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

An alternative method for the rapid verification of the three-dimensional adaptation of splinted implant-supported crowns

Fit accuracy is crucial for the clinical success of implant-supported prostheses. Traditionally, radiographs have been used to assess the marginal fit in 2 dimensions. Three-dimensional (3D) evaluation based on optical scanning techniques requires additional software programs and procedural steps. This article describes an alternative workflow for the rapid verification of the 3D fit of splinted implant-supported crowns. First, the abutments and splinted crowns were positioned onto a printed cast and scanned, with the data exported as a reference. Following the intraoral placement of the abutments and the splinted crowns, an additional scan was made and compared with the reference data to calculate deviations directly within the intraoral scanner. This protocol simplifies the fit evaluation process and provides rapid results, thereby enhancing efficiency and saving time.

Efficacy of immediate loading compared to conventional loading in implant-supported removable prostheses: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the efficacy of two different loading methods in implant-supported removable prostheses (partial dentures and full-maxillary dentures).

METHODS

As of August 2023, three electronic databases and nine oral implant-related journals had been searched. Only randomised controlled trials (RCTs) that compare immediate loading with conventional loading in implant-supported removable prostheses were included. The primary outcome was the implant survival rate. At the same time, a meta-analysis of bone-level changes was performed. Cochrane risk-of-bias tool for randomised trials (RoB 2) was used to evaluate the risk of bias in the included trials.

RESULTS

A total of 16 RCTs were included, including 543 participants with 1595 implants. The included trials compared immediate loading and conventional loading in implant-supported removable prostheses. Regarding implants as the statistical unit, the immediate loading group had a statistically significant lower survival rate (RR = 0.950; 95% confidence interval [CI], (0.926, 0.974); P = 0.027; I² = 47%). When patients were regarded as statistical units, a statistically significant lower survival rate was also observed in the immediate loading group (RR = 0.929; 95% CI, (0.897, 0.961); P = 0.590; I² = 0%). When we analysed the bone level changes, a statistically significant decrease was observed in bone level in the immediate loading group compared with the conventional loading group (weighted mean difference [WMD] = -0.127; 95% CI, (-0.195, -0.059); P < 0.00001).

CONCLUSION

Lower implant survival rates and a decrease in marginal bone level was observed compared to immediate loading with conventional loading.

Impact of adding zirconium oxide nanoparticles to the 3D printable acrylic resin base material for implant-retained overdentures: A clinical comparative parallel study

STATEMENT OF PROBLEM

Three-dimensionally (3D) printed acrylic resin base materials have been adopted in prosthetic dentistry. However, their mechanical and biological properties require improvement.

PURPOSE

The purpose of this clinical study was to evaluate the effect of adding zirconium oxide nanoparticles to a 3D printable acrylic resin base material for a 2-implant-retained complete mandibular overdenture in terms of peri-implant tissue health, surface roughness, and biofilm formation.

MATERIAL AND METHODS

Twenty edentulous patients were enrolled in this clinical parallel study. All patients received maxillary complete dentures opposing a 2-implant-retained mandibular overdenture. The participants were randomly divided into 2 equal groups according to the mandibular overdenture base material, nonmodified 3D printable acrylic resin (control group) or 3D printable acrylic resin base material modified with 3.0 wt% zirconium oxide nanoparticles (study group). Peri-implant tissue health and surface roughness were measured immediately at the insertion of the mandibular overdenture (T0), after 3 months (T1), and after 6 months (T2). Microbiological assessment of the denture base was done after 1 week, 1 month, 3 months, and 6 months of overdenture use. The data were analyzed using a statistical software program. The Wilcoxon signed-rank test, paired t test, and Fisher exact test were used to compare distributed data. The Mann Whitney U test and repeated measures ANOVA test were used to compare distributed data at different times (α=.05).

RESULTS

The gingival index (GI), plaque index (PI), probing depth (PD), and surface roughness values at the baseline, 3 months, and 6 months were statistically higher with the nonmodified compared with the modified group (P=.001). Regarding the microbiological analysis, the nonmodified group also had a statistically higher mean bacterial and Candida albicans count than the modified group (P<.05). No significant increase in the bacteria was found in the nonmodified group with time (P=.252), but, for the modified group, a statistically significant decrease in bacteria count was found with time (P<.001).

CONCLUSIONS

Adding zirconium oxide nanoparticles to a 3D printable acrylic resin base material was found to be promising. This addition improved the peri-implant tissue health and decreased surface roughness and biofilm formation.

Assessment of a novel electrochemically deposited smart bioactive trabecular coating (SBTC®): a randomized controlled clinical trial

OBJECTIVES

A randomized controlled clinical trial of dental implants was conducted to compare the clinical properties of a novel electrochemically deposited calcium phosphate coating to those of a common marketed surface treatment.

MATERIAL AND METHODS

Forty implants of the same brand and type were placed in 20 fully edentulous participants requiring mandibular implantation. The two study groups were defined by the surface treatment of the implants. 20 implants in the control group were coated via a commercial electrochemical surface treatment that forms a mixture of brushite and hydroxyapatite, while the remaining 20 in the test group were coated with a novel electrochemical Smart Bioactive Trabecular Coating (SBTC®). A split-mouth design was employed, with each participants receiving one control implant in one mandibular side and a test implant in the other. To mitigate potential operator-handedness bias, control and test implants were randomly assigned to mandibular sides. All cases underwent digital planning, implant placement with a static surgical guide, and participants received locator-anchored full-arch dentures. The primary outcome was implant stability (measured using Osstell ISQ) assessed at insertion, loading, and then 3 months, 9 months, and 2 years post-insertion. The secondary outcome was bone level change (in millimeters) over the 2-year observation period. Oral health-related quality of life (OHRQL) was monitored using the OHIP-14 questionnaire. Complications and adverse events were recorded.

RESULTS

Successful osseointegration and implant stability were achieved in all cases, allowing loading. ISQ values steadily increased throughout the observation period. While no significant differences were observed between the SBTC® and control coatings, the test group exhibited a higher ISQ gain. Bone resorption was somewhat lower in the SBTC® but not significantly so. Patients' OHRQL significantly improved after denture delivery and remained stable throughout the follow-up. No complications or adverse events were observed.

CONCLUSIONS

Based on the study results, we conclude that the new surface treatment is a safe alternative to the widely used control surface, demonstrating similar osseointegrative properties and time-dependent bone level changes. Further research may explore the broader implications of these findings.

TRIAL REGISTRATION

The study is registered on clinicaltrials.gov under the identifier ID: NCT06034171.

Vertical versus angled immediately loaded implants for assisting maxillary overdentures with locator attachments: A preliminary results of one-year randomized clinical trial

OBJECTIVES

This study aimed to evaluate the clinical outcomes and patient satisfaction of 4-implant-assisted maxillary overdentures using two different designs.

MATERIALS AND METHODS

Thirty edentulous participants received four implants in the maxillary ridge. The patients were randomly divided into two equal groups: (1) the control (CG, Vertical) group (n = 15); participants received four vertical implants with straight locator attachments to retain maxillary overdentures, and (2) the study (SG, Angled) group (n = 15); participants received four angled implants with angled locator attachments to retain maxillary overdentures. Peri-implant tissue health [Plaque (PL) and gingival (GI) indices, pocket depth (PD), implant stability (ISQ) and crestal bone loss (CBL)] were evaluated after denture insertion (T0), 6 (T6), and 12 (T12) months after insertion. Patient satisfaction was evaluated using a visual analog scale (VAS) after 12 months.

