A 1-Year Prospective Study on Co-Axis® Implants Immediately Loaded with a Full Ceramic Crown

Screw loosening in angulation-correcting single implant restorations: A systematic review of in vitro studies

STATEMENT OF PROBLEM

Various options are available to allow angle correction for screw-retained restorations for malaligned implants, including angled abutments, angled screw channel abutments, and angled implants. However, the effect these angle correction components have on prosthetic screw loosening is unclear.

PURPOSE

The purpose of this systematic review was to assess the effect of angled abutments, angled screw channel abutments, and angled implants on prosthetic screw loosening.

MATERIAL AND METHODS

This manuscript followed the Preferred Reporting Items for the Systematic Review and Meta-Analyses (PRISMA) statement. Searches were performed through 31 December 2021 in PubMed/MEDLINE, EMBASE, and Web of Science with no year limit targeting in vitro studies evaluating the effect of angulation correction components on screw loosening.

RESULTS

A total of 460 articles were identified. After removing duplicates, 306 titles were screened. Nine of the remaining 36 articles selected for full-text analysis met the selection criteria. The qualitative analysis used data from 394 implants. All studies featured straight abutments as the control group, and, in 8 studies, the angle correction component was included on the level of the abutment. Only in 1 study was the angle correction component at the level of the implant. The angle correction of the prosthetic component varied from 0 degrees in all studies up to a maximum correction of 30 degrees. Statistically significant increases in screw loosening with increasing abutment angle correction were reported by multiple authors (P<.05). However, other articles reported nonsignificant differences in screw loosening because of angulation after cyclic loading (P>.05). The only study investigating angle correction at the implant level found significantly less screw loosening (P<.05) in the angled implant group compared with the nonangled implant group.

CONCLUSIONS

Several options are available to correct discrepancies between the surgical axis and the ideal prosthetic axis for rehabilitations supported by dental implants. The current evidence does not clearly indicate the superiority of any single solution for minimizing screw loosening.

Dental Implants with External Hex Inclined Shoulder in Full-Arch Immediate Loading Rehabilitations of the Maxilla

Background: Coaxial implants with an inclined neck might overcome some problems related to angulation of the implant axis when using tilted implants. Therefore, the aim of the present work was to conduct a narrative review of the current literature and to present a case series comparing traditional and coaxial external hex implants in full-arch immediate loading rehabilitations of the maxilla. Methods: A total of 13 external hex tapered implants (Southern Implants) was inserted in the upper jaw of 3 patients. Each patient received two tilted implants in distal sites. In one randomly selected quadrant, the tilted implant was a standard implant, while a Co-Axis® implant with a 24° inclination of the implant shoulder was inserted on the other hemi-arch. Straight conical abutments were screwed on coaxial implants while multiunit abutments of appropriate inclination were screwed as needed on the other implants to correct their axes. Peri-implant bone level was recorded radiographically at T0 (delivery of the immediate loading prosthesis), and at 3, 6, 12, and 24 months of healing and then annually. Plaque index, probing depth, and bleeding on probing were also evaluated. Cumulative implant survival rate (CSR) was calculated, and biological or technical complications were recorded as well as the operator satisfaction towards the use of coaxial implants. Results: The preliminary data collected did not show significant differences in peri-implant tissues health and maintenance over time between the two implant types. No implants failed, and both implant types proved to be favorable for full-arch rehabilitation using tilted implants. Coaxial implants facilitated the prosthodontic procedures. However, a learning curve is required in order to optimize their insertion. Conclusions: Both implants proved to be reliable and suitable for achieving clinical success in full-arch immediate loading rehabilitations, but further research with longer follow-up and larger sample size is needed to confirm these preliminary outcomes.

Evaluation of different surface treated implants after provisionalization: A 6-month prospective study

Background

Replacing missing teeth with dental implants has become the best treatment option; therefore, clinicians need to understand the predictability of the treatment. Surface treatment of implants is one of the methods to improve osseointegration, thus improving the quality of treatment. Increasing esthetic awareness among patients has led to the popularity of immediate provisionalization of dental implants. This study investigated the effect of surface treatment on implant stability when loaded with immediate non-functional temporary prostheses and compared the superiority of one surface treatment over the other in terms of osseointegration by evaluating implant stability quotient (ISQ).

