The effect of attachment type and implant number on satisfaction and quality of life of mandibular implant-retained overdenture wearers

doi: 10.1111/j.1741‐2358.2011.00531.x The effect of attachment type and implant number on satisfaction and quality of life of mandibular implant‐retained overdenture wearers Objective: The aim of this study was to compare the quality of life and patient satisfaction outcomes of two attachment systems in mandibular overdentures with different numbers of supporting implants. Materials and methods: Sixty‐two edentulous patients with either splinted or single attachments in mandibular implant overdentures with different numbers of supporting interforaminal implants were investigated for patient satisfaction and quality of life in this retrospective study. Comparisons between groups were perceived by the Mann–Whitney U test. Relations among the parameters were investigated by Spearman’s rho correlation analysis. The results were evaluated statistically at a significance level of p < 0.05. Results: No statistically significant association is found between visual analogue scales scores and attachment type as well as implant number (p > 0.05), whereas Oral Health Impact Profile (OHIP)‐14 total scores for patients with 4‐implant‐supported bars were significantly lower than all the other attachment types (p < 0.05). Additionally, a negative (rate = 32.2%), statistically significant association between period of edentulism and total OHIP‐14 scores was detected (p < 0.05). Conclusions: A mandibular implant‐retained overdenture supported with four implants and bar attachments shows the highest ‘quality of life’ score and patient satisfaction is not influenced by the number of implants or attachment type.     

The effect of different attachment systems with implant‐retained overdentures on maximum bite force and EMG

doi: 10.1111/j.1741‐2358.2010.00389.x The effect of different attachment systems with implant‐retained overdentures on maximum bite force and EMG Objective: To compare the effect of different attachment systems with implant‐retained overdentures on maximum bite force and muscle activity using electromyography (EMG). Background: Denture retention and stability is of considerable interest in prosthetic dentistry. Materials and methods: Thirty‐five patients were examined: 15 edentulous patients treated with mandibular implant‐retained overdentures (MIRO) and maxillary dentures (MCD) (two implant‐ball attachment) (BC); 10 edentulous patients treated with MIRO and MCD (four implants‐bar attachments) (BRC); 10 patients with edentulous mandibular treated with MIRO and maxillary fixed partial dentures (MFPD) (two implant‐ball attachments) (BF). Before implant placement all patients received new dentures. After using these dentures for 3 months the maximum bite force and electrical activity of masseter muscle were measured. Two or four implants were then inserted into the intraforaminal region. After osseointegration periods, patients were treated with MIRO which duplicated their dentures and after three months the measurements were repeated. The data were collected and statistically analysed. Results: Muscle activity and chewing ability increased in the second period of measurements. Also chewing time was significantly decreased at the first measurements. The highest muscle activity was observed in the group of patients treated with group BF. Conclusion: The EMG values of the masseter muscle significantly increased when an implant attachments was used in the overdenture.     

Elders with implant overdentures: a 22-year clinical report

doi: 10.1111/j.1741‐2358.2012.00628.x Elders with implant overdentures: a 22‐year clinical report Objective: To report on the long‐term survival and prosthodontic maintenance of two edentulous adults with mandibular overdentures supported by hydroxyapatite (HA)‐coated implants. Background: Mandibular implant overdentures are a successful treatment option with positive impact on the quality of life of elderly edentulous adults. Long‐term survival of the implants requires continued rigorous prosthodontic maintenance. Clinical report: Two elderly edentulous adults with mandibular overdentures supported by 2 HA‐coated implants were presented for prosthodontic rehabilitation after 22 years of placement. The implants were osseo‐integrated and surviving at presentation based on accepted criteria. The mandibular implant overdentures suffered recurrent loss of retention and stability. Prosthodontic treatment involving the replacement of defective attachment systems and construction of new sets of mandibular implant overdentures opposing complete maxillary dentures is presented. Conclusion: The long‐term survival of mandibular 2‐implant overdentures requires continued prosthodontic maintenance. A conservative approach in the rehabilitation of two older edentulous adults with mandibular 2‐implant overdentures was described including proper selection of attachment systems.     

