Within-subject comparisons of implant-supported mandibular prostheses: choice of prosthesis

Oral-Health-Related Quality of Life in Elderly Edentulous Patients with Full-Arch Rehabilitation Treatments: A Systematic Review

Background: The improvement of oral-health-related quality of life (OHRQoL) with different types of prosthesis for completely edentulous jaws in the elderly population is a critical factor in clinical decision making for these vulnerable patients. This review aims to evaluate the changes in OHRQoL after treatment with different types of full-arch prostheses in the elderly edentulous population to determine the prostheses that result in the greatest improvement in OHRQoL. Materials and Methods: Clinical studies of different types of full-arch prostheses that measured the OHRQoL in edentulous patients 60 years or older were searched for in the PubMed, Embase and Scopus electronic databases, with additional hand searching to summarize the outcomes of the selected studies. Result: Among the 302 identified studies, 10 studies were selected. A total of 504 patients wearing 133 complete dentures, 372 implant overdentures and 39 fixed prostheses were assessed among the selected studies. The overall OHIP and GOHAI scores were evaluated at baseline and in the 3rd, 6th, 12th and 18th months of treatment with the respective prostheses. The improved OHRQoL with overall OHIP scores associated with conventional dentures were 9.21-12.5% from the 3rd month to 1 year after treatment, whereas those associated with implant overdentures and full-arch fixed prosthesis were 9-25.26% at 1 year and 18.53-26.79 at the 18th-month follow-up, respectively. The increased overall GOHAI scores were 21.3-25.43% for conventional dentures, 36.82-41.32% for implant overdentures and 39.48-42.83% for full-arch fixed prosthesis from the 3rd month to the 6th-month follow-up. Conclusion: In general, the improvement in OHRQoL after rehabilitation with implant overdentures declined at one year, and that with full-arch fixed prosthesis declined at the 18th-month follow-up; meanwhile, the OHRQoL associated with conventional dentures improved stably up to one year, but the implant-supported prostheses resulted in an obviously greater improvement in the OHRQoL than that obtained with conventional dentures. However, studies with longer follow-up periods are still required to evaluate the long-term clinical effectiveness.

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.

Within-patient evaluation of chewing efficiency and maximum bite force of conventional dentures, fixed prostheses, and milled bar overdentures used for All-on-4 implant rehabilitation of atrophied mandibular ridges: A short-term randomized trial

PURPOSE

This crossover study aimed to evaluate chewing efficiency and maximum bite force (BF) of conventional dentures, fixed prostheses, and milled bar overdentures (MO) used for All-on-4 implant rehabilitation of atrophied mandibular ridges.

METHODS

Sixteen edentulous participants with resorbed mandibular ridges received new conventional dentures (CD, control). Four implants were inserted after 3 months in the mandible using the All-on-4 protocol and loaded immediately with acrylic prosthesis. In a crossover manner, each patient had either fixed restoration (FR, 12 occlusal units) or MO (14 occlusal units) randomly in a crossover study design. Chewing efficiency was evaluated using the mixing ability test. The hue deviation (HD) of two-colored gum was calculated after being chewed for 5, 10, 20, 30, and 50 masticatory cycles. Maximum BF was evaluated using a BF device. HD and BF were measured after using CD, FR, and MO prostheses.

RESULTS

For all groups, the highest HD (i.e., the lowest chewing efficiency) was noted with 5 strokes, followed by 10, 20, 30 strokes, and the lowest HD (i.e., the highest chewing efficiency) was noted with 50 strokes. For all number of chewing strokes, CD showed the highest HD, then FR, and MO recorded the lowest HD. The highest BF was observed with MO, then FR, and the lowest BF was noted with CD.

CONCLUSION

Within the limitations of this short-term investigation, both FR and MO used for All-on-4 implant rehabilitation of patients with resorbed mandibular ridges improve masticatory efficiency and maximum BFs compared to CD. However, MO was associated with significantly higher chewing efficiency and maximum BFs than fixed prosthesis.

Risk factor analysis of dental implants in patients with irradiated head and neck cancer

Background

We investigated dental implant outcomes in patients who had previously received radiotherapy (RT) for head and neck malignancies.

Methods

We reviewed 90 dental implants in 27 patients who received RT for head and neck cancer and received dental implants afterwards. The cumulative implant survival rate (CISR) was calculated. In addition, the implant quality was assessed using “Health Scale for Dental Implants.”

Results

The CISR at 3 years was 79.6%. The mean radiation dose at the implant site (D_mean) was identified as an independent prognostic factor for implant survival. No implant failed if D_mean was less than 38 Gy. Regarding implant quality, dental implants in grafted bone and D_mean were independent risk factors.

Conclusions

D_mean was identified as an independent prognostic factor for implant survival and quality. Dental implants can be safely considered when D_mean is lower than 38 Gy.