Methods

Twenty implants with different surface treatments were placed, i.e., resorbable blast media (RBM) surface and alumina blasted/acid-etched (AB/AE) surfaces. All the implants were non-functionally loaded, and ISQ was measured immediately after implant placement and 6 and 12 weeks after non-functional loading. Crestal bone levels, mPI, mSBI, and peri-implant probing depths were compared for both groups at 1, 3, and 6 months.

Results

At 12 weeks, all the implants showed desirable ISQ, indicating successful osseointegration. The increase in ISQ at 12 weeks was significantly higher for RBM implants compared to baseline, indicating a more predictable course of osseointegration. Crestal bone levels recorded at 1, 3, and 6 months did not significantly differ between the groups. All other parameters showed comparable values for both groups at all intervals.

Conclusion

Replacing missing teeth with dental implants with immediate non-functional restorations is a predictable treatment option.

Incidence of Peri-Implantitis, Technical and Biological Complications of Single Implants Placed with Flap or Flapless Surgery-A 10-12-Year Case-Series

BACKGROUND

Long-term follow-up of single implants and crowns is scarce, especially when inserted using flapless surgery.

AIM

Evaluate survival, peri-implantitis incidence, and technical/biologic complications of solitary implants/crowns after 10-12 years of function.

MATERIAL AND METHODS

49 patients with 53 single implants, initially operated with a one-stage flap (F) or flapless (FL) surgery and delayed loading, were recalled. Implant survival, radiographic bone-level changes compared to baseline, peri-implant health, and soft tissue aesthetics were registered. Differences in implant level between and within groups were statistically tested using the Mann-Whitney U-Test and Wilcoxon Signed Ranks Test, respectively.

RESULTS

36 patients with 40 implants were reassessed, yielding 100% implant and 97.5% crown survival. The bone loss in F (n = 19) was 0.56 mm (SD 0.89; range -0.9-2.02) and -0.85 mm (SD 0.98; range -2.84-0.53) in FL (n = 21), indicative of bone gain in FL (p = 0.003), the latter due to a difference at baseline but bone-level was comparable (p = 0.126). Groups were comparable for probing pocket depth (PPD); (3.32 vs. 3.19 mm), Bleeding Index (BI); (0.15 vs. 0.22), and gingival recession; (0.38 vs. 0.17 mm). According to international criteria, the peri-implantitis incidence was 0%, but 32.5% of the implants/crowns experienced biological or technical complications irrespective of surgical technique.

CONCLUSIONS

Solitary implants and crowns show good long-term clinical outcomes and peri-implant health. Flapless surgery is a good alternative to conventional in straightforward cases with sufficient bone volume and proper treatment planning.

Clinical Evidence on a Novel Macrohybrid Design Dental Implant with 12° Angled Platform: A Systematic Review

Background: Immediate implant placement with immediate esthetics has become a more common procedure over time, though ensuring good emergence of the axis of the implant has been a challenge. A novel macroimplant design with an angled platform (Co-Axis^®) has been developed to ensure exit of the head of the implant in the correct prosthetic position. A systematic literature review was carried to determine the survival rate and marginal bone loss associated with these implants. Material and Methods: An electronic and manual literature search was made in accordance with the PRISMA statement. The search strategy was limited to human studies, retrospective and prospective clinical trials, cross-sectional studies, and cohort studies reporting outcomes of a novel macrohybrid implant with a 12° angled implant connection. Results: Three articles met the inclusion criteria and were reviewed in the analysis. The estimated success rate was 95.9%. The global marginal bone loss was estimated to be −0.17 ± 0.58 mm in an environment characterized by great heterogeneity (I² = 99%). The estimated mean implant stability was 69.6 ± 0.92 (ISQ). As only two studies provided the required information, it was not possible to determine publication bias. Lastly, mean recession was estimated to be practically zero (0.06 ± 0.23 mm), with great heterogeneity. Conclusions: Within the limitations of this systematic review, it can be affirmed that immediate implant treatment with Co-Axis^® implants shows a survival rate of 95.9% at one year of follow-up, with low marginal bone loss values, near-zero soft tissue recession, and favorable papilla index values. Nevertheless, the great heterogeneity of the data requires the findings to be interpreted with caution.

A systematic review and meta-analysis evaluating the survival, the failure, and the complication rates of veneered and monolithic all-ceramic implant-supported single crowns

Objective

To assess the survival, failure, and complication rates of veneered and monolithic all‐ceramic implant‐supported single crowns (SCs).

