Two to six-year disease resolution and marginal bone stability rates of a modified resective-implantoplasty therapy in 32 peri-implantitis cases

Echo-intensity characterization at implant sites and novel diagnostic ultrasonographic markers for peri-implantitis

AIM

To apply high-frequency ultrasound (HFUS) echo intensity for characterizing peri-implant tissues at healthy and diseased sites and to investigate the possible ultrasonographic markers of health versus disease.

MATERIALS AND METHODS

Sixty patients presenting 60 implants diagnosed as healthy (N = 30) and peri-implantitis (N = 30) were assessed with HFUS. HFUS scans were imported into a software where first-order greyscale outcomes [i.e., mean echo intensity (EI)] and second-order greyscale outcomes were assessed. Other ultrasonographic outcomes of interest involved the vertical extension of the hypoechoic supracrestal area (HSA), soft-tissue area (STA) and buccal bone dehiscence (BBD), among others.

RESULTS

HFUS EI mean values obtained from peri-implant soft tissue at healthy and diseased sites were 122.9 ± 19.7 and 107.9 ± 24.7 grey levels (GL); p = .02, respectively. All the diseased sites showed the appearance of an HSA that was not present in healthy implants (area under the curve = 1). The proportion of HSA/STA was 37.9% ± 14.8%. Regression analysis showed that EI of the peri-implant soft tissue was significantly different between healthy and peri-implantitis sites (odds ratio 0.97 [95% confidence interval: 0.94-0.99], p = .019).

CONCLUSIONS

HFUS EI characterization of peri-implant tissues shows a significant difference between healthy and diseased sites. HFUS EI and the presence/absence of an HSA may be valid diagnostic ultrasonographic markers to discriminate peri-implant health status.

Effectiveness of mechanical and chemical decontamination methods for the treatment of dental implant surfaces affected by peri-implantitis: A systematic review and meta-analysis

OBJECTIVE

To assess which decontamination method(s) used for the debridement of titanium surfaces (disks and dental implants) contaminated with bacterial, most efficiently eliminate bacterial biofilms.

MATERIAL AND METHODS

A systematic search was conducted in four electronic databases between January 1, 2010 and October 31, 2022. The search strategy followed the PICOS format and included only in vitro studies completed on either dental implant or titanium disk samples. The assessed outcome variable consisted of the most effective method(s)-chemical or mechanical- removing bacterial biofilm from titanium surfaces. A meta-analysis was conducted, and data was summarized through single- and multi-level random effects model (p < .05).

RESULTS

The initial search resulted in 5260 articles after the removal of duplicates. After assessment by title, abstract, and full-text review, a total of 13 articles met the inclusion criteria for this review. Different decontamination methods were assessed, including both mechanical and chemical, with the most common method across studies being chlorhexidine (CHX). Significant heterogeneity was noted across the included studies. The meta-analyses only identified a significant difference in biofilm reduction when CHX treatment was compared against PBS. The remaining comparisons did not identify significant differences between the various decontamination methods.

CONCLUSIONS

The present results do not demonstrate that one method of decontamination is superior in eliminating bacterial biofilm from titanium disk and implant surfaces.

In vitro evaluation of different protective techniques to reduce titanium particle contamination during implantoplasty

OBJECTIVES

Our aim is to study titanium remains in a bone model during standardized implantoplasty under different isolation and protective modalities.

MATERIAL AND METHODS

Forty implants were placed in artificial spongy bone blocks mimicking a horizontal bone loss and implant neck protrusion of 5 mm. Samples were randomly divided into four groups (n = 10), which were treated as follows: rubber dam (A), a dental adhesive paste (B), bone wax (C), and an unprotected positive control (D). Implantoplasty was performed using carbide and diamond burs under strict water cooling and standardized suction. After removal of the respective isolation materials, the bone blocks were thoroughly rinsed with tap water for 3 min and titanium chips were collected using a filter integrated in the model. The filter paper was removed and dissolved in 37% hydrochloric acid for 2 h at 120 °C and the titanium remnants were quantified using atomic absorption spectrometry.

