Effects of extraoral storage time on autologous gingival graft early healing: A split-mouth randomized study.

AIMS: Despite the established use of palatal tissue grafts for mucogingival procedures, there are no studies on the effect of extraoral storage time on graft outcomes. This prospective split-mouth randomized experimental clinical trial aimed to assess whether gingival graft extraoral storage time affects graft healing. METHODS: Standardized grafts were harvested from the palate and stored extraorally for 2 (Control) or 40 (Test) minutes before being placed at recipient beds. Intraoral scans, clinical photographs, and tissue blood perfusion were obtained preoperatively, postoperatively, and at follow-up visits (Days 2 (PO2), 3 (PO3), 7 (PO7), and 14 (PO14)). Healing Score Index (HSI) and wound fluid (WF) biomarkers (angiogenin, IL-6, IL-8 (CXCL8), IL-33, VEGF-A, and ENA-78 (CXCL5)) were also assessed. RESULTS: Twenty-three participants completed all study visits. Extraoral storage time was 2.3 ± 1.1 min and 42.8 ± 3.4 min for C and T grafts, respectively (p < .0001). Recipient beds remained open for 21.4 ± 1.7 min. No graft underwent necrosis or failed to heal by PO14. Minimal volumetric changes were observed, without significant intergroup differences (p ≥ .11). Graft perfusion initially decreased post-harvesting before peaking on PO7 for both C and T grafts, with no significant intergroup differences (p ≥ .14). HSI values progressively increased, with no significant intergroup differences (p ≥ .22). WF analysis revealed detectable levels for all biomarkers tested, without significant intergroup differences (p ≥ .23). CONCLUSION: Extraoral storage time of 40 min has neither statistically significant nor clinically discernible effects on autologous graft revascularization, early healing, or survival, as determined by physiological, wound healing, and molecular parameters.

Complications following alveolar ridge augmentation procedures.

Oral rehabilitation through implant supported dental restorations often requires a ridge augmentation procedure (RAP) prior to implant fixture placement since tooth extraction/loss results in alveolar ridge deficiencies. Although RAP-related surgical techniques and biomaterials have been in practice for several decades, outcomes are not always predictable. Post-surgical complications experienced during the early or late wound healing phases may jeopardize the targeted ideal ridge dimensions, required for implant fixture placement, and may have other consequences, such as negatively impacting the patient's quality of life. This review describes reported post-surgical complications following RAP under the following subtitles: complications by tissue type, complications in function and aesthetics, complications by healing time, complications by biomaterial type, and complications by surgical protocol modalities. Specifically, RAP performed by using particulate bone graft substitutes and related complications are explored. Modalities developed to prevent/manage these complications are also discussed.

Wound Fluid Cytokine Profile Following Bone Regeneration Procedures.

Clinical parameters available to evaluate early healing phases of bone regeneration procedures are limited. This study explores wound fluid (WF) content for molecular markers to differentiate wound healing responses in the early postoperative period after bone graft placement. Fifteen patients (50 ± 5 years old; 8 men) scheduled to receive tooth extraction and bone graft placement at maxillary nonmolar single-tooth sites were recruited. Primary wound closure was not intended at time of surgery. Gingival crevicular fluid from adjacent teeth or WF from surgical wound edges were collected (30 seconds) at baseline, at 3, 6, and 9 days, and at 1 and 4 months. Multiplex protein assay was used to determine concentration of various wound healing mediators. Immediately after surgery, 87% of surgical sites exhibited open wound. At day 9, mean wound exposure was 4.8 ± 0.4 mm. At 1 month, all wounds were clinically closed. The WF tripled in volume at day 3 and day 6 (P ≤ .05), compared with baseline gingival crevicular fluid, and gradually decreased as wounds closed. The WF concentrations of interleukin (IL)-6, placental growth factor, plasminogen activator inhibitor 1, insulin-like growth factor binding protein 1, and soluble cluster determinant 40 ligand were increased during early healing days, generally with peak concentration at day 6 (P ≤ .004). Conversely, WF concentrations of IL-18 and epidermal growth factor were decreased after surgery, generally not reaching baseline values until wound closure (P ≤ .008). In general, WF cytokine expression kinetics were concordant with wound closure dynamics (P ≤ .04). These results suggest that WF molecular markers such as IL-6, and to a lesser extent placental growth factor and IL-18, might help differentiate wound healing responses after bone regeneration procedures.

