Long-term outcomes of dental implants with a titanium plasma-sprayed surface: a 20-year prospective case series study in partially edentulous patients

BACKGROUND

Long-term studies of ≥10 years are important milestones to get a better understanding of potential factors causing implant failures or complications.

PURPOSE

The present study investigated the long-term outcomes of titanium dental implants with a rough, microporous surface (titanium plasma sprayed [TPS]) and the associated biologic and technical complications in partially edentulous patients with fixed dental prostheses over a 20-year follow-up period.

MATERIALS AND METHODS

Sixty-seven patients, who received 95 implants in the 1980s, were examined with well-established clinical and radiographic parameters. Based on these findings, each implant was classified as either successful, surviving, or failed.

RESULTS

Ten implants in nine patients were lost during the observation period, resulting in an implant survival rate of 89.5%. Radiographically, 92% of the implants exhibited crestal bone loss below 1 mm between the 1- and 20-year follow-up examinations. Only 8% yielded peri-implant bone loss of >1 mm and none exhibited severe bone loss of more than 1.8 mm. During the observation period, 19 implants (20%) experienced a biologic complication with suppuration. Of these 19 implants, 13 implants (13.7%) had been treated and were successfully maintained over the 20-year follow-up period. Therefore, the 20-year implant success rate was 75.8 or 89.5% depending on the different success criteria. Technical complications were observed in 32%.

CONCLUSION

The present study is the first to report satisfactory success rates after 20 years of function of dental implants with a TPS surface in partially edentulous patients.

A multifactorial analysis to identify predictors of implant failure and peri-implant bone loss

OBJECTIVE

To identify risk factors for failure and bone loss of implants in a large study sample on the basis of multivariate analyses.

MATERIALS AND METHODS

Patient files of all patients referred for implant treatment from November 2004 to December 2007 were scrutinized, and information on implant- and patient-related factors was collected. The study sample in this retrospective cohort study consisted of both partially dentate and fully edentulous patients referred for various indications. The only inclusion criterion was a follow-up of at least 2 years. Implant survival and bone loss were assessed by an external investigator (SV) comparing digital periapical radiographs taken during recall visits with the postoperative ones. Univariate and multivariate tests were adopted to identify possible risk indicators for implant failure and peri-implant bone loss.

RESULTS

Twenty-one of 1,320 (1.6%) implants were lost in 19 of 376 (5.1%) patients (210 female, 166 male; mean age 56, range 17-82) after a mean follow-up of 32 months (range 24-62). Based on multivariate analysis, only smoking (p = .001) and recall compliance (p = .010) had a significant influence on implant failure, with smokers more prone to failure. The overall mean bone loss was 0.36 mm (SD 0.68, range 0.00-7.10). Smoking (p = .001) and jaw of treatment (p = .001) affected peri-implant bone loss. More peri-implant bone loss was observed in smokers and in the maxilla. A clear discrepancy was found between univariate and multivariate analysis with regard to identification of risk factors.

CONCLUSION

Multivariate analysis demonstrated that implant-related factors did not affect the clinical outcome, but smoking was identified as a predictor for implant failure. Predictors for peri-implant bone loss were smoking and jaw of treatment.

Macrophage polarization in aseptic bone resorption around dental implants induced by Ti particles in a murine model

BACKGROUND AND OBJECTIVES

Titanium particles/ions detected in peri-implant tissues have been considered as a potential etiologic factor for crestal bone loss around oral implants. However, the definite impact of titanium wear particles on the health of surrounding structures remains undetermined. The purpose of this study was to investigate the effects of titanium particles-induced foreign body reaction on peri-implant bone level and the related mechanism by using clodronate liposomes to deplete macrophages.

MATERIAL AND METHODS

Sprague Dawley rats with custom-made titanium screw implanted in bilateral maxillary first molar area for 4 weeks to obtain osseointegration were randomly divided into four groups. Twenty microgram titanium particles were introduced into the peri-implant tissue to induce aseptic foreign body reaction, and macrophages were depleted by the local injection of 100 μL clodronate liposome immediately and re-injection every 3 days until the sacrifice of the rats (Ti + LipClod group). Titanium-injected rats also treated with phosphate buffer solution (Ti + PBS) or empty liposome (Ti + Lip) as well as rats injected with PBS alone (Control) were included as controls. Eight weeks later, animals were sacrificed and samples containing implants were collected. Half of the samples were analyzed radiologically to measure bone level change, and macrophage markers (CD68, CCR7, CD163) was also characterized by immunofluorescence to evaluate macrophage number, density, and phenotype distribution (CCR7+M1/CD163+M2). The rest of the samples were used to determine the relative mRNA expression levels of TNF-α, IL-1β, IL-6, and RANKL with real-time PCR analysis.

