Immediate Loading of Two Implants Supporting a Ball Attachment-Retained Mandibular Overdenture: A Prospective Clinical Study

Comparative Assessment of the Adhesion Forces of Soft Silicone Materials to the Denture Base Material (PMMA) Conditioned with Sandblasting

BACKGROUND

In patients undergoing surgery for oral cancer, soft support materials are used to minimise trauma to the soft tissues. Silicone-based liners are widely used in prosthetic dentistry. A prerequisite for long-term Adhesion of the liner to the denture base is largely dependent on the surface preparation of the denture material.

OBJECTIVES

The aim of the present study was to investigate whether surface preparation of the acrylic material by sandblasting increases the adhesion of the silicone support material to the acrylic denture plate.

MATERIAL AND METHODS

The study included adhesion testing of four silicone-based soft cushioning materials (Silagum Comfort, Elite Soft Re-lining, Ufi Gel SC, Mucopren Soft) on a total of 270 samples. Each material was tested on 15 samples. Three subgroups with different surfaces were separated: 1 raw-standard surface treatment with a cutter, and 2 sandblasted, with 100 and 350 µm alumina grain at 90°. The samples were subjected to seasoning: 24 h and six weeks. The adhesion force of silicone to acrylic was measured by performing a tensile test using a universal two-column testing machine.

RESULTS

The highest bond strength was recorded for Silagum on the surface prepared using 100 µm abrasive and seasoned for 6 weeks (291.5 N). The smallest among the maximum forces was recorded for the Mucopren material (81.1 N). For the Mucopren system with a raw and sand-blasted surface (350 µm), the adhesion strength increased after six weeks. In contrast, the durability of the joint decreased for the 100 µm sandblasted surface. The Elite material exhibited similar values for maximum forces (271.8 N) and minimum forces (21.1 N). The highest strength (226.1 N) was recorded for the sample from the group prepared with 350 µm abrasive and seasoned for 24 h. The lowest value (72.6 N) occurred for the sample from the group with 100 µm abrasive and seasoned for 6 weeks.

CONCLUSIONS

Sandblasting of acrylic plastic improves adhesion to selected relining silicones. 2. The size of the abrasive employed has an impact on the adhesion between the acrylic plastic and the bedding silicone. 3. In the case of some relining systems (Mucopren), an increase in roughness through sandblasting has the effect of reducing the durability of the bonded joint.

Patient-reported outcome measures and prosthetic events in implant-supported mandibular overdenture patients after immediate versus delayed loading: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Immediately loaded mandibular overdentures are clinically acceptable treatment options that have gained popularity because their use shortens the treatment duration. However, whether the immediate loading of dental implants can match the prosthetic events, satisfaction, and quality of life of delayed loading is still unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare the prosthetic events, satisfaction, and quality of life of immediate versus delayed loading implants in patients rehabilitated with mandibular overdentures.

MATERIAL AND METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered at The International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021258187). Electronic searches were carried out by 2 independent reviewers in the PubMed/MEDLINE, Cochrane Library, and Web of Science databases up to May 2021. Only randomized clinical trials and prospective studies with at least 10 participants that compared immediate versus delayed loading were selected. A meta-analysis was performed by using the RevMan 5 software program for complications and maintenance outcomes.

RESULTS

Seven articles were included in the qualitative analysis, and 4 were included in the quantitative analysis. The meta-analysis demonstrated no significant difference between immediate and delayed loading for prosthetic complications (RR=1.71; 95% CI=0.67-4.37; I2=85%, P=.27) or maintenance (RR=1.92, 95% CI=0.44-8.28; I2=94%, P=.38).

CONCLUSIONS

Although the prosthetic complications and maintenance were more likely to favor the delayed loading group, available evidence showed no statistical difference for prosthetic complications and maintenance between immediate loading and delayed loading in mandibular overdentures.

Patient satisfaction and crestal bone changes with one-piece and two-piece single implant-retained mandibular overdenture: A randomized controlled clinical study

PURPOSE

The present study was done to assess patient satisfaction and crestal bone changes with one-piece and two-piece single implant-retained mandibular overdentures (SIMOs).

METHODS

The participants included in Group 1 (n=12) received one-piece SIMOs; the participants in Group 2 (n=12) received two-piece SIMOs.Scheduled follow-ups were done at 1 month and 1 year after implant placement. Patient satisfaction and crestal bone changes were evaluated. The data obtained were analyzed statistically with independent Student t-test.