RESULTS

The survival rates were 96.7% and 95% for the control and study groups respectively. PL, GI, and PD increased significantly in both groups with the passage of time. No significant difference in PL, GI, PD, and ISQ was noted between groups at all observation times. CG showed higher CBL than SG at T12. For the VAS results, there was no significant difference between groups. SG recorded significantly higher satisfaction regarding comfort with maxillary and mandibular dentures, retention of mandibular dentures, oral hygiene, the ability to chew hard food, and occlusion than CG.

CONCLUSION

Within the limitations of this study, angled implants with angled locator attachments may be recommended to retain maxillary overdentures opposing intact dentition or fixed restoration as it was associated with improvements of several parameters of peri-implant tissue health and patient satisfaction compared to vertical implants with straight locator attachments.

Patients experience and satisfaction with immediate loading of implant-supported overdentures - A qualitative study

OBJECTIVES

To explore the perspectives and experiences of edentate individuals in regard to the immediate-loading protocol of an implant-supported overdenture.

METHODS

A qualitative approach and interpretive description methodology was used. Seventeen edentate individuals (mean age: 61.9 ± 6.6 years) who received implant-supported overdentures through an immediate-loading protocol participated. Audio-recorded, semi-structured, in-depth interviews, each with a 60-90-minute duration, were conducted by two trained interviewers. The interview guide was developed based on Perneger's Detailed Model. Qualitative data were analyzed using a thematic approach including interview debriefing, transcript coding, data display, inductive thematic analysis, and interpretation.

RESULTS

Three main themes emerged from the interviews: patient awareness and engagement with treatment, experience-shaped expectations, and immediate gratification. All patients expressed satisfaction with the treatment. Providing detailed information, good communication, and accessibility of the dental care provider had a significant impact on patient satisfaction with prosthetic care. Patients highlighted that the high cost of implant therapy was the major barrier to receiving this treatment in the private sector and perceived dental insurance coverage as a facilitator of this process.

CONCLUSIONS

Study findings conclude that patient awareness about immediate-loading protocol improved their treatment engagement, and patient satisfaction with the treatment outcomes was higher than anticipated. The satisfaction was primarily related to prosthesis stability, receiving the prosthesis the same day, and low cost of treatment. Patients' positive experience and satisfaction with the immediate-loading protocol indicate that this treatment modality should be considered in treatment planning for edentate individuals.

CLINICAL SIGNIFICANCE

The perceptions and experiences of edentulous patients gathered in this study highlight their satisfaction with immediate loading for implant-supported overdentures. This therapeutic modality can be considered a viable option in treatment planning for edentulous individuals.

Comparison between Two Design Concepts of Four Implants Placement Used to Support Telescopic Mandibular Overdenture: A Prospective Study of Implant Marginal Bone Height Changes

AIM

The aim of this present study was to compare two placement designs of four implants used to support a telescopic mandibular overdenture regarding the marginal bone height changes.

MATERIALS AND METHODS

Each patient received four implants. Two anterior implants were installed vertically in the canine area. Patients were randomized into two groups according to the direction of posterior implants installed in the premolar area. Group I: where the implants were installed vertically parallel to the anterior implants and group II: where the implants were installed 30^º distally. The implants were delayed loaded with a telescopic mandibular overdenture. The implant's marginal bone changes were evaluated after 6 and 12 months of overdenture insertion.

RESULTS

Mean marginal bone loss of anterior implants showed a statistically significant difference between both groups. The vertically parallel posterior implants in group I showed statistically significant higher marginal bone loss than posterior implants in group II after follow-up periods. The 30^º distally tilted posterior implants maintained the implant marginal bone after 12 months of overdenture insertion.

CONCLUSION

Rehabilitation of the edentulous mandible with telescopic overdenture supported by four parallel implants is a promising successful treatment option.

CLINICAL SIGNIFICANCE

Tilting the posterior implants will improve the anteroposterior spread that in turn increases the support and the survival rate of the implants. Also, using this technique gives us an opportunity to use fewer implants.

Marginal Bone Loss and Treatment Complications with Mandibular Overdentures Retained by Two Immediate or Conventionally Loaded Implants—A Randomized Clinical Trial

This study aimed to assess marginal bone loss and complication rates of mandibular overdentures retained on two implants with conventional and immediate loading protocols. Twenty edentulous patients were treated with mandibular two-implant-retained overdentures and new complete maxillary dentures. In one half of the sample, the implants were loaded immediately by VulkanLoc® abutments. In the counterpart group, these abutments were connected to the implants two months after implant placement (conventional protocol). Treatment outcomes were evaluated at 2, 6, and 12 months after implant placement. According to the pre- and post-insertion radiographs, there was a mean marginal bone loss of 0.25–0.59 mm (CI 95%) after 13.4 ± 2.1 months of follow-up. There were no significant differences between groups. The failure rate (percentage of implants failing per year) was slightly higher in the conventional loading group (14.0 ± 32.7%) than in the immediate loading group (8.3 ± 18.0%). The findings of the present study suggested that there were no differences in marginal bone loss observed at one year for immediately loaded implants (0.40–0.39 mm) versus conventionally loaded implants (0.44- 0.36 mm) placed for the retention of mandibular overdentures. There were no differences in primary and secondary stability of immediately loaded versus conventional implants; however, in the conventional loading group, stability increased significantly between implant placement compared at both 6 and 12 months post-placement.

Peri-implant tissue health and patient satisfaction of vertical versus inclined posterior implants used to support overdentures with bar attachments. A one-year randomized trial

INTRODUCTION

This study aimed to evaluate peri-implant tissue health and patient satisfaction of vertical and inclined posterior implants for mandibular bar overdentures.

MATERIALS AND METHODS

Thirty edentulous participants received four implants in the interforaminal area of the mandible. The patients were randomly assigned into two equal groups; (1) vertical group (control): all implants were inserted vertically parallel to each other. Inclined group (study): the anterior implants were placed vertically, and the posterior implants were tilted 30° distally. Hader bar attachment with two 7 mm-distal cantilevers (vertical group) and without cantilevers (inclined group) was used to connect the implants to mandibular overdentures. Peri-implant tissue health (Plaque [PL] and gingival [GI] indices, pocket depth [PD], and crestal bone loss [CBL]) were evaluated after denture insertion (T0), 6 (T6), and 12 (T12) months after insertion. Patient satisfaction was evaluated using a visual analog scale after 12 months.

RESULTS

At T12, the vertical group showed significantly higher PL, PD, and CBL than the inclined group for anterior (p < 0.037) and posterior (p < 0.017) implants. The vertical group showed significantly higher GI than the inclined group for anterior implants (p = 0.003), and the inclined group showed significantly higher GI than the vertical group for posterior implants (p = 0.016). The inclined group showed significantly higher scores for general satisfaction (p = 0.049), prosthesis as a part of you (p = 0.013), appearance (p < 0.001), stability (p = 0.002), ease of cleaning (p < 0.001), and comfort (p = 0.001) than the vertical group.

CONCLUSION

Inclined posterior implants used to support mandibular bar overdentures are recommended than vertical implants, as it was associated with improved patient satisfaction and peri-implant tissue health.

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.

Immediate loading protocols increase the risk of failure of implants placed by fully guided surgery in partially edentulous jaws: A randomized clinical trial

AIM

To compare the 1-year outcomes of immediate loading (IL) and delayed loading (DL) protocols for implants placed by fully guided surgery in partially edentulous jaws.

