Impact of cement- and screw- retained implant prostheses on marginal bone loss

It has been documented that the long-term clinical outcome of the Brånemark system is very favourable. However, failures do occur before and after loading. This study examined the differences in marginal bone loss between standard and self-tapping fixtures and attempted to explain excessive marginal bone loss or loss of osseointegration during the first 3 years of loading. Marginal bone loss (scored on long cone radiographs) and fixture failure rate were compared for different fixture designs. For standard fixtures, in comparison with self-tapping fixtures, the failure rate was clearly higher before as well as after loading. However, for successful fixtures no difference in marginal bone loss was observed. For the conical fixtures an increased marginal bone loss around the smooth part was observed. The effect of fixture overload, marginal bone height and loss of osseointegration was examined in 69 patients with 1 and 15 patients with 2 fixed full prostheses, and in 9 patients with an overdenture in the upper jaw. Excessive marginal bone loss (more than 1 mm) after the first year of loading and/or fixture loss correlated well with the presence of overload due to a lack of anterior contact, the presence of parafunctional activity and osseointegrated full fixed prostheses in both jaws.

ABSTRACTObjectivesThe aim of this retrospective multicentre cohort study was to compare clinical outcomes, soft tissues conditions and differences in marginal bone loss between implants with a laser-microgrooved collar placed in posterior maxillary extraction sockets grafted by 4 to 5 months, and in posterior maxillary pristine bone (spontaneously healed posterior maxillary extraction sockets) by means of osteotome-mediated sinus floor elevation, over a period of 5 years after functional loading.Material and MethodsPatients of Group 1 underwent extractions with sockets preservation using porcine-derived bone, covered with collagen membrane. Group 2 underwent extractions without socket preservation. Patients of Group 1 received implants in grafted sites, and Group 2 received implants in spontaneously healed bone using a maxillary sinus lift with crestal approach.ResultsOver the observation period, the overall clinical success rate in Group 1 and Group 2 was 98% and 100%, respectively, with no differences between the procedures and implants used. Cumulative radiographic marginal bone loss ranged from 0.03 to 0.39 mm after 60 months of functional loading. There were no statistically significant differences in marginal bone loss between short and standard-length implants placed in grafted extraction sockets and in pristine bone.ConclusionsShort and standard implants with a laser-microgrooved collar, placed in posterior maxillary extraction sockets grafted by 4 to 5 months, and in posterior maxillary pristine bone (spontaneously healed posterior maxillary extraction sockets) by means of osteotome-mediated sinus floor elevation, exhibited no statistical difference in success rate, clinical parameters and marginal bone loss.

The objective of this study was to compare marginal bone loss (MBL) and clinical complications between surviving implants (SIs) and recently placed implants (RIs) splinted together to support a fixed partial restoration (FPR). This retrospective study employed the medical records of patients treated with implant-supported FPRs in the Maccabi-Dent Dental Clinic. Patients were included if they were over the age of 18 years, were treated with RIs adjacent to existing SIs that had previously supported FPRs for more than 1 year, and the RIs and SIs were splinted to support new FPRs. Patients who did not receive annual follow-up or whose records had nondiagnostic radiographs or lacked sufficient restorative data were excluded. MBL was assessed at the last available radiograph and compared to one taken 1 year after loading the splinted RIs and SIs together. Clinical complication data were gathered from patient records. The medical records of 1,907 patients treated with a total of 7,306 implants were examined. Data from 187 implants were extracted from 46 patient records that met the inclusion criteria, with 96 RIs and 91 SIs supporting 56 FPRs. Mean followup was 39 ± 17.5 months. During the follow-up, two implants failed. The overall survival rate was 98.94% (98.96% in RIs and 98.91% in SIs), and the mean MBL in all implants was 0.41 ± 0.58 mm (0.4 ± 0.53 mm in RIs and 0.42 ± 0.45 mm in SIs). Peri-implantitis was reported in eight (4.3%) implants (four RIs and four SIs), screw loosening was reported in nine (4.8%) implants (three RIs and six SIs), ceramic chipping was reported in three (5.3%) restorations supported by four RIs and six SIs, and decementation was reported in one (1.8%) restoration supported by one RI and one SI. There was no statistically significant difference in survival rate, MBL, peri-implantitis, or screw loosening between RIs and SIs. There was no statistically significant difference in MBL or clinical complications between RIs and SIs. Splinting RIs and SIs for new prosthetic restoration support is a reasonable treatment choice with a high implant survival rate, low incidence of complications, and acceptable MBL.