RESULTS

None of the test groups were able to completely prevent titanium particle contamination. Rubber dam (691 ± 249 µg) and bone wax (516 ± 157 µg) were found to be significantly more protective than the positive control (2313 ± 747 µg) (p < 0.001) with respect to the amount of titanium particles that remained in the bone model after implantoplasty. The adhesive paste group (1863.5 ± 538 µg) was not significantly different from the positive control (p = 0.19).

CONCLUSIONS

Despite some limitations of the present study, titanium particles resulting from a standardized implantoplasty can be assumed to be significantly reduced when the tissues/bone were protected with rubber dam and bone wax, or a combination, depending on individual accessibility.

CLINICAL RELEVANCE

Tissue protective measures to reduce or avoid particle contamination during implantoplasty is possible and should be considered and further clinically assessed to avoid iatrogenic inflammatory reactions.

Titanium implant surface roughness after different implantoplasty protocols: A laboratory study

OBJECTIVE

To compare the surface roughness of sandblasted, large grit, acid-etched (SLA) surfaced titanium discs, after implantoplasty (IP) with different combinations of rotating instruments without or with the subsequent use of a silicone polisher.

METHODS

Titanium discs (n = 12 per group) with an SLA surface were treated with the following IP protocols: (1) Tungsten carbide bur sequence from company 1 (Komet Dental) without or with polishing (P) with a silicone polisher (Brownie®), (2) tungsten carbide bur sequence from company 2 (Hager & Meisinger GmbH) without or with P, and (3) diamond bur sequence (125, 40, 15-μm grit) without or with P. Pristine turned (T) and SLA titanium discs were used as negative and positive controls, respectively. Surface roughness measurements were taken with a contact profilometer rendering R_a and R_z values.

RESULTS

All IP protocols, even without P, resulted in significantly reduced surface roughness compared to the SLA group. The tungsten carbide bur protocols, even without P, resulted in a surface roughness similar to or significantly lower than that in the T group in terms of R_a and R_z , respectively. IP with the diamond bur sequence resulted in a significantly rougher surface compared to that achieved with the carbide burs. In all IP groups, P with a silicone polisher resulted in a significantly smoother surface.

CONCLUSIONS

IP with dedicated tungsten carbide burs without or with the subsequent use of a silicone polisher resulted in a surface roughness similar to or significantly lower than that of commercially available turned surfaces. IP with a diamond bur sequence required additional polishing to achieve a comparable surface roughness to that of commercially available turned surfaces.

Non-surgical mechanical therapy of peri-implantitis with or without repeated adjunctive diode laser application. A 6-month double-blinded randomized clinical trial

Objectives

The objective of this study is to investigate the outcomes following non‐surgical therapy of peri‐implantitis (PI) with or without adjunctive diode laser application.

Materials and methods

A double‐blinded randomized controlled clinical trial was carried out in 25 subjects with 25 implants diagnosed with PI. Following curettage of granulation tissue, test implants (T) were treated with adjunctive application of a diode laser for 90 s (settings: 810 nm, 2.5 W, 50 Hz, 10 ms), while at control implants (C) non‐activated adjunctive diode laser was applied. The entire treatment procedure was performed at days 0 (i.e., baseline), 7 and 14. The primary outcome measure was change in mean pocket probing depth (PPD). Clinical and microbiological outcomes, as well as host‐derived inflammatory markers were evaluated at baseline, 3 and 6 months, while radiographic outcomes were assessed at baseline and at the 6‐month follow‐up.

Results

No statistically significant differences with respect to baseline patient characteristic were observed. After 6 months, both test and control implants yielded statistically significant PPD changes compared with baseline (T: 1.28 and C: 1.47 mm) but without statistically significant difference between groups (p = .381). No statistically significant changes in peri‐implant marginal bone levels were detected (p = .936). No statistically significant differences between test and control implants were observed with respect to microbiological and host‐derived parameters (p > .05). At the 6‐month follow‐up, treatment success was observed in 41.7% (n = 5) of test and 46.2% (n = 6) of control patients, respectively (p = .821).