RESULTS

Visual analogue scale (VAS) score for patient satisfaction with one-piece and two-piece SIMOs were statistically significant at 1-year of follow-up. The patient satisfaction level on the VAS score increased (38.1 to 51.1) with group one-piece SIMOs and two-piece SIMOs (36.6 to 46.8) at baseline to 1 month (P=0.13). The patient satisfaction level increased (38.1 to 56.6) with group one-piece SIMOs and two-piece SIMOs (36.6 to 52.2) at baseline to 1 year (P=0.03). At the 1 year follow-ups, group 1 had mean crestal bone loss of 0.80 ± 0.49 mm and group 2 had 1.24 ± 0.90 mm (P=0.16). Crestal bone loss was greater in the two-piece SIMOs group at 1 month and 1 year follow-ups, but statistically it was insignificant.

CONCLUSIONS

One-piece SIMOs seemed to be a viable treatment option with increased patient satisfaction on a VAS. Crestal bone loss was greater in the patients with two-piece SIMOs during follow-up. One-piece SIMOs was comparatively simple with less invasive procedures and needed fewer components,so considerable number of patients requiring implant retained dentures could be benefited.

Patient-reported outcomes with immediate-loaded two-implant-supported mandibular overdentures: Results of a 5-year prospective study

Background/purpose

Few studies have comprehensively assessed long-term patient-reported outcomes for overdentures supported by two immediate implants. The purpose of the study was to evaluate patient-reported outcomes of immediately loaded two-implant-supported overdentures retained by ball attachments over a 5-year evaluation period.

Material and methods

Nineteen participants with edentulous mandibles were provided with immediately loaded two-unsplinted-implant-supported overdentures retained by ball attachments. The participants completed the Japanese version of the Oral Health Impact Profile (OHIP)-EDENT-19 and the Patient's Denture Assessment (PDA). Additionally, patient satisfaction was measured by a 100-mm visual analog scale (VAS). Measurements were performed at baseline, and at 1 and 5 years following implant surgery.

Results

Seventeen participants and 14 participants were evaluated at the 1-year and 5-year assessment, respectively. Considering the OHIP-EDENT-19, there was a significant decrease in the total (p = 0.046), “functional limitation” (p = 0.021), and “physical disability” (p = 0.034) scores at 1 year and the total (p = 0.045) and “physical disability” (p = 0.024) scores at 5 years following surgery, compared to the baseline scores. Considering the PDA, there was a significant increase in the “function” (p = 0.038) and “lower denture” (p = 0.003) scores at 1 year and the “function” (p = 0.032), “lower denture” (p = 0.008), and “esthetic and speech” (p = 0.043) scores at 5 years following surgery, compared to the baseline scores. Patient satisfaction at 1 year following surgery was significantly greater than that at baseline (p = 0.005).

Conclusion

Immediately loaded two-unsplinted-implant-supported overdentures retained by ball attachments improved the oral health-related quality of life and self-assessment of dentures by the patients up to 5 years following implant surgery.

Patient-reported outcomes for the immediate loading of mandibular overdentures supported by two implants soon after implant surgery

Background/purpose

No studies have comprehensively assessed short-term patient-reported outcomes after the provision of overdentures supported by two immediate implants. The purpose of this study was to evaluate short-term patient-reported outcomes for mandibular overdentures retained by ball attachments on two immediately loaded implants.

Materials and methods

Nineteen participants with mandibular edentulism were provided with overdentures retained by ball attachments on two immediately loaded, unsplinted implants. The participants' self-assessment of their dentures and oral health-related quality of life were evaluated with the 22-item Patient's Denture Assessment (PDA), and the 19-item Japanese version of the Oral Health Impact Profile (OHIP-EDENT), respectively. Patient satisfaction was measured on a 100 mm visual analogue scale. Assessments were conducted at baseline, and at 1 and 6 months after implant surgery.

Results

There were significant increases in the PDA “Lower denture” (P = 0.009) at 1 month, as well as “Function” (P = 0.002) and “Lower denture” (P = 0.009) scores at 6 months. Patient satisfaction was also significantly increased at 1 month (P = 0.007) and 6 months (P ≤ 0.000). Significant decreases were observed in the OHIP-EDENT “Physical pain” (P = 0.046) score at 1 month, as well as the summary score (P = 0.033), “Functional limitation” (P = 0.020) and “Psychological discomfort” (P = 0.019) scores at 6 months.

Conclusion

The use of two immediately loaded implants for lower mandibular complete overdentures is associated with improvements in patient's self-assessment of dentures, satisfaction, and oral health-related quality of life, up to 6 months after implant surgery.

Maintenance and risk factors for fractures of overdentures using immediately loaded conventional diameter or mini implants with Locator abutments: A cohort study

BACKGROUND

Fractures in mandibular implant-retained overdentures are a common complication. However, little is known on the related risk factors and outcome differences when using two conventional diameter or two mini implants.

PURPOSE

The purpose of this study was first, to evaluate the required maintenance and complications with the overdentures and second, to analyze risk factors for overdenture fractures.