Methods

Literature search was conducted in Medline (PubMed), Embase, and Cochrane Central Register of Controlled Trials until September 2020 for randomized, prospective, and retrospective clinical trials with follow‐up time of at least 1 year, evaluating the outcome of veneered and/or monolithic all‐ceramic SCs supported by titanium dental implants. Survival and complication rates were analyzed using robust Poisson's regression models.

Results

Forty‐nine RCTs and prospective studies reporting on 57 material cohorts were included. Meta‐analysis of the included studies indicated an estimated 3‐year survival rate of veneered‐reinforced glass‐ceramic implant‐supported SCs of 97.6% (95% CI: 87.0%–99.6%). The estimated 3‐year survival rates were 97.0% (95% CI: 94.0%–98.5%) for monolithic‐reinforced glass‐ceramic implant SCs, 96.9% (95% CI: 93.4%–98.6%) for veneered densely sintered alumina SCs, 96.3% (95% CI: 93.9%–97.7%) for veneered zirconia SCs, 96.1% (95% CI: 93.4%–97.8%) for monolithic zirconia SCs and only 36.3% (95% CI: 0.04%–87.7%) for resin‐matrix‐ceramic (RMC) SCs. With the exception of RMC SCs (p < 0.0001), the differences in survival rates between the materials did not reach statistical significance. Veneered SCs showed significantly (p = 0.017) higher annual ceramic chipping rates (1.65%) compared with monolithic SCs (0.39%). The location of the SCs, anterior vs. posterior, did not influence survival and chipping rates.

Conclusions

With the exception of RMC SCs, veneered and monolithic implant‐supported ceramic SCs showed favorable short‐term survival and complication rates. Significantly higher rates for ceramic chipping, however, were reported for veneered compared with monolithic ceramic SCs.

A 5 to 7-year case series on single angulated implants installed following papilla-sparing flap elevation

BACKGROUND

Bony concavities at the buccal aspect may cause a distortion between the implant axis and ideal prosthetic axis. Angulated implants can overcome this problem, yet long-term data are lacking. In addition, papilla-sparing incisions have been proposed to reduce tissue loss, yet aesthetic outcomes have not been published.

PURPOSE

To evaluate the 5 to 7-year outcome of single angulated implants installed following papilla-sparing flap elevation.

MATERIALS AND METHODS

Patients who had been consecutively treated with a single angulated implant (Co-axis®, Southern Implants, Irene, South Africa) in the anterior maxilla were re-examined after 5 to 7 years. Available data at 1 year (T1) were compared to those obtained at 5 to 7 years (T2).

RESULTS

Twenty out of 22 treated patients (11 females, 9 males, mean age of 52) with 22 implants attended the 5 to 7-year reassessment. All implants survived and stable clinical conditions could be reached with mean marginal bone loss of 1.28 mm at T2. Papilla-sparing flap elevation resulted in Pink Esthetic Score of 9.83 at T1 and 8.23 at T2 (p = 0.072). Mucosal Scarring Index was 4.61 at T1 and 3.50 at T2 (p = 0.165). The overall appearance of scarring significantly improved over time (p = 0.032), yet 59% of the cases still demonstrated scarring at T2.c CONCLUSIONS: Within the limitations of the study, angulated implants (Co-axis®, Southern Implants) reached stable clinical conditions. Papilla-sparing incisions may not be recommended in aesthetically demanding patients due to high risk of scarring.

Rationale for a reverse tapered body shift implant for immediate placement

Immediate implant placement holds considerable value, yet primary implant stability is often a critical factor. The aim of this study was to evaluate the stability, volumetric viability, and buccal gap size of reverse tapered body shift (RTBS) implants after immediate placement. Peak insertion torque measurements of two RTBS designs (apical 40% vs. apical 50%), relative to conventionally tapered implants, were assessed in simulated extraction sockets prepared in synthetic bone blocks. Additionally, the proximity of the RTBS implants to neighbouring teeth and anatomical structures, and the buccal gap distance were evaluated in human cadavers. The mean (± standard deviation) insertion torque was 12.00±1.40N•cm for the conventionally tapered implants (n=50), 35.36±2.74N•cm (n=50) for RTBS-1, and 48.20±2.90N•cm (n=50) for RTBS-2; the difference between designs was statistically significant (P<0.01). In total, 40 RTBS implants (20 per design) were placed in six cadaveric premaxillae. Only one locus was inappropriate for both RTBS implant designs, due to the proximity of neighbouring teeth. The average buccal gap for both implant designs was 2.8mm (P=0.104). The improved primary stability and increased buccal gap size with RTBS implants may enhance the feasibility of immediate placement. The study findings should be further validated in clinical trials.