Prosthetic failures in dental implant therapy

Both fixed and removable implant-supported prostheses are well-established methods for replacing missing teeth in partially or fully edentulous patients. Numerous systematic reviews have been performed in recent years to evaluate the survival and complication rates of implant-retained fixed dental prostheses and implant-retained overdentures, displaying high 5-year survival rates ranging from 97.1% for fixed dental prostheses to 95%-100% for implant-retained overdentures. However, the survival rates only represent the prostheses remaining in use for a defined follow-up time, and do not account for the potential prosthetic complications that may have arisen and influence the general success of the implant treatment. The most common technical complications of fixed implant-retained single crowns are crown fracture, fractures of ceramic implant abutments, and esthetic problems. The predominant technical complication at multiple-unit, implant-retained fixed dental prostheses is fracture/chipping of the veneering ceramic. Reported technical complications for implant-retained overdentures are overdenture fracture or chipping of the veneer materials, whereas mechanical complications include implant fracture, attachment failure, and attachment housing or insert complications. To reduce the risk of such failures, a comprehensive pretreatment diagnostic work-up is essential, including defining the prosthetic goal with the aid of a wax-up or set-up and the associated ideal, prosthetically oriented three-dimensional implant position. Furthermore, selection of the ideal type of prosthesis, including the respective implant components and materials, is important for clinical long-term treatment success.

Osseointegrated implant survival, success and prosthodontic outcomes in composite free flaps: A 10-year retrospective cohort study

OBJECTIVES

To evaluate implant survival, success and prosthodontic outcomes in a variety of composite free flaps.

MATERIAL AND METHODS

A retrospective analysis of patient records was used for data collection of implants placed into flaps. Free flap donor sites included fibula, iliac crest, scapula, medial femoral condyle and radial forearm. Kaplan-Meier survival curves were used to estimate survival. Cox regression was used to assess variables affecting survival, and binary logistic regression was utilised to determine effect of variables on prosthodontic outcomes.

RESULTS

There were 150 implants placed into 45 fibula, 98 implants into 29 iliac crest, 62 implants into 22 scapula, 6 implants into 3 medial femoral condyle and 2 implants in radial forearm composite free flaps. There was no difference in survival or success between or within the various flaps. Active smoking, increasing age, male gender and radiotherapy were associated with implant failure. Of patients completing prosthodontic rehabilitation, 93% were successful. There was no difference in likelihood of failure between different flap types. Fixed implant-supported dentures were associated with poor oral hygiene compared with removable designs (OR2.9, 95%CI 1.1-7.8, p = .03).

CONCLUSIONS

There is adequate survival and success of implants in common flaps. Caution is required when planning implants in patients exposed to radiotherapy and smokers. Ability to maintain adequate oral hygiene is an important prosthetic design consideration.

Considerations for the Prosthetic Dental Treatment of Geriatric Patients in Germany

Demographic changes in the industrialized countries require that dentists adapt to the growing and heterogeneous group of elderly patients and develop concepts for the dental care of fit, frail, and dependent old and very old people. In general, dental care for old and very old people should be based on their individual everyday life. As a result of demographic changes, improved oral hygiene at home, and the establishment of professional teeth and denture cleaning, tooth loss occurs increasingly in higher ages, which implies that first extensive prosthetic rehabilitation with fixed or/and removable dental prostheses is shifting to a higher average age than ever before. This phenomenon requires that the individual diseases, potential multimorbidity and polypharmacy, and associated limitations are taken into consideration. Against this background, the current survey aims to summarize epidemiological trends associated with tooth loss, using Germany as a highly representative country for demographic changes as an example. Furthermore, the current narrative summary outlines general principles that should be followed in dental care, treatment of geriatric patients, and outlines current therapeutic options in prosthetic dentistry.

Patient-reported outcome measures and clinical assessment of implant-supported overdentures and fixed prostheses in mandibular edentulous patients: A systematic review and meta-analysis

STATEMENT OF PROBLEM

A consensus based on patients' perceptions as to whether to use overdentures or fixed prostheses to rehabilitate mandibular edentulous arches is limited.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare the patient-reported outcome measures (PROMs) and clinical outcomes associated with implant-supported overdentures and fixed prostheses in edentulous mandibles.

MATERIAL AND METHODS

Nine electronic databases were searched for randomized clinical trials (RCTs) and nonrandomized clinical trials (N-RCTs). The risk of bias was assessed by the revised Cochrane risk of bias tool for RCTs (RoB 2) and N-RCT (ROBINS-I). Data sets for oral health-related quality of life (OHRQoL), satisfaction, survival rate, implant probing depth, and marginal bone loss were plotted, and the appropriate analyses were applied by using the Rev Man 5.3 software program. Certainty of evidence was also evaluated by means of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Ten eligible trials were included and evaluated quantitatively. For 3 domains of OHRQoL, fixed prostheses showed significantly higher quality of life when compared with overdentures regarding functional limitation (P<.001), physical disability (P=.001), and physical pain (P=.003). Fixed prostheses also improved satisfaction, when compared with overdentures for comfort (P=.02), ease of chewing (P<.001), retention (P<.001), and stability (P<.001). The same pattern was observed for overall OHRQoL (P=.01) and satisfaction (P=.01) in which fixed prostheses improved patient satisfaction. Only ease of cleaning presented greater satisfaction for the overdenture group. Clinical parameters did not differ statistically (P>.05) between both types of prosthesis.