MATERIALS AND METHODS

This cohort study was conducted in edentulous patients with complete dentures. Patients received either two conventional (4.1 mm in diameter) and two mini (2.9 mm or less in diameter) implants, based on available buccal-lingual ridge width. All implants were immediately loaded with mandibular overdentures retained by Locator abutments. The number of prosthodontic after care visits (scheduled and unscheduled) were recorded and compared between the two implant diameter groups. Fracture occurrence was the primary outcome variable. Risk estimates were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The ORs were adjusted for potential clinical confounders (ie, necessity of relining, matrix recapture, abutment loosening, implant diameter, height of the Locator, and retention force).

RESULTS

A total of 50 edentulous patients were analyzed. One conventional diameter and three mini implants failed within a 1-year follow-up period. Prosthetic maintenance requirements for overdentures on both implant diameter groups were comparable. A total of 12 overdenture fractures (four in the mini implant group and eight in the conventional diameter group) occurred. Adjusted OR (AOR) analysis showed a significant association between abutment loosening and overdenture fracture (AOR = 12.00, 95% CI = 1.11-129.45; P = .041).

CONCLUSION

Within the limitations of this study, the present findings suggest that implant diameter does not affect number of prosthetic maintenance and complications, and that abutment loosening is a risk factor for overdenture fractures, regardless of the implant diameter used.

Crestal Bone Changes and Patient Satisfaction with Single Implant-Retained Mandibular Overdentures with Dalla Bona and Locator Attachments with Immediate Loading Protocols. A Randomized Controlled Clinical Study

PURPOSE

There is no enough evidence present on the success of single implant-retained mandibular overdentures (SIMO) with Dalla Bona and Locator attachments. This study aims to compare crestal bone loss and patient satisfaction with SIMO with Dalla Bona and Locator attachment following immediate loading protocols.

MATERIAL AND METHODS

Twelve patients included in Group 1 received immediate SIMO with Dalla Bona attachments, and another twelve patients in Group 2 received immediate SIMO with Locator attachments in the mid symphyseal region. The follow-up was scheduled at 6 and 12 months after implant placement. The patient satisfaction with the denture was evaluated with the visual analog scale (VAS) score. The data obtained were statistically analyzed with the independent student t-test for intergroup comparison and repeated measures of ANOVA followed by Bonferroni's Post hoc analysis for intragroup comparison of mean crestal bone loss at a different time interval.

RESULTS

Ten patients each in both the groups were available for follow-up. Crestal bone loss at 6 months follow-up for Dalla Bona group was 0.42 ± 0.10 mm on the mesial side and 0.43 ± 0.14 mm on the distal side and at 1 year 1.54 ± 0.16 mm on the mesial side and 1.66 ± 0.13 mm on the distal side. The mean crestal bone loss at 6 months follow-up for Locator group was 0.48 ± 0.16 mm on the mesial side and 0.45 ± 0.11 mm on the distal side and at 1 year was 1.71 ± 0.22 mm on mesial side and 1.74 ± 0.28 mm on the distal side. There was difference in bone loss at 6 months (mesial: 0.06 mm, p = 0.327; distal:0.02 mm; p = 0.726) and at 1 year (mesial: 0.17 mm, p = 0.063; distal: 0.08 mm; p = 0.423) in between two groups but the difference was statistically insignificant. There was a significant difference found in the VAS score for patient satisfaction with SIMO with Dalla Bona attachments and Locator attachments at 6 months (54.2 vs. 51.8, p = 0.005) and 1 year (60.6 vs. 55.2, p = 0.005).

CONCLUSIONS

Patient satisfaction with SIMO with Dalla Bona attachments was higher during the follow-up. SIMO with Dalla Bona attachments had less crestal bone loss and less prosthetic complications when compared to Locator attachments, although the difference in the bone loss was statistically insignificant.

Immediate versus delayed loading of mandibular implant-retained overdentures: A 60-month follow-up of a randomized clinical trial

AIM

The purpose of this observational, post-trial follow-up study was to evaluate 60-month outcomes of a randomized controlled clinical trial that compared immediately and delayed loaded two unsplinted implants, supporting a locator-retained mandibular overdenture.

MATERIALS AND METHODS

Patients from a randomized controlled clinical trial, treated with either immediate or delayed loading of two implants, supporting a locator-retained mandibular overdenture, were recalled for 60-month evaluation. Patients underwent a clinical and radiographic examination to evaluate the peri-implant soft tissue parameters and bone. Prosthetic maintenance needs and complications were also recorded.