MATERIALS AND METHODS

This study included 72 patients who received implant surgery with either IL (93 implants, 36 patients) or DL (94 implants, 26 patients). A prefabricated provisional prosthesis was delivered immediately for the IL group (86 implants, 32 patients) with the exception of 4 subjects in whom an initial torque of >20 Ncm and an implant stability quotient of >65 were not achieved, while all DL-group implants were loaded after 3 months. The 1-year implant survival rate estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and the marginal bone loss (MBL) estimated by cone-beam computed tomography were statistically evaluated (p < 0.05).

RESULTS

The survival rate in the DL group was 100% at both patient and implant levels. With only 26 subjects with 78 implants surviving in the IL group, the survival rates were 69.4% and 83.4% at the patient and implant levels, respectively, in the ITT analysis, and 78.1% and 90.2% in the PP analysis. All intergroup differences in survival rates were statistically significant (p < 0.01). MBL was less than 0.1 mm in both groups (p > 0.05).

CONCLUSIONS

IL for implants placed by fully guided surgery in the partially edentulous jaws increased the probability of failure compared to 3-month DL. Regardless of when loading occurred, marginal bone levels remained stable.

Masticatory performances and maximum occlusal forces of immediate and conventional loaded two-implant supported overdentures retained by magnetic attachments: preliminary study of randomized controlled clinical trial

Background

The appropriate loading protocol to improve masticatory performance (MP) is still unclear in elderly patients and two-implant overdentures (2-IODs) wearers. This study aimed to compare the long-term MP and maximum occlusal force of immediate loading (IL) and conventional loading (CL) of 2-IODs retained by magnetic attachments. Nineteen edentulous patients were randomly assigned to either an IL (n=10) or CL group (n = 9). In the IL group, the implant was loaded on the same day as insertion, whereas it was loaded 3 months after insertion in the CL group. Magnetic attachments were used to retain all overdentures to the implants. MP, measured by a piece of color-changeable chewing gum and a gummy jelly test, and maximum occlusal force, measured using an occlusal force measuring device, were assessed in both groups at baseline and at 3-, 4-, and 5-year follow-ups.

Results

No significant differences were observed in the MP and the maximum occlusal force between the IL and CL groups at any time point. However, a significantly higher MP was observed at the 3-year time point in the IL group (P = 0.036). The maximum occlusal force revealed a significant correlation with MP, both with the color-changeable chewing gum and gummy jelly at 5 years.

Conclusion

After long-term observation, no significant differences in MP and maximum occlusal force were observed between the IL and CL groups. However, compared to pre-implant insertion of the complete denture, the MP in the IL group significantly improved at 3 years. Furthermore, the maximum occlusal force was significantly correlated with MP at 5 years.

Trial registration

UMIN, UMIN000009889. Registered on 28 January 2013.

Effects of immediate and delayed loading protocols on marginal bone loss around implants in unsplinted mandibular implant-retained overdentures: a systematic review and meta-analysis

BACKGROUND

Immediate loading has recently been introduced into unsplinted mandibular implant-retained overdentures for the management of edentulous patients due to their increasing demand on immediate aesthetics and function. However, there is still a scarcity of meta-analytical evidence on the efficacy of immediate loading compared to delayed loading in unsplinted mandibular implant-retained overdentures. The purpose of this study was to compare the marginal bone loss (MBL) around implants between immediate and delayed loading of unsplinted mandibular implant-retained overdentures.

METHODS

Randomized controlled trials (RCTs), controlled clinical trials (CCTs), and cohort studies quantitatively comparing the MBL around implants between immediate loading protocol (ILP) and delayed loading protocol (DLP) of unsplinted mandibular overdentures were included. A systematic search was carried out in PubMed, EMBASE, and CENTRAL databases on December 02, 2020. "Grey" literature was also searched. A meta-analysis was conducted to compare the pooled MBL of two different loading protocols of unsplinted mandibular overdentures through weighted mean differences (WMDs) with 95% confidence intervals (95% CIs). The subgroup analysis was performed between different attachment types (i.e. Locator attachment vs. ball anchor). The risk of bias within and across studies were assessed using the Cochrane Collaboration's tool, the Newcastle-Ottawa scale, and Egger's test.

RESULTS

Of 328 records, five RCTs and two cohort studies were included and evaluated, which totally contained 191 participants with 400 implants. The MBL of ILP group showed no significant difference with that of DLP group (WMD 0.04, CI - 0.13 to 0.21, P > .05). The subgroup analysis revealed similar results with Locator attachments or ball anchors (P > .05). Apart from one RCT (20%) with a high risk of bias, four RCTs (80%) showed a moderate risk of bias. Two prospective cohort studies were proved with acceptable quality. Seven included studies have reported 5.03% implant failure rate (10 of 199 implants) in ILP group and 1.00% failure rate (2 of 201 implants) in DLP group in total.

CONCLUSIONS

For unsplinted mandibular implant-retained overdentures, the MBL around implants after ILP seems comparable to that of implants after DLP. Immediate loading may be a promising alternative to delayed loading for the management of unsplinted mandibular implant-retained overdentures. PROSPERO registration number: CRD42020159124.

Effect of 2-implant mandibular overdenture with different attachments and loading protocols on peri-implant health and prosthetic complications: A systematic review and network meta-analysis

STATEMENT OF PROBLEM

A systematic review of the effect of different overdenture attachments with different loading protocols on peri-implant health is lacking.

PURPOSE

The purpose of this systematic review and network meta-analysis was to evaluate the effect of different overdenture attachments with delayed or immediately loaded 2-implant-retained mandibular overdentures on peri-implant tissue health.

MATERIAL AND METHODS

A comprehensive search of the PubMed, EMBASE, and Cochrane library was conducted to identify eligible randomized controlled trials (RCTs). The outcomes were marginal bone loss, probing depth, plaque index, bleeding on probing, implant survival rate, and prosthetic complications. The Bayesian network meta-analysis accompanied by a random effect model and 95% credible intervals was calculated.

RESULTS

Sixteen RCT (n=599 participants receiving 1198 dental implants) were included. Five common overdenture attachment systems with delayed or immediate loading were compared. The difference in marginal bone loss and probing depth was not statistically significant when comparing different overdenture attachments with different loading protocols. The rank probability test showed that bar+ immediate loading ranked highest (63.8%) in terms of marginal bone loss, whereas ball+ delayed loading (73.3%) ranked highest in terms of probing depth. The implant survival rate was 100% for the LOCATOR+ delayed loading, resilient telescopic+ delayed loading, and magnet+ immediate loading; however, bar+ delayed loading, ball+ delayed loading, magnet+ delayed loading, LOCATOR+ immediate loading, ball+ immediate loading, and bar+ immediate loading had survival rates of 99.1%, 98.8%, 96.0%, 94.7%, 93.1%, and 91.2%, respectively.

CONCLUSIONS

All types of overdenture attachment with immediate loading or delayed loading had a similar effect on peri-implant health. Bar+ immediate loading was associated with the least marginal bone loss, whereas ball+ delayed loading showed the least probing depth.