RESULTS

No obvious bacterial contamination was found in all titanium-injected areas, and the implant survival rate was 100% with no implant loss. Compared with Ti + PBS and Ti + Lip group, macrophage density (1.64 ± 0.86%) infiltrated into peri-implant tissue and bone loss (0.17 ± 0.03 mm) around implant decreased significantly in the Ti + LipClod group. Immunofluorescence analysis showed that more macrophage infiltrated into peri-implant tissue in the Ti + PBS and Ti + Lip groups, predominantly with M1 phenotype. In contrast, the macrophage density was lower and M2 phenotype was dominant in the Control group, while macrophages density was significantly reduced and the M1 type macrophages were slightly more than M2 type in the Ti + LipClod group. Accordingly, TNF-α, IL-1β, IL6, and RANKL mRNA expression increased significantly in the Ti + PBS and Ti + Lip groups compared with Control and Ti + LipClod groups.

CONCLUSIONS

Titanium particles had a negative effect on peri-implant tissue by activating macrophages which induced an M1 macrophage phenotype promoting local secretion of inflammatory cytokines. It was found that clodronate liposome treatment attenuated the severity of inflammation and bone loss by depletion of macrophages. Therefore, the present study revealed the marked impact of macrophage polarization with respect to peri-implant bone loss caused by titanium particles.

The impact of cantilevers on biological and technical success outcomes of implant-supported fixed partial dentures. A retrospective cohort study

OBJECTIVE

To investigate the biological and technical success outcomes of implant-supported fixed dental prostheses with and without cantilevers, after a minimum of one year loading.

MATERIAL AND METHODS

One hundred and seven subjects with 128 cantilever FDPs (cFDP) supported by 132 implants were compared with 99 individuals with 144 non-cantilever FPDs (ncFDPs) supported by 203 implants. Outcomes such as marginal bone loss from FDP insertion to final follow-up as well as frequency and extent of biological and technical complications were investigated and correlated with patient, site, implant and FDP design characteristics.

RESULTS

The cFDPs were followed for average of 51 months (1551 days, SD ± 977), and ncFPDs for 49 months (1483 days, SD ± 809 days). Implant survival and success rates were 96.7% and 87.9% for implant supporting cFDPs, and 99.5% and 92.6% for ncFDPs. There was no significant difference in overall bone loss between cFDPs and ncFDPs (cantilever side: 0.58, SD ± 1.16 - non-cantilever side: 0.59, SD ± 0.99), but implants in the cantilever group lost significantly more bone in the posterior mandible (0.50 SD ± 1.3 mm for cFDPs and 0.24 SD ± 0.80 mm for ncFDPs). Within the cantilever group, cantilever arm length and implant location had an influence on bone loss. Regardless of the presence of cantilever, implants associated with technical complications had a higher rate of biological complications as well. Furthermore, the length of the cantilever arm was positively correlated with implant failure, technical complications and bone loss ≥1.5 mm (P = 0.011, <0.001, and 0.007).

CONCLUSION

Overall implants can be successfully used to support cantilever FDPs. However, there are technical and biological implications which appear inter-related.

Peri-implant parameters, tumor necrosis factor-alpha, and interleukin-1 beta levels in vaping individuals

BACKGROUND

To the author's knowledge, there has been no study that has assessed clinical, radiographic, and immunological peri-implant parameters among individuals vaping e-cigarette (e-cig).

PURPOSE

This pilot study aimed to compare clinical and radiographic peri-implant parameters and levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1β levels among individuals vaping e-cigs and never smoker (NS).

MATERIALS AND METHODS

Forty-seven individuals vaping e-cigs (group-1) and 45 NS (group-2) were included. Demographic and implant-related data were collected using a structured baseline questionnaire. Peri-implant plaque index (PI), bleeding on probing (BOP), and probing depth (PD) were recorded and peri-implant bone loss (PIBL) were assessed using standardized digital radiographs. Enzyme-linked immunosorbent assay was used to assess the levels of TNF-α and IL-1β in peri-implant sulcular fluid.

RESULTS

Bleeding on probing showed statistically significantly higher values in group-2 patients as compared to group-1 patients (P < .01). Probing depth ≥ 4 mm and PIBL was statistically significantly higher in group-1 patients as compared to group-2 patients (P < .05). Mean concentrations of TNF-α (P < .001) and IL-1β (P < .01) were statistically significantly increased in individuals in group 1 as compared with group 2. A significant positive correlations were found between TNF-α levels and BOP (P = .024) and PIBL (P = .016); and significant positive correlation was found between IL-1β and PIBL (P = .018) in group 1, respectively.

CONCLUSIONS

Clinical and radiographic peri-implant parameters are compromised among vaping individuals. Increased levels of proinflammatory cytokines in peri-implant sulcular fluid may suggest greater local inflammatory response in vaping individuals for peri-implant inflammation.

What is the influence of implant surface characteristics and/or implant material on the incidence and progression of peri-implantitis? A systematic literature review

OBJECTIVES

To answer the focused question, 'In animals or patients with dental implants, does implant surface characteristics and/or implant material have an effect on incidence and progression of peri-implantitis?'

MATERIAL AND METHODS

Pre-clinical in vivo experiments on experimental peri-implantitis and clinical trials with any aim and design, and ≥5 years follow-up, where the effect of ≥2 different type of implant material and/or surface characteristics on peri-implantitis incidence or severity, and/or progression, implant survival or losses due to peri-implantitis, and/or marginal bone levels/loss was assessed.

