Implant surface modifications and their impact on osseointegration and peri-implant diseases through epigenetic changes: A scoping review.

Dental implant surfaces and their unique properties can interact with the surrounding oral tissues through epigenetic cues. The present scoping review provides current perspectives on surface modifications of dental implants, their impact on the osseointegration process, and the interaction between implant surface properties and epigenetics, also in peri-implant diseases. Findings of this review demonstrate the impact of innovative surface treatments on the epigenetic mechanisms of cells, showing promising results in the early stages of osseointegration. Dental implant surfaces with properties of hydrophilicity, nanotexturization, multifunctional coatings, and incorporated drug-release systems have demonstrated favorable outcomes for early bone adhesion, increased antibacterial features, and improved osseointegration. The interaction between modified surface morphologies, different chemical surface energies, and/or release of molecules within the oral tissues has been shown to influence epigenetic mechanisms of the surrounding tissues caused by a physical-chemical interaction. Epigenetic changes around dental implants in the state of health and disease are different. In conclusion, emerging approaches in surface modifications for dental implants functionalized with epigenetics have great potential with a significant impact on modulating bone healing during osseointegration.

Effect of Abutment Height on Marginal Bone Loss Around Dental Implants: A Systematic Review.

PURPOSE: To analyze the influence of abutment height (AH) on marginal bone loss (MBL). MATERIALS AND METHODS: A literature search was performed for human studies (RCTs, prospective and retrospective cohorts) reporting on AH and MBL. The data obtained-including clinical outcomes, treatment covariates, and patient characteristics-were analyzed. Meta-regression was performed on the effect size of the differences between the shorter and larger AHs on the MBL of each study. The estimation was done using the restricted maximum likelihood method. RESULTS: The initial screening and full-text analysis resulted in 7,936 and 46 articles, respectively. Finally, 14 articles were included in the systematic review, reporting a total of 1,606 implants. An overall high-to-moderate risk of bias was determined among the included investigations. Meta-regression analysis revealed that AH had a significant effect on MBL (b = -1.630, P < .003), demonstrating that longer abutments were correlated with less MBL. No effects were observed for the study type (P = .607), the number of stages (P = .510), or the elapsed time (P = .491). CONCLUSIONS: The height of the abutment has a significant impact on MBL. As such, increased AH is related to less MBL. Nevertheless, the role of confounding variables remains to be studied and determined.

The Root Complex in Posterior Teeth: A Direct Digital Analysis.

The aim of this morphometric study was to precisely determine the 3D characteristics of the root complex of the posterior dentition. Extracted and well-preserved permanent posterior teeth were included in this analysis and grouped based on tooth type and arch location. All teeth were digitally scanned. Morphologic and dimensional features of the root complex were assessed, including length and surface area of the root trunk and individual roots, width of root concavities (RC), and furcation entrance, when present. A total of 240 posterior teeth comprised the study sample. The root complex of multirooted maxillary first premolars presented with a long root trunk (10.49 mm), representing 65.52% of the surface area, and two short roots comprising the remaining 34.8% of the surface area. Root trunks of mandibular molars were an average of 0.8 mm shorter than their maxillary counterparts. Class III furcation involvement is expected in all maxillary and mandibular molars, as well as multirooted maxillary first premolars, after 4.80 mm and 10.49 mm of clinical attachment loss, respectively. RCs were a common finding among the evaluated dentitions. The root complex morphology varies among the maxillary and mandibular posterior dentition. RCs are highly prevalent in both maxillary and mandibular dentition. The findings derived from this study can be utilized in daily clinical practice for the adequate management of posterior dentition and serve as a reference for future investigations in dental anatomy and digital technology. Also, these findings can guide the industry into creating and redefining tools that adequately adapt to the anatomical characteristics and variations of the specific tooth type.

Volumetric changes and graft stability after lateral window sinus floor augmentation: A randomized clinical trial.

