Clinical and radiographic evaluation of implant-retained mandibular overdentures with immediate loading

Heterogeneity of outcomes in randomized controlled trials on implant prosthodontic therapy is hindering comparative effectiveness research: meta-research study

BACKGROUND

Consistency in outcomes across clinical trials allows for comparing and combining results from different studies. A core outcome set (COS), representing a minimally agreed standardized group of outcomes that should be monitored and measured through research in a specific field of medicine, is not yet available for trials in implant prosthodontic (dental implant) therapy. This meta-research study aimed to analyze outcomes used in clinical trials on implant prosthodontic therapy.

METHODS

We searched the Cochrane Oral Health Group (COHG) register to identify systematic reviews of interventions in implant prosthodontic therapy published by October 2023. From the randomized controlled trials (RCTs) included in the relevant reviews, we extracted data on the characteristics of the included trials and the outcomes used. We categorized outcomes into domains.

RESULTS

From 182 systematic reviews in the COHG register, we included 11 systematic reviews on dental implant therapy. The reviews included 117 unique RCTs with 4725 participants, published from 1995 to 2020, which analyzed 74 different outcomes. Using different definitions, implant failure was analyzed in 73 RCTs. Seventeen RCTs did not define implant failure. Failure was most often (30 RCTs) followed up for one year. Only one RCT assessed implant failure after five years. Trials used 17 definitions of implant failure, while 17 trials did not report on the criteria of implant failure. Complications were analyzed in 48 RCTs, although they were not clearly defined in 12 RCTs. Failure of prosthodontic supra-structure was analyzed in 74 RCTs, with definitions of failure and criteria not clearly defined in 44 RCTs. Trials considered adverse events, peri-implant tissue health, patient attitudes, and other outcomes, including cost, aesthetics, or procedure duration. These outcomes were often different between trials. Twenty-six outcomes were used only once per study.

CONCLUSIONS

Clinical trials in implant prosthodontics used different outcomes, different definitions of outcomes and used different times to monitor them. Standardization of outcomes is necessary to allow comparability and evidence synthesis about the effectiveness of implant prosthodontic therapy.

Tissue Surface Adaptation and Clinical Performance of CAD-CAM Milled versus Conventional Implant-Assisted Mandibular Overdenture

Purpose

To evaluate the surface adaptation and maximal biting force of CAD-CAM milled mandibular overdenture (CAD-CAM MOD) compared to conventional compression mold mandibular overdenture (CC MOD).

Materials and Methods

Ten completely edentulous subjects with persistent complaints of their complete mandibular dentures were received four dental implants in the anterior mandible. Three months after osseointegration, subjects were randomly received either conventional compression mold or CAD-CAM MOD in a crossover design. To assess tissue surface adaptation, the fitting surfaces of each denture base were scanned and placed on the reference master cast. Three and six months after each overdenture was inserted, clinical performance in the form of maximum biting force was evaluated.

Results

The results of this study indicated that the tissue surface adaptation of the CAD-CAM MOD bases was significantly better than the conventional (compression mold technique) processed bases where (P=0.0001). Regarding clinical performance (maximum biting force), the CAD-CAM MOD exhibited better clinical performance (P=0.0001).

Conclusions

In denture processing methods, the CAD-CAM overdenture delivered more precise adaption and clinical performance than the compression mold technique.

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.

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.

Immediate versus early or conventional loading dental implants with fixed prostheses: A systematic review and meta-analysis of randomized controlled clinical trials

STATEMENT OF PROBLEM

Immediate loading of dental implants has gained widespread popularity because of its advantages in shortening treatment duration and improving esthetics and patient acceptance. However, whether immediate loading can achieve clinical outcomes comparable with those of early or conventional delayed loading is still unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare the efficacy of immediate loading versus early or conventional loading implants in patients rehabilitated with fixed prostheses.

MATERIAL AND METHODS

Electronic searches of CENTRAL, EMBASE, and MEDLINE were supplemented by manual searches up to October 2018. Only human randomized controlled trials (RCTs) comparing immediate with early or conventional loading dental implants were included. Quality assessment was performed by using the Cochrane Collaboration tool. For the meta-analysis, the dichotomous and continuous variables were pooled and analyzed by using risk ratios (RRs) and weighted mean differences (WMDs), with 95% confidence intervals (95% CIs). The outcomes assessed included survival rate, marginal bone level changes, peri-implant gingival level, probing depth, and implant stability. The subgroup analyses included healing methods, implant time, occlusal contact, number of missing teeth, and tooth position.