Immediate vs conventional loading of mandibular overdentures: A comprehensive systematic review and meta-analysis of randomized controlled trials

Clinicians treating overdenture patients need to know if immediate loading and conventional loading results in similar outcomes. This study aimed to perform a systematic literature search of studies comparing immediate and conventional loading of mandibular overdentures irrespective of the number of implants and conduct a meta-analysis of implant failure and marginal bone loss (MBL). A literature search of PubMed, ScienceDirect, Ovoid, Springer, and Google Scholar databases was performed for randomized controlled trials (RCTs) comparing immediate vs conventional loading of mandibular overdentures. The primary outcome was implant failure and the secondary outcome was marginal bine loss (MBL). A descriptive analysis was performed for other outcomes. Thirteen trials were included. Only one trial compared the immediate and delayed loading of single implant-supported overdenture. Seven trials used two implants, one trial used three implants while four trials used four implants. Meta-analysis indicated no statistically significant difference in implant failure and MBL between immediate and conventional loading of two-implant and four-implant supported overdentures. Descriptive analysis indicated no difference in peri-implant tissue indices, implant stability, and quality of life outcomes between the two loading protocols.There may be no difference in implant failure and MBL with immediate loading or conventional loading of two and four-implant supported mandibular overdentures. Literature review indicates that there may be no difference in peri-implant tissue indices, implant stability, and QoL outcomes between the two loading protocols. The overall quality of evidence is moderate. Further, adequately powered RCTs are required to strengthen the evidence.

Peri-implant mucosal response to implant-supported overdentures: A systematic review and meta-analysis

OBJECTIVES

To systematically review and evaluate the effects of different types of attachments, implant numbers and loading protocols on the peri-implant mucosa of implant-supported overdentures (ISODs).

BACKGROUND

The impact of peri-implant tissue health on the ISOD treatment outcome is unclear, and current evidence is inadequate on this aspect.

MATERIALS AND METHODS

A systematic literature search for randomised controlled trials or prospective studies was conducted in indexed databases from 1995 to April 2020. The focused question was as follows: How does the peri-implant mucosa respond to implant-supported or implant-tissue-supported complete overdentures based on different types of attachments, implant numbers, and loading protocols, in terms of clinical outcomes achieved [plaque index (PI), gingival index (GI), probing pocket depth (PD) and bleeding index (BI)]? A random- or fixed-effects model was applied to measure the significance of standardised mean differences (SMD) of PD between the groups.

RESULTS

Seventeen studies met the eligibility criteria. The SMD for PD between splinted/bar and unsplinted/stud attachments was 0.10 mm (95% CI: -0.27 to 0.47; P = .60) and between 2- and 4-implant groups was 0.15 mm (95% CI: -0.16 to 0.45; P = .34), which were not statistically significant. Significant difference (P = .003) was observed between immediate/early loading and delayed loading (SMD = 0.46 mm [95% CI: 0.16 to 0.75]).

CONCLUSIONS

Probing depth for the immediate loaded implants was significantly higher than for the delayed loading group. No attachment type, implant number or loading protocol seemed to have a clear advantage over the other, in terms of other peri-implant mucosal outcome measures.

Immediate or delayed loading protocols for two-implant mandibular overdentures: A systematic review and meta-analysis of randomized controlled trials

STATEMENT OF PROBLEM

The immediate loading protocol for 2-implant mandibular overdentures has been widely reported. Nevertheless, the clinical effects reported in different articles are quite different.

PURPOSE

The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to compare the clinical effects of immediate and delayed loading of 2-implant mandibular overdentures.

MATERIAL AND METHODS

The review followed the guidelines of Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). PubMed, Cochrane Library, Web of Science, Embase, Scopus, ScienceDirect, CBM, CNKI, and Wan Fang databases were searched electronically for RCTs published before March 25, 2020. Two authors independently conducted literature screening, quality assessment, and data extraction. The outcomes of interest were implant failure rate, marginal bone loss (MBL), implant stability quotient (ISQ), periotest value (PTV), and patient satisfaction.

RESULTS

A total of 2498 unduplicated records were identified. After full-text analysis, 7 eligible RCTs were included. All studies were followed for at least 12 months, and the meta-analysis was based on this. The meta-analysis showed that the implant failure rate in the immediate group was higher than that in the delayed group, but there was no statistically significant difference (I²=0%; n=7; risk difference [RD]=0.03; 95% confidence interval [CI]=-0.01 to 0.08). The difference of MBL between immediate and delayed loading was not significant (I²=88%; n=6; mean difference [MD]=-0.04; 95% CI=-0.16 to 0.24). Because of the limited articles reporting on ISQ, PTV, and patient satisfaction, no quantitative analysis was conducted for these outcomes.

CONCLUSIONS

Although the implant failure rate was more likely to favor the delayed group, available evidence indicates no statistical difference in implant failure and marginal bone loss between immediate and delayed loading protocols.

Immediately loaded mini-implants supporting mandibular overdentures: A one-year comparative prospective cohort study

BACKGROUND

Little is known about differences between mini-implants and conventional immediately loaded implants for overdentures.

OBJECTIVES

To compare clinical outcomes using two immediately loaded conventional or mini-implants for mandibular overdentures.

MATERIALS AND METHODS

Edentulous patients receiving either conventional (4.1 mm) or mini-implants (2.9 mm or less), based on available bone width were analyzed. All implants were immediately loaded with mandibular overdentures installed using locator attachments. Digital periapical radiographs for measuring marginal bone loss and clinical outcomes (ie, periodontal probing, plaque, and bleeding indices) were assessed at 1, 3, 6, and 12-month follow-up periods.

RESULTS

Fifty patients (25 receiving conventional implants-12 females, mean age of 65.3 ± 7.3 years; and 25 receiving mini-implants-11 females, mean age of 66.8 ± 8.1 years) was analyzed. Peak insertion torque (P = .001) and bone loss (P = .02), as well as change in plaque (P = .02) and bleeding (P = .04) indices at 12 months differed significantly between groups. Furthermore, linear regression revealed the height of the locator as a risk factor for bone loss (P = .038).

CONCLUSIONS

The present findings suggest that two mini-implants are significantly more susceptible to bone loss after immediate loading, for which the height of locator might be considered a risk factor.

Immediate vs conventional loading of Facility-Equator system in mandibular overdenture wearers: 1-year RCT with clinical, biological, and functional evaluation

BACKGROUND

The use of immediate loading (IML) is still poorly explored in elderly patients and implant-retained mandibular overdenture (IMO) wearers. For this reason, more comparisons to conventional loading (CL) are required.

PURPOSE

To evaluate the clinical, biological, functional, and oral health-related quality of life (OHRQOL) influence of CL and IML loading on elders wearing IMO retained by the Facility-Equator system up to 1 year after implant installation.

MATERIAL AND METHODS

Twenty edentulous patients received two narrow diameter implants in the mandible; the loading type (CL or IML) was randomized. The clinical parameters were monitored along with prosthetic events, marginal bone loss (MBL) and bone level change (BLC), implant stability quotients (ISQ), masticatory performance outcomes, and Interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) levels in the peri-implant crevicular fluid during the first year of loading. The OHRQoL was assessed via the Oral Health Impact Profile-EDENT questionnaire. Data were analyzed by the Mann-Whitney, χ² , Wilcoxon paired, and McNemar tests.

RESULTS

After 1 year, MBL, BLC and ISQ were statistically identical (P > .05) in the CL and IML groups. The probing depth at 12 months in the CL group (2.19 mm) was higher than in the IML group (1.29 mm; P ≤ .0001). TNF-α was 33.6% higher in the CL group at 6 months (P = .043), while IL-1β was significantly higher in the IML group up to 6 months. The survival rate was 90% in the CL group and 85% in the IML group; 33 prosthetic events occurred in CL group and 23 in IML group.