The Effect of Platform Switching on Periimplant Crevicular Fluid Content During Early Wound Healing.

PURPOSE: The objective of this study was to investigate the soft tissue response and periimplant crevicular fluid (PICF) content around platform-switched (PS) and platform-matched (PM) implants during early healing. MATERIALS AND METHODS: Nonsmokers treatment planned to receive a single implant in 2 quadrants were recruited. Two-stage implant placement protocol with 1 PM and 1 PS implant was implemented. Periimplant probing depths (PDs), modified sulcus bleeding index, and plaque indices were recorded, and PICF was collected at 1, 2, 4, and 6 weeks after abutment connection. RESULTS: PD readings were higher at week 1 than at week 6 for both groups (P = 0.0005). PD was statistically deeper in PM than in PS at week 1 (P = 0.03). There was a time-dependent decrease in total PICF volume for both groups. This decrease was statistically significant for PS (P = 0.0005), with no differences between the 2 groups at any time (P > 0.05). The decrease observed in both PM and PS for PICF interleukin 6 and macrophage inflammatory protein-1ß, and in PS for tumor necrosis factor-α (TNF-α) was statistically significant (P ≤ 0.03). TNF-α was statistically higher in PS than in PM at week 1 (P = 0.005). CONCLUSION: Within the limits of this study, it seems that periimplant soft tissue response around PM and PS implants is mostly similar during the early healing period.

Immediate effects of tooth extraction on ridge integrity and dimensions.

OBJECTIVES: This study aims to assess possible immediate post-extraction changes in ridge integrity and width. METHODS: Tooth extractions (53 teeth in 30 adults) were performed following atraumatic techniques. Root trunk and ridge width were measured at the crest level in buccolingual direction. Similarly, socket width and buccal plate thickness were also determined. Pre- and post-extraction buccal plate dehiscence, fenestration, or fracture was recorded. Diameter and length of extracted tooth root were also measured. Multinomial logistic regression was used to reveal relationships between ridge outcome (expanded, stable, or collapsed groups) and assessed tooth/site parameters. RESULTS: Post-extraction, buccal plate fracture developed in 5 (9%), dehiscence in 15 (28%), and complete buccal plate loss in 2 sites (4%). Following extraction, ridge width was expanded in 30 (57%), collapsed in 12 (23%), and remained unchanged in 11 (21%) sites. In most sites (72%), post-extraction socket size was wider than pre-extraction root trunk width (p < 0.0001). Socket size was a statistically significant predictor for ridge outcome (expansion or collapse compared to stable) (p < 0.01). CONCLUSION: Loss of ridge integrity is uncommon, while ridge width expansion is a common finding immediately following tooth extraction. The significance of such expansion compared to integrity of socket walls remains to be established. CLINICAL RELEVANCE: Tooth extraction approaches that preserve ridge integrity are accompanied by mainly ridge expansion in ridge width. The significance of such immediate changes for the long-term ridge outcomes (i.e., effect on bone remodeling especially in relation to buccal bone integrity) needs further investigation.

Self-rated health among pregnant women: associations with objective health indicators, psychological functioning, and serum inflammatory markers.

BACKGROUND: Biobehavioral correlates of self-rated health in pregnancy are largely unknown. PURPOSE: The goals of this study were to examine, in pregnant women, associations of self-rated health with (1) demographics, objective health status, health behaviors, and psychological factors, and (2) serum inflammatory markers. METHODS: In the second trimester of pregnancy, 101 women provided a blood sample, completed measures of psychosocial stress, health status, and health behaviors, and received a comprehensive periodontal examination. RESULTS: The following independently predicted poorer self-rated health: (1) greater psychological stress, (2) greater objective health diagnoses, (3) higher body mass index, and (4) past smoking (versus never smoking). Poorer self-rated health was associated with higher serum interleukin-1ß (p = 0.02) and marginally higher macrophage migration inhibitory factor (p = 0.06). These relationships were not fully accounted for by behavioral/psychological factors. CONCLUSIONS: This study provides novel data regarding factors influencing subjective ratings of health and the association of self-rated health with serum inflammatory markers in pregnant women.