The advancement in implant dentistry has allowed shortened treatment time by restoring the implants earlier. Whether the timing of restoration has an impact on implant marginal bone level has not been systematically analyzed. The aim of this study is to compare marginal bone loss (MBL) between implants that were restored with the following protocols: 1) immediate restoration/loading (IR/L); 2) early loading (EL); and 3) conventional loading (CL). An electronic literature search from three databases (until November 2011) and a hand search in implant-related journals were conducted. Clinical human studies in English language that had reported a comparison of MBL between implants with IR/L, EL, or CL with ≥12-month follow-up were included. In addition, the minimal number of implants had to be 10 for each group. Implants with both immediate placement (IP) and delayed placement (DP) were included and analyzed separately. An assessment of the publication bias for the included randomized clinical trials (RCTs) was performed. The initial search resulted in 1,640 articles, of which 27 articles in full text were further evaluated for eligibility. Finally, 11 studies (eight RCTs, two controlled clinical trials, and one retrospective study) were qualified and classified into four groups: 1) IR/L + DP versus CL + DP (n = 6 articles); 2) IR + DP versus EL + DP (n = 2 articles); 3) EL + DP versus CL + DP (n = 1 article); and (4) IL + IP versus CL + IP (n = 2 articles). A meta-analysis performed for group 1 showed 0.09 mm (95% confidence interval = -0.27 to 0.09 mm) difference in the mean MBL, favoring the IR/L protocol but without significant difference (P = 0.33). No significant difference in MBL was found for groups 2 through 4 after adjusting for the implant placement level. The eight RCTs were determined to be at moderate-to-high risk of publication bias. This meta-analysis does not show an effect of the timing of restorations on implant MBL. The selection of restoration protocols should be based on factors other than MBL.

To assess differences in marginal bone loss around implants placed in maxillary pristine bone and implants placed following maxillary sinus augmentation over a period of 3years after functional loading. Two cohorts of subjects (Group 1: Subjects who received sinus augmentation with simultaneous implant placement; Group 2: Subjects who underwent conventional implant placement in posterior maxillary pristine bone) were included in this retrospective study. Radiographic marginal bone loss was measured around one implant per patient on digitized panoramic radiographs that were obtained at the time of prosthesis delivery (baseline) and 12, 24, and 36months later. The influence of age, gender, smoking habits, history of periodontal disease, and type of prosthetic connection (internal or external) on marginal bone loss was analyzed in function of the type of osseous support (previously grafted or pristine). A total of 105 subjects were included in this study. Cumulative radiographic marginal bone loss ranged from 0mm to 3.9mm after 36months of functional loading. There were statistically significant differences in marginal bone loss between implants placed in grafted and pristine bone at the 12-month assessment, but not in the subsequent progression rate. External prosthetic connection, smoking, and history of periodontitis negatively influenced peri-implant bone maintenance, regardless of the type of osseous substrate. Implants placed in sites that received maxillary sinus augmentation exhibited more marginal bone loss than implants placed in pristine bone, although marginal bone loss mainly occurred during the first 12months after functional loading. Implants with external implant connection were strongly associated with increased marginal bone loss overtime.