Conclusion

Repeated adjunctive application of diode laser in the non‐surgical management of PI failed to provide significant benefits compared with mechanical instrumentation alone.

Prognostic factors associated with implant loss, disease progression or favorable outcomes after peri-implantitis surgical therapy

BACKGROUND

The treatment of the peri-implantitis remains complex and challenging with no consensus on which is the best treatment approach.

PURPOSE

To examine the key local and systemic factors associated with implant loss, disease progression, or favorable outcomes after surgical peri-implantitis therapy.

MATERIALS AND METHODS

Records of patients treated for peri-implantitis were screened. Patient-, implant- and surgery-related variables on and prior to the day of the surgery were collected (T0: time of peri-implantitis treatment). If the treated implant was still in function when the data was collected, the patient invited to participate for a recall study visit (T1, longest follow-up after treatment). Impacts of the variables on the implant survival, success, and peri-implant bone change after treatment were investigated.

RESULTS

Eighty patients with 121 implants with a mean follow-up of 42.6 ± 26.3 months were included. A total of 22 implants (18.2%) were removed during the follow-up period. When relative bone loss (%) was in range 25%-50%, risk for implant removal increased 15 times compared to lower bone loss <25% (OR = 15.2; CI: 2.06-112.7; p = 0.008). Similarly, relative bone loss of >50% increased 20 times the risk of implant failure compared to the <25% (OR = 20.2; CI: 2.42-169.6; p = 0.006). For post-treatment success rate, history of periodontitis significantly increased the risk of unsuccess treatment (OR = 3.07; p = 0.04) after resective surgery).

CONCLUSION

Severe bone loss (>50%) poses significantly higher risk of treatment failure.

The efficacy of systemic antibiotics as an adjunct to surgical treatment of peri-implantitis: a systematic review

BACKGROUND

Microbial biofilm accumulation is the main cause of peri-implantitis. The majority of surgical peri-implantitis treatment protocols suggests adjunctive use of systemic antibiotics to target specific putative bacteria. The aim of this systematic review was to critically evaluate the adjunctive use of systemically administered antibiotics in surgical treatment of peri-implantitis by reviewing previously published systematic reviews and primary studies.

METHODS

A systematic literature search was conducted in four electronic databases (MEDLINE, The Cochrane Library, EMBASE, and Web of Science) for randomised controlled trials, cohort studies, case-control studies, and systematic reviews reporting surgical treatment of peri-implantitis with and without adjunctive systemically administered antibiotic therapy. The included systematic reviews and primary studies were qualitatively assessed using AMSTAR and GRADE, respectively. No restrictions were set for date of publication, journal, or language.

RESULTS

The literature search identified 681 papers. Only seven systematic reviews and two primary studies met the inclusion criteria. Four out of seven included systematic reviews concluded that no evidence exists for use of systemic antibiotics to improve the clinical outcomes in surgical treatment of peri-implantitis. One review did not estimate the level of evidence, one did not clearly state any beneficial effect, whereas one reported a limited adjunctive effect. Further, the two included primary studies did not show a long-term significant benefit of adjunctive use of systemically administrated antibiotics. However, one study reported a short-term adjunctive effect in patients with modified surface implants. Due to heterogeneity in study design, low number of included primary studies, and grade of bias, no meta-analysis was performed.

CONCLUSION

The use of systemically administered antibiotics as an adjunct to surgical interventions of peri-implantitis cannot be justified as a part of a standard treatment protocol. A pervasive problem is the lack of uniform diagnosis criteria for peri-implantitis, deficient information about patient characteristics, absence of high quality long-term randomised controlled trials, and authors' declaration on conflict of interest.