The clinical performance of all-ceramic implant-supported single crowns: A systematic review and meta-analysis

OBJECTIVE

This review aimed at evaluating the survival and technical complication rates of all-ceramic implant-supported single crowns (SC).

MATERIAL AND METHODS

Three electronic databases were searched for clinical studies conducted at ≥ 15 patients examining implant-supported all-ceramic SCs over ≥ 12 months. Survival rates of implants and restorations plus technical complication rates of SCs were calculated and tested for statistical correlation with confounding variables. Statistical analysis was performed using a negative binomial distribution model to calculate 5- and 10-year survival and complication estimates.

RESULTS

Forty-one included studies reported on implant-supported SCs made of veneered and monolithic high-strength oxide ceramics, monolithic, and veneered glass-based ceramics and of a monolithic resin-nano-ceramic (RNC). Survival estimates for SCs of 93% (95% CI: 86.6%-96.4%) after 5 years and 94.4% (95% CI: 91.1%-96.5%) after 10 years were calculated, corresponding values for implant survival were 95.3% (95% CI: 90.6%-97.7%) and 96.2% (95% CI: 95.1%-97.1%). Technical complication rates after 5/10 years were as follows: chipping 9.0% (95% CI: 5.4%-14.8%)/2.7% (95% CI: 2.1%-3.5%), framework fractures 1.9% (95% CI: 0.7%-4.9%)/1.2% (95% CI: 1%-1.5%), screw loosening 3.6% (95% CI: 1.6%-8.4%)/5.2% (95% CI: 3.6%-7.5%), and decementations with 1.1% (95% CI: 0.4%-2.8%) after 5 years. Some confounding variables influenced the above-mentioned estimates significantly.

CONCLUSIONS

All-ceramic implant-supported SCs showed-with the exception of a RNC material-high survival rates. However, failures and technical complications occurred which have to be considered when informing patients on the treatment with implant-supported all-ceramic SCs.

A prospective study on ultra-wide diameter dental implants for immediate molar replacement

BACKGROUND

Although wide diameter implants are well documented, little is known about ultra-wide diameter implants (>6 mm). This study evaluates the clinical outcome of ultra-wide diameter implants, placed in molar extraction sockets.

MATERIALS AND METHODS

Ultra-wide diameter implants (7-9 mm) were placed immediately after molar extraction in a 1-stage protocol, without raising a flap or using any bone grafts. After 4 months, the implant was loaded with a single screw-retained crown. Bone loss was evaluated using peri-apical radiographs. Plaque and bleeding were recorded. Crown and papilla dimensions were measured and compared with the contra-lateral tooth.

RESULTS

Fifty-one patients (36 male and 15 female), mean ages 61 years old, were treated with 26 implants in the maxilla and 25 implants in the mandible. The majority had a thick (#19) or medium (#31) biotype. After a mean-follow-up period of 23 months, the mean bone level was located 1.16 mm apical of the implant-abutment junction (SD 0.42, range 0.00-2.45) while the actual bone remodeling associated with socket healing resulted in a mean coronal movement of the bone level of 0.15 mm. The mean insertion torque was 116 Ncm (SD 53, range 10-250). There were no differences in papilla height (P = .55), crown length (P = .32), zenith (P = .84), and bucco-palatal dimensions (P = .38). There was a significant difference in the mesio-distal dimension (P = .01). Mean probing depth was 2.59 mm at the implant and 2.23 mm at the contra-lateral tooth (P = .001). There was significantly more plaque at the tooth compared to the implant (P = .01), but there was no significant difference in terms of bleeding on probing (P = .08). Patient satisfaction was high with 72.5% of the patients experiencing no problems at all.

CONCLUSIONS

Ultra-wide diameter implants have a predictable outcome, demonstrating very little bone loss. Papilla and crown dimensions were comparable to the contra-lateral natural tooth.