INTRODUCTION: The present investigation compared the stability and volumetric changes of two different grafting material used for lateral window sinus floor augmentation (LWSFA). METHODS: Sixteen patients with a total 20 maxillary sinuses in need of LWSFA were included in the present study. The sinuses were grafted with either 100% anorganic bovine bone mineral (ABBM) alone (Group 1) or a mixture (0.8:1 ratio) of ABBM and mineralized cortical allograft (MCA) (Group 2). Cone beam computer tomography (CBCT) was obtained pre-operatively, and at 2-weeks, and 6-months after LWSFA to perform linear measurements including lateral window dimensions, sinus anatomy, residual bone height/thickness (RBH/RBT), and Schneiderian membrane thickness (SMT), among others. Three-dimensional segmentation analysis was used to evaluate changes of bone graft volume/height (GV/GH). RESULTS: A total of 10 sinuses per group were included in the analysis. No statistically significant difference was found in between groups regarding mean reduction of GV (Group 1: 14.87% ± 16.60%, Group 2: 18.06% ± 9.81%, p = 0.33). Among the linear measurements, only SMT revealed a significant increase after 2-weeks more pronounce in Group 1 (8.70 mm) when compared with Group 2 (5.70 mm) with plausible effect upon LWSFA outcomes. Sinus width showed weak positive correlation with GH reduction after 6 months. CONCLUSION: This study demonstrated that both ABBM alone and ABBM + MCA represent suitable alternatives for LWSFA with adequate graft stability as they revealed similar volumetric and linear dimensional changes 6 months postoperatively.

Disease resolution following treatment of peri-implant diseases: A systematic review.

The aim of this PRISMA-compliant systematic review was to analyze the evidence pertaining to disease resolution after treatment of peri-implant diseases (PROSPERO: CRD42022306999) with the following PICO question: what is the rate of disease resolution following non-surgical and surgical therapy for peri-implant diseases in adult human subjects? A literature search to identify studies that fulfilled a pre-established eligibility criteria was conducted. Data on primary therapeutic outcomes, including treatment success, rate of disease resolution and/or recurrence, as well as a variety of secondary outcomes was extracted and categorized. Fifty-five articles were included. Few studies investigated the efficacy of different non-surgical and surgical therapies to treat peri-implant diseases using a set of pre-defined criteria and with follow-up periods of at least one year. The definition of treatment success and outcomes of disease resolution differed considerably among the included studies. Treatment of peri-implant mucositis was most commonly reported to be successful in arresting disease progression for ≤60% of the cases, whereas most studies on peri-implantitis treatment reported disease resolution occurring in <50% of the fixtures. In conclusion, disease resolution is generally unpredictable and infrequently achieved after the treatment of peri-implant diseases. A great variety of definitions have been used to define treatment success. Notably, percentages of treatment success and disease resolution were generally underreported. The use of standardized parameters to evaluate disease resolution should be considered an integral component in future clinical studies.

Interproximal Soft Tissue Height Changes After Unassisted Socket Healing versus Alveolar Ridge Preservation Therapy.

The primary aim of this study was to evaluate the efficacy of alveolar ridge preservation (ARP) therapy compared with unassisted socket healing (USH) in attenuating interproximal soft tissue atrophy. Adult subjects that underwent maxillary single-tooth extraction with or without ARP therapy were included in this study. Surface scans and cone beam computed tomography were obtained to digitally assess interproximal soft tissue height changes and measure facial bone thickness (FBT), respectively. Logistic regression models were conducted to investigate the individual effect of demographic and clinical variables. Ninety-six subjects (USH=49; ARP=47) constituted the study population. Linear soft tissue assessments revealed a significant reduction of the interproximal soft tissue over time within and between groups (P<.0001). ARP therapy significantly attenuated interproximal soft tissue height reduction compared to USH (USH mesial: -2.0±0.9mm vs. ARP mesial: -1.0±0.5mm / USH distal -1.9±0.7mm vs. ARP distal: -1.1±0.5mm; P<.0001). Thin FBT (≤1mm) upon extraction was associated with greater interproximal soft tissue atrophy compared with thick FBT (>1mm), independently of the treatment received (P<.0001). Nevertheless, ARP therapy resulted in better preservation of interproximal soft tissue height especially in thin bone phenotype by a factor of 2 for the mesial site (+1.3mm) and a factor of 1.6 (+0.9mm) for the distal site. This study demonstrated that ARP therapy largely attenuates interproximal soft tissue dimensional reduction after maxillary single-tooth extraction compared with USH.