RESULTS

Meta-analyses based on data of pre-clinical experiments, using the ligature induced peri-implantitis model in the dog, indicated that after the spontaneous progression phase implants with a modified surface showed significantly greater radiographic bone loss (effect size 0.44 mm; 95%CI 0.10-0.79; p = .012; 8 publications) and area of infiltrated connective tissue (effect size 0.75 mm² ; 95%CI 0.15-1.34; p = .014; 5 publications) compared to non-modified surfaces. However, in 9 out of the 18 included experiments, reported in 25 publications, no significant differences were shown among the different implant surface types assessed. Clinical and/or radiographic data from 7605 patients with 26,188 implants, reported in 31 publications (20 RCTs, 3 CTs, 4 prospective cohort, and 4 retrospective studies; 12 with follow-up ≥10 years), overall did not show significant differences in the incidence of peri-implantitis, when this was reported or could be inferred, among the various implant surfaces. In general, high survival rates (90-100%) up to 30 years and no clinically relevant differences in marginal bone loss/levels, merely compatible with crestal remodelling, were presented for the various implant types.

CONCLUSION

Pre-clinical in vivo experiments indicate that surface characteristics of modified implants may have a significant negative impact on peri-implantitis progression, while clinical studies do not support the notion that there is a difference in peri-implantitis incidence among the various types of implant surfaces. No assumptions can be made regarding the possible impact of implant material on incidence and/or peri-implantitis progression due to limited information.

Dental Implants with Different Neck Design: A Prospective Clinical Comparative Study with 2-Year Follow-Up

The present study was conducted to investigate whether a different implant neck design could affect survival rate and peri-implant tissue health in a cohort of disease-free partially edentulous patients in the molar–premolar region. The investigation was conducted on 122 dental implants inserted in 97 patients divided into two groups: Group A (rough wide-neck implants) vs. Group B (rough reduced-neck implants). All patients were monitored through clinical and radiological checkups. Survival rate, probing depth, and marginal bone loss were assessed at 12- and 24-month follow-ups. Patients assigned to Group A received 59 implants, while patients assigned to Group B 63. Dental implants were placed by following a delayed loading protocol, and cemented metal–ceramic crowns were delivered to the patients. The survival rates for both Group A and B were acceptable and similar at the two-year follow-up (96.61% vs. 95.82%). Probing depth and marginal bone loss tended to increase over time (follow-up: t₁ = 12 vs. t₂ = 24 months) in both groups of patients. Probing depth (p = 0.015) and bone loss (p = 0.001) were significantly lower in Group A (3.01 vs. 3.23 mm and 0.92 vs. 1.06 mm; Group A vs. Group B). Within the limitations of the present study, patients with rough wide-neck implants showed less marginal bone loss and minor probing depth, as compared to rough reduced-neck implants placed in the molar–premolar region. These results might be further replicated through longer-term trials, as well as comparisons between more collar configurations (e.g., straight vs. reduced vs. wide collars).

Biological aspects: Summary and consensus statements of group 2. The 5th EAO Consensus Conference 2018

OBJECTIVES

This publication reports the EAO Workshop group-2 discussions and consensus statements which provided the scientific evidence on the influence of biological parameters on implant-related clinical outcomes.

MATERIAL AND METHODS

The first publication was a systematic review on the biological effects of abutment material on the stability of peri-implant marginal bone levels and the second, a critical narrative review on how peri-implant diagnostic parameters correspond with long-term implant survival and success. The group evaluated the content of both publications, made corrections and recommendations to the authors and agreed on the consensus statements, clinical recommendations and recommendations for future research, which are described in this consensus report.

RESULTS

Tested abutment materials can be considered appropriate for clinical use according to the observation period studied (mean 3.5 years). Mean peri-implant bone loss and mean probing pocket depths are not adequate outcomes to study the prevalence of peri-implantitis, while the reporting of frequency distributions is considered more appropriate.

CONCLUSIONS

Titanium is currently considered the standard of care as abutment material, although other materials may be more suitable for aesthetic locations. Peri-implantitis should be diagnosed through composite evaluations of peri-implant tissue inflammation and assessment of marginal bone loss with different thresholds.

Influence of abutment disconnection on peri-implant marginal bone loss: A randomized clinical trial

OBJECTIVES

To evaluate the influence of abutment disconnections and reconnections on peri-implant marginal bone loss.

MATERIAL AND METHODS

Twenty-four participants received single-unit implants and were randomly assigned into one of the two groups: the definitive abutment group (DEF), in which the definitive abutments were connected at the same time as the implant was inserted; and as a control, the healing abutment group (HEA), in which the healing abutments were disconnected and reconnected three times, at 8, 10, and 12 weeks after surgery. Peri-implant marginal bone level was measured through radiographic follow-up performed immediately after the surgery (baseline), at 8 weeks and after 6, 12, and 24 months. Implant stability and peri-implant health were assessed by resonance frequency analysis and peri-implant probing, respectively.

RESULTS

At the end of 2 years, the mean bone level was -0.18 ± 0.12 mm for the DEF group and -0.13 ± 0.13 mm for the HEA group, resulting in a cumulative bone loss of -0.61 ± 0.10 mm and -0.81 ± 0.15 mm, respectively, with no statistical difference between groups. Bone level changes showed statistically significant differences only between 0 and 2 months (DEF: -0.70 ± 0.12 mm; HEA: -0.36 ± 0.10 mm) and between 2 and 6 months (DEF: -0.11 ± 0.11 mm; HEA: -0.65 ± 0.14 mm). No differences were observed between the groups for implant stability, probing depth, and bleeding on probing.