BackgroundImplant prosthetic design significantly impacts peri‐implant health. This systematic review and meta‐analysis explored emerging concepts in prosthetic considerations, appraising the level of evidence and clinical significance of these suprastructures on peri‐implant marginal bone loss (MBL).MethodsAn electronic search of three databases and a manual search of peer‐reviewed journals for relevant articles published in English between January 1980 and December 2023 were performed. Eligible studies featured dental implants restored within ≥12 months, with ≥10 implants in each group. Inverse variance meta‐analyses were performed to compare various prosthetic factors and their impact on MBL and the risk of peri‐implantitis.ResultsScrew‐retained versus cement‐retained prostheses demonstrated no significant difference in MBL (six articles, p = 0.51). Nonsplinted implants exhibited lower MBL compared to their splinted counterparts (eight articles, p = 0.04). Platform‐switched abutments were correlated with reduced MBL compared to platform‐matched ones (20 articles, p < 0.0001). Internal connections, particularly conical ones, displayed less MBL than external connections (20 articles, p < 0.0001). The crown‐to‐implant ratio did not significantly affect MBL (five articles, p = 0.32). Abutment heights ≥2 mm are associated with less MBL than heights <2 mm (12 articles, p < 0.0001). Implementing a one abutment‐one time protocol resulted in less MBL than repeated abutment disconnections (10 articles, p < 0.0001). Emergence angles <30° and a concave/straight profile led to lower peri‐implantitis risk (two articles each; p = 0.05 and p = 0.03, respectively).ConclusionsNonsplinted implants, platform‐switched abutments, abutment heights ≥2 mm, and a one abutment‐one time approach yielded significant reductions in MBL compared to their counterparts. Furthermore, emergence angles <30° and a concave/straight emergence profile were linked to decreased peri‐implantitis risk. Meanwhile, factors such as screw‐retained versus cement‐retained prostheses and crown‐to‐implant ratio yielded no significant difference in MBL.Plain Language SummaryThe design of implant‐supported tooth replicas plays a key role in keeping the surrounding gums and bone healthy. This study reviewed research from 1980 to 2023 to examine how different design features of these restorations impact oral tissue health. A total of 93 studies were included, focusing on patients aged 18 years and older, with at least 10 patients in each group. The findings showed that individual tooth replicas (rather than splinted ones) led to better gum health. A horizontal offset at the implant–replica junction helped reduce bone loss. Implants with internal connections (inside the implant body) performed better than those with external connections. Tooth replicas with narrow contours at the implant junction were more beneficial than convex shapes. Additionally, using abutments taller than 2 mm and minimizing the number of times an abutment is removed during fabrication helped preserve surrounding tissues. These findings highlight how careful implant design can improve long‐term oral health, reducing complications and maintaining stability around dental implants.

The aim of this study was to compare marginal bone loss levels between axially and angled installed implants in maxillary rehabilitation utilizing the All-on-Four concept, while also examining the impact of terminal cantilever size on implant/prosthesis set survival. This retrospective cohort study involved 11 patients (44 implants) who received implant-supported prostheses with immediate loading. Radiographic evaluations were conducted on the day of prosthesis delivery, including panoramic and periapical radiographs, establishing the baseline (T0). Follow-up periapical radiographs were taken at 6months (T1), 1year (T2), and 2years (T3) post-prosthesis delivery. Panoramic radiographs were used to determine implant angulation and the size of terminal cantilevers. Marginal bone loss on the mesial and distal aspects of each implant was assessed across study periods. Statistical analysis revealed no significant difference in marginal bone loss between axially and inclined implants. Terminal cantilever lengths ranged from 6.11 to 17.15mm, with a decrease observed in cases with implants tilted up to 30°. However, no significant difference in cantilever lengths was found between the two groups (group 1: tilts 0°-30°, group 2: tilts above 30°). The survival rate of the implant/prosthesis sets was 100%. In conclusion, there were no statistically significant differences in marginal bone loss between axial and inclined implants. Implant inclination allowed for prostheses with smaller terminal cantilevers, contributing to a balanced distribution of stresses on the implant/prosthesis set. Further randomized clinical trial should be conducted to confirm the presented findings.

