCDs (1.68 [CI: 1.15, 2.20]) and IODs (1.26 [CI: 0.99, 1.52]) with no significant difference (p = .165) between the two. Denture stability was the only factor rated significantly higher for IFCDs (ES difference: 2.37 [CI: 0.21, 4.54]; p = .032). Subgroup analyses revealed moderately higher ES for IODs on two implants relative to one implant (ES difference: 0.73 [CI: 0.34, 1.12]; p < .001).

CONCLUSIONS

There is a strong positive effect of implant treatment in edentulous patients, independent of the type of prosthetic rehabilitation. In patients seeking high stability, IFCDs may be preferable. In mandibular IODs on a single implant, there was a significantly positive effect of an additional implant on dPROs.

Prosthodontic outcomes of mandibular overdenture treatment with one or two implants: 4-year results of a randomized clinical trial

OBJECTIVE

To assess the incidence of prosthodontic maintenance events and complications during 4 years of follow-up after mandibular overdenture treatment with one or two implants.

METHODS

Participants received one or two implants inserted in the midline (1-IOD group) or the lateral incisor-canine area bilaterally (2-IOD group). Implants were loaded with an early loading protocol after 3 weeks. Programmed recall visits were scheduled at the 6-, 12-, 36-, and 48-month follow-ups and nonprogrammed visits in case of prosthodontic complaints. The type of maintenance was registered, and the final treatment outcome was classified as successful, surviving, unknown, dead, repair, or retreatment.

RESULTS

Forty-seven participants, mean age 65.4 ± 8.6, 74.5% female, were included (1-IOD = 23; 2-IOD = 24) and 44 completed the 4-year follow-up. A total of 159 prosthodontic maintenance events occurred and 89 in unscheduled visits. The most common event was the need for minor modifications of the denture base due to sore spots in the oral mucosa (n = 56 in 31 patients), matrix activation (n = 54 in 34 patients), and overdenture fracture (n = 25 in 18 patients). A "successful" or "surviving" outcome could be attributed to 57.5% of cases, whereas 38.3% needed repair. No significant differences in the incidence of prosthodontic events or treatment outcomes were found between the two groups.

CONCLUSIONS

Findings show that 1-IODs perform similar to 2-IODs when considering the incidence of fractures and the need for prosthodontic maintenance, including adjustments of the overdenture and the attachment system.

Impact of Platform Switched Implants on Marginal Bone Level in Mandibular Overdentures: A Six-Year Follow-Up Longitudinal Study

PURPOSE

To evaluate the impact of the platform-switched implant on marginal bone loss (MBL) and the probing pocket depth (PPD) in patients wearing mandibular overdenture.

PATIENTS AND METHODS

This longitudinal study included 40 completely edentulous patients aged 51-64 years. All patients received complete dentures and were distributed into two groups randomly; 20 patients each. The first group GI received two platform switched implants; however, the 2nd group GII received two platform matched implants (3.6 × 11.5 mm) in the canine region of the mandible. The radiographic evaluations were carried out every year for six years, whereas probing pocket depth was evaluated every six months for 72 months for both groups. The data were analyzed by repeated ANOVA, Friedman's, and Student's t-test.

RESULTS

This study included 36 patients; 56 ± 3.6 years was the mean age; 17 females (47%) and 19 males (53%) completed the study. Statistically significant differences were observed in MBL and PPD in each of GI and GII after 6 years, p ≤ 0.05. Between GI and GII after 6 years, a statistically insignificant difference was detected in MBL or PPD, p ≥ 0.05, except in PPD at loading, 2 and 6 years, p ≤ 0.05.

CONCLUSION

Time positively affected MBL and PPD in platform switched and matched implants retained mandibular overdentures. Platform switching influences probing pocket depth in implants retained mandibular overdentures.

Evaluation of retention and wear of a titanium-formed stud overdenture attachment with different interimplant angulations after simulated clinical use: An in vitro study

STATEMENT OF PROBLEM

How implant alignment impacts stud attachment retention and wear-induced alterations, notably when the attachment exhibits metal-to-metal frictional interlocking, is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate the effect of the interimplant angulation on retention forces and wear changes before and after 2 years of simulated clinical use of implant overdentures retained by titanium stud overdenture attachments.

MATERIAL AND METHODS

The canine regions of 3 identical edentulous mandibular models were used to receive 2 dental implants analogs with TiTach attachments (Dental Evolutions, Inc) at interimplant angulations of 0, 30, and 60 degrees. Six identical overdentures were constructed over each model (n=6). A universal testing machine was used to determine overdenture retention forces at 0, after 1440, and after 2880 insertion and removal cycles to simulate the average insertion and removal cycles in 12 and 24 months. A stereomicroscope, a laser microscope, and a scanning electron microscope were used to evaluate the wear in the attachments. A linear regression model, ANOVA, and the Kruskal-Wallis tests were used to analyze the data (α=.05).

