Two-part implants inserted in a one-stage or a two-stage procedure. A prospective comparative study

Immediate Implant Placement and Provisionalization in the Esthetic Zone: A 6.5-Year Follow-Up and Literature Review

The success of dental implant therapy in the esthetic zone requires not only functional osseointegration but also a satisfactory esthetic outcome. To establish harmony, balance, and continuity of gingival architecture between an implant restoration and the adjacent natural dentition is challenging. Immediate implant placement and provisionalization following tooth extraction have been documented as a predictable treatment modality, with fewer surgical interventions needed, to replace a missing tooth in the esthetic zone. This case report illustrates immediate implant placement and provisionalization to replace a failing maxillary right central incisor while maintaining optimal gingival esthetics. The maxillary right central incisor was extracted without flap elevation to minimize soft and hard tissue trauma. Immediately afterwards, the implant was installed using a surgical stent and restored with a provisional crown that had no occlusal contacts. During healing, no significant adverse effects were observed clinically or radiographically. This proposed treatment modality provided the patient with immediate esthetics, function, and comfort without any complications during a follow-up period of 6.5 years.

Mandibular implant-supported overdentures in (frail) elderly: A prospective study with 20-year follow-up

Purpose

To prospectively assess long‐term (20 year) clinical, radiographic, and patient‐reported outcomes of an elderly population provided with mandibular implant‐supported overdentures.

Materials and Methods

A total of 53 elderly (aged ≥60 years at the time of treatment) were provided with two endosseous implants supporting a mandibular overdenture and a conventional maxillary denture. Outcome parameters—including implant loss, plaque index, gingival index, bleeding index, presence of calculus, probing depth, and satisfaction with implant‐supported overdenture—were scored 1, 5, 10, and 20 years after prosthetic treatment. Radiographic analysis was performed to assess peri‐implant bone changes. At the 20‐year evaluation, frailty (Groningen Frailty Index) and quality of life (EuroQol 5D) were additionally assessed.

Results

A total of 15 patients completed the 20‐year follow‐up. The 20‐year implant survival rate was 92.5%. Plaque index, bleeding index, and probing depth increased slightly over time, while gingival index and presence of calculus remained unchanged. Radiographic analysis revealed minor marginal bone loss during the first 10 years and no further loss thereafter. Participants were very satisfied with their prosthesis and reported a good quality of life. At the 20‐year evaluation, 64.3% of the patients were classified as frail.

Conclusions

The long‐term survival of implants supporting a mandibular overdenture is high. Although most elderly in the study became frail over time, peri‐implant health and marginal bone level remained at a satisfactory level.

WITHDRAWN: Interventions for replacing missing teeth: 1- versus 2-stage implant placement

BACKGROUND

Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention.

OBJECTIVES

To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure.

SEARCH METHODS

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 21 January 2009.

SELECTION CRITERIA

All RCTs of osseointegrated dental implants comparing the same dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals.

MAIN RESULTS

Five RCTs were identified and included reporting data on 239 patients in total. On a patient, rather than per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured 2-stage (submerged) implants.

AUTHORS' CONCLUSIONS

The number of patients included in the trials was too small to draw definitive conclusions. The 1-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a 2-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability or when barriers are used for guided tissue regeneration, or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments especially in fully edentulous patients.

Impact of surface topography and coating on osteogenesis and bacterial attachment on titanium implants

Titanium (Ti) plays a predominant role as the material of choice in orthopaedic and dental implants. Despite the majority of Ti implants having long-term success, premature failure due to unsuccessful osseointegration leading to aseptic loosening is still too common. Recently, surface topography modification and biological/non-biological coatings have been integrated into orthopaedic/dental implants in order to mimic the surrounding biological environment as well as reduce the inflammation/infection that may occur. In this review, we summarize the impact of various Ti coatings on cell behaviour both in vivo and in vitro. First, we focus on the Ti surface properties and their effects on osteogenesis and then on bacterial adhesion and viability. We conclude from the current literature that surface modification of Ti implants can be generated that offer both osteoinductive and antimicrobial properties.

Immediate Versus Delayed Loading of Implant for Replacement of Missing Mandibular First Molar: A Randomized Prospective Six Years Clinical Study

INTRODUCTION

Emergence of dental implants made the replacement of missing tooth easy. During the early days of introduction, implants were loaded three to six months after implant insertion, but understanding of healing cascade and improved production technology has changed the phase of restoration from delayed to immediate loading.

