Peri-implantitis induction and resolution around zirconia versus titanium implants.

BACKGROUND: This study compared titanium and zirconia implant ligature-induced peri-implant defect progression and response to regenerative surgical intervention. METHODS: Eight tissue-level endosseous implants were placed in 6 mixed-breed foxhounds, with 2 zirconia and 2 titanium alternating in each hemimandible. Cotton ligatures were placed subgingivally for 16 weeks followed by 8 weeks of spontaneous progression. Standardized radiographs were captured every 2 weeks to evaluate the rate of bone loss. Regenerative surgery was performed utilizing water-jet decontamination, enamel matrix derivative, and locally harvested autogenous bone. After 16 weeks of healing, final radiographic bone levels as well as probing depths, recession, and clinical attachment levels were assessed. RESULTS: All 48 implants integrated successfully. The final average post-ligature radiographic defects were 2.88 and 3.05 mm for titanium and zirconia implants, respectively. There was no significant difference between materials in the rate of radiographic bone loss (p = 0.09). Following regenerative surgery, the total average amount of radiographic bone gain was 1.41 and 1.20 mm for titanium and zirconia, respectively. The percentage of defect fill was 51.56% and 37.98% (p = 0.03) for titanium and zirconia, respectively. Inter-group differences were minimal for clinical parameters at the time of sacrifice including periodontal pocket depths (p = 0.81), recession (p = 0.98), or clinical attachment levels (p = 0.51). CONCLUSIONS: No significant difference was found in the rate of peri-implant defect development between titanium and zirconia implants. Both materials gained significant radiographic bone following regenerative surgery with significantly greater defect percentage fill in titanium implants. The final clinical parameters were similar in both groups.

Impact of surface chemical treatment in surgical regenerative treatment of ligature-induced peri-implantitis: A canine study.

BACKGROUND: Implant surface decontamination is a critical step in peri-implantitis treatment. The aim of this study was to assess the effect chemotherapeutic agents have on reosseointegration after treatment on ligature-inducted peri-implantitis. METHODS: Six male canines had 36 implants placed and ligatures were placed around them for 28 weeks to establish peri-implantitis. The peri-implant defects were randomly treated by 1 of 3 methods: 0.12% chlorhexidine (CHX test group), 1.5% sodium hypochlorite (NaOCl test group), or saline (Control group). Sites treated with NaOCl and CHX were grafted with autogenous bone, and all sites then either received a collagen membrane or not. Histology sections were obtained at 6 months postsurgery to assess percentage of reosseointegration. RESULTS: Thirty-five implants were analyzed (CHX: 13; NaOCl: 14; Control:8). NaOCl-treated sites demonstrated reosseointegration with direct bone-to-implant-contact on the previously contaminated surfaces (42% mean reosseointegration), which was significantly higher than Controls (p < 0.05). Correspondingly, clinical improvement was noted with a significant reduction in probing depth from 5.50 ± 1.24 mm at baseline to 4.46 ± 1.70 mm at 6-months postsurgery (p = 0.006). CHX-treated sites demonstrated a nonsignificant reosseointegration of 26% (p > 0.05); however, in the majority of cases, the new bone growth was at a distance from the implant surface without contact. Probing depths did not improve in the CHX group. The use of membrane did not influence reosseointegration or probing depths (all p > 0.05). CONCLUSION: Titanium implants with peri-implantitis have the capacity to reosseointegrate following regenerative surgery. However, treatment response is contingent upon the chemotherapeutic agent selection. Additional chemical treatment with 1.5% NaOCl lead to the most favorable results in terms of changes in defect depth and percentage of reosseointegration as compared to CHX, which may hinder reosseointegration.

Donor site wound healing following free gingival graft surgery using platelet rich fibrin: A randomized controlled trial.