RESULTS

Twenty three of the 30 patients were available for the 60-month follow-up. The mean radiographic bone level change measured using standardized periapical radiographs from baseline to 60 months was 0.89 mm (±0.74) and 0.18 (±0.41) for delayed loading and immediate loading groups, respectively. A statistically significant difference was observed at 60 months with a smaller radiographic bone level change in the immediate loading group. No implants were lost between 12 and 60 months. At 60 months, per-protocol implant survival rate was 100% for both the groups. No difference was found in the peri-implant soft tissue parameters and prosthetic needs between the groups.

CONCLUSION

Both immediately and delayed loaded implants supporting a locator-retained mandibular overdenture showed similar clinical outcomes.

Comparison of immediate and conventional loading protocols with respect to marginal bone loss around implants supporting mandibular overdentures: A systematic review and meta-analysis

Purpose

To compare marginal bone level changes (MBLCs) of immediately- and conventionally-loaded implants supporting a mandibular implant overdenture (IOD).

Materials and methods

Both electronic (MEDLINE, PubMed, and The Cochrane Library) and manual searches were conducted for all relevant studies published from 1 January 2000 to 1 November, 2017. Randomized controlled trials (RCTs) and prospective studies with a minimum follow-up of 12 months were selected. Studies which utilized implants narrower than 3 mm were excluded from analysis.

Results

Four studies met the criteria, with two evaluating horizontal bone loss. There were 70 patients in the test group (immediate loading) and 60 in the control group (conventional loading). Follow-up lasted 6–36 months, with MBLCs being interpreted from standardized periapical x-rays, panoramics or cone beam computed tomography. Each patient was given 2–3 implants.

After 6 and 12 months, the differences in MBLCs were 0.04 mm (95% CI: −0.21, 0.29) and 0. 00 mm (95% CI: −0.35, 0.36) respectively. Subgroup analysis of RCTs with 2 implants revealed group differences in MBLCs as 0.13 mm (95% CI: −0.22, 0.48) and that in horizontal bone loss as 0.04 mm (95% CI: −0.02, 0.10). No statistically significant differences were identified (p > 0.05).

Conclusion

The MBLCs of immediately-loaded implants for mandibular IODs seems comparable to those of conventional loading.

New mini dental implant attachments versus O-ring attachment after cyclic aging: Analysis of retention strength and gap space

Overdenture as a treatment modality for both partially and fully edentulous patients is costeffective and less expensive. The purpose of the present study was to examine the newly fabricated attachments by comparing them with conventional O-ring attachment in vitro in terms of retention force and cyclic aging resistance. A total of 150 samples were prepared and divided into five groups according to the materials used (O-ring attachment, Deflex M10 XR, Deflex Classic SR, Deflex Acrilato FD, and flexible acrylic resin). The retention force of different attachments was measured by a mini dental implant after three subsequent aging (0, 63, and 126) cycles in the circumstances similar to the oral environment. The gap space between the head of the implant and the inner surface of the attachments was detected. Two-way analysis of variance (ANOVA) analysis with multiple comparisons test was applied for statistical analysis. The results showed that Deflex M10 XR had the highest retention force and the lowest gap space after cyclic aging; in addition, by comparing the relative force reduction, the lowest values were obtained in the O-ring attachment and the highest values in the flexible acrylic resin attachment. The retention force measured after cyclic aging for the Deflex M10 XR attachment was greatly improved when compared with the O-ring attachment and other types of attachment materials; in addition, the Deflex M10 XR attachment exhibited the minimum gap space between the inner surface and the mini dental implant head. In conclusion, Deflex M10 XR has the ability to withstand weathering conditions and retains its durable and retentive properties after aging when compared with other attachments.

The effect of 2 versus 4 implants on implant stability in mandibular overdentures: A randomized controlled trial

STATEMENT OF PROBLEM

Dental research is rich with articles that investigated the influence of host-site variables, some implant-related variables (implant length, diameter, taper, design, location, and surface topography), different loading protocols or surgical procedures, and measurement methodology on dental implant stability. However, the number of implants and its effect on implant stability remain unclear.

PURPOSE

The purpose of this randomized clinical trial was to investigate the influence of implant number on implant stability by comparing 2 versus 4 implants in mandibular implant overdentures.

MATERIAL AND METHODS

The trial included 20 participants with edentulous mandibular ridges. Participants were randomly assigned to 2 equal groups, a 4-implant (experimental) group consisting of 4 implants installed in lateral-canine and premolar regions; and a 2-implant (control) group, consisting of 2 implants in lateral-canine regions. Implant stability was measured using resonance frequency analysis at implant placement and then at 1, 3, 6, 9, and 12 months. The Student t test was used to compare the implant stability quotient (ISQ) values of the anterior implants in the 4-implant and 2-implant groups. One-way ANOVA followed by the post hoc Bonferroni test was used to compare ISQ values among the different follow-up periods within each group (α=.05).