CONCLUSIONS

Fixed rehabilitations for mandibular edentulous patients seem to be a well-accepted treatment from the patients' oral health perspective. However, mandibular overdentures are no less efficient than fixed prostheses in terms of clinical outcomes.

Comparative evaluation of biting force and chewing efficiency of all-on-four treatment concept with other treatment modalities in completely edentulous individuals

Aim:

To compare and evaluate biting force and chewing efficiency of all-on-four treatment concept, implant-supported overdenture, and conventional complete denture.

Settings and Design:

Invivo – comparative study.

Materials and Methods:

A total of 12 edentulous patients were included in the study and conventional complete dentures were fabricated. Patients were divided into two groups. In Group 1, complete dentures were replaced with implant-supported overdenture, and in Group 2, complete dentures were replaced with hybrid denture supported by all-on-four treatment concept. The biting force was assessed using a bite force sensor and electromyographic recordings were made by electromyogram for masticatory muscles when chewing three different consistencies of foods.

Statistical Analysis Used:

The data was statistically analyzed using software SPSS version 22.0. Paired t-test was used for intra-group comparison and unpaired t-test was used for intergroup comparison.

Results:

The difference in biting force and chewing efficiency for all-on-four treatment concept was statistically significant for overdenture and complete denture. The highest biting force and chewing efficiency were observed for all-on-four treatment concept, followed by implant-supported overdenture and complete denture.

Conclusion:

The study concluded that the completely edentulous individuals with atrophic posterior alveolar ridges can be rehabilitated successfully with improved biting force and chewing efficiency by All-on-four treatment concept.

Educational inequalities in access to fixed prosthodontic treatment in Norway. Causal effects using the introduction of a school reform as an instrumental variable

OBJECTIVES

Equality in access to dental services, independent of level of education, is an important aim of Scandinavian welfare policy. In Norway, this policy is the main justification for a dental public subsidy scheme for adults. An important part of the subsidy scheme is to cover the cost of fixed prosthodontic treatment, including implant-based crowns and bridges for premolars, canines and incisors. A stated policy goal is to secure equal access to everybody in need of these services, independent of their level of education. The aim of this study was to estimate the causal effect of education on the probability of receiving fixed prosthodontic treatment in the adult Norwegian population.

METHODS

During the period 1960-1972, all municipalities in Norway were required to increase the number of compulsory years of education from seven to nine years. We used this education reform as the instrumental variable to create exogenous variation in the individual's number of years of education. The education data were combined with data from the Norwegian Health Economics Administration, which contained our outcome variable. Our sample included individuals with 9 years education or less. Altogether 113 237 individuals were included in the study.

RESULTS

For men, the first stage regression coefficient was 0.87 (confidence interval: 0.82-0.92). This means that the reform resulted in 0.87 additional years of education. For men, the probability of receiving fixed prosthodontic treatment increased by 0.67 percentage points per additional year of schooling. For women, the first stage regression coefficient was 0.84 (confidence interval: 0.79-0.88). The second stage regression coefficient was small (= 0.0022) and not statistically significant at a conventional level.

CONCLUSION

From a welfare policy point of view, for men, the subsidy scheme has not succeeded to redistribute resources so that dental services are accessible independent of their social status.

Impact of immediately loaded implant-supported maxillary full-arch dental prostheses: a systematic review

OBJECTIVE

The immediate loading of implant-assisted fixed prostheses in edentulous maxillae may achieve favorable success rates with reduced treatment time. An evidence summary of clinical trials is key to recommend loading protocols in these cases.

OBJECTIVES

To compare immediately loaded, fully implant-supported complete dentures to early and conventional/delayed loading in the edentulous maxillae of adult patients by a systematic review of controlled clinical trials (CCT).

METHODOLOGY

CCTs reports were identified up to January 17, 2019 from Cochrane Oral Health Group's Trial register, Cochrane Central Register of controlled trials (CENTRAL), MEDLINE (Ovid), BIOSIS, EMBASE, CINAHL, Web of Science, and DARE. Two independent reviewers screened titles/abstracts and confirmed inclusion using full texts. Data were extracted and quality assessed (Cochrane Risk of Bias tool) independently and in duplicate. Study heterogeneity prevented pooling by meta-analysis.