BACKGROUND: The primary purpose of this two-arm, parallel design, randomized controlled study is to compare healing of the palatal tissue donor site when platelet-rich fibrin (PRF) is used as a wound dressing compared to the use of a hemostatic agent. Secondary outcomes of patient pain perception and analgesic intake were also evaluated. METHODS: Seventy-four patients receiving free gingival grafts were randomized to receive either PRF (test) or hemostatic agent (control) as a palatal wound dressing by patients selecting a sealed envelope containing their group assignment (initially 37 envelopes for PRF group and 37 for hemostatic agent group). Patient pain assessment and analgesic consumption were documented using a 21-point numerical scale (NMRS-21) at 24, 48, and 72 hours post-surgery. At 1-, 2-, 3-, and 4-week follow-up appointments palatal early healing index (PEHI) scores including wound color, epithelialization, presence or absence of swelling, granulation tissue, and bleeding on gentle palpation were generated by direct intraoral examination by a blinded examiner unaware of the patients' treatment group. RESULTS: NMRS-21 pain scores showed a significant reduction in pain over time in both groups, with no significant difference between groups at any time point. No significant between-group difference was found in the amount of analgesics taken by patients at 24, 48, and 72 hours. There was significant improvement in PEHI scores over the 4-week time period in both groups, but there was no significant difference in PEHI score at each time point (1, 2, 3, 4 weeks) between groups.  CONCLUSIONS: Study findings suggest that there is no difference in early palatal wound healing, patient pain perception, or analgesic consumption between use of PRF or a hemostatic agent as donor-site wound dressings.

The association between cystic fibrosis-related diabetes and periodontitis in adults: A pilot cross-sectional study.

OBJECTIVES: Periodontitis is a highly prevalent complication of diabetes. However, the association between cystic fibrosis-related diabetes (CFRD) and periodontitis has not yet been evaluated. The objective of this study was to assess if: 1) CFRD is associated with periodontitis among adults with CF, and 2) periodontitis prevalence differs by CF and diabetes status. METHODS: This was a pilot cross-sectional study of the association between CFRD and periodontitis in adults with cystic fibrosis (CF) (N = 32). Historical non-CF controls (N = 57) from the U.S. National Health and Nutrition Examination Survey (NHANES) dataset were frequency matched to participants with CF on age, sex, diabetes status, and insulin use. We defined periodontitis using the U.S. Centers for Disease Control and Prevention and the American Academy of Periodontology (CDC/AAP) case definition, as the presence of two or more interproximal sites with CAL ≥3 mm and two or more interproximal sites with PD ≥4 mm (not on the same tooth) or one site with PD ≥5 mm. Because NHANES periodontal data were only available for adults ages ≥30 years, our analysis that included non-CF controls focused on this age group (CF N = 19, non-CF N = 57). Based on CF and diabetes status, we formed four groups: CFRD, CF and no diabetes, non-CF with diabetes, and non-CF and no diabetes (healthy). We used the Fisher's exact test for hypotheses testing. RESULTS: There was no association between CFRD and periodontitis for participants with CF ages 22-63 years (CFRD 67% vs. CF no diabetes 53%, P = 0.49), this was also true for those ages ≥30 years (CFRD 78% vs. CF no diabetes 60%, P = 0.63). For the two CF groups, the prevalence of periodontitis was significantly higher than for healthy controls (CFRD 78% vs. healthy 7%, P<0.001; CF no diabetes 60% vs. healthy 7%, P = 0.001) and not significantly different than the prevalence for non-CF controls with diabetes (CFRD 78% vs. non-CF with diabetes 56%, P = 0.43; CF no diabetes 60% vs. non-CF with diabetes 56%, P = 0.99). CONCLUSION: Among participants with CF, CFRD was not associated with periodontitis. However, regardless of diabetes status, participants with CF had increased prevalence of periodontitis compared to healthy controls.

Subgingival scaling and root planing during minimally invasive periodontal surgery: A randomized controlled split-mouth trial.