Principles of endocrinology.

The endocrine system plays a major role in human survival. Endocrine glands secrete chemical messengers or hormones that affect every tissue of the body, including the periodontium, during the life of the individual. As the endocrine system influences a broad assortment of biological activities necessary for life, a general understanding of the principal components and functions of this system is essential. A fundamental assessment of hormone structure, mechanism of action and hormone transport, as well as influence on homeostasis is reviewed. A concise evaluation of the functions of the central endocrine glands, the functions of the major peripheral endocrine glands (other than gonadal tissues) and the known relationships of these hormones to the periodontium is examined.

Peri-implant versus periodontal wound healing.

AIM: Peri-implant gingival healing following one-stage implant placement was investigated and compared to periodontal healing. METHODS: Healing at surgical sites [implant (I) and adjacent teeth (T+)] was compared to non-operated tooth (T-) in non-smokers receiving one-stage implant. Periodontal Indices (PI, GI) were recorded at surgery and up to 12 weeks post-operatively. Peri-implant (PICF) and gingival crevicular fluids (GCF) were analysed for cytokines, collagenases and inhibitors. Data were analysed by linear mixed model regression analysis and repeated measures anova. RESULTS: Forty patients (22 females; 21-74 years old) completed the study. Surgical site GI, increased at week 1, decreased significantly during early healing (weeks 1-3; p = 0.0003) and continually decreased during late healing (weeks 6-12) for I (p < 0.01). PICF volume decreased threefold by week 12 (p = 0.0003). IL-6, IL-8, MIP-1ß and TIMP-1 levels significantly increased at surgical sites at week one, significantly decreasing thereafter (p < 0.016). Week one IL-6, IL-8 and MIP-1ß levels were ~threefold higher and TIMP-1 levels 63% higher, at I compared to T+ (p = 0.001). CONCLUSION: Peri-implant gingival healing, as determined by crevicular fluid molecular composition, differs from periodontal healing. The observed differences suggest that peri-implant tissues, compared to periodontal tissues, represent a higher pro-inflammatory state.

Determinants of alveolar ridge preservation differ by anatomic location.

AIM: To investigate and compare outcomes following alveolar ridge preservation (ARP) in posterior maxilla and mandible. METHODS: Twenty-four patients (54 ± 3 years) with single posterior tooth extraction were included. ARP was performed with freeze-dried bone allograft and collagen membrane. Clinical parameters were recorded at extraction and re-entry. Harvested bone cores were analysed by microcomputed tomography (micro-CT), histomorphometry and immunohistochemistry. RESULTS: In both jaws, ARP prevented ridge height loss, but ridge width was significantly reduced by approximately 2.5 mm. Healing time, initial clinical attachment loss and amount of keratinized tissue at extraction site were identified as determinants of ridge height outcome. Buccal plate thickness and tooth root length were identified as determinants of ridge width outcome. In addition, initial ridge width was positively correlated with ridge width loss. Micro-CT revealed greater mineralization per unit volume in new bone compared with existing bone in mandible (p < 0.001). Distributions of residual graft, new cellular bone and immature tissue were similar in both jaws. CONCLUSION: Within the limitations of this study, the results indicate that in different anatomic locations different factors may determine ARP outcomes. Further studies are needed to better understand determinants of ARP outcomes.

Factors affecting the accuracy of buccal alveolar bone height measurements from cone-beam computed tomography images.