CONCLUSION

Immediate connection of the prosthetic abutments did not reduce bone loss in comparison with three disconnections of the healing abutments.

Implants Survival Rate in Regenerated Sites with Innovative Graft Biomaterials: 1 Year Follow-Up

In thirteen different dental clinics in Singapore, Spain, Czech Republic and Italy, 504 patients were selected, and 483 dental implants were placed in maxillary sites after alveolar socket preservation (ASP) procedures with an autologous demineralized tooth extracted as graft material from an innovative Tooth Transformer device was obtained. All procedures used were reported in n°638 Ethical Committee surgical protocol of University of Chieti and approved. After 4 months, at dental implant placing, bone biopsies were performed to evaluate the histologic outcomes, and 12 months after implant loading, global implant survival rate, failure percentage and peri-implant bone loss were detected. After ASP, only 27 post-operative complications were observed and after 4 months, bone biopsy histomorphometric analysis showed a high percentage of bone volume (BV) 43.58 (±12.09), and vital new bone (NB) 32.38 (±17.15) with an absence of inflammation or necrosis areas. Twelve months after loading, only 10 dental implants failed (2.3%), with a 98.2% overall implant survival rate, nine cases showed mucositis (1.8%) and eight showed peri-implantitis (1.6%). At mesial sites, 0.43 mm (±0.83) of bone loss around the implants was detected and 0.23 mm (±0.38) at the distal sites with an average value of 0.37 mm (±0.68) (p > 0.568). Several studies with a longer follow-up will be necessary to confirm the preliminary data observed. However, clinical results seem to suggest that the post-extraction socket preservation procedure using innovative demineralized autologous tooth-derived biomaterial may be a predictable procedure to produce new vital bone able to support dental implant rehabilitation of maxilla edentulous sites.

A cohort study on short mini-implants for mandibular overdentures compared to those of standard length

OBJECTIVES

To assess peri-implant bone level, survival and success rates of short (6 or 8 mm long) one-piece mini-implants (MDIs) in edentulous patients with extremely resorbed alveolar ridge (interforaminal height <10 mm) rehabilitated with mandibular implant overdentures and to compare them with patients having standard length MDIs in 1-year prospective clinical study.

MATERIAL AND METHODS

The Short MDI group consisted of 28 participants with interforaminal height ≤10 mm. Implants being, both, short and slim (short MDIs: 6 or 8 mm long, 2 or 2.5 mm wide) were inserted. The Standard-MDI group included 35 participants (interforaminal height >13 mm) who received standard length MDIs (10-14 mm long, 2 or 2.5 mm wide). Primary outcomes were assessments of MDI peri-implant bone level, survival and success rates; secondary outcomes were assessments of peri-implant tissue, oral hygiene, and prosthodontic maintenance.

RESULTS

The Short MDI group had mean marginal bone loss (MBL) of 0.26 ± 0.35 mm, 6.4% of failure, and 92.6% of, both, success and survival rates. The Standard-MDI group had mean MBL of 0.34 ± 0.40 mm, 5% of failure, 95% of survival, and 94.3% success. There were no significant differences in MBL (p = .420), survival (p = .414), and success (p = .571) between the groups. The Short MDI group had significantly less plaque (p = .001) and bleeding on probing (p < .001).

CONCLUSION

Within the limitations of this study, short MDIs (6 or 8 mm long) in extremely atrophied mandibles (interforaminal height <10 mm) showed good clinical results in the first year of function.

Transforming growth factor-β, interleukin-17, and IL-23 gene expression profiles associated with human peri-implantitis

OBJECTIVES

The mRNA expression profiles of IL-23/Th17 and the Treg-associated cytokine TGF-β in peri-implantitis are currently under research. This study characterized the IL-17, IL-23, and TGF-β gene expression levels in healthy and diseased peri-implant tissues and correlated these data with radiographic bone loss.

MATERIAL AND METHODS

Peri-implant soft tissues from 40 subjects (20 healthy controls with mean age of 59.4 ± 6.3, and 20 with peri-implantitis with mean age of 56.6 ± 5.5) were enrolled in this study, and real-time PCR (RT-PCR) was used to define the profile of IL-17, IL-23, and TGF-β gene expression.

RESULTS

Higher levels of TGF-β mRNA were observed in biopsies taken from healthy controls, and the IL-23 mRNA levels were significantly increased in the peri-implantitis group (P < 0.0001). No differences in IL-17 mRNA levels were observed between the two groups (P > 0.05).

CONCLUSIONS

Data presented in this report demonstrated a predominant Th17 response in peri-implantitis subjects based on the higher levels of IL-23 and lower levels of TGF-β detected.