RESULTS

Out of 1,052 candidate studies, four CCTs were included. Two trials had patient satisfaction as an outcome: (1) A randomized trial compared immediately and early loaded fixed dentures and found more satisfaction with the first after 12 months; (2) A non-randomized study found better satisfaction with immediate fixed dentures compared to conventional loading after 3 months (no more at 12 months). Regarding implant success and prosthetic complications, three trials did not report significant differences comparing immediate loading to other protocols.

CONCLUSIONS

This review found weak evidence of differences between immediate load and other loading regimens, regarding patient satisfaction and maintenance events/adversities. The potential of immediate loading for favorable results in edentulous maxillae reinforces the need for well-designed RCTs, for solid clinical guidelines. Registration number CRD42018071316 (PROSPERO database).

A within-subject clinical trial on the conversion of mandibular two-implant to three-implant overdenture: Patient-centered outcomes and willingness to pay

OBJECTIVES

To examine the impact of adding a third midline implant with stud attachment to a mandibular two-implant overdenture on patient-oriented outcomes.

METHODS

In this pre-post design clinical trial, following the standard procedures, mandibular two-implant overdentures of 17 edentulous individuals (61.9 ± 6.6 years) were converted to three-implant overdentures by adding a stud attachment to an unloaded midline implant. Patient-oriented outcomes included patient expectations and satisfaction with implant overdenture as well as willingness to pay the cost of conversion. Data were collected at baseline and at the 6-week follow-up using visual analog and binary scales as well as open-ended questions. Statistical analysis included descriptive statistics, Spearman's correlation, Fisher exact test, Mann-Whitney U test, and the exact sign test.

RESULTS

After connecting the third midline implant to the mandibular two-implant overdenture, there was a statistically significant decrease in the anteroposterior movement (p = 0.005) as evaluated by clinicians. Moreover, study participants reported an increase in perceived stability of the overdenture (95% CI; 0.68-1.00, p = 0.002) and in their ability to speak (95% CI; 0.63-1.00, p = 0.008). The addition of a third implant met the expectations of 94% of patients in regard to lower denture stability, 100% for retention, and 82.4% for comfort. The mandibular three-implant overdenture increased patient general satisfaction over a short period of time, but this improvement was not statistically significant. About 80% of patients would recommend this type of prosthesis to their peers but only 47% of them would agree to pay a large increase in the cost of treatment compared to a two-implant overdenture.

CONCLUSIONS

The addition of a midline third implant to an existing mandibular two-implant overdenture resulted in several improved patient-reported outcomes.

Patient-Reported and Clinical Outcomes of Implant-Supported Fixed Complete Dental Prostheses: A Comparison of Metal-Acrylic, Milled Zirconia, and Retrievable Crown Prostheses

The purpose of this retrospective study was to assess the incidence of biologic and technical complications for implant-supported fixed complete dental prostheses (IFCDPs) and their relationship to oral health-related quality of life (OHQoL) and patient-reported outcomes. Metal-acrylic (MA), retrievable crown (RC), monolithic zirconia (MZ), and porcelain veneered zirconia (PVZ) prostheses were included. Patients who received an IFCDP at least 1 year prior to recall were identified. Exclusion criteria were: (1) an opposing complete denture and (2) time in service &gt;70 months. A total of 37 patients with 49 prostheses, including 22 MA, 14 RC, 7 MZ, and 6 PVZ prostheses were recalled. Patient-reported outcomes were assessed via OHIP-49 (Oral Health Impact Profile) and a scripted interview with open-ended questions. All designs had high complication rates (12 of 22 MA, 10 of 14 RC, 2 of 7 MZ, and 5 of 6 PVZ). The most common complications were: (1) MA: posterior tooth wear, (2) RC: chipping and fracturing of the restorations, (3) MZ: wear of opposing restorations, and (4) PVZ: chipping of opposing restorations. Average OHIP-49 scores ranged from 7 to 29, indicating high OHQoL, patient satisfaction, regardless of prosthetic design (P = .16). The standardized interview highlighted that although most patients were extremely satisfied (73%), some continued to be bothered by material bulk (14%) and felt that maintenance of oral hygiene was excessively time-consuming (16%). In the context of this study, despite high complication rates and maintenance needs, all IFCDP designs resulted in high OHQoL and patient satisfaction.

Implant Supported Fixed Restorations versus Implant Supported Removable Overdentures: A Systematic Review

AIM:

The aim of this study is to systematically evaluate and compare implant retained fixed restoration versus implant retained over denture.

MATERIAL AND METHODS:

Search was made in 2 databases including PubMed and PubMed Central. Title and abstract were screened to select studies comparing implant retained fixed restorations versus implant retained removable overdentures. Articles which did not follow the inclusion criteria were excluded. Included papers were then read carefully for a second stage filter, this was followed by manual searching of bibliography of selected articles.