INTRODUCTION: The reasons for inaccuracies in alveolar bone measurement from cone-beam computed tomography (CBCT) images might be multifactorial. In this study, we investigated the impact of software, the presence or absence of soft tissues, the voxel size of the scan, and the regions in the jaws on buccal alveolar bone height measurements in pigs at an age equivalent to human adolescents. METHODS: Marker holes, apical to the maxillary and mandibular molar roots, and mesiodistal molar occlusal reference grooves were created in 6 fresh pig heads (12 for each jaw), followed by CBCT scans at 0.4-mm and 0.2-mm voxel sizes under soft-tissue presence and soft-tissue absence conditions. Subsequently, buccolingual sections bisecting the marker holes were cut, from which the physical alveolar bone height and thickness were measured. One blinded rater, using Dolphin (version 11.5 Premium; Dolphin Imaging, Chatsworth, Calif) and OsiriX (version 3.9; www.osirix-viewer.com) software, independently collected alveolar bone height measurements from the CBCT images. Differences between the CBCT and the physical measurements were calculated. The mean differences and the limit of agreement (LOA, ±1.96 SD) for every jaw, voxel-size, soft-tissue, and software condition were depicted. Each measurement was then assessed for clinical inaccuracy by using 2 levels of criteria (absolute differences between CBCT and physical measurements ≥1 mm, or absolute differences between CBCT and physical measurements ≥0.5 mm), and the interactions between soft-tissue and voxel-size factors for every jaw and software condition were assessed by chi-square tests. RESULTS: Overall, the mean differences between the CBCT and the physical measurements for every jaw, voxel-size, soft-tissue, and software condition were near 0. With all other conditions kept equal, the accuracy of the maxillary CBCT measurements was inferior (larger limit of agreement ranges and higher frequencies of clinical inaccuracy) to the mandibular measurements. The physical thickness of the maxillary alveolar crestal bone was less than 1 mm and significantly thinner than the mandibular counterparts. For every jaw and software condition, the accuracy of measurements from the 0.2-mm soft-tissue presence CBCT images was consistently superior (smaller limit of agreement ranges and lower frequencies of clinical inaccuracy) to those from the 0.4-mm soft-tissue presence, the 0.4-mm soft-tissue absence, and the 0.2-mm soft-tissue absence images; all showed similar accuracies. Qualitatively, the soft-tissue absence images demonstrated much brighter enamel and alveolar bone surface contours than did the soft-tissue presence images. CONCLUSIONS: At an adolescent age, the buccal alveolar bone height measured from the maxillary molar region based on 0.4-mm voxel-size CBCT images can have relatively large and frequently inaccurate measurements, possibly due to its thinness. By using 0.2-mm voxel-size scans, measurement accuracy might be improved, but only when the overlying facial and gingival tissues are kept intact.

Therapeutic Effects of Gingival Mesenchymal Stem Cells and Their Exosomes in a Chimeric Model of Rheumatoid Arthritis.

Background: Rheumatoid arthritis is a chronic systemic autoimmune disease that involves transformation of the lining of synovial joints into an invasive and destructive tissue. Synovial fibroblasts become transformed, invading and destroying bone and cartilage of the affected joint(s). Due to the significant role these cells play in the progression of the disease process, developing a therapeutic strategy to target and inhibit their invasive destructive nature could help patients who are affiicted with this debilitating disease. Gingival-derived mesenchymal stem cells are known to possess immunomodulatory properties and have been studied extensively as potential cell-based therapeutics for several autoimmune disorders. Methods: A chimeric human/mouse model of synovitis was created by surgically implanting SCID mice with a piece of human articular cartilage surrounded by RASF. Mice were injected once with either GMSC or GMSCExo at 5-7 days post-implantation. Histology and IHC were used to assess RASF invasion of the cartilage. Flow cytometry was used to understand the homing ability of GMSC in vivo and the incidence of apoptosis of RASF in vitro. Results: We demonstrate that both GMSC and GMSCExo are potent inhibitors of the deleterious effects of RASF. Both treatments were effective in inhibiting the invasive destructive properties of RASF as well as the potential of these cells to migrate to secondary locations and attack the cartilage. GMSC home to the site of the implant and induce programmed cell death of the RASF. Conclusions: Our results indicate that both GMSC and GMSCExo can block the pathological effects of RASF in this chimeric model of RA. A single dose of either GMSC or GMSCExo can inhibit the deleterious effects of RASF. These treatments can also block the invasive migration of the RASF, suggesting that they can inhibit the spread of RA to other joints. Because the gingival tissue is harvested with little difficulty, relatively small amounts of tissue are required to expand the cells, the simple in vitro expansion process, and the increasing technological advances in the production of therapeutic exosomes, we believe that GMSCExo are excellent candidates as a potential therapeutic for RA.