CONCLUSIONS

After 12 months, both loading protocols are viable and result in similar clinical, biological, functional, and OHRQOL outcomes. However, IML generates better adaptation of the peri-implant tissues, faster improvement in OHRQoL and fewer prosthetic intercurrences than CL.

Implant loss and crestal bone loss in immediate versus delayed load in edentulous mandibles: A systematic review and meta-analysis

STATEMENT OF PROBLEM

The current trend is to shorten the loading times of dental implants. However, information about the risk of early loss of implants that have been loaded immediately is scant if compared with data available for those conventionally loaded.

PURPOSE

The purpose of this systematic review and meta-analysis was to study immediate (IL) and delayed loading (DL) protocols in edentulous mandibles to determine whether differences exist in implant success and crestal bone loss and to evaluate these possible differences in relation to the type of prosthesis and the splinting of the implants.

MATERIAL AND METHODS

The literature review was conducted in PubMed, Scopus, and the Cochrane Library. Nine randomized clinical trials were included.

RESULTS

The result of a meta-analysis of implant loss before 1 year was 2.63 (95% CI: 1.22, 5.68), favoring the DL control group, while the outcome for crestal bone loss at the observation year was 0.42 (95% CI: -0.35, 1.20), with a tendency toward reduced bone loss for DL.

CONCLUSIONS

The risk of early loss in the IL group was higher than that in the DL group. For removable prostheses and nonsplinted implants, DL was preferred. The quality of scientific evidence significantly favors DL.

Retrospective evaluation of marginal bone loss around implants in a mandibular locator-retained denture using panoramic radiographic images and finite element analysis: A pilot study

BACKGROUND

The follow-up of the peri-implant marginal bone loss is the most important criterion for the determination of implant success.

PURPOSE

The purpose of this study is to measure marginal bone loss using panoramic radiographic images (PRI) of patients treated using a mandibular, two implant-supported, locator-retained denture and to evaluate the compatibility of these findings with those of the finite element analysis (FEA).

MATERIALS AND METHODS

The PRI of patients who had a mandibular, two implant-supported, locator-retained denture were assessed, and the mesial and distal marginal bone loss of both right- and left-sided implants was measured. Mandibular and maxillary models, which have the features of bilateral balanced occlusion, were created. The surfaces of the generated models were converted in a computer-aided design model that could be transferred to the FEA software, and the forces were defined on contacts formed in maximum intercuspation, lateral, and protrusive movement position for bilateral balanced occlusion.

RESULTS

The bone loss in the mesial and distal regions at the right- and left-sided implants was not statistically significant. Higher stresses were formed on the vestibular side under protrusive movement, on the lingual side under maximum intercuspation, on the distolingual side under left unilateral biting, and on the mesiolingual side under right unilateral biting in the FEA.

CONCLUSION

According to FEA, peri-implant bone resorption may be higher in the buccal and palatal regions, implying that panoramic radiographs can be misleading in understanding the amount of peri-implant bone resorption.

Immediate Loading of Unsplinted Implant Retained Mandibular Overdenture: A Randomized Controlled Clinical Study

This clinical study aimed to clinically and radiographically compare the implant survival rate and peri-implant tissue response between immediate and delayed loading protocols for unsplinted implant retained mandibular overdentures. Twenty patients were enrolled to participate in this study. Each subject was randomly assigned to 1 of 2 treatment groups: test group patients' implants (n = 10), which were immediately loaded, and control group patients' implants (n = 10), which were conventionally loaded. Locator abutments were torqued to 15 Ncm at delivery. Attachments were picked up intraorally immediately after implant placement for the test group and at 3 months for the control group, and 3-lb retention inserts were placed. Marginal bone levels based on cone beam computed tomography fixed reference points were recorded at baseline and 12 months. Modified plaque index, gingival index, and implant stability quotients were recorded at baseline, 3 months, and 12 months. After 12 months, implant survival rate was 100% in both groups. Marginal bone levels, keratinized mucosa, modified plaque index, and gingival index were significantly different among the groups at 3- and 12-month intervals, whereas no significant differences were found in implant stability quotients between the groups. The fact that implant survival rate was 100% in both treatment groups suggests that, within the limitations of this study, immediate loading protocol for unsplinted implant retained mandibular complete overdenture is as predictable, safe, and successful as the delayed loading protocol. Implementing the immediate loading protocol for mandibular implant retained overdentures could shorten treatment time, which could lead to better patient's satisfaction.

Peri-implant marginal bone loss rate pre- and post-loading: An exploratory analysis of associated factors

OBJECTIVES

To perform an exploratory analysis of factors influencing annual rates of peri-implant marginal bone loss (RBL) calculated over different time frames, at implants unaffected by peri-implantitis.

MATERIAL AND METHODS

A total of 154 implants from 86 patients were reviewed at 1.6-6.8 years after placement. Marginal bone levels (MBL) were assessed on intraoral radiographs at three time-points: immediately post-placement, time of loading, and least 1-year post-loading. RBLs (mm/year) were computed using these three time frames and corresponding MBL changes as: RBL placement-loading, RBL loading-review, RBL placement-review. Exploratory ordination of three RBLs, corresponding time durations, and 17 background factors were used for visualization. Hierarchical linear mixed-effects models (MEM) with predictor selection were applied to RBL outcomes. The correlation of actual MBL with MBLs predicted by RBL placement-loading and RBL loading-review was tested.

RESULTS

Median RBL placement-loading was 0.9 mm/year (IQR = 2.02), loading-review was 0.06 mm/year (IQR = 0.16), and overall RBL placement-review was 0.21 mm/year (IQR = 0.33). Among-patient variance was highest for RBL placement-loading (SD = 0.66). Longer time predicted lower RBL in all time frames. Shorter time of loading significantly predicted lower RBL placement-review. Augmentation predicted lower RBL placement-loading, while anterior location and older age predicted lower RBLs placement-loading placement-review. Only MBL projected using RBL placement-loading significantly correlated with actual MBL.

CONCLUSIONS

Exploratory analysis indicated RBL varied with the time duration used for calculation in pre- and post-loading, and overall periods. In each period, RBL declined with increasing time. Earlier loading predicted lower overall RBL. Higher pre-loading RBL predicted worse actual bone level.

Assessment of the Effect of Clinical Independent Risk Factors on Marginal Bone Loss in 2-Implant-Supported Locator-Retained Mandibular Overdentures

The objective of this study is to evaluate the effect of clinical parameters of gender, age, implant length, implant diameter, interimplant distance, and locator height on marginal bone loss in 2-implant-supported locator-retained mandibular overdenture prostheses in 6, 12, and 24 recall sessions after loading. Clinical and radiographic data of patients who were treated between January 1, 2014, and January 4, 2018, were retrieved from the archives. The clinical data of gender, age, implant length, implant diameter, and locator height were recorded. The mesial and distal marginal bone levels of all implants and interimplant distances were determined at baseline and at 6-, 12-, and 24-month recall sessions on panoramic radiographs in a computer program. Statistical analysis was used to evaluate the effect of implant length, implant diameter, gender, age, interimplant distance, and locator height on marginal bone loss at the 6-, 12-, and 24-month control evaluations. A total of 57 patients with a mean age of 59.2 ± 9.8 years and 114 implants were included in the study. Among the aforementioned parameters, only the locator height had a major effect on the distal and mesial marginal bone loss (P < .05). A locators with a 4-mm height showed statistically significant distal and mesial marginal bone loss compared with locators with 2- and 3-mm heights in all control periods (P < .05). The locator with a 4-mm height generated more stress compared with locators with 2- and 3-mm heights, leading to marginal bone loss. The absence of oral hygiene evaluation was identified as a limitation of the study. Clinical parameters of gender, age, implant length, implant diameter, and interimplant distance did not seem to affect marginal bone loss in the study population of the current study.