Reversal of Osseointegration as a Novel Perspective for the Removal of Failed Dental Implants: A Review of Five Patented Methods

Osseointegration is the basis of successful dental implantology and the foundation of cementless arthroplasty and the osseointegrated percutaneous prosthetic system. Osseointegration has been considered irreversible thus far. However, controlled heating or cooling of dental implants could selectively damage the bone at the bone–implant interface, causing the reversal of osseointegration or “osseodisintegration”. This review compares five methods for implant removal, published as patent documents between 2010 and 2018, which have not yet been discussed in the scientific literature. We describe these methods and evaluate their potential for reversing osseointegration. The five methods have several technical and methodological similarities: all methods include a handpiece, a connecting device for coronal access, and a controlling device, as well as the application of mechanical and/or thermal energy. The proposed method of quantifying the temperature with a sensor as the sole means for regulating the process seems inadequate. A database used in one of the methods, however, allows a more precise correlation between a selected implant and the energy needed for its removal, thus avoiding unnecessary trauma to the patient. A flapless, microinvasive, and bone-conserving approach for removing failed dental implants, facilitating successful reimplantation, would benefit dental implantology. These methods could be adapted to cementless medical implants and osseointegrated percutaneous prosthetics. However, for some of the methods discussed herein, further research may be necessary.

Overcoming Complications with Implants in the Esthetic Zone: An Innovative Approach

Owing to the satisfactory esthetic and functional outcomes of implant surgery for the anterior teeth, some dentists consider it the gold standard treatment. However, the risk of developing peri-implantitis is positively associated with the long-term use of the implant. This necessitates the development of an implant design that reduces the risk of peri-implantitis, especially considering the long-term use of implants in young patients. This case report describes a new approach for an implant surgery using a two-stage implant in a 28-year-old woman. Her clinical course was satisfactory during the 4-year postoperative follow-up period; no inflammation was noted in the surrounding tissues. The two-stage implants allow for the removal of an implant body from an infected area and its replacement with a new abutment if peri-implantitis develops in the future.

Prevalence and risk indicators of midfacial peri-implant soft tissue dehiscence at single site in the esthetic zone: A cross-sectional clinical and ultrasonographic study

BACKGROUND

Esthetic complications of dental implants in the esthetic zone can have a major negative impact on patients' quality of life and perception of implant therapy. The aim of the present study was to evaluate the prevalence of peri-implant soft tissue dehiscence (PSTD) and the clinical and ultrasonographic risk indicators for this condition.

METHODS

Subjects with one or more healthy single dental implants in the esthetic area were identified and recruited. Clinical and ultrasonographic measurements, including PSTD class and subclass, pocket depth, keratinized mucosa width (KMW), mucosal thickness (MT) at 1 mm and 3 mm, buccal bone distance (BBD) and buccal bone thickness, were evaluated in healthy implants and implants with PSTD.

RESULTS

153 subjects with a total of 176 dental implants were included. The prevalence of PSTD was 54.2% and 56.8% on a patient and implant level, respectively. The most frequent type of PSTD was the one characterized by having both an implant-supported crown longer than the clinical crown of the homologous tooth and a visible abutment/implant fixture exposed to the oral cavity. The multi-variate analysis showed that the presence of an adjacent implant, a longer time of the implant in function, limited MT, reduced KMW and increased BBD were significantly associated with the presence of a PSTD.

CONCLUSIONS

PSTDs are common findings in the esthetic region. Several risk indicators for this condition, such as presence of an adjacent implant, increased time in function of the implant, higher BBD, lower KMW and MT were identified. This article is protected by copyright. All rights reserved.

Reduced fracture load of dental implants after implantoplasty with different instrumentation sequences. An in vitro study

OBJECTIVES

To assess the mechanical stability of implants after implantoplasty and thermocyclic loading, the residual thickness of the instrumented areas and neighbouring tooth injury due to implantoplasty.

MATERIALS AND METHODS

Using a phantom head simulator and maxillary model implants were subjected to an implantoplasty procedure. Thirty implants were randomly assigned to receive one of three instrumentation sequences. After instrumentation, injury on neighbouring teeth was assessed. Instrumented implants and non-instrumented controls were subjected to 1.2 million cycles of thermo-mechanical loading in a chewing machine. Afterwards, maximum fracture load for all implants and an additional five pristine control implants was tested.