Managing maxillary proclination with novel designed angulated implants

Implant-supported removable dental prostheses may be supported by a variety of splinted (bar and clip) attachment systems or nonsplinted abutment-based attachments (ball, magnets, and resilient stud attachments such as locators [Zest Anchors], ERA [Sterngold], and nonresilient-stud attachments such as ANKYLOS SynCone [Dentsply Implants]). Nonsplinted attachments are preferred as they are more economical, less technique sensitive, easier to clean, repair, and maintain than splinted (bar and clip) attachment systems, but they work favorably only when implants in the arch are placed parallel to each other. Often implants in the anterior maxilla have to be placed with a labial inclination (due to the proclination of the premaxilla), resulting in lack of parallelism between the anterior and posterior implants, making it challenging to fabricate a removable dental prostheses supported by nonsplinted attachments, and necessitating the use of angled abutments. Recently, a novel implant design with a 12° restorative platform angulation has been introduced by Southern Implants (Co-axis, Keystone Dental, Inc., Burlington, MA, USA). These new angulated implants aid in minimizing the divergence between the anterior and posterior maxillary implants without using angled abutments. The purpose of this article was to report a case utilizing the novel angulated implants (Co-axis, Keystone Dental, Inc., Burlington, MA, USA) in the premaxilla for fabrication of maxillary removable dental prostheses supported and retained by nonsplinted attachments.

Clinical and radiographic outcome following immediate loading and delayed loading of single-tooth implants: Randomized clinical trial

BACKGROUND

Immediate loading of single implants is generally considered a reliable procedure.

PURPOSE

The objective of the present prospective randomized clinical study was to compare the overall treatment outcome following immediate loading (IL) and delayed loading (DL) of single implants after 1 year of follow-up.

MATERIALS AND METHODS

Patients with a missing maxillary tooth (15-25) were randomly assigned to IL or DL. The protocol included implant installation in healed sites, immediate loading, delayed loading, temporary screw-retained restoration, and replacement with a permanent single implant crown. Outcome measures were implant survival, marginal bone level, soft tissue changes, papillae index, pink, and white esthetic score (PES and WES), patient judged aesthetics, and oral health impact profile (OHiP-14).

RESULTS

Implant survival rate was 100% and 96% for IL and DL, respectively. Implant success rate was 96% and 88% for IL and DL, respectively. Statistically significant lower papilla index scores were found in the IL group at temporary crown and definitive crown placement. An overall statistically significant improvement after 12 months for PES, WES and OHIP-14 was found.

CONCLUSION

This prospective randomized study showed that single implants in the maxilla can present satisfactory results with respect to either immediate loading or delayed loading after 12 months.

Impact of Second Stage Surgery on Bone Remodeling Around New Hybrid Titanium Implants: A Prospective Clinical Study in Humans

OBJECTIVE

The present prospective study aimed to more precisely identify the time points of bone changes around hybrid titanium implants up to 30 months of follow-up.

MATERIALS AND METHODS

Twelve hybrid T3 implants (Biomet 3i) were placed in 9 healthy patients with the 2-stage surgical approach. Standardized digital Rx were taken at implant insertion (T0); healing-abutment connection after 3.1 ± 0.2 weeks (TX); loading stage after 7.5 ± 0.6 weeks (T1); after 12 months (T2); and after 30 months (T3) of functional loading. The marginal bone loss was digitally measured.

RESULTS

The mean marginal bone loss was 0.76 ± 0.37 mm after 30 months. More than 60% (0.42 ± 0.29 mm) of the bone loss took place at healing-abutment connection (TX-T1). No statistically significant bone loss was found between T1-T2 and T2-T3, after 12 and 30 months, respectively. Approximately 40% of bone loss (0.34 mm) was noted between T1 and T3 (P < 0.05), which corresponds to the loading period.

CONCLUSIONS

The implant-oral environment connection represents a critical step point in crestal bone loss. The amount of marginal bone loss, measured after 30 months of loading (T1-T3), was much less than that reported in the literature, showing that correct loading has a minor impact on the periimplant bone remodeling as compared to surgical implant reopening.

Long-Term Effect of Surface Roughness and Patients' Factors on Crestal Bone Loss at Dental Implants. A Systematic Review and Meta-Analysis