AIM

To evaluate and compare the clinical outcome of immediate and delayed loaded implant supported prosthesis for missing mandibular first molar. The objectives were bleeding on probing, probing depth, implant mobility, marginal bone level and peri-implant radiolucency were evaluated during follow up period.

MATERIALS AND METHODS

Twenty patients were included in this study who were in the need of fixed implant supported prosthesis for missing mandibular first molar. Single tooth implant with immediate loading done within two days of implant insertion in one group and another group were loaded after three months of implant insertion. These groups were evaluated clinically and radiographically over a period of 72 months after loading using Wilcoxon matched pairs test and Mann-Whitney U test.

RESULTS

The study consists of 14 male and six female patients with the age range of 19 to 31 years. There was no bleeding on probing and probing depth remained well within the normal range even after 72 months of loading among both the groups. Minimal marginal bone loss observed with no mobility and peri-implant radiolucency.

CONCLUSION

Implant supported prosthesis for missing mandibular first molar with immediate loading can be used as a successful treatment modality. It reduces treatment time, provides early function and prevents undue migration of adjacent tooth. Immediate loading showed similar clinical and radiographic results as that of delayed loading, indicating it as an equally efficient technique for implant supported prosthesis.

Impact of platform switching on inter-proximal bone levels around 8.5 mm implants in the posterior region; 5-year results from a randomized clinical trial

AIM

To assess the medium-term results of 8.5 mm implants supplied with a conventional platform-matched implant-abutment connection or a platform-switched design.

MATERIALS AND METHODS

Eighty patients with one or more missing teeth in the maxillary or mandibular posterior zone were randomly assigned for treatment with implants with a conventional (control group) or platform-switched (test group) implant-abutment connection. Follow-up visits were conducted 1 month, 1 year and 5 years after functional loading. Inter-proximal bone loss, assessed with standardized peri-apical radiographs, clinical parameters, survival of implants and satisfaction of patients were the outcome parameters studied.

RESULTS

After 5 years of loading, five of the 80 patients were lost to follow-up. The inter-proximal bone loss in the test group (0.38 ± 0.61 mm) was comparable to the bone loss in the control group (0.41 ± 0.47 mm; p = 0.201). Remarkably, bone loss has not progressed compared to the 1-year results. Implant survival, clinical parameters and satisfaction of the patients were favourable and comparable for the test and control group.

CONCLUSION

The 5-years results showed that inter-proximal bone resorption was minor and comparable around platform-matched and platform-switched implants, and implant survival, peri-implant health and patients' satisfaction were favourable.

Review finds failure rates lower for delayed loaded submerged dental implants

DATA SOURCES

PubMed, Web of Science, Cochrane Oral Health Group Trials Register, ClinicalTrials.gov, CenterWatch.com, ClinicalConnection.com.

STUDY SELECTION

Randomised and non-randomised studies were included comparing implant failure rates in any group of patients receiving submerged versus immediately loaded non-submerged dental implants. Selection was conducted independently by three reviewers. DATA EXTRACTION AND synthesis: Titles and abstracts of all reports identified through the electronic searches were read independently by the three authors. Studies were selected based on inclusion and exclusion criteria, with disagreements resolved through discussion. Study quality was assessed using the Cochrane risk of bias tool. Implant failure and post-operative infection were the dichotomous outcome measures evaluated. Weighted mean differences (WMD) were calculated and meta-analysis conducted.

RESULTS

Twenty eight studies, consisting of six randomized clinical trials, 14 controlled clinical trials and eight retrospective analyses were included. 23 studies were considered to be at high risk of bias, one at moderate risk and four at low risk of bias. The relative risk (RR) of failure was higher in immediately loaded implants RR = 1.78 (95% CI; 1.12- 2.83). The number needed to treat (NNT) to prevent one patient having an implant failure is 50 (95% CI; 25-100). Analysis suggests the possibility of publication bias.

CONCLUSIONS

The difference between immediately loading and delayed loading of an implant statistically affected the implant failure rate. No statistically significant effects on the occurrence of post-operative infection were observed between the two techniques. Results should be interpreted with caution due to lack of control of confounding factors, the retrospective design of some studies included and the small cohort sizes within the studies.