To compare time-dependent outcome of immediately loaded 1-piece (1P) implants with delayed loaded 1P and 2-piece (2P) implants. A cohort of 33 patients divided into 3 groups: group A, 13 patients, 49 immediately placed and loaded 1P implants; group B, 11 patients, immediately placed and delayed loaded 1P implants; and group C, 10 patients, 39 2P implants delayed placed and loaded in a two-stage procedure. Marginal bone loss (MBL) was analyzed using x-ray radiography every 6 months, 1 year, and 3 years. A statistically significant mean MBL was observed between baseline, 6 months, 1 year, and 3 years in all groups. There was no statistical significant difference in MBL between immediate and delayed loaded 1P implants. MBL around mandibular implants was lower compared with maxillary implants. 2P implants showed less MBL compared with 1P implants in both maxilla and mandible. There was no statistical difference in MBL between immediate and delayed loaded 1P implants. Immediate loaded implants show more MBL in maxilla.

BackgroundOcclusal loading refers to a modality in which an implant-supported prosthesis is subjected to functional loading, maintaining contact with the opposing dentition from the onset of prosthetic placement. In contrast, non-occlusal loading represents a non-functional approach, wherein a provisional implant prosthesis is initially placed in infra-occlusion or fully relieved of contact with the opposing dentition, which is subsequently (at a later stage) followed by functional (occlusal) loading with the definitive prosthesis.AimTo compare clinical outcomes in partially edentulous cases following an occlusal modality of loading versus non-occlusal modality of loading.MethodA search on Pubmed, Scopus and Embase databases was conducted to identify randomised controlled trials (RCTs) comparing occlusal versus non-occlusal modalities of implant loading in partially edentulous patients receiving implants with single crowns or fixed bridges, between January 1 (2004) to June 12 (2024), examining implant survival, complications and marginal bone loss (MBL) of implants. The inclusion criteria involved RCTs of evidence level II (Oxford Centre for Evidence-Based Medicine Levels of Evidence). For assessing bias in the included studies, the Cochrane Risk of Bias tool was used.ResultsThis review identified seven RCTs investigating 273 implants over 1–3 years follow-up periods. seven studies reported 1-year MBL data and three reported 3-year data. Publication bias was noted at the 1-year follow-up (p < 0.01) but not at 3 years (p > 0.05). Differences in MBL were not statistically significant at both 1 year (Hedges’ d = 0.01, p = 0.920, 95% CI: [−0.21, 0.24]) and 3 years (Hedges’ d = 0.01, p = 0.952, 95% CI: [−0.28, 0.30]). Differences in complication occurrences were not statistically significant (RR = 0.882, p = 0.759, 95% CI: [0.397, 1.964]). The nature of data on implant survival rates prevented a meaningful meta-analysis.ConclusionFor short-term periods of 1–3 years, no significant evidence supports clinical superiority in terms of complication rates and MBL between non-occlusal and occlusal modalities of implant loading. Future studies should explore functional and aesthetic aspects, as well as patient reported outcomes to determine any short-term differences or consider long-term follow-up with large sample sizes to detect significant clinical differences.

A total of 123 patients were followed between January 1983 and July 1998 with 140 tooth-implant connected prostheses. The age of the patients at prosthesis installation ranged from 20 to 79 years (mean 51.8). 339 (Brånemark(R) system) implants were connected to 313 teeth. The loading time ranged from 1.5 to 15 years (mean: 6.5). 123 patients were randomly selected as a control group with freestanding implant-supported prostheses only. The age of the patients at prosthesis installation ranged from 22 to 78 years (mean 52.3). The loading time for the 329 freestanding (Brånemark(R) system) implants ranged from 1.3 to 14.5 years (mean: 6.2). Evolution of the marginal bone stability around the implant in the tooth-implant connected as well as the freestanding group was studied with respect to the prognosis of the implants. Over the period from 0 to 15 years, there was significantly more marginal bone loss (0.7 mm) in tooth-implant connected versus freestanding prostheses. No significant difference in marginal bone loss was found between the non-rigid tooth-implant connected prostheses versus freestanding prostheses. However, there was a significant difference in marginal bone loss for rigid and multi-connected tooth-implant connected prostheses versus freestanding ones. The results of this study indicate that more bone is lost around implants which are rigidly connected to teeth. This suggests that bending load, which is increased in tooth-implant connected prostheses, might be responsible for this phenomenon. These observations favor the use of freestanding prostheses whenever possible. However, the clinical significance of greater bone loss in rigid versus non-rigid connections might outweigh the annoying phenomenon of tooth intrusion in the case of non-rigid tooth connection, when connection is considered.