RESULTS

All groups demonstrated reduced retention over the study duration (P<.001). The retention forces of the 0- and 30-degree groups were not significantly different after 2880 insertion and removal cycles, but both were significantly higher than those of the 60-degree group (P=.002). Within each group, the wear pattern of the matrix cap was more noticeable than that of the patrix abutment, with increased wear changes as interimplant angulation increased (P<.001).

CONCLUSIONS

TiTach attachments could retain overdentures on parallel and divergent implants with a 30-degree angle of interimplant angulation. However, at a 60-degree angle of interimplant angulation, considerable reduction in retention forces and increased wear changes were observed after 2 years of simulated clinical use.

Using Cone-Beam Computed Tomography to Assess Changes in Alveolar Bone Width around Dental Implants at Native and Reconstructed Bone Sites: A Retrospective Cohort Study

The aim of this study was to use a cone-beam computed tomography (CBCT) to assess changes in alveolar bone width around dental implants at native and reconstructed bone sites before and after implant surgery. A total of 99 implant sites from 54 patients with at least two CBCT scans before and after implant surgery during 2010–2019 were assessed in this study. Demographic data, dental treatments and CBCT scans were collected. Horizontal alveolar bone widths around implants at three levels (subcrestal width 1 mm (CW1), subcrestal width 4 mm (CW4), and subcrestal width 7 mm (CW7)) were measured. A p-value of < 0.05 indicated statistically significant differences. The initial bone widths (mean ± standard deviation (SD)) at CW1, CW4, and CW7 were 6.98 ± 2.24, 9.97 ± 2.64, and 11.33 ± 3.00 mm, respectively, and the postsurgery widths were 6.83 ± 2.02, 9.58 ± 2.55, and 11.19 ± 2.90 mm, respectively. The change in bone width was 0.15 ± 1.74 mm at CW1, 0.39 ± 1.12 mm at CW4 (p = 0.0008), and 0.14 ± 1.05 mm at CW7. A statistically significant change in bone width was observed at only the CW4 level. Compared with those at the native bone sites, the changes in bone width around implants at reconstructed sites did not differ significantly. A significant alveolar bone width resorption was found only at the middle third on CBCT scans. No significant changes in bone width around implants were detected between native and reconstructed bone sites.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.

Postsurgical oral symptoms after insertion of one or two implants for mandibular overdentures: short-term results of a randomized clinical trial

Objective

This randomized clinical trial aimed to compare the short-term postsurgical symptoms after insertion of one or two implants for retention of a mandibular overdenture. This study investigated whether the less invasive single-implant approach results in lower postoperative symptoms compared to the conventional two-implant overdenture.

Materials and methods

Patients received new complete dentures and were randomly assigned to groups receiving one or two single-stage, early-loaded hydrophilic implants, inserted in the midline (n = 23), or the lateral incisor-canine area bilaterally (n = 24). Patient-reported postoperative symptoms were measured in a 0–100 visual analogue scale concerning pain in the surgical area, pain when chewing, bleeding, swelling, and unpleasantness. Data collection occurred 24 h and 7 and 21 days after surgery. Demographic and clinical features (smoking habit, classification of the residual ridges, and mucosal width and thickness at the implant sites), osteotomy for alveolar bone reduction, and surgery time were tested as predictors of symptom levels.

Results

Overall reported symptoms were mild and self-limited, with high rates of complete remission after the early loading period of 3 weeks. Progressive improvement of symptoms occurred from the 24-h to the 7-day and 21-day follow-ups (p < 0.001), similarly in both groups. None of the clinical predictors was significantly associated with the changes in symptoms.

Conclusions

Findings suggest that the insertion of one or two implants may result in similar postoperative outcomes.

Clinical relevance

The severity of short-term postoperative symptoms may not be a critical factor for the decision between overdenture treatment with one or two implants.

Single-implant mandibular overdentures: Clinical, radiographic, and patient-reported outcomes after a 5-year follow-up

STATEMENT OF PROBLEM

Previous studies on single-implant mandibular overdentures have reported favorable results for clinical and patient-reported outcomes. However, information from longer term clinical studies is lacking.

PURPOSE

The purpose of this clinical study was to assess clinical, radiographic, and patient-reported outcomes of edentulous individuals rehabilitated with single-implant mandibular overdentures after a 5-year follow-up.