BACKGROUND: The purpose of this randomized, controlled split-mouth study was to evaluate a videoscope as a visual adjunct to scaling and root planing when utilized in combination with minimally invasive surgery. METHODS: Twenty-five pairs (89 interproximal surfaces) of periodontally hopeless teeth planned for extraction were scaled and root planed with minimal surgical access using surgical loupes (control) or adjunctive use of a videoscope (test). Teeth were extracted with minimal trauma, stained with methylene blue, and photographed with a digital microscope for analysis. The primary outcome of residual calculus was calculated as a percentage of the total interproximal area of interest. Secondary outcomes included treatment time, as well as residual calculus according to probing depth, tooth location, and treatment date. Data were analyzed using Student's paired t-tests, two-way analyses of variance, and Spearman's correlation tests. RESULTS: Residual calculus area was 2.61% on control and 2.71% on test surfaces with no significant difference between groups. Subgroup analysis showed no difference in residual calculus between groups at moderate or deep sites. Treatment time per surface was significantly longer in the test group compared to the control group. Treatment order, tooth location, and operator experience did not significantly affect the primary outcome. CONCLUSIONS: Though the videoscope provided excellent visual access, it did not improve the efficacy of root planing for flat interproximal surfaces during minimally invasive periodontal surgery. Small amounts of calculus remain after instrumentation even with minimal surgical access and when root surfaces appear visually clean and tactilely smooth.

Interdental oral hygiene interventions elicit varying compositional microbiome changes in naturally occurring gingivitis: Secondary data analysis from a clinical trial.

AIM: To evaluate the effect of different oral irrigators on the sub-gingival microbiome composition in patients with naturally occurring plaque-induced gingivitis. MATERIALS AND METHODS: Sub-gingival plaque was collected from adults participating in a clinical trial assessing the efficacy of oral hygiene with two different oral irrigators (Waterpik Water Flosser [Group 1] and Oral-B Water Flosser [Group 2]) versus dental flossing (Group 3) for microbiome analysis. Plaque samples were reflective of naturally occurring plaque-induced gingivitis at baseline and of gingival health at the endpoint (4 weeks). Clinical measures of gingival inflammation were collected, and the sub-gingival microbiome was analysed by 16S rRNA sequencing to identify amplicon sequence variants. RESULTS: Oral hygiene instruction with self-performed manual toothbrushing and water-jet irrigation led to significant reductions in inflammation for all groups; both oral irrigators outperformed flossing in bleeding-on-probing reduction (p < .001). Microbiome diversity of sub-gingival plaque remained relatively stable over time, but significant changes were noted in certain taxa, consistent with increases in the relative abundance of commensals and reductions in late colonizers and periodontal pathogens in the water-jet groups. CONCLUSIONS: Reduction in gingival inflammation at 4 weeks within the water-jet groups is accompanied by slight but critical changes in microbiome composition. Although biodiversity does not substantially change within 4 weeks during the resolution of naturally induced gingivitis, significant relative increases in commensal early colonizers such as Streptococcus, Veillonella and Fusobacterium were accompanied by a shift towards a less anaerobic microbiota associated with return to health. These changes were contingent upon the type of interdental hygiene, with Group 1 exhibiting more significant alterations in microbiome composition towards a periodontal-health-compatible community.

Localized microbially induced inflammation influences distant healthy tissues in the human oral cavity.

Variation in human immune response to the same bacterial or viral pathogen is well established in the literature. Variation in immune response to microbial challenge has also been observed within the human oral cavity. Our recent study focused on characterizing observed variations in microbially induced gingival inflammation-resulting in three distinct clinical Inflammatory Responder Types (IRTs): High-IRT, Low-IRT, and Slow-IRT. Here, we applied a high-resolution temporal multiomic analysis during microbially induced inflammation in order to characterize the effects of localized oral inflammation on distant healthy tissues in young healthy adults. Our results highlight a nonlocalized subclinical effect with alterations in proinflammatory host mediators and an ecological shift toward dysbiosis within the subgingival microbiome in an IRT-dependent manner-despite maintained oral hygiene. Our results provide mechanistic insight into how healthy tissues within humans are influenced by distant localized inflammation and may ultimately become susceptible to disease.