RESULTS:

The search resulted in 5 included papers. One study evaluated the masticatory function, while the other 4 evaluated the patient satisfaction. Two of them used Visual Analogue Scale (VAS) as a measurement tool, while the other two used VAS and Categorical Scales (CAT). Stability, ability to chew, ability to clean, ability to speak and esthetics were the main outcomes of the 4 included papers.

CONCLUSION:

Conflicting results was observed between the fixed and removable restorations.

Prevention of distal extension cantilever fracture in mandibular overdentures

OBJECTIVES

Fractures of distal bar extensions, supporting a mandibular overdenture, do occur with significant functional and economic consequences for the patient. This study therefore aims to evaluate the effect of different bar cross-sectional shapes and surfaces, bar extension lengths and the placement of a support rib under the distal bar extension on fracture resistance.

MATERIALS AND METHODS

The 2nd moment area and static strength were calculated for 11 frequently used bar designs using finite element analysis (FEA). For two specific designs (Ackermann round Ø 1.8mm and Dolder-Y macro, the former with and without a support rib) additional physical static and fatigue strength tests were included.

RESULTS

The FEA static strength data corresponded well to the 2nd moment area (a similar ranking when maximum allowed force was considered). The application of a rib support (Ackermann Ø 1.8mm) and limitations of the bar extension length (6mm for the Ackermann Ø 1.8mm, 8mm for the Dolder-Y macro) allowed the bars to exceed 5 × 10(6) cycles of 120 and 250N, respectively, before fracture. The region of highest stresses in FEA corresponded well with the locations of the fractures observed in static- and fatigue-testing.

CONCLUSIONS

With some simple guidelines/modifications, the number of bar extension fractures can be reduced significantly.

CLINICAL SIGNIFICANCE

This study focusses on distal bar extensions which improve the positioning of an implant supported overdenture. By combining laboratory testing and finite element simulations we aim to: (1) explain why fractures occur (dependent on physical characteristics of the bar), and (2) give clinical guidelines on how to prevent such fractures.

Retentive characteristics of a vinylpolysiloxane overdenture attachment system

OBJECTIVES

Numerous different attachments are used to retain overdentures on implants. The purpose of this study was to evaluate a new chairside attachment system based on polyvinylsiloxane (PVS).

MATERIAL AND METHODS

A total of 250 specimens were fabricated (n = 10) to measure the retention force (RF) in dependence of the following parameters: fatigue (after 100, 200, 500, 1,000, and 5,000 cycles of dislodging), thermal undulation (10,000 cycles between 5 and 55 °C), implant angulation (0°, 5°, and 10°), and disinfection (three different agents). Three different PVS materials (shore hardness (SH), SH25, SH50, and SH65) were evaluated; locator attachments (LR blue) served as controls. Data were imported into a statistical program and analyzed at a 5 % level of significance.

RESULTS

Initial RFs were dependent on the shore hardness (p ≤ 0.001, ANOVA). No changes in RFs were observed for PVS groups after repeated dislodging and thermal undulation. Locator attachments revealed a significant decrease in retention force of up to 58 % (p ≤ 0.001, Fig. 3). No significant changes in RFs were induced by implant angulation. Retention force was decreased in some PVS groups after storage in disinfection solution.

CONCLUSIONS

Polyvinylsiloxane attachments provide an alternative to locator attachments, exhibiting better stability of the retention force.

CLINICAL RELEVANCE

The presented directly fabricated chairside attachment system represents RFs superior to existing attachment systems after artificial aging.

Single dental implant retained mandibular complete dentures--influence of the loading protocol: study protocol for a randomized controlled trial

Background

Over the years, there has been a strong consensus in dentistry that at least two implants are required to retain a complete mandibular denture. It has been shown in several clinical trials that one single median implant can retain a mandibular overdenture sufficiently well for up to 5 years without implant failures, when delayed loading was used. However, other trials have reported conflicting results with in part considerable failure rates when immediate loading was applied. Therefore it is the purpose of the current randomized clinical trial to test the hypothesis that immediate loading of a single mandibular midline implant with an overdenture will result in a comparable clinical outcome as using the standard protocol of delayed loading.

Methods/design

This prospective nine-center randomized controlled clinical trial is still ongoing. The final patient will complete the trial in 2016. In total, 180 edentulous patients between 60 and 89 years with sufficient complete dentures will receive one median implant in the edentulous mandible, which will retain the existing complete denture using a ball attachment. Loading of the median implant is either immediately after implant placement (experimental group) or delayed by 3 months of submerged healing at second-stage surgery (control group). Follow-up of patients will be performed for 24 months after implant loading. The primary outcome measure is non-inferiority of implant success rate of the experimental group compared to the control group. The secondary outcome measures encompass clinical, technical and subjective variables. The study was funded by the Deutsche Forschungsgemeinschaft (German research foundation, KE 477/8-1).

Discussion

This multi-center clinical trial will give information on the ability of a single median implant to retain a complete mandibular denture when immediately loaded. If viable, this treatment option will strongly improve everyday dental practice.