RESULTS

Mean ISQ values for anterior implants in the 4-implant group were slightly higher than those recorded for the 2-implant group at all follow-up periods. However, these differences were not statistically significant (P>.05). Within-group comparison revealed an initial decrease in implant stability for all implants. This decrease was statistically significant for the 2-implant group (P<.001) and for posterior implants in the 4-implant group (P<.001). This was then followed by a gradual increase in ISQ values for all implants in both groups.

CONCLUSIONS

Increasing the number of implants from 2 to 4 in mandibular implant overdentures did not have a significant influence on implant stability.

Dental Implants With Immediate Loading Using Insertion Torque of 30 Ncm: A Systematic Review

OBJECTIVE

This study aimed to perform a review of the literature regarding the survival rate of dental implants with immediate loading using insertion torque of 30 Ncm.

MATERIAL AND METHODS

A systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook for Systematic Reviews of Interventions (PROSPERO CRD42014015323). The search was performed in the PubMed, Web of Science, Cochrane Library electronic, OVID, and Scielo databases. Manual searches were also performed. The articles identified were assessed independently by 3 researchers. Clinical trials reporting dental implants with immediate loading and 30 Ncm torque in patients ages 18 years or older were included.

RESULTS

The searches yielded 589 studies. Six studies were included in the systematic review. The survival rate of dental implants was 96.8%. Three studies showed a low potential risk of bias.

CONCLUSION

There is not strong evidence that insertion torque of 30 Ncm is enough for implant survival in cases of immediate loading.

Long-term success of dental implant-supported dentures in postirradiated patients treated for neoplasms of the maxillofacial skeleton: a retrospective study

OBJECTIVES

The reconstruction of oral function in irradiated patients with craniofacial tumors is a significant challenge. The aim of this study was to detect long-term success of dental implant-supported dentures in postirradiated patients treated for neoplasms of the maxillofacial skeleton.

MATERIALS AND METHODS

From 2004 to 2011, 36 irradiated patients underwent oral function reconstruction using implant-supported prostheses. Bone augmentation was completed using vascularized bone grafts in 22 patients. Fourteen patients were treated by hyperbaric oxygen therapy (HBO). A total of 198 dental implants were used in jaw rehabilitation. After loading, implant success rates, biological and prosthetic complications, patient satisfaction, and psychological changes were recorded.

RESULTS

Bone augmentation of the jaw was successful and vascularized grafts provided an additional vascular supply in compromised irradiated tissue. Rehabilitation was successful in all of the patients after loading. Thirty-eight dental implants failed, and 35 implants were removed. The success rate of the implants was 93.6 % for 10 years after loading. It was not a significant difference in implant success rate between the HBO group and the other groups. The prosthodontic maintenance results and complication rates showed that patients required intervention 0.19 times per year. All patients were satisfied with the oral restoration results.

CONCLUSION

The restoration of oral function in radiotherapy patients with tumor resection using implant-supported prostheses is a viable treatment option.

CLINICAL RELEVANCE

Either alone or in combination with HBO, dental implant-supported prostheses can be used an effective therapeutic approach for irradiated patients with oral function reconstruction.

Implant survival in 1- versus 2-implant mandibular overdentures: a systematic review and meta-analysis

OBJECTIVE

This systematic review was performed to compare the survival of 1- vs. 2-implant overdentures (IODs) in the edentulous mandible.

MATERIALS AND METHODS

Manual and electronic database (PubMed, EMBASE and CENTRAL) searches were performed to identify scientific articles, published in English, reporting on mandibular IODs utilizing unsplinted attachments. Studies were included if they were prospective human studies reporting on two-piece microrough surface implants with a diameter ≥3 mm. Data were extracted by two independent investigators, and an overall inter-investigator kappa score was calculated. A meta-analysis was performed on the included comparative studies.

RESULTS

The search shortlisted 30 prospective studies for data extraction and statistical analysis. The included studies comprised of only two randomized controlled trials (RCTs) comparing 1- vs. 2-IODs, and a further 28 prospective studies. The kappa score calculated was between 0.86 and 1 for the various parameters. One RCT favored 1-IODs (RD: 0.08, 95% CI: 0.01, 0.14) while the other favored 2-IODs (RD:-0.04, 95% CI: -0.27, 0.19). However, the overall random effects model did not reveal a significant risk difference (RD) for implant failure between the two interventions (I(2) = 36.6%, P = 0.209; RD: 0.05, 95% CI: -0.07, 0.18).

CONCLUSIONS

The results of this meta-analysis conclude that the postloading implant survival of 1-IODs is not significantly different from 2-IODs. However, the existing scientific evidence in the literature in terms of prospective comparative studies is scarce. Hence, before recommending the 1-IOD as a treatment modality, long-term observations are needed and a larger range of functional, prosthodontic, and patient-centered outcome measures should be considered.