Periodontitis Risk Factors in Adults with Cystic Fibrosis: A pilot study.

Purpose Individuals with cystic fibrosis (CF) present with multiple condition-specific risk factors for periodontitis including CF-related diabetes, chronic inhaled treatments that induce xerostomia, and increased systemic inflammation because of frequent lung infections. General factors like age, oral hygiene, and diet may also contribute to the risk of periodontitis. However the relative importance of these specific risk factors and periodontitis in individuals with CF has not yet been evaluated. The purpose of this pilot study was to assess the associations between CF condition-specific and general risk factors and the prevalence of periodontitis in adults with CF.Methods This cross-sectional pilot study was designed to assess a multifactorial model of periodontitis risk factors in a population in adults with CF who were recruited from the University of Washington Adult CF center. Periodontitis was defined using the Centers for Disease Control and Prevention and the American Academy of Periodontology (CDC/AAP) case definition. Risk factors included condition-specific and general factors. Differences between participants with moderate/severe periodontitis and those with no/mild periodontitis was assessed using the Mann-Whitney test, the Fisher's exact test, and the exact chi-square test (α=0.05).Results Thirty-two participants were enrolled. Twenty-eight percent of the participants had moderate periodontitis, 72% had no/mild periodontitis; none of the participants had severe periodontitis. There were no significant differences in condition-specific factors between between the two study groups. Participants with moderate periodontitis were older (p=0.028) and reported daily flossing in higher proportions than those with no/mild periodontitis (p=0.023).Conclusions The findings from this pilot study suggest that future research is needed to determine whether sociodemographic and other general risk factors are more important contributors to periodontitis risk than CF-specific factors.

Assessment of titanium release following non-surgical peri-implantitis treatment: A randomized clinical trial.

BACKGROUND: Peri-implantitis is a frequent finding. Initial treatment involves non-surgical debridement of the implant surface. Recent studies have found a correlation between titanium (Ti) particle release and peri-implantitis, yet there is a dearth of information regarding the effect of various non-surgical instrumentation on particle release or peri-implantitis resolution. METHODS: Patients with peri-implantitis were recruited for a randomized, blinded, parallel-group clinical trial. The implants were randomized to treatment composed of Ti curettes ("Mech" group) or implant-specific treatment composed of rotary polymer microbrushes ("Imp" group). Ti release in submucosal peri-implant plaque pre- and 8 weeks posttreatment was assessed as the primary outcome. Peri-implant probing depth, bleeding on probing, and suppuration on probing were evaluated and compared between groups. RESULTS: Thirty-four participants completed treatment; 18 were randomized to the Mech group and 16 to the Imp group. The groups were comparable for Ti levels and probing depths at baseline. A trend was noted for 10-fold greater Ti dissolution in the Mech group posttreatment compared to the Imp group (p = 0.069). The Imp group had a significant reduction in probing depth posttreatment (p = 0.006), while the Mech group reduction was not significant. CONCLUSION: Peri-implantitis treated non-surgically with implant-specific instruments (Imp group) had a significantly greater decrease in probing depth versus the Mech treatment group. This improvement was linked with a trend for less Ti release to the peri-implant plaque by the non-abrasive treatment.

A randomized controlled trial evaluating the effect of epithelial removal on free soft tissue autograft healing.

BACKGROUND: The purpose of this study is to determine if there is a difference in dimensional change of a free soft tissue autograft (FSTA) with epithelium compared to without epithelium. The secondary aim is to determine the patient and professional evaluation of color match and graft texture between the two groups. METHODS: Patients with ≤2 mm keratinized tissue indicated for a FSTA were randomly assigned to control group (FSTA with epithelium) or test group (de-epithelialized FSTA). The vertical and horizontal measurements of the grafts were taken at surgery, and 1, 3, and 6 months postoperatively. Patients were asked to evaluate the color match at each postoperative time point on a 21-step Numeric Rating Scale (NRS-21). Professional assessment of color match and graft texture were evaluated on images at the same time points. RESULTS: Forty-six patients and 55 grafts were included in the study. For change in graft height, width, and area, there were no significant differences between the treatment groups at any time point. Graft height and area in both groups decreased significantly from baseline to month 1 (p < .001), but no other difference was significant over time. When patients and professionals used the NRS-21 for evaluation of color match between the graft site and the surrounding soft tissue, there was no significant difference between the treatment groups. Similarly, evaluation of texture match on color images and black-and-white images revealed no significant differences between or within groups. CONCLUSION: De-epithelialized FSTA showed no difference in dimensional change or color and texture match compared to FSTA with epithelium.