Clinical feasibility of mandibular implant overdenture retainers submitted to immediate load

Gerodontology 2010; doi: 10.1111/j.1741‐2358.2010.00374.x
Clinical feasibility of mandibular implant overdenture retainers submitted to immediate load Introduction: Millions of people around the world do not have access to the benefits of osseointegration. Treatments involving oral rehabilitation with overdentures have been widely used by specialists in the oral medicine field. This is an alternative therapy for retention and stability achievement in total prosthesis with conventional treatment, and two implants are enough to establish a satisfactory overdenture. Objective: The objectives of the study were to evaluate 16 patients of both sexes, with an average age of 47.4 ± 4 years, using electromyographic analysis of masseter and temporal muscles and analyse the increase of incisive and molar maximal bite force with their existing complete dentures and following mandibular implant overdenture therapy to assess the benefits of this treatment. Materials and methods: For these tests, the Myosystem‐BR1 electromyograph and the IDDK Kratos dynamometer were used. Statistical analysis was performed using the repeated measures test (SPSS 17.0). Results: A decrease in electromyographic activity during the rest, lateral and protrusion movements and increase of the maximal incisive and molar bite force after 15 months with a mandibular implant overdenture was observed. Conclusion: All the patients in this study reported a considerable improvement in the masticatory function and prostheses stability following treatment. It is possible to propose that the use of mandibular implants overdenture should become the selected treatment for totally edentulous patients to facilitate oral function and quality of life.     

The comparison of marginal bone loss around mandibular overdenture‐supporting implants with two different attachment types in a loading period of 36 months

doi:10.1111/j.1741‐2358.2009.00334.x
The comparison of marginal bone loss around mandibular overdenture‐supporting implants with two different attachment types in a loading period of 36 months Objective: The aim of this study was to assess the influence of attachment types on the marginal bone loss (MBL) around dental implants supporting mandibular overdentures (OVD). Background: There are a number of in vitro studies evaluating the influence of several factors on MBL around implants. Material and methods: Mandibular OVD patients appearing at routine recall sessions consecutively 6, 12, 24 and 36 months after loading were included in the study group. All patients received mandibular OVD with either ball or bar attachments. Measurements were obtained from images of successive radiographs, which were scanned and digitised before, and analysed at ×20 magnification. Statistical analyses were utilised in this study to assess the mean marginal bone level changes as well as to explore the potential effect of several parameters such as the cantilever or the attachment type on bone loss. Results: One hundred and twenty‐six implants in 51 patients with a mean age of 59.39 ± 9.99 years were evaluated. There was no statistical significant difference between the distal and mesial bone loss rates of single or splinted attachment types, whereas bone loss rates were statistically higher in cantilever situations. Conclusion: Within the limitations of this study, gender, age and diameter of the implants do not play a role in MBL. Length of the implant is an important factor in marginal bone level maintenance. The attachment type for OVD support seems not to influence MBL, but cantilevering of the bars increases bone loss significantly.     

Outcome of implant-supported overdenture treatment--a survey of 58 patients

Gerondontology 2012; doi: 10.1111/j.1741‐2358.2011.00524.x
Outcome of implant‐supported overdenture treatment – a survey of 58 patients Objective: The aim of this follow‐up study was to evaluate the long‐term outcome of implant‐supported or implant‐retained mandibular overdenture treatment. Material and methods: Altogether 112 patients treated with implant‐supported overdentures between 1985 and 2004 were invited to the follow‐up and 58 attended the clinical examination. The total amount of implants examined and still in use was 197. The average number of implants installed was three (range 2–4), and the mean length of the implants was 12 mm (range 8–21 mm). There were altogether 48 overdentures with a bar connection and 10 with a ball connection. Results: The most frequent prosthetic complications were technical: loosening of the retentive mechanism (39.7%) and breakage of the matrices (5.2%). The most common peri‐implant soft‐tissue findings were bleeding and slight hyperplasia. The implant‐supported overdentures of 19 patients (32.8%) had been renewed, while 39 patients (67.2%) still used their original overdentures, of which the oldest was 20 years old. Conclusion: The results of this long‐term follow‐up study show that the outcome of implant‐supported mandibular overdenture treatment was excellent. The patients were satisfied with the treatment, regardless of the attachment type used. Removable overdentures are more easy to clean and can be cleaned outside the patient’s mouth, whereas fixed‐implant full‐arch dentures in the edentulous mandible require much more time‐consuming hygiene. This kind of overdenture treatment is suitable also in the elderly, even though their ability to practice appropriate oral hygiene might be decreased.     