RESULTS

Generally, damage of neighbour teeth was a frequent finding (33 ± 56% of all cases) with considerable inter-group differences. No considerable inter-group difference for the residual implant thickness was found for different areas assessed. No implant fractured during cyclic loading. Fracture load was reduced after cyclic loading of uninstrumented implants from 2,724 ± 70 N to 2,299 ± 127 N, and after implantoplasty to 1,737 ± 165 N, while no effect by the instrumentation sequence could be observed.

CONCLUSIONS

Both implantoplasty and cyclic loading were shown to reduce the implants' maximum bending strength. Cyclic loading in a laboratory masticator, simulating a five-year equivalent of chewing, did not result in fractured implants. Since neighbouring tooth injury was assessed often, care should be taken with the selection of suitable instruments.

Resolution of peri-implantitis by means of implantoplasty as adjunct to surgical therapy: A retrospective study

BACKGROUND

There is a paucity of data on the effectiveness of implantoplasty as adjunct to the surgical management of peri-implantitis.

PURPOSE

To evaluate the resolution of peri-implantitis by means of implantoplasty as adjunct to surgical resective (RES) and reconstructive (REC) therapies and supportive maintenance.

METHODS

Patients that underwent surgical therapy to manage peri-implantitis with a follow-up of ≥12 months and enrolled in a regular peri-implant supportive care were recruited. RES group consisted of two interventions that included osseous recontouring and apically position flap (APF) and soft tissue conditioning (STC). REC was performed in the infra-osseous compartment of combined defects. Implant survival rate was recorded. Clinical and radiographic parameters were evaluated to define a "dogmatic" (case definition #1) and a "flexible" (case definition #2) therapeutic success. Univariate and multivariate multilevel backward logistic regression were applied for statistical analysis.

RESULTS

Overall, 43 patients (n_implants  = 135) were retrospectively assessed. Mean observational period was ∼24 months. Implant survival rate was 97.8%, being significantly higher for APF, STC, and APF + STC (RES) when compared with REC (P = 0.01) therapy, in particular for advanced lesions (>50% of bone loss). The overall therapeutic success rate at implant-level was 66% and 79.5% for case definition #1 and #2, respectively. APF group displayed more efficient disease resolution when considered success definition #1 (72%). Contrarily, when the data were adhered to success definition #2, STC group showed a slightly higher disease resolution rate (87%). For RES group, location, favoring anterior (P = 0.04) and defect type, favoring class II (P = 0.02) displayed statistical significance for therapeutic success. For REC group, implants exhibiting a wider band of keratinized mucosa (KM) demonstrated higher therapeutic success (P = 0.008).

CONCLUSION

Implantoplasty as an adjunct to surgical therapy proved effective in terms of disease resolution and implant survival rate. Implant location, defect morphology as well as the buccal width of KM are indicators of therapeutic success.

A Mini Review on Non-augmentative Surgical Therapy of Peri-Implantitis—What Is Known and What Are the Future Challenges?

Non-augmentative surgical therapy of peri-implantitis is indicated for cases with primarily horizontal bone loss or wide defects with limited potential for bone regeneration and/or re-osseointegration. This treatment approach includes a variety of different techniques (e.g., open flap debridement, resection of peri-implant mucosa, apically positioned flaps, bone re-contouring, implantoplasty, etc.) and various relevant aspects should be considered during treatment planning. The present mini review provides an overview on what is known for the following components of non-augmentative surgical treatment of peri-implantitis and on potential future research challenges: (1) decontamination of the implant surface, (2) need of implantoplasty, (3) prescription of antibiotics, and (4) extent of resective measures.

Surgical and non-surgical debridement for the treatment of peri-implantitis: a two-center 12-month randomized trial

OBJECTIVES

To compare surgical (ST) and non-surgical (NST) debridement for the treatment of peri-implantitis in a two-center randomized trial.