Clinical outcomes of retention of the buccal root section combined with immediate implant placement: A systematic review of longitudinal studies.

INTRODUCTION: Immediate implant placement in conjunction with partial extraction therapy has been shown to result in functional osseo- and dento-integration with partial preservation of the periodontal ligament (PDL) in humans. Strategic buccal root retention for PDL preservation is a biologically driven procedure that maintains alveolar ridge dimensions and esthetics, while allowing for implant placement. The aim of this study was to conduct a systematic review of longitudinal clinical outcomes of PDL-mediated ridge preservation in conjunction with implant placement in adults, compared with conventional immediate implant placement with total extractions. The primary outcome for this study was marginal bone level (MBL) changes after strategic buccal root retention implant placement techniques. MATERIALS AND METHODS: To address a predefined PICOS question, a systematic search of randomized clinical trials and cohort studies with at least 10 participants per group and a minimum 12-month follow-up was conducted. A two-phase systematic selection strategy, data extraction, and risk of bias assessment, was performed independently and in duplicate. Randomized trials were quantitatively analyzed in a meta-analysis. RESULTS: Ten human studies fulfilled the predefined criteria and were included; three clinical trials and seven cohort studies, for a total of 506 patients and 587 implants. PDL-mediated implant placement of single-rooted periodontally healthy teeth was found to reduce marginal peri-implant bone loss and buccal plate changes as compared to conventional immediate implants across studies, while implant survival and success rates were comparable between the two procedures. A meta-analysis found that bone changes were significantly less when retention of the buccal root section was performed as compared to total extractions (standardized mean difference: [-4.53, -0.11]); the three clinical trials were, however, largely heterogeneous (I2 : 93.1%; Q = 28.98, p < 0.001). CONCLUSION: Strategic retention of the buccal root section has a benefit in terms of dimensional ridge stability over conventional immediate implantation when implemented in carefully selected cases of single-rooted teeth.

Wound healing after ridge preservation: A randomized controlled trial on short-term (4 months) versus long-term (12 months) histologic outcomes.

BACKGROUND: The amount of time it takes for bone allograft particles to be replaced with new vital bone during ridge preservation is unclear. The purpose of this article was to compare the wound healing and vital bone formation following ridge preservation using a combination allograft of 70% mineralized and 30% demineralized freeze-dried bone allograft at 4 months (short-term, ST) versus 12 months (long-term, LT). METHODS: Fifty-seven patients were enrolled in the study who required extraction of a single tooth (excluding second and third molars) and were planned for replacement with a dental implant. After tooth extraction, all sites were grafted with a combination allograft procured from a single donor, and patients were randomized into the ST or LT healing groups. Patients returned for implant placement and an 8-mm bone core biopsy was harvested using a trephine drill during initial implant osteotomy preparation. The cores were then analyzed histologically to determine the percentages of vital bone formation, residual graft particles, and connective tissue/other. RESULTS: There was significantly greater vital bone formation in the LT group (51.38%) compared with the ST group (31.39%) (p = 0.0025) and significantly fewer residual graft particles in the LT group (18.04%) compared with the ST group (40.38%). CONCLUSIONS: A longer healing time following ridge preservation results in more vital bone formation and less residual graft particles at the time of implant placement. However, residual allograft material still remains at 12 months after ridge preservation.

Aesthetic and radiographic outcomes using the root membrane technique in immediate adjacent implant placement: A retrospective clinical study with a 5- to 9-year follow-up.