The influence of mandibular implant-retained overdentures in masticatory efficiency

doi: 10.1111/j.1741‐2358.2011.00539.x The influence of mandibular implant‐retained overdentures in masticatory efficiency Objective: To evaluate the masticatory efficiency of patients rehabilitated with conventional dentures (CDs) or implant‐retained mandibular overdentures. Background: Despite the evident benefits of implants on mastication as assessed by subjective patient‐based outcomes, the extent of implant overdenture treatment effect on food comminution is not well established. Materials and methods: A randomised clinical trial was carried out with 29 completely edentulous patients divided into two groups. The first group was rehabilitated with a mandibular overdenture retained by two splinted implants with bar‐clip system, while the second group was rehabilitated with a mandibular CD. Both groups also were rehabilitated with maxillary CDs. Masticatory efficiency and patient satisfaction were assessed 3 months after denture insertion. Masticatory efficiency was evaluated through the colorimetric method with the beads as the artificial test‐food. Comparisons for masticatory efficiency and patient satisfaction were performed using Student’s t‐test (α = 0.05). Results: No significant statistical difference was found for masticatory efficiency (p = 0.198). Patient overall satisfaction was significantly higher for the mandibular overdenture (p < 0.001). In addition, mandibular overdenture patients were significantly more satisfied with chewing experience (p < 0.05) and retention of the lower denture (p < 0.005). Conclusion: The results of this study suggest that mandibular overdenture significantly improves chewing experience, although limited effect on masticatory efficiency has been observed.     

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

doi:10.1111/j.1741‐2358.2009.00294.x
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.     

Implant supported dentures: an estimation of chewing efficiency

doi: 10.1111/j.1741‐2358.2009.00303.x
Implant supported dentures: an estimation of chewing efficiency Background: Treatment of edentulous patients is one of the most demanding tasks the dentist can meet in his everyday practice. Implant based methods help to improve functioning of dentures and life quality of so treated patients. Objectives: The aim of the study was to evaluate the chewing efficiency of patients treated with lower complete implant‐supported overdentures and the simultaneous evaluation of treatment results by patients. Materials and methods: For the investigation were chosen edentulous patients, treated with upper conventional complete dentures and lower complete overdentures supported on two implants. In this group of patients, were conducted investigations of chewing efficiency changes, based on the Optocal test and overdentures functioning evaluation made by patients in the survey. Results: The objective evaluation of the chewing efficiency indicated the decrease of this value in the five years of observations. Lower complete overdentures supported on implants significantly increased the comfort of chewing of edentulous patients. Conclusions: The results of the study let us to assess positively the result of the therapy using titanium implants and lower complete overdentures. The therapy described significantly increases the life comfort of the edentulous patients. Decreasing chewing efficiency indicated by the research result should be compensated with the dentures maintaining or the prostheses exchange after about five years of use.     