RESULTS

Thirty-nine trials (49 articles) were included from the initial 763 references evaluated. When compared with conventional loading, with implants regarded as a statistical unit, a statistically significant lower survival rate was observed in the immediate loading dental implant (RR=0.974; 95% CI, 0.954, 0.994; P=.012). Regarding other outcomes, including marginal bone level changes, peri-implant gingival level, probing depth, and implant stability, no statistically significant differences were observed when comparing immediate versus early or conventional loading (P>.05).

CONCLUSIONS

Compared with early loading, immediate loading could achieve comparable implant survival rates and marginal bone level changes. Compared with conventional loading, immediate loading was associated with a higher incidence of implant failure.

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.

Clinical and radiological investigations of mandibular overdentures supported by conventional or mini-dental implants: A 2-year prospective follow-up study

STATEMENT OF PROBLEM

Conventional dental implants are not applicable in the mandibular interforaminal region if bone volume is limited. Mini-dental implants offer an alternative means of supporting mandibular overdentures in a narrow residual ridge, without additional surgery.

PURPOSE

The purpose of this nonrandomized clinical trial was to compare the ability of mini-dental implants with that of conventional dental implants in supporting mandibular overdentures during a 2-year clinical follow-up. Bone quality, bone resorption, implant stability, and oral health were assessed radiographically.

MATERIAL AND METHODS

A total of 32 participants with edentulism were included. Twenty-two participants (99 implants) received 4 to 5 mini-dental implants (diameter: 1.8-2.4 mm; length: 13-15 mm, study group), and 10 participants (35 implants) received 2 to 4 conventional dental implants (diameter: 3.3-3.7 mm; length: 11-13 mm, control group). The selection of the participants in the study or control group was based on the available bone volume in the mandible. The selection was not randomized. The density of cortical bone thickness was measured in Hounsfield units (HU) from computed tomography data, and patients were followed for 2 years. The participants were examined 3, 6, 12, and 24 months after surgery. Primary stability immediately after the insertion of dental implants (Periotest), secondary stability 6 months after implantation, modified plaque, bleeding on probing indices, and probing depth were measured and analyzed statistically (α=.05).

RESULTS

The mean HU value 6 months after implantation in the participants who received mini-dental implants was significantly (P=.035) higher (1250 HU) than that in the participants who received conventional dental implants (1100 HU). The probing depths around the conventional dental implants (1.6 and 1.8 mm, respectively) were significantly higher than those around the mini-dental implants (1.3 and 1.2 mm, respectively) 12 and 24 months after surgery, respectively (P<.001). The mean primary and secondary stability values for conventional dental implants were -4.0 and -4.9, respectively. The primary and secondary stability values for the mini-dental implants were -0.3 and -1.4, respectively. The Periotest values of the primary (measured immediately after implant insertion) and secondary implant stabilities (measured 6 months after implant insertion) were significantly higher for the conventional dental implants than for the mini-dental implants (P<.001).

CONCLUSIONS

Based on this 2-year clinical trial, patients receiving mini-dental implants had clinical outcomes similar to those of patients receiving conventional dental implants to support overdenture prostheses.

Clinical efficacy of immediate implant loading protocols compared to conventional loading depending on the type of the restoration: a systematic review

BACKGROUND AND OBJECTIVES

Immediate loading has become a predictable option to restore all clinical situations. The aim of this systematic review was to assess whether immediate loading protocols achieve comparable clinical outcomes when compared to conventional loading protocols depending on the type of prosthetic restoration.

METHODS

A protocol was developed aimed to answer the following focused question: "What are the effects of immediate implant loading protocols compared to conventional implant loading, in terms of implant failure, marginal bone levels, and biological and mechanical complications based on the type of restoration?" The next subanalysis were performed as follows: the extent, type, and material of the restoration and the type of occlusal contact in function. This systematic review only included randomized controlled trials (RCTs) with a follow-up of at least 6 months after implant loading.