The therapeutic effects of gingival mesenchymal stem cells and their exosomes in a chimeric model of rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis is a chronic systemic autoimmune disease that involves transformation of the lining of synovial joints into an invasive and destructive tissue. Synovial fibroblasts become transformed, invading and destroying the bone and cartilage of the affected joint(s). Due to the significant role these cells play in the progression of the disease process, developing a therapeutic strategy to target and inhibit their invasive destructive nature could help patients who are afflicted with this debilitating disease. Gingival-derived mesenchymal stem cells are known to possess immunomodulatory properties and have been studied extensively as potential cell-based therapeutics for several autoimmune disorders. METHODS: A chimeric human/mouse model of synovitis was created by surgically implanting SCID mice with a piece of human articular cartilage surrounded by RASF. Mice were injected once with either GMSC or GMSCExo at 5-7 days post-implantation. Histology and IHC were used to assess RASF invasion of the cartilage. Flow cytometry was used to understand the homing ability of GMSC in vivo and the incidence of apoptosis of RASF in vitro. RESULTS: We demonstrate that both GMSC and GMSCExo are potent inhibitors of the deleterious effects of RASF. Both treatments were effective in inhibiting the invasive destructive properties of RASF as well as the potential for these cells to migrate to secondary locations and attack the cartilage. GMSC home to the site of the implant and induce programmed cell death of the RASF. CONCLUSIONS: Our results indicate that both GMSC and GMSCExo can block the pathological effects of RASF in this chimeric model of RA. A single dose of either GMSC or GMSCExo can inhibit the deleterious effects of RASF. These treatments can also block the invasive migration of the RASF, suggesting that they can inhibit the spread of RA to other joints. Because the gingival tissue is harvested with little difficulty, relatively small amounts of tissue are required to expand the cells, the simple in vitro expansion process, and the increasing technological advances in the production of therapeutic exosomes, we believe that GMSCExo are excellent candidates as a potential therapeutic for RA.

Titanium as a Possible Modifier of Inflammation Around Dental Implants.

PURPOSE: The exact etiopathogenesis of peri-implant diseases remains unclear. While significant information on molecular markers is available, studies on biomarkers related to possible biocorrosion are sparse. This study aimed to evaluate periimplant crevicular fluid (PICF) for possible titanium (Ti) contamination and explore associations between clinical findings, inflammatory mediators, and Ti levels. MATERIALS AND METHODS: Patients with implant-supported restoration (≥ 1 year in function) were recruited for this cross-sectional study. Demographics, systemic, and periodontal health history were recorded. Clinical evaluations were conducted to reach peri-implant/periodontal diagnoses and grade severity of peri-implant soft tissue inflammation. Crevicular fluid (CF) was collected from both implants and adjacent teeth (PICF, gingival crevicular fluid [GCF]) and analyzed for Ti (inductively coupled plasma mass spectrometry) and inflammatory mediators (V-plex assays). Multiple regression analysis with a linear mixed effect model was used to analyze possible associations between clinical diagnosis, PICF/GCF cytokine, and Ti concentrations. RESULTS: Seventy-seven patients (aged 62 ± 2 years; 39 male) with 117 implants (9 ± 1 years in function) were recruited. Diabetes, positive periodontitis history, and current/former smoking were reported by 8%, 39%, and 39% of subjects, respectively. Seventy-nine implant sites (63 patients) were included in CF cytokine analysis, and 45 of these sites (42 patients) were paired with Ti analysis. Statistically significant increases from health to disease were noted in log-transformed PICF concentrations of IL-1ß, IL-6, IL-10, and INF-γ (P ≤ .05). Also, statistically significant increases from health to severe clinical inflammation were detected in log-transformed PICF concentrations of IL-8, IL-13, and TNF-α (P ≤ .05). Ti was detected in the majority (82%) of PICF and GCF samples. There was no statistically significant difference in log-transformed Ti concentration based on disease status. However, log-transformed Ti concentration was positively correlated to IL-1ß, IL-2, IL-4, IL-8, IL-13, and INF-γ concentrations when data were adjusted for site-specific health (P ≤ .05). CONCLUSION: Ti was detectable in PICF and adjacent GCF, even in health. Specific inflammatory mediator concentrations were increased in peri-implant disease and significantly associated with Ti concentrations, even when data were adjusted for peri-implant health status. Increased GCF inflammatory mediator concentrations were also associated with increased Ti concentrations. Ti effects on peri-implant as well as periodontal tissues require additional longitudinal investigations.