PURPOSE: The root membrane technique was designed to preserve the buccal portion of the root in situ, preventing postextraction bundle bone loss and overlying soft tissue recession. Nevertheless, maintenance of the aesthetic gingival architecture around two or multiple adjacent implants, particularly in the anterior maxilla, remains a challenge, notably regarding the gingival contour and the interimplant papillae. The present study aimed to evaluate the clinical, aesthetic and radiographic outcomes for immediate adjacent implants placed using the root membrane technique in the anterior maxilla in a sample with a 5- to 9-year follow-up. MATERIALS AND METHODS: A retrospective clinical study was designed using the medical records of two private dental practices. A total of 40 patients who were treated using the root membrane technique for at least two adjacent implants and single-crown restorations between January 2010 and February 2019 were selected (100 implants). The clinical and radiographic data were analysed to assess implant survival/success, marginal bone loss and the pink aesthetic score. RESULTS: The cumulative survival rate after a mean follow-up period of 81.5 ± 30.5 months was 99.0% (implant-based) and 97.5% (patient-based), respectively. Between 1 and 5 years (n = 99), the mean marginal bone loss changed from 0.39 ± 0.07 mm to 0.36 ± 0.07 mm and subsequently to 0.37 ± 0.07 mm at the 7-year follow-up (n = 71) and 0.33 ± 0.07 mm at the 9-year follow-up (n = 14). The improvement from 1 year was significant at all the follow-up time points (P = 0.000). The mean global pink aesthetic score increased from baseline (11.33 ± 1.03) to 3 months after placement of the final restoration (11.73 ± 0.95) and the final observation (12.01 ± 0.87). This was a significant increase (P = 0.000 baseline to 3 months, 3 months to final observation and baseline to final observation). CONCLUSIONS: In this non-controlled retrospective study, adjacent implants placed using the root membrane technique achieved a satisfactory survival and success rate. The variation in marginal bone loss showed a significant positive trend from 1 year to 5 and 7 years. The overall pink aesthetic scores improved significantly between sequential observation periods. CONFLICT-OF-INTEREST STATEMENT: Dr Leitão-Almeida receives personal fees (for sponsored lectures) and non-financial support from MegaGen (Daegu, South Korea) outside of the submitted work; the other authors declare no conflicts of interests relating to this study.

Comparison of antibacterial and antibiofilm activity of bioactive glass compounds S53P4 and 45S5.

BACKGROUND: Bone loss and deformation due to damage caused by injury or recurrent invasive infections presents a major clinical obstacle. While bone substitute biomaterials promote osseous tissue regeneration, their application in sites complicated by microbial infections such as osteomyelitis, is limited. Bioactive glass biomaterials (Bioglass) have been shown to have efficient mechanisms of repairing the integrity of bone, while inhibiting growth of a range of bacterial strains. There are several commercially available bioactive glass compounds, each with a unique chemical composition. One compound in particular, S53P4, has demonstrated antimicrobial effects in previous studies but the antimicrobial activity of the parent compound 45S5 has not been investigated. RESULTS: To assess whether antimicrobial activity is common among bioglass compounds, 45S5-the parent compound, was evaluated in comparison to S53P4 for antibacterial and antibiofilm effects against multiple strains of aerobic and anaerobic bacteria associated with various types of osteomyelitis. Experiments of antimicrobial effects in liquid cultures demonstrated that both compounds were antimicrobial against various microbial genera including S. gordonii, V. parvula, P. aeruginosa and MRSA; particles of the smallest size (32-125 µm) invariably showed the most robust antimicrobial capabilities. When employed against biofilms ecological biofilms grown on hydroxyapatite, 45S5 particles produced a stronger reduction in biofilm mass compared to S53P4 particles when considering small particle ranges. CONCLUSION: We found that 45S5 seems to be as effective as S53P4 and possibly even more capable of limiting bacterial infections. The efficacy of bioactive glass was not limited to inhibition of planktonic growth, as it also extended to bacterial biofilms. The increased antibacterial activity of 45S5 compared to S53P4 is true for a variety of size ranges.