RESULTS

Thirty-seven final papers were included. The results from the meta-analyses have shown that the immediately loading implants demonstrated a statistically significant higher risk of implant failure [RR = 1.92; 95% CI (1.04; 3.54); P = 0.036], a statistically significant lower bone loss [WMD = 0.046; 95% CI (0.043; 0.049); P = 0.000] and a smaller increase in ISQ values [WMD = -1.096; 95% CI (-1.615; -0.577); P < 0.001, although both groups attained high survival rates (98.2% in the test and 99.6% in the control). Single teeth implants were greater risk of failure, when compared to immediately loaded full arch restorations (RR = 2 vs. 0.9), so as the occlusal pattern when compared to non-occlusal (RR = 1.9 vs. 1.4).

CONCLUSIONS

Immediate loading may impose a greater risk for implant failure when compared to conventional loading, although the survival rates were high for both groups.

Early and immediate loading protocols for overdentures in completely edentulous maxillas: a comprehensive review of clinical trials

A comprehensive review was conducted to answer the question 'Does the immediate loading of dental implants with an overdenture in the maxilla provide predictable clinical and psychological outcomes?' Detailed search strategies were used to identify pertinent articles in English that were published between 1975 and August 2013 and indexed in PubMed, MEDLINE, Embase, The Cochrane Central Register of Controlled Trials, and a personal library; in addition, relevant journals were manually searched. Only randomized controlled clinical trials (RCTs), controlled clinical trials (CCTs), and prospective studies with a follow-up period of at least one year, all involving 10 or more adult participants, were considered. Six prospective studies reporting on outcomes of up to 2 years were included, five of which employed a bar-retained overdenture, and one of which used a ball attachment as a retention mechanism. Short term reports demonstrate that immediate/early loading of dental implants with a maxillary overdenture is a predictable treatment approach and results in favorable implant/prosthesis survival, soft tissue health, and patient satisfaction outcomes. However, for a definitive conclusion, well-designed long-term trials are required to establish a consensus on treatment planning, longevity, long-term complications and maintenance, cost-effectiveness, and patients-mediated outcomes.

Immediate loading and implant-bar overdenture

Immediate loaded implants may be used with an implant-bar overdenture to provide fixed splinting. This is a relatively new system that provides for immediate implant placement and restoration.

Immediate loading of overdentures: systematic review

INTRODUCTION

The goal of implant treatment is the formation of a direct bone-implant interface contact.

PURPOSE

This study aimed to evaluate the possibilities of immediate loading treatment for edentulous patients rehabilitated with mandibular and maxillary overdentures.

MATERIAL AND METHODS

A literature review using the PubMed and BIREME databases between the periods of 1977 and 2011 was performed.

RESULTS

From an initial yield of 218 titles, 78 articles were selected for text analysis, finally resulting in 23 studies (16 prospective, 6 prospective randomized, and 1 prospective multicenter) that met the inclusion criteria.

CONCLUSION

The immediate loading protocol through which the implants are subjected to occlusal function immediately after their placement was introduced to overcome this limitation.

Interventions for replacing missing teeth: different times for loading dental implants

BACKGROUND

To minimise the risk of implant failures after their placement, dental implants are kept load-free for 3 to 8 months to establish osseointegration (conventional loading). It would be beneficial if the healing period could be shortened without jeopardising implant success. Nowadays implants are loaded early and even immediately and it would be useful to know whether there is a difference in success rates between immediately and early loaded implants compared with conventionally loaded implants.

OBJECTIVES

To evaluate the effects of (1) immediate (within 1 week), early (between 1 week and 2 months), and conventional (after 2 months) loading of osseointegrated implants; (2) immediate occlusal versus non-occlusal loading and early occlusal versus non-occlusal loading; (3) direct loading versus progressive loading immediately, early and conventionally.

SEARCH METHODS

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 8 June 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2012, Issue 4), MEDLINE via OVID (1946 to 8 June 2012) and EMBASE via OVID (1980 to 8 June 2012). Authors of identified trials were contacted to find unpublished randomised controlled trials (RCTs). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

All RCTs of root-form osseointegrated dental implants, having a follow-up of 4 months to 1 year, comparing the same implant type immediately, early or conventionally loaded, occlusally or non-occlusally loaded, or progressively loaded or not. Outcome measures were: prosthesis and implant failures and radiographic marginal bone level changes.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by at least two review authors. Trial authors were contacted for missing information. Risk of bias was assessed for each trial by at least two review authors, and data were extracted independently, and in duplicate. Results were combined using fixed-effect models with mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI). A summary of findings table of the main findings was constructed.