Immediate loading of two freestanding implants placed by computer-guided flapless surgery supporting a mandibular overdenture with magnetic attachments

PURPOSE

The present article describes a novel clinical procedure for mandibular overdentures supported by two freestanding implants loaded immediately after placement via computer-guided flapless surgery.

METHODS

A conventional acrylic complete denture was fabricated, and CT scans obtained using the denture as a radiographic guide. Preoperative computer-assisted planning was performed using commercially available software, permitting simulation of implant placement at optimal positions. Using simulation data, a surgical guide was manufactured and used during surgery. The surgical guide was placed and local anesthesia injected for drilling of anchor pins to stabilize the surgical guide. The drilling protocol for each osteotomy site achieved an insertion torque greater than 35 Ncm. Immediately after implant placement, a keeper of the magnetic attachment was connected to each implant, and the magnetic assembly incorporated into the denture. The mucosal surface of the denture around the magnet was relieved to avoid excessive tissue pressure. The patients were instructed to wear the denture in place continually for the following 7 days. After six months of healing and follow-up, a final denture with a metal framework may be fabricated if necessary.

CONCLUSION

A novel treatment protocol for immediately loaded implant-supported mandibular overdentures is described in detail. The protocol ensures secure precise and safe implant placement, successful osseointegration, and immediate improvement of oral health-related quality of life for patients with unstable complete dentures.

Patients' expectations, satisfaction, and quality of life with immediate loading protocol

OBJECTIVES

To examine patients' expectations, the level of satisfaction, and the oral health-related quality of life (OHRQoL) with regard to the implants' immediate loading protocol (ILP) in edentate individuals.

METHODS

This pilot trial used a pre-post design to assess patient-centered outcomes in 18 edentate individuals (mean age 62.4 ± 7.7 years) who have received a 2-implant (unsplinted) mandibular overdenture through an ILP. Visual analog scales, the McGill denture satisfaction questionnaire, and the oral health impact profile (OHIP-20) questionnaire were used to evaluate patients' expectations, satisfaction, and OHRQoL at baseline, 2 weeks, 1 month, and 4 months after surgery. Personality trait and socio-demographic information were obtained using the revised NEO personality inventory and a self-administered questionnaire, respectively. Non-parametric methods and Brunner-Langer approach were used to analyze the data.

RESULTS

The participants had a wide range of expectations regarding the ILP. Expectations included short-term positive impact on aesthetics (83.3%) and social life (55.7%), as well as negative effects on comfort (5.6%), the ability to chew (11.1%), and the ability to clean the lower denture (11.1%). The ILP satisfied 94.4% of the participants, regardless of socio-demographic and personality profiles. There was a statistically significant improvement in overall satisfaction, comfort, perceived aesthetics, stability of the overdenture, and ability to chew from baseline to 2-week, 1-, and 4-month follow-up (P < 0.001). There was 100% agreement among patients on recommending this procedure to others. There was a statistically significant decrease in the total OHIP scores and all its domains (P < 0.001) from baseline to 2 weeks. These differences remained statistically significant at 4-month follow-up. The ILP improved patients' OHRQoL, regardless of the implant loss, the socio-demographic characteristics, and personality traits.

CONCLUSIONS

The ILP of two unsplinted implants with a mandibular overdenture significantly improved satisfaction and short-term OHRQoL, and appears to meet expectations in edentulous elders. There was 100% agreement among patients on recommending this procedure to others.

Immediate loading: from biology to biomechanics. Report of the Committee on Research in fixed Prosthodontics of the American Academy of fixed Prosthodontics

One of the key issues of modern implant rehabilitation is the overall shortening of treatment time. High survival rates for immediately loaded implants have been reported in many but not all treatment modalities. In recent years, considerable evidence for the successful immediate loading outcome has been documented in both animal and human studies. The mechanical force generated by immediate loading may explain the favorable biologic response of bone and surrounding tissue when the design is biomechanically sound. However, in certain treatment modalities, including but not limited to immediately placed maxillary anterior single implants, immediately placed single molar implants, unsplinted implants in overdentures, and implants in maxillary anterior partial fixed dental prostheses, loading dental implants indiscriminately and immediately is not safe because of potentially unfavorable stress distribution and a negative cellular response under such high stress during early healing.

Prospective study of treatment outcome of implant retained mandibular overdenture: Two years follow-up

Aims:

The aim of this study is to evaluate the treatment outcome of immediately loaded Implants in the interforaminal region of anterior mandible.

Materials and Methods:

A total of 15 completely edentulous patients aged between 50 and 70 years were selected satisfying certain inclusion and exclusion criteria. Two implants were placed in 33 and 43 region (B and D location) and the implants were loaded immediately by mandibular overdenture retained with O-ring attachments. The implants were evaluated for various clinical parameters at 6 months, 1 year, 1.5 years, and 2 years intervals after initial placement.