The Influence of Prosthesis Design on the Outcomes of Tooth Implants Immediately Placed and Loaded by Means of One-Piece Titanium Machined Restoration

Our purpose was to evaluate the occurrence of complications and the degree of bone loss in a cohort of patients treated with fixed prostheses supported by immediately loaded dental implants. The primary aim was to compare partial versus full-arch fixed dental prostheses. We then tested the effect of sinus lifting. In the present retrospective cohort study, the patients had their implants restored with fixed dental prostheses supported by dental implants positioned in the posterior maxilla and mandible. When necessary, the maxillary sinuses were grafted with particulate autogenous bone. Patients were then ranked according to the following predictors: length of prosthesis, crown-to-implant ratio, number of crowns to number of implants ratio, and presence of sinus lifting. Outcomes were evaluated for up to 2 years regarding the peri-implant marginal bone loss and implant/prosthesis survival rates. Fifty-eight subjects (209 implants) were rehabilitated with 25 fixed full-arch prostheses and 33 partial fixed dental implant bridges (16 supported by implants placed in grafted sinus). The mean marginal bone loss for implants supporting partial fixed dental prostheses amounted to 0.81 mm, whereas that for implants within the group of full-arch fixed dental prostheses was 1.21 mm; the comparison of the levels in the 2 groups showed a significant difference ( P = .0055). A statistically significant difference ( P = .0006) was found between the bone loss around maxillary implants (1.53 mm) and the bone loss around mandibular implants (1.10 mm). Two implants and 4 prostheses failed; 2-year survival rates of partial and of full-arch fixed dental prostheses, respectively, were 94.1% and 96%. Bone loss in full-arch prostheses appeared to be higher than in that of partial prosthesis. Implant-supported prostheses in the maxillae exhibited a bone loss higher than that registered in mandibles.

Analysis of Peri-Implant Bone Loss with a Convergent Transmucosal Morphology: Retrospective Clinical Study

OBJECTIVE

The aim of this study was to analyze the peri-implant bone loss of infracrestal, supracrestal, and crestal implants from the day of placement and up to 1 year of prosthetic loading.

MATERIAL AND METHODS

A retrospective clinical study was carried out. The sample consisted of 30 implants placed on 30 patients. It was divided into three groups: infracrestal (n = 10), crestal (n = 10), and supracrestal (n = 10) implants.

RESULTS

Following the statistical analysis, it was observed that, 4 months after implant placement, the mean values of total peri-implant bone loss were 0.04 mm in infracrestal implants, 0.26 mm in crestal implants, and 0.19 mm in supracrestal implants. At the end of one year of prosthetic loading, the peri-implant bone loss was 0.12 mm in infracrestal implants, 1.04 mm in crestal implants, and 0.27 mm in supracrestal implants. It was determined that peri-implant bone loss in crestal implants was significantly higher than in supracrestal implants, and these in turn were significantly higher than in infracrestal implants.

CONCLUSIONS

The implants that obtained a better biological behavior on peri-implant bone tissue were the infracrestal implants with a converging transmucosal abutment.

Comparison of Corrosion Products From Implant and Various Gold-Based Abutment Couplings: The Effect of Gold Plating

This study compared titanium (Ti), palladium (Pd), platinum (Pt), and gold (Au) ion release following induced accelerated tribocorrosion from three Au alloy abutment groups coupled with Ti implants over time; investigated contacting surface structural changes; and explored the effect of Au plating. Three abutment groups, G (n = 8, GoldAdapt, Nobel Biocare), N (n = 8, cast UCLA, Biomet3i), and P (n = 8, cast UCLA, Biomet3i, Au plated), coupled with implants (Nobel Biocare), immersed in 1% lactic acid, were cyclically loaded. Ions released (ppb) at T1, T2, and T3, simulating 3, 5, and 12 months of function, respectively, were quantified by inductively coupled plasma mass spectrometry (ICP-MS) and compared. Surface degradation and fretted particle composition after T3 were evaluated with scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX). ICP-MS data were nonparametric, expressed as medians and interquartile ranges. SEM/EDX showed pitting, crevice corrosion, and fretted particles on the components. Released ion concentrations in all groups across time significantly decreased for Pd (P < .001, median range: 1.70-0.09), Pt (P = .021, 0.55-0.00), and Au (P < .001, 1.01-0.00) and increased for Ti (P = .018, 2.49-5.84). Total Ti release was greater than other ions combined for G (P = .012, 9.86-2.30) and N (P < .001, 13.59-5.70) but not for P (P = .141, 8.21-3.53). Total Ti release did not differ between groups (P = .36) but was less variable across group P. On average, total ion release was 13.77 ppb (interquartile range 8.91-26.03 ppb) across the 12-month simulation. Tribocorrosion of Ti implants coupled with Au abutments in a simulated environment was evidenced by fretted particles, pitting, and crevice corrosion of the coupling surfaces and release of ions. More Ti was released compared with Pd, Pt, and Au and continued to increase with time. Abutment composition influenced ion release. Au-plated abutments appeared to subdue variation in and minimize high-concentration spikes of titanium.

A Multivariate Logistic Regression Analysis of Risk Factors for Peri-implant Bone Loss

PURPOSE

To evaluate multiple risk factors for peri-implant bone loss via a statistical analysis with a multivariate logistic regression model to provide recommendations for clinical treatment.