Influence of healing time on the outcomes of alveolar ridge preservation using a collagenated bovine bone xenograft: A randomized clinical trial.

AIM: To evaluate the healing outcomes in non-molar post-extraction sockets filled with deproteinized bovine bone mineral with collagen (DBBM-C) as a function of time. MATERIALS AND METHODS: Patients in need of non-molar tooth extraction were randomly allocated into one of three groups according to the total healing time (A-3 months; B-6 months; C-9 months). The effect of alveolar ridge preservation (ARP) therapy via socket filling using DBBM-C and socket sealing with a porcine collagen matrix (CM) was assessed based on a panel of clinical, digital, histomorphometric, implant-related, and patient-reported outcomes. RESULTS: A total of 42 patients completed the study (n = 14 in each group). Histomorphometric analysis of bone core biopsies obtained at the time of implant placement showed a continuous increase in the proportion of mineralized tissue with respect to non-mineralized tissue, and a decrease in the proportion of remaining xenograft material over time. All volumetric bone and soft tissue contour assessments revealed a dimensional reduction of the alveolar ridge overtime affecting mainly the facial aspect. Linear regression analyses indicated that baseline buccal bone thickness is a strong predictor of bone and soft tissue modelling. Ancillary bone augmentation at the time of implant placement was needed in 16.7% of the sites (A:2; B:1; C:4). Patient-reported discomfort and wound healing index scores progressively decreased over time and was similar across groups. CONCLUSIONS: Healing time influences the proportion of tissue compartments in non-molar post-extraction sites filled with DBBM-C and sealed with a CM. A variable degree of alveolar ridge atrophy, affecting mainly the facial aspect, occurs even after performing ARP therapy. These changes are more pronounced in sites exhibiting thin facial bone (≤1 mm) at baseline (Clinicaltrials.gov NCT03659617).

Effect of Abutment Height on Marginal Bone Loss Around Dental Implants: A Systematic Review.

PURPOSE: To analyze the influence of abutment height (AH) on marginal bone loss (MBL). MATERIALS AND METHODS: A literature search was performed for human studies (randomized controlled trials, prospective and retrospective cohorts) reporting on the AH and MBL. The data obtained-including clinical outcomes, treatment covariates and patient characteristics-were analyzed. Meta-regression was performed on the effect size of the differences between the shorter and larger AHs on the MBL of each study. The estimation was done using the restricted maximum likelihood method. RESULTS: The initial screening and full-text analysis resulted in 7,936 and 46 articles, respectively. Finally, 14 articles were included in the systematic review, reporting a total of 1,606 implants. An overall high-to-moderate risk of bias was determined among the included investigations. Meta-regression analysis revealed that AH had a significant effect on MBL (b = - 1.630, P < .003), demonstrating that longer abutments were correlated with less MBL. No effects were observed for the study type (P = .607), the number of stages (P = .510), or the elapsed time (P = .491). CONCLUSION: The height of the abutment has a significant impact on MBL. As such, increased AH is related to less MBL. Nevertheless, the role of confounding variables remains to be studied and determined.

Understanding the role of endotoxin tolerance in chronic inflammatory conditions and periodontal disease.

OBJECTIVE: This review aims to present the current understanding of endotoxin tolerance (ET) in chronic inflammatory diseases and explores the potential connection with periodontitis. SUMMARY: Subsequent exposure to lipopolysaccharides (LPS) triggers ET, a phenomenon regulated by different mechanisms and pathways, including toll-like receptors (TLRs), nuclear factor kappa-light-chain enhancer of activated B-cells (NFκB), apoptosis of immune cells, epigenetics, and microRNAs (miRNAs). These mechanisms interconnect ET with chronic inflammatory diseases including periodontitis. While the direct correlation between ET and periodontal destruction has not been fully elucidated, emerging reports point towards the potential tolerization of human periodontal ligament cells (hPDLCs) and gingival tissues with a significant reduction of TLR levels. CONCLUSIONS: There is a potential link between ET and periodontal diseases. Future studies should explore the crucial role of ET in the pathogenesis of periodontal diseases, as evidence of a tolerized oral mucosa may represent an intrinsic mechanism capable of regulating the oral immune response. A clear understanding of this host immune regulatory mechanism might lead to effective and more predictable therapeutic strategies to treat chronic inflammatory diseases and periodontitis.