Implant overdentures for edentulous elders: study of patient preference

Background: Studies show that elders wearing implant overdentures have improved nutrition and quality of life. However, upfront costs of this therapy are high, and the income of elderly edentulous populations is low. Objectives: This study was designed (i) to measure the preferences of edentulous patients for mandibular two‐implant overdentures using Willingness‐To‐Pay (WTP) and Willingness‐To‐Accept (WTA), (ii) to assess the effect of long‐term financing on WTP and (iii) to assess the desired role of health care plans in financing dental prostheses. Methods: Edentulous elders (68–79 years; n = 36) wearing maxillary dentures and either a mandibular conventional denture (CD, n = 13) or a two‐implant overdenture with ball attachments (IOD, n = 23) participated in this study. All had received their prostheses 2 years previously, as part of a randomised clinical trial. A three‐part questionnaire was completed during a 20‐min interview with a trained researcher. Results: Forty‐six per cent (6/13) of the CD wearers and 70% (16/23) of the IOD wearers were willing to pay three times more than the current cost of conventional dentures for implant prostheses. These percentages were increased to 77% (CD) and 96% (IOD) if participants could pay for implant overdentures in monthly instalments. Eighty‐six per cent (31/36) of all participants in both groups (21/23 IOD; 10/13 CD) thought that the government should cover at least some of the cost of implant overdentures. Conclusions: This study shows that, the majority of elderly edentate individuals who have not experienced mandibular two‐implant overdenture therapy are willing to pay the cost, particularly when payment can be made in monthly instalments.     

下颌种植覆盖义齿的生物力学研究进展

口腔生物力学是用生物力学的概念和方法,研究口腔医学中的有关基础性科学问题、解决口腔医学中的临床实际问题、发展口腔临床技术的一门学科。在口腔正畸学、修复学、种植学及口腔颌面外科学等领域存在着大量的生物力学问题,生物力学已成为口腔医学的基础科学之一。传统全口义齿修复常常会出现固位稳定差、咀嚼效率低、患者有疼痛感、适应时间长等情况,很大程度上不能满足患者的修复要求。种植覆盖义齿对于下颌牙槽嵴严重吸收的患者,效果尤为明显。种植覆盖义齿是义齿与种植体之间以不同的附着体作为连接,形成患者可以自行摘戴的种植体支持的覆盖义齿修复。下颌种植覆盖义齿因其能有效地提高下半口义齿的固位性和稳定性、显著提高了患者的咀嚼效率,目前已成为修复下颌牙槽骨严重吸收的无牙颌患者的有效修复方法。本文针对下颌种植覆盖义齿的生物力学研究进展作一综述。     

Comparison of mandibular bone mineral density in osteoporotic, osteopenic and normal elderly edentulous subjects measured by the dual-energy X-ray absorptiometry technique

doi: 10.1111/j.1741‐2358.2012.00625.x Comparison of mandibular bone mineral density in osteoporotic, osteopenic and normal elderly edentulous subjects measured by the dual‐energy X‐ray absorptiometry technique Objective: The aim of this study was to compare the mandibular body bone mineral density according to bone mineral density status of spine and femur measured by dual‐energy X‐ray absorptiometry (DXA) technique in elderly edentulous individuals. Background: One of the factors that affect the survival rate of implants is bone mineral density (BMD) of the jaws. Materials and methods: Fifty edentulous elderly patients’ (27 women and 23 men) spine, femur and the mandibular body BMDs were measured using DXA technique. BMD scans of the AP lumbar spine (L2–L3) and femur were classified using World Health Organisation criteria for bone mass. Results: There was a statistically significant difference between the normal femur group’s–osteoporosis group’s mandibular body BMD (p = 0.001) and femoral osteopaenia group’s–osteoporosis group’s mandibular body BMD (p < 0.001). The femoral osteoporosis group’s mandibular body BMDs were lower than those of both the normal femoral and the femoral osteopaenia group subjects’. Conclusion: Classification of edentulous mandibles according to low and high bone mineral densities is a problem in implant dentistry. The results of this study demonstrated that femoral bone mineral density status may be used to provide preliminary information about the bone mineral density of the mandibular body region in elderly edentulous subjects.     