Immediately loaded non-submerged versus delayed loaded submerged dental implants: a meta-analysis

The purpose of the present meta-analysis was to test the null hypothesis of no difference in the implant failure rate, postoperative infection, and marginal bone loss for patients being rehabilitated with immediately loaded non-submerged dental implants or delayed loaded submerged implants, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. The search strategy resulted in 28 publications. The inverse variance method was used for a random- or fixed-effects model, depending on the heterogeneity. The estimates of an intervention were expressed as the risk ratio (RR) and mean difference (MD) in millimetres. Twenty-three studies were judged to be at high risk of bias, one at moderate risk of bias, and four studies were considered at low risk of bias. The difference between procedures (submerged vs. non-submerged implants) significantly affected the implant failure rate (P = 0.02), with a RR of 1.78 (95% confidence interval (CI) 1.12-2.83). There was no apparent significant effect of non-submerged dental implants on the occurrence of postoperative infection (P = 0.29; RR 2.13, CI 0.52-8.65) or on marginal bone loss (P = 0.77; MD -0.03, 95% CI -0.23 to 0.17).

An Overview of Zirconia Dental Implants: Basic Properties and Clinical Application of Three Cases

Due to the possible aesthetic problems of titanium implants, the developments in ceramic implant materials are increasing. Natural tooth colored ceramic implants may be an alternative to overcome aesthetic problems. The purpose of this article is to give information about the basic properties of dental zirconia implants and present 3 cases treated with two-piece zirconia implants. Two-piece zirconia dental implants, 4.0 mm diameter and 11.5 mm in length, were inserted into maxillary incisor region. They were left for 6 months to osseointegrate. Panoramic and periapical radiographs were obtained and examined for bone-implant osseointegration. During the follow-up period the patients were satisfied with their prosthesis and no complication was observed.

In Vivo Evaluation of Two-Piece Implants Placed Following One-Stage and Two-Stage Surgical Protocol in Posterior Mandibular Region. Assessment of Alterations in Crestal Bone Level

BACKGROUND

Endosseous implants can be placed following either two-stage technique requiring second-stage surgery or one-stage technique, which does not involve a second surgical intervention.

PURPOSE

The present study was undertaken to evaluate and compare the changes in crestal bone level when two-piece implants were placed in posterior mandibular region following one-stage and two-stage surgical protocol.

MATERIALS AND METHODS

A parallel group randomized prospective study was designed in which 20 two-piece implants were placed in the posterior mandibular region of 16 partially edentulous healthy patients following either one-stage (Group I) or a two-stage surgical protocol (Group II). Alterations in crestal bone level were assessed with the help of DentaScan at baseline, that is, at the time of implant placement, third month and sixth month.

RESULTS

Nonsignificant differences were seen in both groups in terms of changes in crestal bone level at the final evaluation.

CONCLUSIONS

Hence, it could be concluded that two-piece implants can be placed following one-stage surgical protocol as predictably as when two-stage surgical technique is followed.

Impact of platform switching on inter-proximal bone levels around short implants in the posterior region; 1-year results from a randomized clinical trial

AIM

To assess the outcome of short implants (8.5 mm) supplied with a conventional platform-matched implant-abutment connection or a platform-switched design.

MATERIALS AND METHODS

Eighty patients with one or more missing teeth in the posterior zone were randomly assigned to be treated with implants with either a conventional (control) or a platform-switched (mismatch 0.35-0.40 mm) implant-abutment connection (test). Follow-up visits were conducted 1 month and 1 year after placing the implant crown. Outcome measures were inter-proximal bone loss, using standardized peri-apical radiographs, implant survival, clinical parameters and patients' satisfaction.

RESULTS

One year after loading, inter-proximal bone loss around test implants (0.51 ± 0.51 mm) was significantly less than around control implants (0.73 ± 0.48 mm) (p = 0.011). Moreover, bone loss was less around 1 versus 2 adjacent implants (p = 0.001), in both the test (0.29 ± 0.36 versus 0.71 ± 0.55 mm) and control (0.46 ± 0.42 versus 0.88 ± 0.45 mm) group. With regard to implant survival, clinical parameters and patients' satisfaction no differences were observed between the test and control group.

CONCLUSION

This study suggested that crestal bone resorption may be reduced by platform switching. One year after loading, inter-proximal bone levels were better maintained at implants restored according to the platform switching concept.