Influence of implant surface characteristics on the initiation, progression and treatment outcomes of peri-implantitis: A systematic review and meta-analysis based on animal model studies.

PURPOSE: To evaluate the impact of implant surface characteristics on the initiation, progression and treatment outcomes of peri-implantitis based exclusively on in vivo investigations. MATERIALS AND METHODS: A literature search was conducted by two independent reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify animal studies comparing at least two different implant surfaces affected by experimental peri-implantitis, with distinct characteristics and with or without subsequent surgical treatment that aims to arrest disease progression. The parameters evaluated included both radiographic (e.g., marginal bone level) and clinical (e.g., probing depth, bleeding on probing) aspects to determine changes in disease progression and treatment outcomes. RESULTS: No statistically significant differences were found among the different implant surfaces during the initiation of peri-implantitis. On the other hand, the progression and treatment outcomes of peri-implantitis displayed statistically significant differences among the different implant systems, with turned surfaces reporting less bone loss during the progression period and greater bone gain after treatment. CONCLUSIONS: Implant surface characteristics play a critical role in the progression and treatment outcomes of peri-implantitis. Turned implant surfaces demonstrated the least amount of bone loss after ligature removal and recorded the most favourable treatment outcomes.

Impact of mucosal phenotype on marginal bone levels around tissue level implants: A prospective controlled trial.

BACKGROUND: The aim of this 1-year prospective clinical trial was to compare clinical parameters and marginal bone levels (MBLs) around tissue level implants with a partially smooth collar between patients with thin (≤2 mm) and thick (>2 mm) vertical mucosal phenotypes. METHODS: Thirty patients needing a single dental implant were recruited and allocated to thin (n = 14) or thick (n = 16) phenotype groups. Post-restoration, clinical (probing depth, recession, width of keratinized mucosa, bleeding on probing, suppuration, implant mobility, plaque index, and gingival index) and radiographic bone level measurements were recorded at different timepoints for 1 year. RESULTS: Twenty-six patients (13 per group) completed the 1-year examination. No implants were lost (100% survival rate). There were no significant differences (P >0.05) between thin and thick vertical mucosal phenotypes for any clinical parameter or for the radiographic MBL. CONCLUSIONS: Tissue level implants at 1 year of function placed in thin vertical mucosa achieved similar clinical parameters and radiographic MBLs as those in thick tissue. The formation of the peri-implant supracrestal tissue height plays a key role in MBL than mucosal thickness in tissue level implant.

Expression of MicroRNAs in Periodontal and Peri-Implant Diseases: A Systematic Review and Meta-Analysis.

AIM: The purpose of this review was to evaluate the expression patterns of miRNAs in periodontal and peri-implant diseases, while identifying potential miRNAs with the greatest diagnostic ability as an oral fluid biomarker. MATERIALS AND METHODS: Human and animal studies were included when evaluating expression of miRNAs between health and different forms/stages of diseases, in which microarray and/or real-time polymerase chain reaction (RT-PCR) was carried out to detect fold changes in gene expression. After full-text analysis, 43 articles were considered for a qualitative assessment, and 16 miRNAs were selected to perform meta-analysis. RESULTS: Based on human studies, results showed an overall upregulation of most of the evaluated miRNAs in periodontitis, with miRNA-142-3p and miRNA-146a being the most conclusive on both microarray and RT-PCR values and potentially serving as diagnostic biomarkers for disease activity. Conversely, miR-155 was the only miRNA revealing a statistically significant difference (SSD) (p < 0.05*) in experimental periodontitis models from RT-PCR values. Scarce scientific evidence is available from peri-implant diseases, however, most explored miRNAs in peri-implantitis were downregulated except for miR-145. CONCLUSIONS: Although our results revealed that a distinct differential expression of specific miRNAs can be noted between the state of health and disease, future research remains necessary to explore the functional role of specific miRNAs and their potential as therapeutic targets in periodontal and peri-implant diseases. MeSH Terms: periodontitis, peri-implantitis, epigenomics, microarray analysis, real-time polymerase chain reaction, microRNAs. CLINICAL RELEVANCE: Scientific background: Although most research identified different expression levels of miRNAs in periodontal and peri-implant diseases compared to their counterparts, their actual role in the pathogenesis of these conditions remains unclear. Therefore, we aimed to present a systematic review and meta-analysis on the expression patterns of miRNAs in periodontitis and peri-implantitis, while identifying potential miRNAs with the greatest diagnostic ability as an oral fluid biomarker. PRINCIPAL FINDINGS: In periodontitis-related studies, miRNA-142-3p and miRNA-146a were the most conclusive on both microarray and RT-PCR values. Scarce scientific evidence is available from peri-implant diseases. PRACTICAL IMPLICATIONS: Both miRNA-142-3p and miRNA-146a might serve as future diagnostic biomarkers for disease activity in periodontitis. Yet, future research remains necessary to explore the functional role of specific miRNAs and their potential as therapeutic targets in periodontal and peri-implant diseases.