Trial registration

The trial has been registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00003730 since 23 August 2012. (http://www.germanctr.de).

Small-diameter titanium Grade IV and titanium-zirconium implants in edentulous mandibles: three-year results from a double-blind, randomized controlled trial

OBJECTIVE

The aim of this study was to compare crestal bone-level changes, soft tissue parameters and implant success and survival between small-diameter implants made of titanium/zirconium (TiZr) alloy or of Grade IV titanium (Ti) in edentulous mandibles restored with removable overdentures.

MATERIALS AND METHODS

This was a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann bone-level implants (diameter 3.3 mm), one of Ti Grade IV (control) and one of TiZr (test), in the interforaminal region. Implants were loaded after 6-8 weeks and removable Locator-retained overdentures were placed within 2 weeks of loading. Modified plaque and sulcus bleeding indices, radiographic bone level, and implant survival and success were evaluated up to 36 months.

RESULTS

Of 91 treated patients, 75 completed the three-year follow-up. Three implants were lost (two control and one test implant). The survival rates were 98.7% and 97.3%, and the mean marginal bone level change was -0.78 ± 0.75 and -0.60 ± 0.71 mm for TiZr and Ti Grade IV implants. Most patients had a plaque score of 0 or 1 (54% for test and 51.7% for control), and a sulcus bleeding score of 0 (46.1% for test and 44.9% for control). No significant differences were found between the two implant types for bone-level change, soft tissue parameters, survival and success.

CONCLUSIONS

After 36 months, similar outcomes were found between Ti Grade IV and TiZr implants. The results confirm that the results seen at 12 months continue over time.

Rehabilitation with implant-supported overdentures in total edentulous patients: A review

Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on the mentioned subject from 1986 to 2011. As a searching strategy, we used the following words: implant-supported overdentures, attachment systems, Locator attachment, cantilever, fixed prosthesis. Results and conclusions: Implant-supported overdentures constitute an accurate and predictable treatment option and achieve a higher patients’ satisfaction. This type of treatment constitutes a cheaper treatment than fixed prostheses and in some patients, with loss of lip support or with an interoclusal space larger than 15 mm, the choice of implant-supported overdentures seems to prevent future aesthetic or phonetic problems.

Key words:Overdentures, implant occlusion, implant rehabilitation, total edentulous rehabilitation, fixed prosthesis.

Effect of sociodemographic variables on complete denture satisfaction

PURPOSE

The objective of this study was to evaluate the effect of sociodemographic factors on quality of satisfaction towards denture treatment.

MATERIALS AND METHODS

One hundred subjects (filling inclusion criteria) who were wearing a denture for at least two months were enrolled and divided into five groups on the basis of sociodemographic variables (age, gender, literacy level, socio-economic and marital status). Questionnaires consisting of 38 questions (positive and negative attitude towards denture satisfaction) related to patients' perception of clinical outcome in different domains such as mastication, appearance, speech, comfort, health, denture care and social status were scored by the subjects. Questions reflecting positive attitude were scored as 2, 1, or 0 (yes, uncertain and no, respectively) and reversely for the negative questions. Statistical analysis was done by using Statistical Package for Social Sciences (α = .05).

RESULTS

Level of denture satisfaction was higher in age subgroup belonging to 45 - 65 years of age in relation to comfort, health and denture care. Female and male showed significant priority for denture treatment because of esthetic and function respectively. Level of satisfaction was statistically significant with literacy level. Upper high income group showed significantly higher level of satisfaction only in case of social status. Married group showed significantly higher satisfaction level only with comfort.

CONCLUSION

Patients' sociodemographic variables were influential factors on denture satisfaction.

A prospective study of early loaded single implant-retained mandibular overdentures: preliminary one-year results

Purpose. To investigate the predictability of simplifying mandibular overdenture treatment using one-stage surgery and early prosthetic loading of a single implant. Materials and Methods. Twenty edentulous patients with problematic existing mandibular dentures were treated. A single implant with a chemically modified surface (SLActive, Straumann AG, Basel, Switzerland) was placed into the mandibular midline. The patients were recalled at 3, 6 and 12 months. Clinical assessments and marginal bone loss using standardized radiographs were recorded. All complications, failures and maintenance were noted. Visual analog-scale questionnaires were used to record patient satisfaction in five categories. ANOVA was used to determine differences between means of marginal bone loss and different categories of patient staisfaction (P = 0.05). Results. The 20 early loaded implants were all surviving at the 12-month recall. All implants showed less than 1 mm of marginal bone loss by the end of the 1-year with a significant increase during the follow-up period. Few prosthetic problems were reported. Patient satisfaction was high with a significant increase in all comfort and functional parameters. Conclusions. These preliminary 1-year results indicate that early loading of a single chemically modified surface implant used to retain a mucosa-borne mandibular overdenture is a safe, reliable, and cost-effective treatment.