[Oral hygiene maintenance of locator attachments implant overdentures in edentulous population: A longitudinal study]

OBJECTIVE

To investigate the oral hygiene status of edentulous patients with locator attachments implant overdentures (IOD) and to analyze the relationship among daily hygiene behavior, oral hygiene status and peri-implant diseases.

METHODS

Edentulous patients who received IOD treatment with locator attachments from January 2012 to May 2016 were recruited. Clinical and radiographic examinations were conducted to assess the peri-implant tissue status. Modified plaque index (mPLI), sulcus bleeding index (SBI), gingival index (GI), and probing depth (PD) were recorded and peri-implant marginal bone loss (MBL) was measured using paralleling projection technique. Patients' peri-implant oral hygiene maintainence habits were investigated. The correlation between peri-implant diseases and oral hygiene status and behaviors was analyzed.

RESULTS

Fifty patients (125 implants) with an average follow-up time of 22 months (6-54 months) were enrolled. The mean values of mPLI, SBI, and GI were 1.4±1.2, 0.8±0.7, and 0.7± 0.6, respectively. Average PD was (2.2±0.7) mm. Mesial and distal maginal bone resorptions were (1.1±1.1) mm and (0.9±0.9) mm, respectively. The prevalance of mucositis and peri-implantitis of the implants were 49.6% and 0. The prevelance of mucositis in the patients with poor oral hygiene (mPLI≥2) was 11.9 times as much as that of those with adequate oral hygiene (mPLI<1). The patients who performed oral hygiene procedure on attachments at least twice a day achieved much lower mPLI scores than those who cleaned less than twice a day.

CONCLUSION

Oral hygiene condition in the group of patients with implant overdentures was poor, and it contributed to increased risk of peri-implant mucositis. The prevelance of musositis of the paitients with poor oral hygiene was 11.9 times as much as that of those with proper oral hygiene. Patients wearing IOD should pay more attention to the hygiene of the attachments.

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.

Rehabilitation of the edentulous mandible with implant-supported overdentures on telescopic abutments and immediate loading. A controlled prospective clinical study

The rehabilitation of the edentulous mandible with implant-supported overdentures is an established clinical procedure but immediate loading of implants supporting mandibular overdentures has not been equally documented.

AIM

The aim of this prospective clinical study was to evaluate the rehabilitation of the edentulous mandible with immediate loading and implant-supported overdentures.

MATERIALS AND METHODS

10 patients were restored with immediate loading of the implants and 5 with delayed loading. The treatment planning included placement of four implants in the interforaminal area of the mandible. Prefabricated titanium abutments with 4 degrees of conical inclination were fixed on the implants and the telescoping conical caps were connected to the base of the mandibular denture. Bone loss was assessed by comparison of panoramic x-rays at baseline 3, 6, and 36 months by visual observation from clinicians.

RESULTS

A total of 60 implants were restored, 40 with immediate and 20 with delayed loading. The follow-up period ranged from 4 to 10 years with 72 months mean observation time. Prosthetic complications appeared with low frequency and no implant loss occurred during the follow-up period. No statistical significance was observed in the bone loss in the cervical area of the immediate and late loaded implants.

CLINICAL SIGNIFICANCE

The rehabilitation of the edentulous mandible with implant-supported overdentures and telescopic copings is a viable clinical solutions with multiple clinical advantages both for the clinician and the patient. . Immediate loading can be applied in cases where increased initial stability can be achieved. More extended long-term clinical studies with increased number of patients and implants are needed, however, to verify the efficacy of the treatment method.

Effect of implant loading protocols on failure and marginal bone loss with unsplinted two-implant-supported mandibular overdentures: systematic review and meta-analysis

The aim of this study was to compare implant failure and radiographic bone level changes with different loading protocols for unsplinted two-implant-supported mandibular overdentures. An electronic search of two databases (PubMed, Cochrane Library) was performed, without language restriction, to identify randomized controlled trials (RCTs) comparing immediate or early versus conventional dental implant loading protocols for unsplinted two-implant-supported mandibular overdentures. Data were extracted independently by two reviewers. The Cochrane tool was used to assess the quality of included studies. A meta-analysis was performed. Eight RCTs were identified, seven of which were included; one trial was excluded because related outcomes were not measured. Four of the seven studies were considered to have a high risk of bias and three an unclear risk. Meta-analysis revealed no difference between immediate versus conventional or early versus conventional implant loading protocols regarding implant failure (risk difference (RD) -0.02, 95% confidence interval (CI) -0.13 to 0.10; RD 0.09, 95% CI -0.03 to 0.20) or marginal bone loss (mean difference (MD) 0.09, 95% CI -0.10 to 0.28; MD -0.05, 95% CI -0.12 to 0.02) for implants supporting mandibular overdentures. These findings should be interpreted with great caution given the serious numerical limitations of the studies included.

Impact of crestal bone resorption on quality of life and professional maintenance with conventional dentures or Locator-retained mandibular implant overdentures

STATEMENT OF PROBLEM

The influence of the mandibular resorption profile on clinical outcome after converting a conventional complete denture into a Locator-retained implant overdenture is unknown.

PURPOSE

The purpose of this prospective study was to assess the oral health-related quality of life (OHRQoL) and prosthetic maintenance of mandibular overdentures on 2 Locator abutments in relation to the resorption degree of the edentulous mandible.

MATERIAL AND METHODS

Twenty-five participants were treated and classified according to the Cawood and Howell (CAW-H) resorption classification for the resorption profile of the mandible, CAW-H group III-IV (n=14) and CAW-H group V (n=11). Participants received conventional complete dentures (CDs) before implant placement and immediate nonfunctional loading on Locators with a resilient liner. After 3 months, the attachments were functionally activated. Assessments were made using the Oral Health Impact Profile 14 (OHIP-14) questionnaires with existing CDs and new CDs at 1, 3, and 15 months after loading. Prosthetic maintenance (repairs, rebasings, replacement of retention parts) and biological prosthetic aftercare were assessed. For comparison between groups, the Kruskal-Wallis and Mann-Whitney U tests were applied for continuous and ordinal variables and the chi-square test for cross-tabulations. To analyze repeated OHIP-14 scores, the Friedman test was used for ordered alternatives to test whether the measurements differed (overall significance level α=.05). Then the Wilcoxon signed rank test was conducted to detect specific differences (α=.05).

RESULTS

OHIP-14 scores decreased significantly after implant placement and functional connection for the whole population (P<.001) and for both sub groups, the CAW-H group III-IV (P<.001) and the CAW-H group V (P=.013). CAW-H group V participants needed more retention inserts than CAW-H group III-IV participants (26 versus 3, respectively; P=.006). The incidence of repair and rebasing was limited for both groups, and biological aftercare and pain relief were comparable.

CONCLUSIONS

Changing a CD to an overdenture significantly improved ORLQoL regardless of the resorption degree, but heavily resorbed mandibles require more replacements of retention inserts.