Influence of keratinized mucosa on the surgical therapeutical outcomes of peri-implantitis.

AIM: To assess the impact of keratinized mucosa (KM) width around dental implants on surgical therapeutic outcomes when treating peri-implantitis. MATERIAL AND METHODS: Surgically treated peri-implantitis implants were divided into two groups (KM width < 2 mm and ≥2 mm). Retrospective data were obtained after implant placement (T0) and the day of peri-implantitis surgical treatment (T1). Patients were later recruited (≥1 year after T1) for clinical and radiographic examination (T2). Outcomes were analysed using generalized estimating equation (GEE) models. RESULTS: A total of 40 patients (68 implants) (average follow-up: 52.4 ± 30.5 months) were included in this study. From T0 to T1, no differences were found between KM groups in terms of peri-implant probing depths (PPD) and bleeding on probing (BOP). However, sites with <2 mm KM exhibited significantly higher suppuration (SUP) and lower marginal bone level (MBL) (p > .01). Between T1 and T2, no major differences were noted on PPD reduction, BOP and MBL changes between the two groups. GEE modelling demonstrated that MBL severity prior to surgical therapy was a better predictor for implant survival than KM width. CONCLUSION: Surgical outcome in treating peri-implantitis was influenced by the severity of bone loss present at the time of treatment and not by the presence of KM at the time of treatment.

Outcomes of root resection therapy up to 16.8 years: A retrospective study in an academic setting.

BACKGROUND: Root resection has been considered a viable treatment option for molars with furcation defects. However, need of a multidisciplinary approach could potentially deem this procedure less successful. The aim of the present article was to determine survival rates of root resection procedure and reasons for failure in an academic setting. METHODS: Patient-related demographic data, medical history information, and relevant data pertaining to the root-resected teeth performed from January 1990 to September 2017 were reviewed through electronic and paper chart. Survival rates were analyzed using Kaplan-Meier estimate. Association between the reasons for failure and independent variables was established by a Pearson Chi-squared and Kruskal-Wallis test. RESULTS: A total of 85 patients with an average follow-up of 5 ± 4.3 years (range: 1 to 16.8 years) were included in the present article. A total of 47 molar teeth treated with root resection remained as part of the dentition (55.3%) and 38 (44.7%) failed. The mean survival time with the Kaplan-Mayer analysis was 109.9 months (9.1 years). Fracture (39.5%), caries (26.3%), and periodontal disease (23.7%) were the most common causes for failure. Interestingly, the majority of failures occurred in the first 4 years after therapy (n = 31; 81.5% of all failures). CONCLUSIONS: Root resection therapy remains a treatment solution for molars with furcation defects. In an academic setting, >50% of teeth remained functional after 9 years of root resection therapy.

Quantitative tooth mobility evaluation based on intraoral scanner measurements.