Multicentre prospective evaluation of implant-assisted mandibular bilateral distal extension removable partial dentures: patient satisfaction

OBJECTIVE

To compare the levels of patient satisfaction with either conventional mandibular bilateral distal extension partial dentures or those assisted by bilateral distal implants.

MATERIALS AND METHODS

Forty-eight participants who were dissatisfied with their existing conventional mandibular distal extension dentures opposing complete maxillary dentures were selected for a multicentre prospective study in New Zealand, Colombia and the Netherlands. A control group of 12 participants in New Zealand received conventional mandibular partial dentures. Three test groups involving 36 participants in New Zealand (12), Colombia (12) and the Netherlands (12) received bilateral distal implants in the second molar regions. After conventional loading, the test group participants initially had healing caps placed on the distal implants providing support only, followed after approximately 6 months by ball abutments (retentive anchors) for support and retention. Patient outcomes were determined with questionnaires completed at specific stages of the study for up to 3 years.

RESULTS

Visual analogue scale, Likert and oral health impact questionnaires before and after treatment indicated improved results. There were significantly improved parameters of overall satisfaction, stability, chewing and appearance after 3 years (P < 0.05). There were also improvements on stability, chewing and overall satisfaction. Speech also improved, but not significantly. Ball abutments (retentive anchors) on the distal implants, as opposed to healing caps improved patient satisfaction for stability, chewing and overall satisfaction. Changing to ball abutments (retentive anchors) revealed significant improvement by participant response when evaluating parameters of stability, chewing and overall satisfaction (P < 0.05).

CONCLUSION

Mandibular implant-assisted removable partial dentures are a preferable treatment option for patients with complaints about their conventional distal extension partial dentures.

An early loaded implant-supported mandibular complete arch fixed prosthesis in a young completely edentulous patient: a case report

The restoration of the mandibular arch up to the first molars with 5 one-piece implants presents a viable and cost-effective treatment plan in patients with adequate bone volume and favorable ridge relationships. The early loading of the implants with a provisional restoration reduces the period of edentulousness and restores the patient's ability to eat, talk, and smile effectively. Implants in younger patients prevent resorption of the residual alveolar ridge. This article presents a case report of the restoration of an edentulous mandibular arch with an early loaded implant-supported fixed restoration in a young patient.

Relationship between personality and impacts of implant treatment on daily living

PURPOSE

The objective of this study was to investigate the relationship between satisfaction with implant-supported fixed rehabilitations (ISFPR), their impacts on daily living, and personality profiles.

MATERIALS AND METHODS

Fifty patients (15 men and 35 women; mean age 44.3 ± 9 years), with fitted ISFPR, and 50 partially dentate controls matched with age and gender participated in this study. A Dental Impact on Daily Living questionnaire was used to assess dental satisfaction and impacts of ISFPR on daily living. NEO Five Factor inventory was used to assess participants' personality profiles. Pearson correlation, analysis of variance, and linear regression tests were used for statistical analysis of the data.

RESULTS

Patients with ISFPR were more satisfied with their dentition than controls (p < .05). Patients and controls demonstrated different relationships between personality, impacts on daily living, and satisfaction. Neuroticism, extraversion, and conscientiousness had significant relationships with satisfaction and impacts on daily living in both groups (p < .05). Openness and agreeableness had significant relationships with satisfaction and impacts on daily living in patients' group (p < .05).

CONCLUSION

ISFPR had positive impacts on participants' daily living and dental satisfaction. Personality traits (neuroticism, extraversion, openness, agreeableness, and consciousness) impact on daily living and satisfaction with ISFPR, and might predict satisfaction with ISFPR and their impacts on daily living.

The influence of maximum bite force on patient satisfaction and quality of life of patients wearing mandibular implant overdentures

The treatment of edentulism with traditional complete dentures can often induce impaired masticatory function due to limited retention and stability, especially in the lower jaw. Mandibular interforaminal implants have been widely used to stabilize the dentures, consequently improving masticatory performance in edentulous individuals. The aim of the present study was to document the influence of this improved masticatory function on patient satisfaction and quality of life of patients wearing mandibular implant-supported overdentures. Sixty-two patients treated with various types of implant-supported mandibular overdentures between 2004 and 2007 were included in this retrospective study. Maximum bite force (MBF) was measured bilaterally using a device with 2 strain gauges connected to a strain gauge measurement system. All the included patients were asked to fill out visual analog scale (VAS) forms based on general and chewing satisfaction and OHIP-14 forms. Results were analyzed by the Spearman rho test. No statistically significant correlation was found between MBF values and VAS general or VAS chewing satisfaction or Oral Health Impact Profile scores (P > .05). The results indicate that MBF is not associated with the satisfaction or quality of life of implant-supported mandibular overdenture wearers.