One-year clinical outcomes of locking taper Equator attachments retaining mandibular overdentures to narrow diameter implants

BACKGROUND

Narrow diameter implants (NDI) are recommended to retain mandibular overdentures (MOs) in cases of limited bone thickness. It is necessary to evaluate the clinical behavior of NDI as MO retainers connected to a new screwless locking taper abutments, their predictability and maintenance problems.

OBJECTIVES

To evaluate the peri-implant tissue behavior around NDI and the performance of locking taper stud abutments as MO retainers.

METHODOLOGY

Thirty patients (average age of 67.5 years) received 2 NDI implants (2.9 × 10 mm) loaded after 12 weeks using Equator stud attachments. The plaque index (PI), calculus index (CI), gingival index (GI), probing depth (PD), bleeding on probing (BOP), and implant stability quotient (ISQ) were monitored during osseointegration at 0, 4, 8, and 12 weeks and postloading at 24, 48, and 60 weeks. The marginal bone level (MBL) and bone level changes (BLC) were determined at baseline and 60 weeks.

RESULTS

The cumulative success rate was 83.3%. The PI oscillated in the first 24 weeks and decreased from 48 weeks onward, while the CI score showed significantly higher values at week 8 (22%). The GI also peaked at week 8 (18.6%) and decreased from week 12 onward. The PD decreased gradually over time, but no significant differences were found between weeks 8 and 12. The ISQ decreased significantly between 0 and 12 weeks. After MO loading, the ISQ values increased linearly and significantly between 12 and 24, 24 and 48, and 48 and 60 weeks and reached values similar to the primary stability after 60 weeks [56.1(42.0-65.3)]. No significant MBL was observed at 60 weeks, with an average BLC of -0.06 ± 0.64 mm.

CONCLUSION

NDI connected to locking taper Equator attachments showed a stable clinical behavior as an MO retainer for edentulous patients with clinical mandibular atrophy.

Effect of the different implant protocols on peri-implant bone: a 6-month prospective study in beagle dogs

OBJECTIVE

To compare the effects of different implant placement and loading protocols on the marginal bone loss (MBL) in beagles by intraoral radiography.

METHODS AND MATERIALS

61 dental implants were inserted on 9 beagle dogs at bilateral lower posteriors according to 8 different protocols: immediate implant placement and immediate loading for 3 months (IIP + IL3) or 6 months (IIP + IL6) and unloading (IIP + UL), immediate implant placement and delayed loading for 3 months (IIP + DL3) or 6 months (IIP + DL6), delayed implant placement and immediate loading for 3 months (DIP + IL3) or delayed loading for 3 months (DIP + DL3) and unloading (DIP + UL). Intraoral radiography was performed to analyze the MBL during each surgery, before and after the implant placement and at 3-month intervals after the procedure.

RESULTS

In total, 57 samples were included. There was less MBL (p<0.05) in the IIP + IL3 group (1.22 ± 0.63 mm) compared to the DIP + IL3 group (1.89 ± 0.9 mm). The longer the loading time, the more bone loss appeared in the IIP + IL group; however, the results were reversed in the IIP + DL group. The MBL during the latter 3-month period was dramatically decreased compared to the former 3-month period in the IIP + DL3 group (p<0.05).

CONCLUSIONS

The IIP + IL group seems superior to the DL protocol and the MBL changed significantly during the first three months and thereafter became stable.

Three-year Prospective Evaluation of Immediately Loaded Mandibular Implant Overdentures retained with Locator Attachments

INTRODUCTION

Immediate implant-loading protocol has progressed because of various clinical advantages offered by this treatment approach. However, available studies on edentulous patients are still few compared to those in which delayed implant-loading protocol was applied.

AIM

This prospective study was to evaluate the implant survival rate and the peri-implant tissue response in a group of patients who received two unsplinted immediately loaded dental implants in the mandibular anterior region to retain a complete overdenture using locator attachments.

MATERIALS AND METHODS

A total of 24 edentulous patients with a mean age of 63.4 years were involved in this study following certain inclusion criteria. All patients received a new set of complete dentures before implant positioning. Two Prima Connex tapered implants were put in the interforaminal area of the mandible with a flapless surgical procedure, and the prefabricated dentures were immediately retained with a zest locator attachment. Clinical and radiographic records of the patients were reviewed immediately after placement of the implant, at 3 months, and at 1, 2, and 3 years following fixture installation. The obtained data were analyzed using paired samples t-test and the Wilcoxon signed-rank test at 0.05 significance level.

RESULTS

At 3 years, all implants had osseointegrated with a 100% survival rate. In addition, the total mean marginal bone change was -0.89 ± 0.14 mm, and the mean periotest value was -7.631 ± 0.921.

CONCLUSION

Results of this study propose that immediate loading of mandibular implant overdentures that are retained with locator attachments was a feasible treatment alternative for this particular group of patients.

CLINICAL SIGNIFICANCE

Immediate implant- loading of mandibular implant overdentures that are retained with locator attachments is a reliable treatment option Keywords: Immediate implant loading, Implant survival rate, Locator attachments, Overdenture.

Relationship between implant stability on the abutment and platform level by means of resonance frequency analysis: A cross-sectional study

Resonance frequency analysis (RFA) has become the main tool used to assess the osseointegration of dental implants. The objective of this study was to verify the relationship between the ISQ values with different prosthetic abutments and with the implant platform. The hypothesis was that ISQ values changes according to the abutment height. Twelve patients were included, whose contribution to the study was 31 dental implants (external hexagon connection implants, 4.1x10 mm). The temporary implant-supported crown and prosthetic components were removed and the following smartpegs were inserted, one at a time: type 1, in the implant platform (G1); type A3, in the microunit component with 1mm transmucosal height (G2) and type A3, in the microunit component with 5mm transmucosal height (G3). In all the smartpegs, RFA measurements were taken on mesial, distal, buccal and lingual surfaces. All evaluations were performed by a single calibrated examiner (ICC = 0.989). Data were analyzed by Friedman and Spearman correlation tests and log-linear marginal regression (p<0.05). The mean age of participants was 52.83 (± 3.77) years. There was statistically significant difference (p<0.001) among the mean ISQ of G1 (88.27 ±5.70); G2 (72.75 ±4.73) and G3 (66.33 ±3.67). There was statistically significant negative correlation between the ISQ and the measurement distance (rs:-0.852; p<0.001; R2:0.553). Measurement distance was significantly associated (p<0.001) with ISQ value in the log-linear regression. The abutment height has a significant impact on resonance frequency analysis measurements. The higher the transmucosal abutment height, the lower the implant stability quotient value. Clinically, the ISQ measured on the abutment cannot be compared with values measured on the implant platform.

Immediate and delayed loading of two-piece reduced-diameter implants with locator-analog attachments in edentulous mandibles: One-year results from a randomized clinical trial examining clinical outcome and patient expectation

BACKGROUND

Prosthetic management of thin alveolar ridges in the edentulous mandibles of elderly patients, especially the time of loading, the number of implants needed, and patient expectations and perception, is a challenge in implant dentistry.

PURPOSE

Survival of conventionally and immediately loaded 2-piece reduced-diameter implants in the interforaminal region of the edentulous mandible supporting locator-analog attachments was evaluated. Prosthetic complications and peri-implant hygiene were also studied, and patient expectation and subjective evaluation of the treatment were documented.