MATERIALS AND METHODS

This case-control study was conducted on patients who had received dental implant treatment from January 2018 to December 2021. Patients who had implants with bone loss were included in the case group, and patients who had implants with no bone loss were included in the control group. The following risk factors were evaluated: history of periodontitis, abutment connection type, implant surface type, implant diameter, implant location, implant 3D position, opposing dentition, adjacent teeth, prosthetic type, retention type, and the use of custom abutments. A multivariate logistic regression model was used to evaluate these risk factors, providing corresponding odds ratios (ORs) and 95% CIs.

RESULTS

A total of 776 implants in 479 patients were included in the analysis. The number of implants in the case group and the control group were 84 and 692, respectively. Cement-retained prostheses (OR = 2.439, 95% CI = 1.241-4.795) and non-platform-switched designs (OR = 2.055, 95% CI = 1.167-3.619) were identified as weak risk factors. Horizontal deviation (OR = 4.177, 95% CI = 2.265-7.703) was demonstrated to be a moderate risk factor. Vertical deviation (OR = 10.107, 95% CI = 5.280-19.347) and implants located in the mandibular molar region (OR = 10.427, 95% CI = 1.176-92.461) were considered high risk factors.

CONCLUSIONS

Implants in the molar region, cement-retained prostheses, non-platform-switched designs, and poor 3D implant positioning were identified as significant risk factors for peri-implant bone loss.

Finite Element Analysis (FEA) for Influence of Variation in Dental Implant Dimensions (Length and Diameter) on Peri-implant Bone Stress/Strain Distribution: A Systematic Review

Background & Objective

Currently, there are many implants in clinical use, making it hard to choose the right one for the patient. The success rate of an implant depends on its diameter, length, and direction of insertion in bone. In implant dentistry, Finite Element Analysis (FEA) simulates intraoral conditions in vitro and analyzes the effects of implant material, diameter, size, and other components related to oral structure on the implant and peri-implant tissues. The objective of the present systematic review was to evaluate the influence of variation in Dental Implant dimensions on Peri-implant Bone Stress/strain distribution, where Finite Element Analysis (FEA) is used as a method of analysis.

Method

Research papers published in PubMed, EBSCO, Web of Science, MEDLINE, CINAHL database from January 2012 until December 2022 using the keywords, (finite element analysis) AND (dental implant) AND (length) AND (diameter). The modified CONSORT checklist was used to assess the quality of the included research.

Result

Total hits from the original search were 402 (PubMed:127, Web of Science: 135 and CINHAL:22, EBSCO: 96, ProQuest:22). After duplicates were removed and titles and abstracts were screened, 371 articles were (n =371) selected for review. Of these, 342 were excluded and removed after initial screening, and 33 entire texts met the initial eligibility as per inclusion criteria. Four articles were further excluded in the final eligibility process and a total of 31 in vitro study articles were included for qualitative synthesis.

Conclusion

The evidence from the most recent literature suggests that the use of FEA showed promising results in understanding the stress distribution surrounding the implant. It was discovered that the material of the dental implant and the prosthesis, the type of loading, the direction and magnitude of force (axial or non-axial), the quality and quantity of the bone that surrounds the implant, as well as other factors, all play a role in the maintenance of bone around dental implants.

Assessing the Impact of Dental Implant Length on Early Failure Rates: A Retrospective Analysis

Introduction

The selection criteria of implant is very critical. Implant length determines the mechanics of osseointegration.

Objective

To investigate the influence of dental implant length on early failure rates, osseointegration success, peri-implant bone loss, and patient-reported outcomes.

Materials and Methods

A retrospective analysis was conducted involving 124 participants who underwent dental implant placement. Implant lengths were categorized as short (n = 54), standard (n = 35), or long (n = 35) based on standard industry classifications. Baseline characteristics, implant lengths, and early failure rates within the first six months post-implantation were extracted from clinical records.

Results

Preliminary analysis revealed variations in early failure rates among different implant length categories. Short implants demonstrated a distinct pattern of complications compared to standard and long implants. Early failure rates were 8% for short implants, 4% for standard implants, and 2% for long implants (P = 0.04). Osseointegration success rates were 90%, 95%, and 98% for short, standard, and long implants, respectively. Peri-implant bone loss was 1.5 mm, 1.0 mm, and 0.8 mm for short, standard, and long implants, respectively (P = 0.02). Patient-reported outcomes indicated higher satisfaction levels in the long implant group (P = 0.03).

Conclusion

The study highlights the importance of considering implant length in clinical decision-making and suggests potential associations with osseointegration success, peri-implant bone loss, and patient satisfaction.

The influence of vertical ridge augmentation techniques on peri-implant bone loss: A systematic review and meta-analysis

INTRODUCTION

The primary aim of this systematic review was to investigate and compare the outcomes of different vertical ridge augmentation (VRA) techniques in relation to peri-implant bone loss (PBL), after at least 12 months of functional loading.

MATERIAL AND METHODS

The search was conducted to find all the studies about VRA and measurements of PBL with at least 12 months follow-up. Three pairwise meta-analysis (MA) was performed to completely evaluate the outcomes.