PURPOSEThe purpose of this study was to evaluate survival rates and marginal bone loss (MBL) of implants in IC-RPDs.MATERIALS AND METHODSSeventy implants were placed and used as surveyed crowns in 30 RPDs. The survival rates and MBL around implants based on multiple variables, e.g., position, sex, age, opposing dentitions, splinting, type of used retainer, and first year bone loss, were analyzed. Patient reported outcome measures (PROMs) regarding functional/esthetic improvement after IC-RPD treatment, and complications were also inspected.RESULTSThe 100% implant survival rates were observed, and 60 of those implants showed MBL levels less than 1.5 mm. No significant differences in MBL of implants were observed between implant positions (maxilla vs. mandible; P = .341) and type of used retainers (P = .630). The implant MBL of greater than 0.5 mm at 1 year showed significantly higher MBL after that (P < .001). Splinted implant surveyed crowns showed lower MBL in the maxilla (splinted vs. non-splinted; P = .037). There were significant esthetic/functional improvements observed after treatment, but there were no significant differences in esthetic results based on implant position (maxilla vs. mandible). Implants in mandible showed significantly greater improvement in function than implants in the maxilla (P = .002). Prosthetic complication of IC-RPD was not observed frequently. However, 2 abutment teeth among 60 were failed. The bone loss of abutment teeth was lower than MBL of implants in IC-RPDs (P = .001).CONCLUSIONClass I RPD connected to residual teeth and strategically positioned implants as surveyed crowns can be a viable treatment modality.

Purpose: To conduct a comprehensive systematic review and meta-analysis on marginal bone loss (MBL) in dental implants, enhancing the understanding and management of both bone-level and tissue-level implants. Methods: MEDLINE-PubMed and Scopus databases were searched for relevant English articles (up to April 2024), assessing the MBL as the primary outcome. The relevant data were extracted, and a meta-analysis was performed to evaluate the effect of implant neck design. Results: A total of 17 studies were included for qualitative analysis. Out of the 21 articles included, 15 studies established a statistically significant difference in MBL between the study groups; however, the differences were not found to be clinically relevant. Bone-level implants with platform-switched abutments in most of the cases showed better marginal bone stability compared to tissue-level implants or bone-level implants with matching abutments. Seven RCT studies were evaluated for the MBL between bone-level and tissue-level implants. The difference in MBL between bone-level implants and tissue-level implants was statistically significant, with a greater loss of bone in bone-level implants (Mean Difference: 0.11, 95% CI:0.02 to 0.19, p = 0.01 and I2 heterogeneity: 81%, p &lt; 0.0001). Conclusions: This review underscores the need for standardized measurement techniques, consideration of patient-specific factors in clinical decision-making, and further long-term studies to optimize dental implant success and patient outcomes.

An angulation of the implant connection could overcome the problems related to angulated abutments. This study compares conventional implants with angulated abutment to tilted implants with an angulated connection. Twenty patients were treated in the edentulous mandible. In the posterior jaw locations, one conventional tilted implant with angulated abutment and one angulated implant without abutment were placed. In the anterior jaw, two conventional implants were placed, one with and one without abutment. Implants were immediately loaded and 3 months later, the final bridge (PFM or monolithic zirconia) was placed. After a follow-up of 48 months, 17 patients were available for clinical examination. The mean overall marginal bone loss (MBL) was 1.26 mm. No significant differences in implant survival, MBL, periodontal indices, patients' satisfaction, or complications was found between implants restored on abutment or implant level, between the posteriorly located angulated implant nor angulated abutment, and between both anterior implants with or without abutment. The posterior implants demonstrated less MBL compared to the anterior implants (P < .001). There was no significant difference in MBL between the implants restored with zirconia or PFM bridges (P = .294). Overall mean pocket depth was 2.83 mm. More plaque was found in the PFM group compared to the full-zirconia group, at the bridge (P = .042) and the implants (P = .029). There was no difference between both materials in pocket depth (P = .635) or bleeding (P = .821). One zirconia bridge fractured, two angulated abutment were replaced and four loose bridge screws connected to the angulated abutments had to be tightened. Patients were overall satisfied (4.74/5). An implant with angulated connection may results in a stronger connection but does not affect the marginal bone loss. No difference in MBL was seen between implants restored on abutment or implant level. Zirconia seems to reduce the amount of plaque.