BACKGROUND: Tooth mobility assessment is subjective and current techniques require the translation of a continuous variable to a categorical variable based on the perception of the examiner. The aim of this study was to evaluate the reliability of a novel technique to assess tooth mobility. METHODS: Three experienced periodontists were asked to push tooth #16 into a buccal position to in a typodont model with different mobility (M1-M2). Tooth position was obtained using an intraoral scanner and files were compared in metrology software. Mobility was calculated at three reference points at the cervical (C), middle (M), and occlusal (O) regions of the buccal surface of the tooth to determine the linear deviation in the three axes (x, y, and z). Reliability was determined by intraclass-correlation coefficient, differences between M1 and M2 determined by t test, and the analysis of variance (ANOVA) was used to compare the data at the C-M-O regions. RESULTS: Excellent reliability was assessed by Cronbach alpha >0.9 on the x-y-z axes for both mobility tested, except for M1-C X (0.85), M1-M Y (0.89), and M2-M Z (0.89). The correlation between the examiners demonstrated excellent (˃0.90) or good (0.75˃ x ˂0.90) consistency, except for M1-C Y (0.73; examiner 1 to 2) and M1-M X (0.69; examiners 1 to 3). Significant changes were detected in all axes at the three reference points comparing M1 and M2, and a similar proportional change was observed between O-M-C reference points for M1 and M2. CONCLUSION: A novel technique to assess tooth mobility based on intraoral scanner measurements provided reliable data in an in vitro experiment.

Characterization of macrophages infiltrating peri-implantitis lesions.

OBJECTIVES: The mechanisms involved in the initiation and progression of peri-implantitis lesions are poorly understood. It was the aim to determine the content and activation status of macrophages present in human peri-implantitis lesions and compare the current findings with the macrophage polarization associated with periodontitis lesions. MATERIAL AND METHODS: A total of 14 patients were studied in this investigation. Seven were soft tissue biopsies from dental implants affected by peri-implantitis that required explantation. Seven biopsies were from chronic periodontal disease. Immunofluorescence stains were performed using biomarkers to identify macrophages (CD68+ ) undergoing M1 polarization (iNOS+ ) and M2 polarization (CD206+ ), along with Hoechst 33,342 to identify DNA content. All samples were stained and photographed, and double-positive cells for CD68 and iNOS or CD68 and CD206 were quantified. RESULTS: All peri-implantitis biopsies examined revealed a mixed population of macrophages undergoing M1 polarization and M2 polarization. Further analysis demonstrated the co-expression of iNOS and CD206, which indicates the presence of a heterogenic immune response on peri-implantitis lesions. Macrophage polarization in peri-implantitis lesions presents a distinct pattern than in periodontitis. We observed a significant increase in the population of M1 macrophages on peri-implantitis samples compared to periodontal disease samples. CONCLUSION: Our results demonstrate that peri-implantitis has higher numbers of macrophages displaying a distinct macrophage M1 polarization signature compared to periodontitis lesions. This pattern may explain, in part, the distinct nature of peri-implantitis progression vs. periodontitis in humans.

Effects of Mechanical Instrumentation with Commercially Available Instruments Used in Supportive Peri-implant Therapy: An In Vitro Study.

PURPOSE: To evaluate topographic changes and effectiveness of mechanical instrumentation upon machined (MA) and roughened (RG) surfaces of dental implants. MATERIALS AND METHODS: The coronal one-third of seven RG and seven MA implants was coated with a mixture of cyanoacrylate and toluidine blue dye to resemble calculus. Implants were cleaned with three curettes (SS: stainless steel, PT: plastic, TI: titanium), two ultrasonic tips (UM: metal tip, UP: plastic tip), a titanium brush (TB), and an air-polishing device (AA) until visibly clean. Additionally, a simulation of 1- and 5-year supportive peri-implant therapy (SPT) was performed on 14 implants using the aforementioned instruments with 20 strokes/40 s (T1) or 100 strokes/200 s (T5). Each implant was evaluated using stereomicroscopy, atomic force microscopy, and scanning electron microscopy. RESULTS: UM was the most effective instrument, with 0% average percentage of residual artificial calculus (RAC), followed by TB (2.89%) and UP (4.90%). SS was more effective than TI (15.43% vs 20.12% RAC, respectively), while PT failed to remove any deposit (100% RAC). AA completely removed deposits on RG surfaces but not MA surfaces (26.61% RAC). Noticeable topographic changes were observed between both implant surfaces. RG surfaces became less rough, whereas MA surfaces became rougher at both T1 and T5 with the exception of AA. Plastic- and titanium-like remnants were noted after debridement with PT, SS, and TI, respectively. CONCLUSION: Artificial calculus removal by mechanical instrumentation, with the exception of PT, was proven to be clinically effective. All instruments induced minor to major topographic changes upon dental implant surfaces. AA did not remarkably change MA and RG surfaces at both micrometer and nanometer levels. Findings from this study may impact the selection of instruments or devices used during SPT protocols.