MAIN RESULTS

Forty-five RCTs were identified and, from these, 26 trials including a total of 1217 participants and 2120 implants were included. Three trials were at low risk of bias, 12 were at high risk of bias and for the remaining 11 the risk of bias was unclear. In nine of the included studies there were no prosthetic failures within the first year, with no implant failures in 7 studies and the mean rate of implant failure in all 26 trials was a low 2.5%. From 15 RCTs comparing immediate with convential loading there was no evidence of a difference in either prosthesis failure (RR 1.87; 95% CI 0.70 to 5.01; 8 trials) or implant failure (RR 1.65; 95% CI 0.68 to 3.98; 10 trials) in the first year, but there is some evidence of a small reduction in bone loss favouring immediate loading (MD -0.10 mm; 95% CI -0.20 to -0.01; P = 0.03; 9 trials), with some heterogeneity (Tau² = 0.01; Chi² = 14.37, df = 8 (P = 0.07); I² = 44%). However, this very small difference may not be clinically important. From three RCTs which compared early loading with conventional loading, there is insufficient evidence to determine whether or not there is a clinically important difference in prosthesis failure, implant failure or bone loss. Six RCTs compared immediate and early loading and found insufficient evidence to determine whether or not there is a clinically important difference in prosthesis failure, implant failure or bone loss. From the two trials which compared occlusal loading with non-occlusal loading there is insufficient evidence to determine whether there is a clinically important difference in the outcomes of prosthesis failure, implant failure or bone loss. We did not identify any trials which evaluated progressive loading of implants.

AUTHORS' CONCLUSIONS

Overall there was no convincing evidence of a clinically important difference in prosthesis failure, implant failure, or bone loss associated with different loading times of implants. More well-designed RCTs are needed and should be reported according to the CONSORT guidelines (www.consort-statement.org/).

Management of atrophic mandibular ridge with mini dental implant system

Mini dental implants (MDI) are ultra-small diameter (l.8 mm width), biocompatible titanium alloy implant screws, conceived and designed over 20 years ago by a board-certified Manhattan dentist, Sendax Victor. Dr. R. A. Bulard added a single-piece “O-ball” design to Dr. Sendax Victor concept. These implants can be used in atrophic ridges, flabby ridges, or in other cases where there is denture instability or lack of retention due to poor availability of residual bone. In this article, a case report of 55-year-old female patient is presented, with a severely atrophic mandibular ridge that was managed by the MDI system with an overdenture.

Implants Inserted in Mandible: A Case Series

It is generally accepted that the mandible (especially in the interforaminal region) has better bone quality than the maxilla, and this fact is probably the reason why several reports are available regarding implants inserted into the mandible. Since no report is available on a new type of implants, a retrospective study was performed. A total of 185 two-piece implants (FMD srl, Rome, Italy) were inserted in mandible, 102 in female and 83 in males. The median age was 58 ± 13 (min-max 25–80 years). Implants replaced 14 incisors, 7 cuspids, 49 premolars and 115 molars. Implant' length was x ≤ 10 mm, 10,30 ≤ x ≤ 12.30, equal to 13 mm and x ≥14 mm in 80, 90,13 and 2 cases, respectively. Implant' diameter was narrower than 3.5 mm, equal to 3.8 mm and wider than 4.0 mm in 25, 17,143 cases, respectively. There were 36,41,106 and 2 Elisir, I-fix, Shiner, and Storm implant types, respectively. One implant was lost, survival rate = 98.15%. Among the studies variables immediate loaded implants on single tooth rehabilitations (p=0.017) have a worse clinical outcome. Then peri-implant bone resorption (i.e. delta IAJ) was used to investigate SCR. Among the remaining 184 implants, 20 fixtures have a crestal bone resorption greater than 1.5 mm (SCR = 89.13). Statistical analysis demonstrated signifiance only for surgeon (p=0.001). In conclusion FMD implants are reliable devices for oral rehabilitation with a very high SCR and SVR.

The Role of Timing of Loading on Later Marginal Bone Loss Around Dental Implants: A Retrospective Clinical Study

The aim of this study was to assess the relation between marginal bone loss (MBL) around dental implants after a loading period of 36 months and the timing of loading. A total of 87 patients with 252 implants were included in the study group. The time span from implant placement to beginning of loading of the implants was evaluated. Delay of loading of implants seems to increase MBL around dental implants as the result of disuse atrophy. Implants next to a tooth on 1 or 2 sides suffered less from MBL. No statistically significant difference in MBL rate was noted between single and splinted implants or between smooth collar and microgeometry neck implants. Results of this study encourage early loading, especially for the mandibular overdenture supporting implants.