An electronic search was performed in PubMed, Web of Science and the Cochrane Central Register of Controlled Trials up to February 2015. References of included studies were also searched. No language restrictions were applied. Study selection: Prospective, retrospective and randomised clinical trials that compared marginal bone loss and failure rates between smokers and non-smokers. Implant failure was considered as total loss of the implant. Studies with patients who had periodontal disease prior to treatment or who had metabolic diseases were excluded. Two reviewers were involved in the research and screening process and disagreements were resolved by discussion. The quality of the studies was analysed using the Newcastle-Ottawa scale for non-randomised clinical trials. Data extracted from the studies included, when available: follow up period, number of subjects, smoking status, number of implants placed, implant system, implant length and diameter, healing period, antibiotics and mouth-rinse use, marginal bone loss, failure rate and drop-outs. For binary outcomes (implant failure) the estimate of the intervention effect was expressed in the form of an odds ratio (OR) with the confidence interval (CI) of 95%. For continuous outcomes (marginal bone loss) the average and standard deviation (SD) were used to calculate the standardised mean difference with a 95% CI. Meta-analysis was performed for studies with similar outcomes, I(2) a statistical test was used to express the heterogeneity among the studies. Publication bias was explored as well. A total of 15 observational studies were included in the review. The number of participants ranged from 60 to 1727 and the average age was 52.5 years. The follow-up period ranged from eight to 240 months. The total number of implants placed was 5840 in smokers and 14,683 in non-smokers. The Branemak system, (Noble Biocare AB, Goteborg, Sweden), was the most commonly used implant system. There was a statistically significant difference in marginal bone loss favouring the non-smoking group (SMD 0.49, 95% CI 0.07-0.90). There was an increase in marginal bone loss in the maxillae of smokers compared to the mandible (SMD 0.40, 95% CI 0.24-0.55) and a statically significant difference in implant failure in favour of the non-smoking group OR 1.96, 95% CI 1.68-2.30. The risk of marginal bone loss and implant failure is increased in smokers compared to non-smokers, however, the results should be interpreted with caution since the data from the review are provided by retrospective and cohort studies.

To verify the survival rates and marginal bone loss (MBL) of implants in patients with different disability types. Clinical and radiographic assessments were performed in a total of 189 implants for fixed implant prostheses in 72 patients. Data were collected on loaded implants at least 1 year in function, and the mean observation time was 37.3 months. Implant survival was examined, and MBL was observed around the implants of two groups (mental disability vs physical disability) based on age, sex, implant location (anterior vs posterior), and prosthetic connection (internal vs external). Of the 189 implants, 4 failed; the total implant survival rate was 97.8% across a mean of 37.3 months. The cumulative survival rate at 85 months in a Kaplan-Meier survival curve analysis was 94.3% ± 3% in patients with mental disability and 50% ± 35.4% in patients with physical disability, which was a statistically significant difference between the disability groups (P = .006). Fisher exact test showed significant differences in MBL only with age (P < .001). The implant MBL by disability type-adjusted for age and observation period-showed significant differences in multiple linear regression analyses (P = .003). The implant survival rates in patients with disability were in line with those reported for nondisabled patients. The MBL of the implants was within the physiologic bone loss after implant loading. Implants in patients with mental disability showed higher cumulative survival rates than in patients with physical disability, but also a higher amount of MBL. Within the limitations of this study, dental implants for patients with disability are viable. These results can establish future implant treatment plans for this population. Int J Oral Maxillofac Implants 2023;38:562-568. doi: 10.11607/jomi.9880.