Characterization of macrophage polarization in periodontal disease.

AIM: To explore the M1/M2 status of macrophage polarization from healthy, gingivitis, and periodontitis patient samples. MATERIALS AND METHODS: Gingival biopsies were collected from 42 individuals (14 gingivitis, 18 periodontitis, and 10 healthy samples) receiving periodontal therapy. Histomorphology analysis was performed with haematoxylin and eosin staining. Immunofluorescence was performed using a combination of CD68 (macrophages), iNOS (M1), and CD206 (M2) in order to acquire changes in macrophage polarization at a single-cell resolution. Macrophages were quantified under microscopy using narrow wavelength filters to detect Alexa 488, Alexa 568, Alexa 633 fluorophores, and Hoechst 33342 to identify cellular DNA content. RESULTS: Gingivitis and periodontitis samples showed higher levels of macrophages compared with healthy samples. Unexpectedly, periodontitis samples displayed lower levels of macrophages dispersed in the stromal tissues compared with gingivitis samples; however, it remained higher than healthy tissues. The polarization of macrophages appears to be reduced in periodontitis and showed similar levels to those observed in healthy tissues. CONCLUSIONS: Our study found that gingivitis and periodontitis differ from each other by the levels of macrophage infiltrate, but not by changes in macrophage polarization.

Dental implants-associated release of titanium particles: A systematic review.

OBJECTIVES: The presence of titanium (Ti) particles around dental implants has been reported in the literature for decades. The prospective presence of Ti debris on soft tissues surrounding dental implants has not been systematically investigated and remains to be explored. Hence, this review aimed to evaluate the origin, presence, characteristics, and location of Ti particles in relation to dental implants. MATERIAL AND METHODS: Literature searches were conducted by two reviewers independently based on the PRISMA guidelines. The systematic review identified studies on Ti particles derived from dental implants. We evaluated several parameters, including anatomical location, and the suspected methods of Ti particles release. RESULTS: The search resulted in 141 articles, of which 26 were eligible and included in the systematic review of the literature. The investigations reported Ti and metal-like particles in the soft (i.e., epithelial cells, connective tissue, and inflammatory cells) and hard (bone crest and bone marrow) tissues around the dental implants. Shape and size of the particles varied. The current literature reported a size range from 100 nm to 54 µm identified by multiple particles identification methods. CONCLUSION: Ti particles surrounding peri-implant tissues are a common finding. Peri-implantitis sites presented a higher number of particles compared to healthy implants. The particles were mostly around the implants and inside epithelial cells, connective tissue, macrophages, and bone. Various mechanisms were described as causes of Ti release, including friction during implant insertion, corrosion of the implant surface, friction at the implant-abutment interface, implantoplasty, and several methods used for implant surface detoxification.

Decision Making for Management of Periimplant Diseases.

INTRODUCTION: Nonsurgical and surgical management of periimplant mucositis and periimplantitis have shown promising results in arresting periimplant marginal bone loss (MBL) and preventing implant loss. However, management of periimplant diseases still remains unpredictable for full reconstruction of lost tissues and completely arrests disease progression. The present study proposes a decision tree that compiles both clinical and radiographic presentation of failing implants to aid in the decision making for their management. MATERIALS AND METHODS: An extensive literature review was performed using 3 electronic databases (PubMed, Ovid MEDLINE, and Cochrane Central) on the most recent treatment modalities for the management of periimplant diseases. DISCUSSION: Evidence-based treatment suggestions were primarily derived from periimplant defect morphology, presence, and severity of periimplant MBL. More evidence is required supporting soft-tissue augmentation for the treatment of periimplant diseases. CONCLUSION: Management of periimplant diseases can include lasers, mechanical instrumentation, chemical detoxification, and antimicrobial agents for nonsurgical approaches. On the other hand, removal of failing implants, resective surgery, guided bone regeneration, and soft-tissue grafting are presented as valid options for the surgical treatment of periimplantitis.