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.

Interventions for replacing missing teeth: different times for loading dental implants

BACKGROUND

To minimize the risk of implant failure, osseointegrated dental implants are conventionally kept load-free during the healing period. During healing removable prostheses are used, however many patients find these temporary prostheses rather uncomfortable and it would be beneficial if the healing period could be shortened without jeopardizing implant success. Nowadays immediately and early loaded implants are commonly used in mandibles (lower jaws) of good bone quality. It would be useful to know whether there is a difference in success rates between immediately or early loaded implants compared with conventionally loaded implants.

OBJECTIVES

To evaluate the efficacy of (1) immediate (within 1 week), early (between 1 week and 2 months), and conventional (after 2 months) loading of osseointegrated implants, and of (2) immediate occlusal versus non-occlusal loading during the bone healing phase.

SEARCH STRATEGY

The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching included several dental journals. Authors of all identified trials, an Internet discussion group and 55 dental implant manufacturers were contacted to find unpublished randomised controlled trials (RCTs). The last electronic search was conducted on 4 June 2008.

SELECTION CRITERIA

All RCTs of root-form osseointegrated dental implants, having a follow up of 4 months to 1 year, comparing the same implant type immediately, early and conventionally loaded or occlusally and non-occlusally loaded. Outcome measures were: prosthesis and implant failures and radiographic marginal bone level changes.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two review authors. Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. The Cochrane Collaboration's statistical guidelines were followed.

MAIN RESULTS

Thirty RCTs were identified and 22 trials including 976 participants in total were included. Twelve trials compared immediate versus conventional loading, three early versus conventional loading, six immediate versus early loading, and one occlusally versus non-occlusally loaded implants. On a patient, rather than per implant basis, there were no statistically significant differences for any of the meta-analyses.

AUTHORS' CONCLUSIONS

It is possible to successfully load dental implants immediately or early after their placement in selected patients, though not all clinicians may achieve optimal results. It is unclear whether it is beneficial to avoid occlusal contacts during the osseointegration phase. Trends suggest that immediately loaded implants fail more often than those conventionally loaded, but less commonly than those loaded early. If a clinician wishes to load the implants early, it might be wiser to load them immediately (within 1 week) rather than waiting for 1 or 2 months. A high degree of primary implant stability (high value of insertion torque) seems to be one of the prerequisites for a successful immediate/early loading procedure. More well designed RCTs are needed and should be reported according to the CONSORT guidelines (www.consort-statement.org/).

Immediate Loading of Single-Tooth Restorations: One-Year Prospective Results

Immediate loading of splinted implant restorations is a growing trend, but limited clinical documentation hampers evidence-based treatment planning for single-tooth applications. This study prospectively evaluated the clinical efficacy of placing implant-supported, single-tooth restorations into immediate, full-occlusal loading. Sixty consecutive patients (intent-to-treat group) with 1 missing tooth between 2 intact teeth were treated with a total of 69 implants. At placement, final impressions were made and implants were provisionalized with nonoccluding prostheses. Definitive prostheses were delivered 2 weeks later. A claim of noninferiority was made with a 95% confidence interval (Mann-Whitney U test) if the success rates between the experimental group and a 97% historical control was &gt;7%. Standardized radiographs taken at placement and bimonthly intervals were analyzed for crestal bone changes at a type I (alpha) error level of .05; significance levels were not adjusted for multiplicity (Fisher exact tests and Student t tests). Sixteen patients (18 implants) were withdrawn for protocol deviations. The resulting treated-per-protocol group consisted of 44 subjects with 51 implants. Cumulative implant success rates were 98.55% (n = 68/69) for the intent-to-treat group and 98.04% (n = 50/51) for the treated-per-protocol group. There were no significant adverse events or statistically significant differences between the experimental and historical control groups. At 12 months mean crestal bone loss was 1.05 mm, and ranged from 0.38 to 1.5 mm (77%) and 1.6 to 2.69 mm (23%). Immediate full-occlusal loading of single-tooth restorations was safely performed in selected subjects when good primary implant stability and an appropriate occlusal load were achieved.