Strategies for implant surface decontamination in peri-implantitis therapy.

Peri-implantitis is an infectious disease that leads to progressive bone loss. Surgical therapy has been advocated as a way of halting its progression and re-establishing peri-implant health. One of the most challenging but crucial tasks in the management of peri-implantitis is biofilm removal to achieve reosseointegration and promote the reduction of peri-implant pockets. A wide variety of strategies have been used for implant surface decontamination. Mechanical means have been demonstrated to be effective in eliminating calculus deposits and residual debris; however, the presence of undercuts and the grooves and porosities along the roughened implant surface make it difficult to achieve an aseptic surface. In conjunction with mechanical measures, use of chemical adjuncts has been advocated to dilute bacterial concentrations, destroy the bacteria's organic components and eliminate endotoxins. Pharmacological adjuncts have also been recommended to diminish the bacterial load. Other strategies, such as use of lasers, implantoplasty and electrolysis, have been suggested for implant surface decontamination to promote predictable clinical and radiographic outcomes.

C3-targeted host-modulation approaches to oral inflammatory conditions.

Periodontitis is an inflammatory disease caused by biofilm accumulation and dysbiosis in subgingival areas surrounding the teeth. If not properly treated, this oral disease may result in tooth loss and consequently poor esthetics, deteriorated masticatory function and compromised quality of life. Epidemiological and clinical intervention studies indicate that periodontitis can potentially aggravate systemic diseases, such as, cardiovascular disease, type 2 diabetes mellitus, rheumatoid arthritis, and Alzheimer disease. Therefore, improvements in the treatment of periodontal disease may benefit not only oral health but also systemic health. The complement system is an ancient host defense system that plays pivotal roles in immunosurveillance and tissue homeostasis. However, complement has unwanted consequences if not controlled appropriately or excessively activated. Complement overactivation has been observed in patients with periodontitis and in animal models of periodontitis and drives periodontal inflammation and tissue destruction. This review places emphasis on a promising periodontal host-modulation therapy targeting the complement system, namely the complement C3-targeting drug, AMY-101. AMY-101 has shown safety and efficacy in reducing gingival inflammation in a recent Phase 2a clinical study. We also discuss the potential of AMY-101 to treat peri-implant inflammatory conditions, where complement also seems to be involved and there is an urgent unmet need for effective treatment.

Comparing the histological assessment following ridge preservation using a composite bovine-derived xenograft versus an alloplast hydroxyapatite-sugar cross-linked collagen matrix.

BACKGROUND: This randomized controlled trial was designed to evaluate the histological wound healing and alveolar ridge dimensional changes following ridge preservation using two different xenograft/collagen matrices. METHODS: Fifty-four patients each with non-molar teeth that required extraction and replacement with dental implants were enrolled. Teeth extractions were completed with minimal flap reflection and were randomized to receive ridge preservation with either 90% bovine-derived xenograft granules in a 10% porcine collagen matrix (Group A) or a sponge-like matrix of 80% microparticulate hydroxyapatite alloplast graft with 20% sugar cross-linked porcine type 1 collagen (Group B). After 16 weeks of healing and at the time of implant placement, a bone core biopsy was harvested followed by dental implant placement. The primary histological outcome evaluated were percentage of vital bone formation and connective tissue/other (fibrous tissue and marrow space). Secondary outcomes included the change in alveolar ridge width and the buccal and lingual ridge height. Statistical analysis was completed with two-sample t-test and Fisher exact test. RESULTS: Forty-four patients completed the study, 23 in group A and 21 in group B. Group B presented with statistically significantly (p = 0.02) more percentage of vital bone (39.3 ± 17.8) than group A (26.8 ± 15.8). No statistically significant difference was observed for changes in alveolar ridge dimensions. CONCLUSIONS: Group B, when used for ridge preservation, yields statistically significantly more vital bone over a 4-month healing period. Ridge dimension changes were similar between the two groups and were adequate for implant placement.