Results:

There was increased marginal bone loss around implants during the 1^st year after that the bone loss was insignificant. Clinical stability of immediately loaded implants was lower initially for 6 months, but improved by the end of 1^st year. Survival rate for immediately loaded implants was 96.6% at the end of the period of study.

Conclusion:

Immediate loading of interforaminal mandibular implants demonstrated a highly acceptable clinical success at the end of 2 years. However, initially the marginal bone level and clinical stability were significantly lower which showed improvement with time.

Marginal bone resorption around immediate and delayed loaded implants supporting a locator-retained mandibular overdenture. A 1-year randomised controlled trial

The aim of this 1-year study was to evaluate and compare crestal bone loss and clinical outcomes of immediate and delayed loaded implants supporting mandibular overdentures with Locator attachments. In a randomised controlled clinical trial, 36 completely edentulous patients (mean age 59.6 years) who desired to improve the stability of their mandibular dentures were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible after a minimal flap reflection. Implants were loaded by mandibular overdentures either 3 months (delayed loading group, G1) or the same day (immediate loading group, G2) after implant placement. Locator attachments were used to retain all overdentures to the implants. Peri-implant vertical (VBL) and horizontal (HBLO) bone losses and clinical parameters [plaque scores (PI), gingival scores (GI), probing depths (PD) and implant stability (ISQ)] were assessed at time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. After 12 months of overdenture insertion, two implants (5.5%) failed in G2. Vertical bone loss was significantly higher in G2 compared with G1, while HBLO demonstrated insignificant differences between groups. All clinical parameters (PI, GI, PD and ISQ) did not differ significantly between groups. Vertical bone loss was significantly correlated with PD and HBLO. Immediately loaded two implants supporting a Locator-retained mandibular overdenture are associated with more vertical bone resorption when compared to delayed loaded implants after 1 year. Clinical outcomes do not differ significantly between loading protocols.

Implant-retained overdentures: a review

Implant-retained overdentures represent a treatment option for many patients unable to tolerate conventional dentures. They may be specifically indicated in patients with altered anatomy, neuromuscular disorders, a pronounced gag reflex or severe residual ridge resorption. This article discusses the different ways in which implant overdentures can be retained, outlines some of the clinical stages involved in planning and providing these prostheses, and highlights long-term maintenance requirements associated with implant-retained overdentures.

CLINICAL RELEVANCE

Patients with implant-retained overdentures are likely to present in general dental practice. Practitioners should be aware of issues associated with the design, treatment planning and maintenance of these prostheses.

An in vitro investigation into retention strength and fatigue resistance of various designs of tooth/implant supported overdentures

Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440 and 2880 insertion and removal cycles. During the tensile test a cross-head speed of 10 mm/min was applied. Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey's tests between groups and cycles periods. The results of fatigue tests showed a 50% reduction in retention force in the subgroups with flexible attachments. A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF. The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention. Furthermore, the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces.

Retention force of plastic clips on implant bars: a randomized controlled trial

OBJECTIVES

Retention of overdentures is important for patients' satisfaction. The study tested whether the clinical performance of retentive clips made of poly-ether-ether-ketone (PEEK) is superior to those made of poly-oxy-methylene (POM).

METHODS

A total of 30 patients received complete dentures with round bars (SFI-Bar) on two implants in a chairside technique. Two types of clip matrices (PEEK/POM) were used in a split-mouth technique. Retention forces were measured separately for both materials at baseline when the dentures were inserted and after 1, 3 and 6 months. The measurement was performed extraorally and intraorally by using a measuring stylus equipped, respectively, with an opposing matrix or bar part. Simultaneously, at each point in time the patient and the dentist judged the retention either to be good, or to be too high or too low. Statistical analysis involved performance of global non-parametric testing of dependence of retention force on time and material was performed with Brunner-Langer model; non-parametric 95% confidence intervals (CIs) were calculated.

RESULTS

At baseline the median force for POM matrices was 6.89N (95% CI: 6.50-8.21) and for PEEK matrices 7.17N (95% CI: 6.97-7.93). After 6 months, the retention of POM decreased to 5.53N (95% CI: 4.81-7.00) and of PEEK to 6.42N (95% CI: 5.15-7.51). The retention force changed significantly over time (P = 0.004) without differences between POM and PEEK (P = 0.135). No significant alteration of the retention force over time was measured at the bar (P = 0.289). Retention was estimated to be good with 90% at baseline and with 80% after 6 months, equally by patients and dentist.

CONCLUSIONS

POM as well as PEEK material fulfills the requirements of retentive clips on round bars.