MATERIAL AND METHODS

A prospective clinical study was performed including completely edentulous individuals who received new conventional complete dentures and then an external hexagon implant in the mandibular midline region, followed by the incorporation of a retention system (O-ring/ball attachment; Neodent). Data collection occurred at baseline and 3, 6, 12, 24, and 60 months after implant loading. Assessed outcomes included implant stability, peri-implant soft tissue condition, peri-implant marginal bone level, satisfaction with the prostheses, and oral health-related quality of life (OHRQoL). Clinical maintenance events were also recorded. Descriptive statistics, incidence rates, Wilcoxon Signed Ranks test, and Generalized Estimating Equation regression were used for data analysis (α=.05).

RESULTS

Thirty of 34 eligible participants attended the 5-year follow-up visit, mean ±standard deviation age was 68.1 ±7.8 years, and 70% were women. The overall implant survival rate was 88.9%. After 5 years, the OHRQoL showed statistically significant improvement for all evaluation periods compared with baseline (P<.001). Regarding satisfaction with the mandibular denture, a significant increase was found between all evaluation periods compared with baseline in terms of comfort, stability, and ability to masticate (P<.001). Implant stability significantly increased (P=.003), and a mean bone loss of 1.46 mm was observed compared with baseline measures. The most frequent maintenance event was replacement of the O-ring matrix (n=80). Twenty-one midline fractures of the overdenture occurred in 14 study participants. No significant changes in peri-implant soft tissue conditions were observed.

CONCLUSIONS

A single-implant mandibular overdenture effectively maintained the positive effect of the intervention on oral health-related quality of life and patient satisfaction, stable peri-implant condition, and acceptable rates of prosthetic events.

Single versus two-implant mandibular overdentures using early-loaded titanium-zirconium implants with hydrophilic surface and ball attachments: 1-year randomized clinical trial

OBJECTIVE

This randomized clinical trial aimed to compare the outcomes of the mandibular overdenture retained by one (1-IOD) or two (2-IOD) implants.

MATERIALS AND METHODS

Participants received new complete dentures, were assessed at baseline and randomly assigned to groups. Early loaded single midline implant (1-IOD) or two implants in the canine regions bilaterally (2-IOD). Ball attachments were used for overdenture retention. Post-treatment outcomes (6- and 12-month follow-ups) included patient satisfaction, oral health-related quality of life measures, and chewing function. Data analysis included within- and between-group comparisons, and Generalized Estimating Equations. Both superiority and non-inferiority hypotheses were tested.

RESULTS

Forty-seven participants were included (1-IOD = 23; 2-IOD = 24). Significant improvements in OHIP-Edent were observed after insertion of new dentures and at the 1-year follow-up compared with baseline. No differences were found between the 1- and 2-IOD groups for the OHIP-Edent and QoLFAST scores. Patient satisfaction with the mandibular denture improved significantly from baseline to the 6-month follow-up and remained unaltered until 1 year, with no differences between groups. The magnitudes of treatment effect sizes were moderate to large for patient-reported outcomes. Progressive improvement in chewing function occurred in both groups. Non-inferiority testing based on a 15% non-inferiority margin showed inconclusive results for patient-reported outcomes, whilst chewing function in the 1-IOD group was concluded to be not inferior to the 2-IOD group.

CONCLUSIONS

Results support the use of both 1- and 2-IOD. The 1-IOD was also an acceptable alternative to the 2-IOD as a secondary option for the treatment of the edentulous mandible.

Cost-effectiveness of three different concepts for the rehabilitation of edentulous mandibles: Overdentures with 1 or 2 implant attachments and hybrid prosthesis on four implants

BACKGROUND

There are scarce data regarding the combined assessment of the costs and effects of implant treatments for edentulous patients when multiple options are available.

AIM

This randomised clinical trial aimed to assess the cost-effectiveness of three different concepts for treatment: mandibular overdenture retained by a single (Group I; n = 11) or two implants (Group II; n = 13) and fixed hybrid prosthesis on four implants (Group III; n = 13).

METHODS

Treatment effectiveness was measured as the 1-year before-after changes in patient satisfaction with the mandibular prosthesis. Costs were prospectively quantified from the perspective of the health provider, including all direct cost items attributed to the delivery of treatments and up to the 1-year follow-up, using a "bottom-up" costing estimation method.

RESULTS

Patient satisfaction after treatment improved significantly for the three groups. The overall costs were R$ 2370.66, R$ 3185.21 and R$ 5739.52 for Groups I, II and III, respectively (P < .001). Analysis of incremental cost-effectiveness ratios suggested that the overdentures retained by one or two implants were more cost-effective than the fixed implant treatment, considering the mean cost and effectiveness values and the ±20% one-way sensitivity analysis.

CONCLUSION

This study suggests that the incremental costs for the fixed hybrid prosthesis, compared to the overdenture treatments, is not proportional to the respective gain in effectiveness. Therefore, although all treatment options had satisfactory outcomes, the use of implants to retain a mandibular overdenture, irrespective of the use of one or two implants, is more cost-effective than the fixed implant treatment for the edentulous mandible.