Implications of considering peri-implant bone loss a disease, a narrative review.

BACKGROUND: Peri-implantitis has been suggested to cause significant increasing proportions of implant failure with increasing time. PURPOSE: To assess whether implant failure rates in long term studies are matching the supposed high prevalence of peri-implantitis. MATERIAL AND METHODS: This paper is written as a narrative review of the long-term clinical investigations available in the literature. RESULTS: Some implant systems have seen unacceptable marginal bone loss figures with time coupled to increased implant failure rates, resulting in the withdrawal of these systems. The reasons for such mishap are generally unknown, with the exception of one system failure that was found to be due to improper clinical handling. Modern, moderately rough implant systems have functioned excellently over 10-15 years of follow up with minor problems with marginal bone loss and implant failure rates within a few per cent. Machined implants have functioned adequately over 20-30 years of follow up. Implant failures occur predominantly during the first few years after implant placement. No significant increase of implant failures has been observed thereafter over 20-30 years of follow up. Over the years of our new millennium, scientific and technical advances have allowed the discovery of numerous molecular pathways and cellular interactions between the skeletal and immune system promoting the development of the interdisciplinary field called osteoimmunology. Nowadays, this knowledge has not only allowed the emergence of new etiologic paradigms for bone disease but also a new dynamic approach on the concept of osseointegration and MBL around oral implants, re-evaluating our older disease oriented outlook. This facilitates at the same time the emergence of translational applications with immunological perspectives, scientific approaches based on omics sciences, and the beginning of an era of personalized dental implant therapy to improve the prognosis of oral implant treatment. CONCLUSIONS: Oral implant systems have been found to function with very good clinical outcome over follow-up times of 20-30 years. Registered implant failures have occurred predominantly during the first few years after implantation, and there has been no significant increase in late failures due to peri-implantitis.

Biological mechanisms underlying complications related to implant site preparation.

Implant site preparation is a critical stage of implant surgery that may underpin various complications related to implant surgery. This review discusses the latest available scientific information on risk factors related to implant site preparation. The role of the drilling process in relation to the density of the available alveolar bone, the effects of insertion torque on peri-implant osseous healing, and implant-related variables such as macrodesign and implant-abutment connection are all factors that can influence implant success. Novel information that links osteotomy characteristics (including methods to improve implant initial stability, the impact of drilling speed, and increase of the implant insertion torque modifying the bone-implant interface) with the appropriate instrumentation techniques will be discussed, as well as interactions at the bone-biomaterial interface that may lead to biologic complications mediated by implant dissolution products.

Long-term preservation of ridge dimension following tooth extraction and ridge preservation: A randomized controlled trial of healing at 4- and 12-month healing time points.

BACKGROUND: To date, the efficacy of ridge preservation in the maintenance of the residual alveolar ridge dimension beyond 6 months after treatment is unknown. The purpose of this study was to compare the differences in alveolar ridge dimensional change following ridge preservation between 4- and 12-month healing time points using cone-beam computed tomography (CBCT). METHODS: Fifty seven patients planned for tooth extraction and implant placement were enrolled. Following extraction, ridge preservation was performed. CBCT scans were taken within 72 hours following extraction with a customized resin stent containing a fixed radiographic marker. At either 4 months (short-term, ST group) or 12 months (long-term, LT group) after ridge preservation, patients had a second CBCT taken and an implant placed. Changes in ridge height and width were measured using the standardized radiographic marker. RESULTS: No significant differences were detected between the ST and LT groups in loss of buccal and lingual ridge height. Similarly, when adjusted for baseline ridge width, no significant differences were detected in ridge width loss at 3, 5, and 7 mm apical to the crest between the ST and LT groups. CONCLUSIONS: The efficacy of ridge preservation in the maintenance of ridge width and height at the 12-month time point is similar to that of the 4-month time point. Clinicians may feel confident that a delay in implant placement for up to a year has no significant negative impact on the height and width of the healed ridge.