Publications from 2011 to 2015 were selected to evaluate effect of implant surface roughness on long-term bone loss as surrogate for peri-implantitis risk. 87 out of 2,566 papers reported the mean bone loss after at least 5 years of function. Estimation of the proportion of implants with bone loss above 1, 2, and 3 mm as well as analysis the effect of implant surface roughness, smoking, and history of periodontitis was performed. By means of the provided statistical information of bone loss (mean and standard deviation) the prevalence of implants with bone loss ranging from 1 to 3 mm was estimated. The bone loss was used as a surrogate parameter for "peri-implantitis" given the fact that "peri-implantitis" prevalence was not reported in most studies or when reported, the diagnostic criteria were unclear or of dubious quality. The outcome of this review suggests that peri-implant bone loss around minimally rough implant systems was statistically significant less in comparison to the moderately rough and rough implant systems. No statistically significant difference was observed between moderately rough and rough implant systems. The studies that compared implants with comparable design and different surface roughness, showed less average peri-implant bone loss around the less rough surfaces in the meta-analysis. However, due to the heterogeneity of the papers and the multifactorial cause for bone loss, the impact of surface roughness alone seems rather limited and of minimal clinical importance. Irrespective of surface topography or implant brand, the average weighted implant survival rate was 97.3% after 5 years or more of loading. If considering 3 mm bone loss after at least 5 years to represent the presence of "peri-implantitis," less than 5% of the implants were affected. The meta-analysis indicated that periodontal history and smoking habits yielded more bone loss.

A Classification Proposal for Peri-Implant Mucositis and Peri-Implantitis: A Critical Update

Definitions of peri-implant mucositis and peri-implantitis vary in the literature, and no clear criteria have been established for the diagnosis and treatment of such disorders. This study proposes a classification for peri-implant mucositis and peri-implantitis based on the severity of the disease, using a combination of peri-implant clinical and radiological parameters to classify severity into several stages (Stage 0A and 0B = peri-implant mucositis, and Stage I to IV = periimplantitis). Following a review of the literature on the subject and justification of the proposed peri-implant disease classification, the latter aims to facilitate professional communication and data collection for research and community health studies.

Prosthetic failure in implant dentistry

Although osseointegrated dental implants have become a predictable and effective modality for the treatment of single or multiple missing teeth, their use is associated with clinical complications. Such complications can be biologic, technical, mechanical, or esthetic and may compromise implant outcomes to various degrees. This article presents prosthetic complications accompanied with implant-supported single and partial fixed dental prostheses.

A prospective cohort study on the impact of smoking on soft tissue alterations around single implants

OBJECTIVES

To compare smokers to non-smokers in terms of soft tissue alterations following single implant treatment in healed bone.

MATERIAL AND METHODS

Non-smoking and smoking patients with sufficient bone volume in need of a single implant in the anterior maxilla (15-25) were consecutively recruited in three centres. Conventional single implant surgery was performed and an immediate provisional crown was installed. Eight to 12 weeks later, the latter was replaced by a permanent one (baseline). Papilla regrowth and midfacial recession was registered after 2 years of function.

RESULTS

The sample consisted of 39 non-smokers (21 females; mean age 42) and 46 smokers (22 females; mean age 45). Smokers had three early failures, whereas all implants integrated successfully in non-smokers. Statistically significant papilla regrowth was observed in non-smokers (distal 0.63 mm, mesial 0.76 mm), whereas smokers showed stable papillae (between cohorts: P ≤ 0.025). Midfacial soft tissue level demonstrated statistically significant regrowth in non-smokers (0.53 mm), whereas it remained stable in smokers (between cohorts: P = 0.004).

CONCLUSION

Smokers failed to demonstrate papilla regeneration and showed more midfacial recession following single implant treatment when compared to non-smokers.

Surface Damage on Dental Implants with Release of Loose Particles after Insertion into Bone

BACKGROUND

Modern dental implants present surface features of distinct dimensions that can be damaged during the insertion procedure into bone.

PURPOSE

The aims of this study were (1) to quantify by means of roughness parameters the surface damage caused by the insertion procedure of dental implants and (2) to investigate the presence of loose particles at the interface.

MATERIALS AND METHODS

Three groups of dental implants representing different surface topographies were inserted in fresh cow rib bone blocks. The surface roughness was characterized by interferometry on the same area before and after the insertion. Scanning electron microscopy (SEM)-back-scattered electron detector (BSD) analysis was used to identify loose particles at the interface.

RESULTS

The amplitude and hybrid roughness parameters of all three groups were lower after insertion. The surface presenting predominance of peaks (Ssk [skewness] > 0) associated to higher structures (height parameters) presented higher damage associated to more pronounced reduction of material volume. SEM-BSD images revealed loose titanium and aluminum particles at the interface mainly at the crestal cortical bone level.

CONCLUSIONS

Shearing forces during the insertion procedure alters the surface of dental implants. Loose metal particles can be generated at bone-implant interface especially around surfaces composed mainly by peaks and with increased height parameters.