RESULTS

A total of 42 studies were included, of which 11 were randomized clinical trials (RCTs). RCTs were available only for guided bone regeneration (GBR), onlay, and inlay techniques. The weighted mean estimate (WME) of PBL value was found to be 1.38 mm (95% confidence interval [95% CI]: 1.10-1.66) after a mean follow-up of 41.0 ± 27.8 months. GBR, Inlay, Onlay, osteodistraction, and SBB represented in weight 32.9%, 30.6%, 25.0%, 7.6%, and 3.9%, respectively; and their WME (95% CI) were 1.06 (0.87-1.26) mm, 1.72 (1.00-2.43) mm, 1.31 (0.87-1.75) mm, 1.81 (0.87-1.75) mm, and 0.66 (0.55-0.77) mm, respectively. Among the secondary outcomes, the analysis was conducted for vertical bone gain, healing complication rate, surgical complication rate, implant survival, and success rate.

CONCLUSIONS

The primary findings of the meta-analysis, based on the changes between final and baseline values, showed that the peri-implant bone loss could be influenced by the type of intervention but there is a need to evaluate in RCTs the behavior of the peri-implant bone levels after long-term follow-up for all techniques.

Marginal Bone Loss in Internal Conical Connection Implants Placed at the Crestal and Subcrestal Levels before Prosthetic Loading: A Randomized Clinical Study

The vertical position concerning the bone in which the implants are placed has been related as one of the factors causing marginal bone loss. The objective of this study was to evaluate the bone loss that occurs before prosthetic loading around tapered internal connection (CIC) implants placed at the crestal (C) and subcrestal (S) levels. Method: A randomized clinical trial (RCT) was carried out, with a sample size of 62 implants placed in 27 patients who underwent radiological controls on the day of placement, at one month, and at 4 months, and stability was measured by resonance frequency analysis (RFA) on three occasions. Results: Bone loss in implants C and S from the time of placement (T0) and the month after (T1) was not significant (p = 0.54) (C = 0.19 mm and S = 0.15 mm). The difference between one month (T1) and four months (T2) (C = 0.17 mm and S = 0.22 mm) was not significant either (p = 0.26). The difference between the day of placement (T0) and the third and last measurement (T2) was almost null (p = 0.94) (C = 0.35 mm and S = 0.36). The overall success rate of the implants was 97.8%. The stability of the implants measured with RFA went from 70.60 (T0) to 73.16 (T1) and 74.52 (T2). Conclusions: No significant differences were found in the bone loss for implants placed at the C and S levels. The millimeters of bone loss detected in both vertical positions did not have a significant impact on the stability of the implants.

Long-term effects of titanium-base abutments on peri-implant health: A 5-year randomised controlled trial

PURPOSE

Titanium bases are used frequently in daily practice for bonding to CAD/CAM abutments or crowns. Due to intimate contact between the adhesive gap of the titanium-base abutment and the peri-implant bone, the physical and chemical characteristics of the bonding material, or the gap itself, may affect peri-implant inflammatory reactions. The present study therefore aimed to examine the long-term effects of individualised abutments bonded to titanium bases on peri-implant health.

MATERIALS AND METHODS

A total of 24 patients, each with one test and one control abutment, participated in the present prospective, single-blind, randomised controlled clinical trial. The test abutments were CAD/CAM titanium abutments bonded to titanium bases. As the control abutments were individualised, one-piece CAD/CAM titanium abutments were used. Clinical and radiographic parameters were assessed at abutment insertion and then on a yearly basis over the following 5 years.

RESULTS

No significant differences in marginal bone level were observed between the titanium-base and one-piece abutments at any of the follow-up time points; however, when intragroup marginal bone levels were compared to the baseline values, significant differences were found at several follow-up time points. Intergroup differences were only found to be significant for pocket depth at the 4- (P = 0.006) and 5-year follow-ups (P = 0.024), favouring titanium-base abutments.

CONCLUSIONS

Within the limitations of the present study, it appears that the peri-implant tissues of this specific patient cohort responded to titanium-base abutments in a rather similar manner to one-piece abutments over a 5-year period; however, no definitive conclusions can be drawn due to the low power of the present study.

Radiographic peri-implant bone loss after a function time up to 15 years

OBJECTIVE

The aim was to assess the degree of radiographic peri-implant bone loss over a follow-up period up to 15 years. In addition, another aim was to identify risk indicators for peri-implant bone loss and for moderate-severe peri-implantitis at patient- and implant level.

MATERIALS AND METHODS

This is a cross-sectional clinical and radiological study of 147 patients with a total of 425 implants in combination with data collected retrospectively for baseline variables. To calculate the peri-implant bone loss (primary outcome variable), the radiographic bone level measurements from baseline were compared to the radiographic bone level measurements at the final radiographic measurement. Multilevel analyses were adopted with peri-implant bone loss and peri-implantitis as outcome variables.

RESULTS

The mean follow-up time was 12.5 years (range 10-15) and the mean age of the patients was 63 years (range 29-83). The mean peri-implant bone loss was 0.94 mm (S.D. 1.3). The prevalence of moderate-severe peri-implantitis at patient level was 17% and 8.9% at implant level. The peri-implant bone loss was significantly more pronounced in healthy implants if moderate-severe peri-implantitis was present in at least one implant within the same patient. The presence of moderate-severe peri-implantitis was significantly associated with general periodontitis Stages III or IV at follow-up and smoking.