MATERIAL AND METHODS

Twenty-five patients with adapted complete dentures received 4 reduced-diameter implants. All anterior implants were immediately loaded. Three months later, patients were allocated by randomization to 1 of 2 treatment groups: 2 locator-analog attachments on the anterior implants (Group A); or 4 locator-analog attachments (Group B). After another 3 months patient allocation was changed (crossover design) for the next 3 months. Questionnaires with Likert scales and numeric rating scales were used to assess patients' expectations and subjective overdenture-related variables, respectively.

RESULTS

One implant was lost in the immediate-loading group. Survival was 98% and 100% for immediate and delayed loading, respectively. During 12-month observation, 8 complications required aftercare. At the beginning of treatment, patients' expectations were highly positive. Subjective assessment of overdenture-related variables 3 months after immediate loading of 2 implants revealed a statistically significant improvement for most of the variables studied; this was maintained 1 year later. In the subjective assessments, there were no statistically significant differences between Groups A and B.

CONCLUSION

Immediate loading of reduced-diameter implants supporting locator-analog attachments resulted in high implant survival, few prosthetic complications, good oral hygiene, and improvement of subjective denture perception in the short-term. It might be a promising treatment option, especially for elderly patients with a narrow mandibular ridge.

Microthreaded Implants and Crestal Bone Loss: A Systematic Review

This systematic literature review investigated the effect of microthreaded-neck dental implants on crestal bone loss. Using the participants, interventions, comparison groups, outcomes, and study design (PICO) system, we addressed the following focused question: Do microthreaded-neck dental implants positively affect the crestal bone level around dental implants? We searched 3 electronic databases to find articles published between January 1995 and June 2016 that contained any combination of the following keywords: dental implant, microthread, microthreaded, crestal bone level, crestal bone loss, and alveolar bone level. We excluded case reports, review articles, letters to the editor, commentaries, and articles published in a language other than English. We found a total of 70 articles. After eliminating duplicates and applying PICO eligibility criteria, we selected only articles that reported the results of randomized controlled trials, prospective or retrospective cohort studies, case control studies, cross-sectional studies, or other types of clinical trials that compared the microthreaded implant design with other implant designs. We were left with 23 articles for review. The 23 articles reported crestal bone loss ranging from .05 mm to .9 mm, with a range of 12 to 96 months of follow-up. Less crestal bone was lost with dental implants that had a microthreaded neck design than with machined-surface or conventional rough-surface dental implants. Thus, microthreaded dental implants are a better choice than are implants with other designs. Future studies should use standardized imaging techniques to evaluate the placement of these implants in bone-augmented sites.

Immediate loading for implant restoration compared with early or conventional loading: A meta-analysis

PURPOSE

This meta-analysis was to further confirm the no inferiority of immediate loading in clinical and radiographic outcomes compared with non-immediate loadings (early or conventional loading).

MATERIALS AND METHODS

Literature search on Pubmed and Embase was performed up to August 2015. The overall risk radios (RRs) and standard mean differences (SMDs) as well as their 95% confidence intervals (CI) were calculated for comparison.

RESULTS

Total 29 RCT with 1342 implants receiving immediate loading and 1279 implants receiving non-immediate loadings were included in this meta-analysis. Results indicated that there was no significant difference between immediate and non-immediate loadings in implant failure rate based on patients (RR = 1.45, 95% CI: 0.79 to 2.68) and implants (RR = 1.38, 95% CI: 0.86 to 2.21), MBL (SMD = -0.11, 95% CI: -0.39 to 0.17), and ISQ (SMD = -0.26, 95% CI: -0.53 to 0.01). Meanwhile, immediate loading showed significantly less MBL change than non-immediate loading. In addition, subgroup analyses showed that the immediate loading indicated slightly higher implant failure rate and lower ISQ than conventional loading.

CONCLUSIONS

Although overall analysis confirmed no inferiority of immediate loading compared with non-immediate loadings, the technique still need to be explored for improving implant success and stability during immediate loading based on the results in subgroup analyses.

Locators versus magnetic attachment effect on peri-implant tissue health of immediate loaded two implants retaining a mandibular overdenture: a 1-year randomised trial

This study aimed to evaluate peri-implant tissue health of immediate loaded two implants retaining a mandibular overdenture with either magnetic or locator attachment. Thirty two completely edentulous patients (20 males/12 females) were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible using flapless surgical technique. Mandibular overdentures were immediately connected to the implants with either magnetic (group I, GI) or locator (group II, GII) attachments. Peri-implant tissue health was evaluated clinically in terms of plaque scores (PI), bleeding scores (BI), probing depth (PD), implant stability (ISQ) and interleukin-1-β (IL-1b) concentrations in peri-implant sulcular fluid. PI, BI and PD were measured at mesial, distal, buccal and lingual surfaces of each implant. Radiographic evaluation was performed in terms of vertical (VBL) and horizontal (HBLO) alveolar bone loss. Evaluations were performed 2 weeks (T0), 6 months (T1) and 12 months (T2) after overdenture insertion. Plague scores, PD, IL-1b, VBL and HBLO increased significantly with time. ISQ decreased significantly with time. BI showed no significant differences between observation times. GI recorded significant higher PI, ISQ and IL-1b at T2 compared to GII. GII recorded significant higher VBL than GI at T2 only. For HBLO, no significant differences between groups were noted. VBL and HBLO showed a significant positive correlation with PD. Locator attachments for immediate loaded implants retaining mandibular overdentures are associated with decreased plaque accumulation, decreased implant stability, decreased interleukin-1β concentration in peri-implant crevicular fluid and increased per-implant vertical bone loss compared to magnetic attachments after 1 year.

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.

Maxillary Four Implant-retained Overdentures via Locator® Attachment: Intermediate-term Results from a Retrospective Study

BACKGROUND

Maxillary overdentures have been utilized to restore oral function in scenarios where limited bone structure represents a drawback for financial issues and for cases where oral hygiene is uncertain.

PURPOSE

The aim of this study was to evaluate the intermediate-term clinical outcome of four locator attachment retaining maxillary overdentures and to test their reliability.

MATERIALS AND METHODS

A retrospective study was conducted from January 2007 to October 2013. After the placement of four maxillary dental implants and a healing period of approximately 3 months, all the implants were restored with locator-retained overdentures with partial palatal coverage. Subjects and implant characteristics, implant position (anterior vs posterior maxilla), bone quality, and opposing dentition were recorded. Peri-implant clinical parameters and marginal bone loss (MBL) were evaluated after delivery of the final prosthesis and annually thereafter. The performance of locator components and the prosthetic restoration were also recorded at follow-up.

RESULTS

A total of 104 implants were placed in 26 subjects (11 women, 15 men; mean age, 64 years; age range, 55-76 years). One implant failed before loading. One subject dropped out of the study during a mean follow-up period of 46 months (range: 7-73 months), achieving an overall survival rate of 95.2%. Clinical parameters revealed healthy tissues around most of the implants, with low scores of plaque and bleeding indices. At the last follow-up evaluation, the mean MBL was 1.7 ± 1.1 mm (0.4-2.6 mm). Regression model analysis indicated that MBL for implants in the posterior maxilla was significantly higher than that for implants in the anterior maxilla (p = .0487). Overall, 26 technical and prosthetic complications were reported.

CONCLUSION

Within the limitations of this study, maxillary four implant-retained overdentures via Locator attachment seem to be a predictable alternative for oral rehabilitation.