MATERIALS AND METHODS

Forty-five individuals with 63 implants with probing depth (PPD) ≥5mm, bleeding on probing (BOP), and radiographic bone loss ≥2mm were included. In the NST (30 implants), submucosal debridement was performed. In the ST (33 implants), a mucoperiosteal flap was raised and surfaces were decontaminated only by debridement as performed in NST. Clinical parameters and radiographs were compared at baseline and after 12 months. Means and standard errors were reported.

RESULTS

PPD considering all implant sites reduced significantly in NST from 4.14±0.25 to 3.25±0.18mm. In ST, PPD also significantly changed (3.74±0.22 to 3.00±0.29mm). No significant differences were observed between the two groups. For deep sites (≥7mm), PPD was 7.82±0.20mm at baseline and reduced to 5.10±0.30mm in NST, while in ST group, it was 7.11±0.11mm and changed to 5.22±0.91mm (between-groups p value=0.51). BOP significantly reduced from ~60 to 35% of all sites in both groups, without significant differences between them. When sites with radiographic bone level ≥3mm at baseline were analyzed, there was a significant difference between groups in bone gain after 12 months in favor of ST (ST=0.78±0.30mm compared to NST=0.25mm±0.13; p=0.03).

CONCLUSIONS

Surgical and non-surgical debridement for the treatment of peri-implantitis present similar clinical outcomes. Bone levels were better improved in ST than NST for sites with higher initial bone loss.

CLINICAL RELEVANCE

The treatment of peri-implantitis is still a challenge in clinical practice, since less than half of affected implants achieve health after surgical or non-surgical debridement. Considering the lack of clinically relevant differences between these two treatments, non-surgical debridement should be considered the first therapeutic choice for peri-implantitis, mainly mild to moderate cases.

Peri-Implantitis: A Clinical Update on Prevalence and Surgical Treatment Outcomes

Dental implants may be considered a reliable routine procedure in clinical practice for the replacement of missing teeth. Results from long-term studies indicate that implant-supported dental prostheses constitute a predictable treatment method for the management of fully and partially edentulous patients. Implants and their restorations, however, are not free from biological complications. In fact, peri-implantitis, defined as progressive bone loss associated to clinical inflammation, is not a rare finding nowadays. This constitutes a concern for clinicians and patients given the negative impact on the quality of life and the sequelae originated by peri-implantitis lesions. The purpose of this narrative review is to report on the prevalence of peri-implantitis and to overview the indications, contraindications, complexity, predictability and effectiveness of the different surgical therapeutic modalities to manage this disorder.

Implantoplasty: Carbide burs vs diamond sonic tips. An in vitro study

OBJECTIVES

Implantoplasty (IP) is a treatment option for peri-implantitis. Mechanical concerns were raised on fracture resistance of implants subjected to this procedure. This study aimed to compare two methods of IP in terms of implant wear and fracture resistance, and of surface topography.

MATERIAL AND METHODS

Eighteen cylindrical screw-shaped dental implants (4 mm diameter, 13 mm length) with an external hexagonal connection were used. IP was performed on the first 6-mm implant surface with a sequence of burs or diamond sonic tips, both followed by an Arkansas finishing. IP duration and implant weight variation were recorded. Micro-computed tomography (micro-CT) was used to evaluate material loss. Implant fracture resistance was assessed by static compression test. Surface topography analysis was performed with a stylus profilometer. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) was applied for implant surface morphology and elemental characterization.

RESULTS

Micro-CT showed less material loss in sonic compared to burs. No statistically significant difference was found between the mean fracture resistance values reached in bur and sonic, both followed by Arkansas, and with respect to control. IP performed with burs led to a smoother surface compared to sonic. Equivalent final surface roughness was found after Arkansas in both IP procedures. SEM-EDS showed a deburring effect associated to sonic and revealed carbon and aluminum peaks attributable to contamination with sonic diamond tips and Arkansas bur, respectively.

CONCLUSIONS

IP with sonic diamond tips was found to be more conservative in terms of structure loss. This could have a clinical relevance in case of narrow-diameter implants.