Comparing the efficacy of mandibular implant-retained overdentures and conventional dentures among elderly edentulous patients: satisfaction and quality of life

Objectives: The aim of this study was to compare the satisfaction and the quality of life in an elderly population using either mandibular conventional dentures or implant‐retained overdentures. Materials and methods: A total of 34 patients were divided into two groups: group I – complete dentures users; group II – users of upper complete dentures opposed by implant‐retained overdentures. The subjects were submitted to a questionnaire based on Oral Health Impact Profile and oral health related quality of life to evaluate their satisfaction levels and quality of life with their prostheses. Data were evaluated using a non‐parametric statistical analysis (Fischer test) with significant difference at α = 0.05. Results: There were no significant differences between the groups in relation to comfort, aesthetics, chewing ability, overall satisfaction, pain, functional, phonetic, social, and psychological limitations (p > 0.05). Comparing the stability of mandibular dentures, group II presented the better results (p < 0.05). Conclusion: Although the stability of the mandibular implant‐retained overdenture was enhanced compared to a conventional denture, the quality of life and satisfaction levels were similar for both the groups.     

Resonance frequency analysis of overdenture retainer implants with immediate loading

doi: 10.1111/j.1741‐2358.2011.00488.x
Resonance frequency analysis of overdenture retainer implants with immediate loading Objective: To evaluate 16 patients of both sexes with lower overdenture and upper complete dentures, by analysing the resonance frequency of the initial and late stability of implants used to retain the overdenture under immediate loading. Background: Oral rehabilitation treatment with complete dentures using implants has been increasingly more common among the specialists in the oral rehabilitation area. This is an alternative for obtaining retention and stability in treatments involving conventional complete dentures, where two implants are enough to retain the overdenture satisfactorily. Materials and methods: The Osstell? Mentor device was used for the analysis in the initial period (primary stability), 3 and 15 months after the installation of the lower overdenture (secondary stability). The statistical analysis was performed with the repeated measures model (p < 0.01). Results: The implant stability quotients were observed to increase after 15 months of the rehabilitating treatment. Conclusion: The use of overdentures over two lower implants should become the treatment of choice for individuals who have a fully edentulous mandible.     

Maximum bite force after the replacement of complete dentures

Objective: The aim of the present study was to investigate whether the maximum bite force ( MBF ) can be improved by the replacement of complete dentures for elderly people. Design: Nine edentulous volunteers, mean age 74.2 (± 5.5) years and average denture experience 19.4 ± 19.5 years (1 to 50 years) had replacement dentures made. After a rehearsal session, MBF was recorded with the old dentures, and with the new dentures immediately at insertion, at 3, 8 days, 2–3 weeks, 1, 2, 3 and 6–10 months post insertion ( p‐i. ). MBF was recorded with the central bearing point method using a full‐bridge strain gauge load cell. Data were analysed off‐line using the mean of two peak readings per patient per session. Results: The results indicate that MBF tended to be impaired when replacement dentures were first fitted (n.s.). However, this trend reversed during the first month p‐i. for patients with a “moderate” lower ridge resorption of Atwood grade 3 or 4 (n = 5). Patients with more severe lower ridge resorption Atwood grade 5 or 6 (n = 4) showed a significantly lower MBF over the entire observation period (p0.05) and took longer to regain bite strength. Only patients with moderate bone resorption exceeded their pre‐insertion level of MBF within the observation period of 6–10 months p‐i. Conclusion: The present pilot study suggests that, at least for elderly patients with severe bone resorption, delayed improvement of MBF should be expected with replacement complete dentures.     

Impact of Human Genome Project on treatment of frail and edentulous patients

Objective: Because of ongoing increases in life expectancy and deferment of edentulousness to older age, dentists are facing a different challenge to satisfy elderly denture wearers with a higher prevalence of chronic diseases. This discussion introduces the Human Genome databases as novel and powerful resources to re‐examine the core problems experienced by frail and edentulous patients. Background: Recent studies demonstrated that mandibular implant overdentures do not necessarily increase masticatory function, perception and satisfaction in denture wearers with adequate edentulous residual ridges. It has been demonstrated that the rate of edentulous residual ridge resorption significantly varies among individuals. The prognosis and cost‐effectiveness of denture treatment, with or without implants, may largely depend on how the edentulous ridge is maintained. However, reliable clinical methods permitting dentists to predict the long‐term health of the edentulous residual ridge are lacking. Materials and methods: With the completion of the Human Genome Project, the genomic sequence database from this multinational consortium will provide a unique resource to determine the genetic basis of similarity and diversity of humans. Results: One base pair in every 100 to 300 base pairs of the genome sequence varies among humans, suggesting that genetic diagnosis using the single nucleotide polymorphisms (SNPs) may provide a novel opportunity to differentiate our edentulous patients. Conclusions: Future dental service for the elderly will require a personalized care paradigm, using highly sensitive diagnostic technology such as SNP genomic analysis, for recommending the treatment with greatest potential benefit.     