Interventions for replacing missing teeth: 1- versus 2-stage implant placement

BACKGROUND

Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention.

OBJECTIVES

To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure.

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 21 January 2009.

SELECTION CRITERIA

All RCTs of osseointegrated dental implants comparing the same dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals.

MAIN RESULTS

Five RCTs were identified and included reporting data on 239 patients in total. On a patient, rather than per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured 2-stage (submerged) implants.

AUTHORS' CONCLUSIONS

The number of patients included in the trials was too small to draw definitive conclusions. The 1-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a 2-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability or when barriers are used for guided tissue regeneration, or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments especially in fully edentulous patients.

Effect of loading time on the success of complete mandibular titanium implant retained overdentures: a systematic review

OBJECTIVES

The aim of this review was to compare conventional against early/immediate loading protocols of implant-retained overdentures (IOD) in the edentulous mandible.

MATERIAL AND METHODS

Medline search via Ovid to extract prospective comparative studies on trials comparing the effect of timing of loading initiation on the success of mandibular IOD. The outcome of major interest was marginal bone loss. Probing depth, plaque, bleeding index and mobility were also assessed. Indices at 12 and 24 months were compared and changes assessed. Outcomes were entered into RevMan (version 4.2.5) for meta-analysis.

RESULTS

Of 239 articles, only nine trials fulfilled the criteria and involved 30 immediate, 71 early, 77 one-stage conventional, and 66 two-stage conventional subjects. Three immediate loading trials showed an increase in the amount of marginal bone loss over time, while the majority of early and conventionally loaded implants exhibited a decrease in the amount of bone loss in the second year compared with the first 12-month period. Probing depth at 24 months showed a significant difference between early and conventional loading; SMD 0.5 (95% confidence interval 0.03, 0.97). No other statistically significant differences were found between either immediate or early and conventional loading for any indices.

CONCLUSIONS

No deleterious effects up to 24 months have been shown from immediate or early loading. Conventional loading after a 3-month healing period has not been proven to be the only acceptable protocol for mandibular IOD, but further long-term studies are needed to confirm this.

Interventions for replacing missing teeth: 1- versus 2-stage implant placement

BACKGROUND

Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention.

OBJECTIVES

To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure.

SEARCH STRATEGY

The Cochrane Oral Health Group's Trials Register, The Cochrane Central Register of Controlled Trials, 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 15 January 2007.

SELECTION CRITERIA

All RCTs of root-form osseointegrated dental implants comparing the same 2-piece osseointegrated root-form dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals (CI). Heterogeneity was to be investigated including both clinical and methodological factors.

MAIN RESULTS

Three RCTs were identified and two trials including 45 patients in total were included. On a patient, rather than per implant basis, there were no statistically significant differences.

AUTHORS' CONCLUSIONS

The number of patients included in the trials was too small to draw reliable conclusions, however it appears that the two procedures did not show clinical significant differences. If these preliminary results will be confirmed by more robust trials, a 1-stage procedure might be preferable since it avoids one minor surgical intervention and shortens the waiting time to provide the final restoration. There might be specific situations though, such as when optimal implant stability is not obtained at placement or when barriers are used in conjunction with implants, in which a 2-stage approach might be preferable.

A Technique for Standardized Evaluation of Soft and Hard Peri-Implant Tissues in Partially Edentulous Patients

BACKGROUND

There is a growing need to evaluate the esthetics of implant-supported crowns and bridges. An important tool for such an evaluation is standardized assessment of the soft and hard peri-implant tissue levels.

METHODS

A simple acrylic device has been developed for reliable and reproducible assessment of soft and hard peri-implant tissues using standardized color slides and standardized dental x-rays. With this device, changes in both the soft and hard tissues around implant-supported crowns can be evaluated as a function of time. The reproducibility of the technique was tested on color slides as well as on dental x-rays in a series of implant-supported crowns and their neighboring teeth.

RESULTS

The reproducibility of this technique was excellent. The measuring errors for repeated measurements of the soft and hard tissues were 0.14 +/- 0.02 mm and 0.13 +/- 0.01 mm, respectively.

CONCLUSIONS

The device is a reliable tool to assess changes in both soft and hard tissues around crowns and implants over time. Likewise, it is suggested that this technique also can be used to objectively assess soft and hard tissue changes around natural teeth with or without prosthetic restorations.