Seven-year follow-up results of TiUnite implants supporting mandibular overdentures: early versus delayed loading

BACKGROUND AND PURPOSE

Implant-supported mandibular overdentures have recently become a popular treatment alternative for edentulous patients desiring increased retention of complete dentures. The goal of this study was to evaluate and present treatment outcomes of mandibular overdentures retained by two unsplinted, early-loaded implants and compare these results with those for delayed-loaded implants.

MATERIAL AND METHODS

Twenty-six edentulous patients had two interforaminal implants placed with a one-stage protocol. The patients were each treated with a mandibular overdenture supported by ball abutments. In the test group, the overdenture was loaded 1 week after surgery and in the control group, the overdenture was loaded 3 months after surgery. Standardized clinical and radiographic parameters were recorded at surgery, and after 3, 6, 12, and 18 months, and 2, 3, 4, 5, and 7 years.

RESULTS

Because two patients did not make the 7-year recall, only 24 patients (48 implants) were evaluated in this study. No implants were lost, and 1.31 ± 0.2 mm marginal bone resorption was noted for all implants after 7 years. Implant stability measurements, clinical peri-implant parameters and marginal bone levels exhibited no statistically significant differences between the two groups over 7 years.

CONCLUSION

The results of this clinical trial show that there is no significant difference in the clinical and radiographic outcomes of patients treated with mandibular overdentures supported by TiUnite implants that are either early or delayed loaded.

Immediate loading of mandibular overdentures supported by unsplinted direct laser metal-forming implants: results from a 1-year prospective study

BACKGROUND

At present, only some studies have dealt with immediate loading of unsplinted implants supporting mandibular overdentures. The aim of this prospective study is to evaluate treatment outcomes of mandibular overdentures supported by four one-piece, unsplinted, immediately loaded, direct laser metal-forming (DLMF) implants by assessing implant survival rate, implant success, marginal bone loss, and prosthetic complications.

METHODS

A total of 96 one-piece DLMF implants were inserted in the edentulous mandible of 24 patients. Four implants were placed in each edentulous mandible. Immediately after implant placement, a mandibular overdenture was connected to the implants. At 1-year follow-up, clinical, radiographic, and prosthetic parameters were assessed. Success criteria included absence of pain, suppuration, and implant mobility; absence of continuous peri-implant radiolucency; and distance between the implant shoulder and the first visible bone contact <1.5 mm.

RESULTS

After a 1-year loading time, the overall implant survival rate was 98.9%, with only one implant lost. Among the surviving 95 implants, two did not fulfill the success criteria; therefore, the implant success rate was 97.8%. The mean distance between the implant shoulder and the first visible bone contact was 0.28 ± 0.30 mm (95% confidence interval, 0.24 to 0.32). Some prosthetic complications were reported.

CONCLUSION

Based on the present results and within the limits of this study, the immediate loading of four unsplinted DLMF implants by means of ball attachment-supported mandibular overdentures seems to represent a safe and successful procedure.

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.

Loading protocols for mandibular implant overdentures: a systematic review with meta-analysis

BACKGROUND

Mandibular overdentures are a successful treatment option for the edentulous patients with long-term predictable outcomes, using conventional loading protocols. Currently, both early and immediate loading protocols for mandibular implant overdentures are prevalent in the literature.

PURPOSE

A systematic review and meta-analysis of the current published literature on comparative studies using conventional versus either early and/or immediate loading protocols for mandibular implant overdentures.

MATERIALS AND METHODS

The review was carried out in accordance with the QUOROM (Quality of Reporting of Meta-Analyses) guidelines. The PICO (Population, Intervention, Comparisons, Outcomes) format was used in conjunction with predefined inclusion criteria. A literature search of PubMed (1969-October 2008), EMBASE (1998-October 2008), the Cochrane Database of Systematic Reviews, and the Cochrane Controlled Trial Register was conducted. In addition, hand searching through refereed dental journals was also performed for the years 2000 to 2008. The meta-analysis was conducted by using the MIX software v.1.7 (Kitasato Clinical Research Center, Kanagawa, Japan).

RESULTS

A total of 191 studies were identified through the electronic search. After full-text screening and cross-matching with the predefined inclusion criteria, only 10 studies with a minimum follow-up of 2 years were eligible for inclusion in this review. Of the 10 included studies, seven have compared the outcome of conventional versus early loading of implants supporting mandibular overdentures. The remaining three studies, on the other hand, compared the outcome of conventional versus immediate loading. The meta-analysis revealed no significant difference in the outcome between conventional and either early (p = .72) or immediate (p = .08) loading of implants supporting mandibular implant overdentures.

CONCLUSIONS

Short-term outcomes of early or immediate loading protocols for mandibular implant overdentures achieved comparable success to conventional loading ones. No evidence was found of long-term studies to support or refute either early or immediate loading protocols for mandibular implant overdentures.