CONCLUSION

The presence of moderate-severe peri-implantitis at patient level was found to be a risk indicator of peri-implant bone loss in healthy implants, while smoking and general periodontitis Stages III and IV were risk indicators of moderate-severe peri-implantitis.

Comparing the Long-term Success Rates of Immediate Implant Placement vs. Delayed Implant Placement in Patients with Periodontally Compromised Teeth

Background

This study aims to compare the long-term success rates of immediate implant placement and delayed implant placement in patients with periodontally compromised teeth.

Materials and Methods

A total of 30 patients presenting with periodontally compromised teeth requiring extraction and subsequent implant placement were enrolled in this retrospective study. Patients were divided into two groups based on the timing of implant placement: Group A (immediate implant placement) and Group B (delayed implant placement). Implants were placed according to standard protocols. Patient records were reviewed for implant survival, peri-implant bone loss, and prosthetic complications. Data were statistically analyzed using appropriate tests.

Results

The mean follow-up period was 5 years. In Group A, the implant survival rate was 90%, while in Group B, it was 83%. The mean peri-implant bone loss was 1.5 mm in Group A and 2.2 mm in Group B. Prosthetic complications were observed in three cases in Group A and five cases in Group B. The differences in implant survival and bone loss between the two groups were not statistically significant (P > 0.05).

Conclusion

Both immediate implant placement and delayed implant placement demonstrated comparable long-term success rates in patients with periodontally compromised teeth.

Single-Piece Implant Systems and its Longterm Stability: An Evaluative Research

Objective

The objective of this research was to compare the longstanding stability of single-piece implant systems to typical two-piece systems by analyzing patient records retrospectively.

Methods

A retrospective examination of patient records from January 2010 to December 2020 was undertaken at the Department of Oral Implantology, University Hospital. The research included dental rehabilitation patients who got single- or two-piece implant systems. Patient demographics, implant features, surgical procedures, and follow-up results were extracted. Implant success rates, stability defined by resonance frequency analysis (RFA) utilizing Osstell ISQ®, and peri-implant bone loss evaluated by standardized periapical radiographs at baseline and follow-up visits were the main outcomes.

Results

The research involved 320 patients (160 per cohort). The average patient age was 52.7 years, with 55% men. The mandibular region received 65% of implants, and the maxillary region the rest. Single-piece cohort A had 94.6% implant success, and two-piece cohort B 96.2%. Implant success rates were similar between cohorts (P = 0.412). The mean ISQ scores were 72.4 ± 4.8 in cohort A and 74.8 ± 5.1 in cohort B (P = 0.086). Peri-implant bone loss was 1.8 ± 0.7 mm in cohort A and 1.4 ± 0.6 mm in cohort B (P = 0.031).

Conclusion

Single-piece implant systems provide a stable and successful alternative to classic two-piece systems. However, patient selection, surgical technique, and monitoring are essential to reduce peri-implant problems and improve clinical results. To improve implant dentistry patient care and evidence-based clinical practice, single-piece and two-piece implant systems' design, biomechanical features, and longstanding performance should be studied.

Relationship Between Radiographic Bone Loss and Salivary IL- 1β Levels in Peri-Implantitis

PURPOSE

Peri-implantitis is a progressive inflammatory condition characterized by peri- implant bone loss and clinical signs of inflammation. Traditional diagnostic methods, including clinical and radiographic evaluations, have limitations in detecting the disease in its early stages. Salivary biomarkers, including interleukin-1β (IL-1β), have been identified as potential non-invasive indicators for diagnosing peri-implantitis. This study aimed to investigate the relationship between salivary IL-1β levels, radiographic bone loss, and clinical peri-implant parameters.

MATERIALS AND METHODS

60 patients enrolled in this cross-sectional study (24 peri-implant health [PIH] and 36 with peri-implantitis [PI]), accounting for a total of 152 implants. Clinical parameters, including peri-implant pocket depth (PIPD), modified plaque index (mPI), and bleeding on probing (BOP), were recorded. Periapical radiographs were obtained to assess peri-implant bone loss in mesial (PIBLm) and distal (PIBLd) aspects. Unstimulated whole saliva samples were analyzed for IL-1β expression using quantitative real-time polymerase chain reaction (PCR). The correlations between IL-1β expression levels in saliva and peri-implant clinical and radiographic findings were analyzed using Pearson's correlation coefficient.

RESULTS

IL-1β expression levels in saliva were significantly higher in the PI compared to PIH (p<0.001). A strong positive correlation was observed between IL-1β levels and peri-implant bone loss (PIBLm: r=0.515, p<0.01; PIBLd: r=0.535, p<0.01), as well as with clinical parameters including PIPD (r=0.59, p<0.01) and BOP (r=0.792, p<0.001).

CONCLUSION

The significant correlation between salivary IL-1β levels and peri-implant disease parameters suggests its potential as a non-invasive biomarker for early peri- implantitis detection. Further large-scale studies with standardized methodologies are required to validate these findings and enhance diagnostic accuracy.