下颌LOCATOR种植覆盖义齿咀嚼效率的比较

目的：种植支持的覆盖义齿是针对下颌骨后牙区没有足够骨量的病人的一种适当的治疗方案。LOCATOR是近年来一种新型改良的种植体附着系统。本研究在病人佩戴LOCATOR附着系统支持的下颌种植覆盖义齿后,通过比较不同种植体数量对咀嚼效率的影响,以期用最小的成本达到较好的临床效果。方法：19名下颌无牙颌患者中,10名植入2枚种植体,9名植入3枚种植体。三月后行LOCATOR附着系统支持的种植覆盖义齿修复,并计算咀嚼效率增加量。结果：通过SPSS20．0软件进行统计分析,采用95％可信区间,α=0．05,对两组覆盖义齿咀嚼效率的增加量进行t检验：P〉0．05,两组之间咀嚼效率的增加量无显著性差异。针对下颌LOCATOR种植覆盖义齿,植入两枚种植体和三枚种植体提升的咀嚼效率并无统计学差异。结论：针对LOCATOR系统支持的下颌种植覆盖义齿,两枚种植体既能有效地提高咀嚼效率。     

Influence of connection type on the biomechanical behavior of distal extension mandibular removable partial dentures supported by implants and natural teeth

Few studies are performed to evaluate the influence of connection type on the stress distribution of distal extension mandibular removable partial dentures (RPDs) supported by both implants and natural teeth. In this study, five three-dimensional finite element models were prepared to simulate mandibular bilateral partially edentulous arches. Four were RPDs supported by both implants and natural teeth, and the other one was RPDs supported only by natural teeth. The maximum equivalent (EQV) stress values of bone around implants, the abutments, and the mucosa displacements of the related supporting structures were measured. It was found that a non-rigid telescopic coping was more favorable to protect the implant than a rigid telescopic coping. Compared with other connection types, the easy resilient attachment (ERA) system seemed to be effective to associate implant without complications. However, the results obtained in the present study should be cautiously interpreted in the clinic.     

A comparison of patient satisfaction between treatment with conventional complete dentures and overdentures in the elderly: a literature review

doi:10.1111/j.1741‐2358.2009.00299.x
A comparison of patient satisfaction between treatment with conventional complete dentures and overdentures in the elderly: a literature review Background: It has been stated that mandibular overdentures are more satisfactory than conventional dentures, but problems relating to the use of retrospective ratings, lack of control group and sequential provision of treatment may compromise the findings. Objective: To establish a comparison between treatment with conventional complete dentures and implant‐retained overdentures in elderly patients by conducting a literature review. Materials and methods: A search of English language peer‐review literature was completed using Medline up to 2008 focusing on evidence‐based research. Randomised clinical trials (RCTs) and longitudinal prospective studies were favoured in the review, using a general hierarchical classification. Articles that did not focus exclusively on the comparison of patient satisfaction between complete dentures and overdentures were excluded from further evaluation. The last search was conducted in February 2008. Key terms included quality of life, patient satisfaction, edentulism, complete denture and overdenture. Results: Among the 90 articles found in the initial search, 27 met the inclusion criteria. This included 18 RCTs and eight prospective and one cohort study. Most of the articles stated superiority of the mandibular implant‐retained overdenture therapy over the conventional complete denture regarding patient satisfaction and quality of life. Conclusion: Even with implant treatment presenting higher patient satisfaction and improvement of quality of life, it was not possible to establish a direct comparison between the studies due to differences in adopted methodologies.