Patient satisfaction and dissatisfaction with mandibular two-implant overdentures using different attachment systems: 5-year outcomes

BACKGROUND

Different attachment systems for mandibular two-implant overdentures could influence levels of patient satisfaction. Positive consensus of the majority of patients being satisfied does not preclude the possibility of dissatisfaction for some.

PURPOSE

To evaluate patient satisfaction and dissatisfaction before and after 5 years of wearing mandibular two implant overdentures using different attachment systems ; to determine the prognostic relevance of pretreatment complete denture complaints to treatment outcomes.

MATERIALS AND METHODS

A total of 106 edentulous participants enrolled in a clinical trial completed a preliminary self-report inventory of their original complete denture complaints.New complete maxillary dentures and mandibular two-implant overdentures were provided to each participant using one of six different attachment systems. Patient satisfaction was determined at pretreatment; at baseline with mandibular two-implant overdenture insertion; and then annually for 5 years, using visual analogue and Likert-type scales.

RESULTS

Patient satisfaction with mandibular two-implant overdentures showed significant changes pre- to posttreatment(baseline) in all domains, but these were significant immediately and maintained without further significance for 5 years, other than pain with the overdenture. After 5 years, no significant differences were observed with all the attachment systems. Highly significant differences were found with some social and psychological aspects by the fifth year compared to baseline. Diagnostic and prognostic indicators from a pretreatment inventory identified 12 participants (13.5%) who were dissatisfied. These indicators revealed a maladaptive predisposition to mandibular two-implant overdentures.

CONCLUSIONS

The provision of mandibular two-implant overdentures will, in the majority of patients, significantly enhance levels of patient satisfaction for 5 years, as compared to complete mandibular dentures, regardless of the attachment system. Careful evaluation of pretreatment complaints with conventional dentures can possibly identify patient dissatisfaction with mandibular two-implant overdentures [corrected].

Methodology for measuring the in vitro seating and unseating forces of prefabricated attachment systems used to retain implant overdentures

PURPOSE

The purpose of this in vitro investigation was to measure the forces generated during the continuous seating and unseating of prefabricated attachment systems used to retain implant overdentures.

MATERIALS AND METHODS

An experimental design consisting of interchangeable fixture mounts, a radially indexable fixture holder, and a materials testing systems (MTS) machine was used to measure forces generated during the insertion and removal of spherical stud attachments (Straumann, Inc, Waltham, WA). Three separate experiments were conducted measuring the seating and unseating forces of a vertically aligned patrix/matrix assembly, a 20 degrees angled patrix opposing a vertically positioned matrix, and a vertically positioned patrix opposing a 20 degrees angled matrix. For each patrix/matrix combination, three specimens were tested. Measurements were continuously recorded under reproducible conditions in the presence of artificial saliva. All specimens were subjected to 10,000 seating/unseating cycles. Statistical analysis was performed with rank analysis of variance (ANOVA) for a group comparison (alpha= 0.05).

RESULTS

Results showed variability in the initial insertion and removal forces among experimental groups and among specimens within each experiment. A marked increase in the seating and unseating forces was recorded for all specimens during the first 300 cycles, followed by a gradual decrease in these forces. The exact p-values for the Kruskal-Wallis test showed no significant difference between the initial and final seating/unseating forces (p > 0.1) nor in the maximum seating/unseating forces (p > 0.6) among the three experimental groups.

CONCLUSIONS

Spherical stud attachments exhibited consistent seating and unseating forces over 10,000 cycles. A 20 degrees angle between the patrix and matrix had no effect on the overall seating and unseating force values.

Should edentulous patients be constrained to removable complete dentures? The use of dental implants to improve the quality of life for edentulous patients

BACKGROUND

Nowadays, there is some speculation among dental educators that the need for complete dentures will significantly decrease in the future and that training in their provision should be removed from the dental curriculum.

OBJECTIVE

To sensitise the reader to the functional shortcomings of complete denture therapy in the edentulous patient and present restorative options including implants to improve edentulous quality of life in these patients.

METHODS

Information retrieval followed a systematic approach using PubMed. English articles published from 1964 to 2008, in which the masticatory performance of patients with implant-supported dentures was assessed by objective methods and compared with performance with conventional dentures, were included.

RESULTS

National epidemiological survey data suggested that the adult population in need of one or two complete dentures will increase from 35.4 million adults in 2000 to 37.9 million adults in 2020. Clinical studies have showed that the ratings of general satisfaction were significantly better in the patients treated with implant overdentures post-delivery compared with the complete denture users. In addition, the implant group gave significantly higher ratings on comfort, stability and ability to chew. Furthermore, patients who received mandibular implant overdentures had significantly fewer oral health-related quality of life problems than did the conventional group.

CONCLUSION

Implant-supported dentures including either complete overdentures or a hybrid prosthesis significantly improve the quality of life for edentulous patients compared with conventional removable complete dentures. Therefore, the contemporary dental practitioner should consider other options as well as conventional removable complete dentures to restore edentulous patients.