Nanointeraction: The profound influence of nanostructured and nano-drug delivery biomedical implant surfaces on cell behavior

Nanostructured surfaces feature promising biological properties on biomaterials attracting large interest at basic research, implant industry development, and bioengineering applications. Thou, nanoscale interactions at a molecular and cellular level are not yet completely understood and its biological and clinical implications need to be further elucidated. As follows, the aim of this comprehensive review was to evaluate nanostructured surfaces at biomedical implants focusing on surface development, nanostructuration, and nanoengineered drug delivery systems that can induce specific cell interactions in all relevant aspects of biological, reparative, anti-bacterial, anti-inflammatory and clinical processes. The methods and the physio-chemical properties involved in nanotopography performance, the main cellular characteristics involved at surface/cell interaction, and a summary of results and outlooks reported in studies applying nanostructured surfaces and nano-drug delivery systems is presented. The future prospects and commercial translation of this developing field, particularly concerning multifunctional nanostructured surfaces and its clinical implications are further discussed. At a cellular level, nanostructured biomedical implant surfaces can enhance osteogenesis by targeting osteoblasts, osteocytes, and mesenchymal cells, stimulate fibroblast/epithelial cells proliferation and adherence, inhibit bacterial cell proliferation and biofilm accumulation, and act as immune-modulating surfaces targeting macrophages and reducing pro-inflammatory cytokine expression. Moreover, several methodological options to create drug-delivery systems on metallic implant surfaces are available, however, the clinical translation is yet incomplete. The efficiency of which nanostructured/nano-delivery surfaces may target specific cell interactions and favor clinical outcomes needs to be further elucidated in pre-clinical and clinical studies, along with engineering solutions for commercial translation and approval of controlling agencies.

Strategies to Reduce Biofilm Formation in PEEK Materials Applied to Implant Dentistry-A Comprehensive Review

Polyether-ether-ketone (PEEK) has emerged in Implant Dentistry with a series of short-time applications and as a promising material to substitute definitive dental implants. Several strategies have been investigated to diminish biofilm formation on the PEEK surface aiming to decrease the possibility of related infections. Therefore, a comprehensive review was carried out in order to compare PEEK with materials widely used nowadays in Implant Dentistry, such as titanium and zirconia, placing emphasis on studies investigating its ability to grant or prevent biofilm formation. Most studies failed to reveal significant antimicrobial activity in pure PEEK, while several studies described new strategies to reduce biofilm formation and bacterial colonization on this material. Those include the PEEK sulfonation process, incorporation of therapeutic and bioactive agents in PEEK matrix or on PEEK surface, PEEK coatings and incorporation of reinforcement agents, in order to produce nanocomposites or blends. The two most analyzed surface properties were contact angle and roughness, while the most studied bacteria were Escherichia coli and Staphylococcus aureus. Despite PEEK's susceptibility to biofilm formation, a great number of strategies discussed in this study were able to improve its antibiofilm and antimicrobial properties.

Does implantoplasty affect the failure strength of narrow and regular diameter implants? A laboratory study

Objective

To assess whether the impact of implantoplasty (IP) on the maximum implant failure strength depends on implant type/design, diameter, or material.

Methods

Fourteen implants each of different type/design [bone (BL) and tissue level (TL)], diameter [narrow (3.3 mm) and regular (4.1 mm)], and material [titanium grade IV (Ti) and titanium-zirconium alloy (TiZr)] of one company were used. Half of the implants were subjected to IP in a computerized torn. All implants were subjected to dynamic loading prior to loading until failure to simulate regular mastication. Multiple linear regression analyses were performed with maximum implant failure strength as dependent variable and IP, implant type/design, diameter, and material as predictors.

Results

Implants subjected to IP and TL implants showed statistically significant reduced implant failure strength irrespective of the diameter compared with implants without IP and BL implants, respectively. Implant material had a significant impact for TL implants and for regular diameter implants, with TiZr being stronger than Ti. During dynamic loading, 1 narrow Ti TL implant without IP, 4 narrow Ti TL implants subjected to IP, and 1 narrow TiZr TL implant subjected to IP were fractured.

Conclusion

IP significantly reduced the maximum implant failure strength, irrespective implant type/design, diameter, or material, but the maximum implant failure strength of regular diameter implants and of narrow BL implants remained high.

Clinical Relevance

IP seems to have no clinically relevant impact on the majority of cases, except from those of single narrow Ti TL implants, which may have an increased risk for mechanical complications. This should be considered for peri-implantitis treatment planning (e.g., communication of potential complications to the patient), but also in the planning of implant installation (e.g., choosing TiZr instead of Ti for narrow implants).

Efficacy of growth factors for the treatment of peri-implant diseases: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to conduct a systematic review and meta-analysis on the efficacy of growth factors (GF) on clinical outcomes after treatment (surgical/non-surgical) of peri-implant diseases (peri-implant mucositis and peri-implantitis).

MATERIALS AND METHODS

A protocol was developed to answer the following focused question: Is there any difference for the use of GF for treatment of peri-implant diseases versus comparative GF treatment or without GF? Electronic database and manual searches were independently conducted to identify randomized controlled trials (RCTs). Publications were selected based on eligibility criteria and then assessed for risk-of-bias using the Cochrane Handbook. The primary outcome was probing depth (PD) and bleeding on probing (BOP) reduction along with changes in vertical defect depth (VDD). Changes in clinical attachment level, gingival recession, and plaque index, among others, were studied as secondary outcomes. Based on primary outcomes, random-effects meta-analysis was conducted.

RESULTS

A total of five RCTs were included. GF enhance the reduction of PD (standardized mean difference (SMD) = - 1.28; 95% confidence interval (CI) - 1.75, - 0.79; p = < 0.0001) and BOP (SMD = - 1.23; 95% CI - 1.70, - 0.76; p = < 0.0001) in the management of peri-implant mucositis. For the treatment of peri-implantitis, the use of GF yielded to significantly greater improvement in VDD (SMD = 0.68; 95% CI 0.22, 1.14; p = 0.004); however, there were no significant differences in terms of PD (SMD = 0.08; 95% CI - 1.08, 1.26; p = 0.887) and BOP (SMD = 0.211; 95% CI - 0.20, 0.63; p = 0.317). The overall risk of bias of the included studies was low to unclear.

CONCLUSION

The results of the present systematic review suggest that the addition of GF might enhance the outcomes in the treatment of peri-implant mucositis. However, there is a lack of evidence for supporting additional benefit of GF managing peri-implantitis.

CLINICAL RELEVANCE

Within the limitations of the current systematic review and based on the meta-analyses, (1) the addition of GF for the treatment peri-implant mucositis might be associated with better outcomes in terms of PD and BOP, and (2) an additional benefit of GF for the treatment peri-implantitis could not be determined on the basis of the selected evidence.

Histological characteristics of advanced peri-implantitis bone defects in humans

BACKGROUND

Inflammatory osteolysis is the clinical hallmark of peri-implantitis. The morphology of the remaining peri-implant bone and the level of osseointegration, however, remain unknown. Our aim was to characterize advanced peri-implantitis bone defects in humans.

METHODS

Four patients (3 female and 1 male) were diagnosed with peri-implantitis. A total of 5 implants with machined surfaces and a mean loading time of 12 ± 6 years were removed due to advanced bone loss. The defect extension, the peri-implant bone density (bone area per tissue area in percentage), bone-to-implant contact (%), and the number of filled and empty osteocyte lacunae were calculated based on undecalcified histological specimens.

RESULTS

The defect extension was on average 4.2 mm (95% CI 0.8-3.4). Remaining peri-implant bone showed a high density of 85.5% (95% CI 79.1-91.3) and covered in total 74% (95% CI 70.5-77.5) of the implant surface. Filled and empty osteocyte lacunae density was on average 191 and 165/mm2 (95% CI 132-251; 103-225), respectively. Histology further revealed signs of ongoing bone formation and resorption.

CONCLUSION

There are signs that suggest that once the original cortical bone is lost due to peri-implantitis, the remaining apical trabecular bone is reinforced and transformed into cortical bone that might take over the functional load.