3D engineered human gingiva fabricated with electrospun collagen scaffolds provides a platform for in vitro analysis of gingival seal to abutment materials.

In order to advance models of human oral mucosa towards routine use, these models must faithfully mimic the native tissue structure while also being scalable and cost efficient. The goal of this study was to develop a low-cost, keratinized human gingival model with high fidelity to human attached gingiva and demonstrate its utility for studying the implant-tissue interface. Primary human gingival fibroblasts (HGF) and keratinocytes (HGK) were isolated from clinically healthy gingival biopsies. Four matrices, electrospun collagen (ES), decellularized dermis (DD), type I collagen gels (Gel) and released type I collagen gels (Gel-R)) were tested to engineer lamina propria and gingiva. HGF viability was similar in all matrices except for Gel-R, which was significantly decreased. Cell penetration was largely limited to the top layers of all matrices. Histomorphometrically, engineered human gingiva was found to have similar appearance to the native normal human gingiva except absence of rete pegs. Immunohistochemical staining for cell phenotype, differentiation and extracellular matrix composition and organization within 3D engineered gingiva made with electrospun collagen was mostly in agreement with normal gingival tissue staining. Additionally, five types of dental material posts (5-mm diameter x 3-mm height) with different surface characteristics were used [machined titanium, SLA (sandblasted-acid etched) titanium, TiN-coated (titanium nitride-coated) titanium, ceramic, and PEEK (Polyetheretherketone) to investigate peri-implant soft tissue attachment studied by histology and SEM. Engineered epithelial and stromal tissue migration to the implant-gingival tissue interface was observed in machined, SLA, ceramic, and PEEK groups, while TiN was lacking attachment. Taken together, the results suggest that electrospun collagen scaffolds provide a scalable, reproducible and cost-effective lamina propria and 3D engineered gingiva that can be used to explore biomaterial-soft tissue interface.

Effectiveness of Er,Cr:YSGG laser on dentine hypersensitivity: a controlled clinical trial.

AIM: Attempts have been made to treat dentine hypersensitivity (DH) with lasers. However, there is limited knowledge on the effects of erbium, chromium-doped:yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser on DH. The aim of this study was to evaluate the efficacy of Er,Cr:YSGG laser on reduction in DH. METHODS: Forty-two patients (146 teeth) were included. Teeth were assigned to an experimental group and irradiated with the Er,Cr:YSGG laser. In the control group same clinical instrument was used without laser emission. DH was assessed for both groups utilizing the visual analog scale. Plaque index (PI) scores were recorded immediately following treatment, at 1 week, 1 and 3 months. RESULTS: The results showed that Er,Cr:YSGG laser irradiation had a significantly higher desensitizing effect compared with the placebo immediately after treatment (p<0.05). Intra-group comparisons revealed no statistically significant differences within the placebo group (p>0.05). For the test group, the differences between baseline and all time points following treatment were statistically significant (p<0.05). No significant differences were observed in PI between the test and control groups at any follow-up examination (p>0.05). CONCLUSION: Within the limits of this study, it appears that Er,Cr:YSGG laser is effective in the treatment of DH compared with the placebo treatment.

Bone grafting history affects soft tissue healing following implant placement.

BACKGROUND: This study aimed to determine and compare soft tissue healing outcomes following implant placement in grafted (GG) and non-grafted bone (NGG). METHODS: Patients receiving single implant in a tooth-bound maxillary non-molar site were recruited. Clinical healing was documented. Volume and content of wound fluid (WF; at 3, 6, and 9 days) were compared with adjacent gingival crevicular fluid (GCF; at baseline, 1, and 4 months). Buccal flap blood perfusion recovery and changes in bone thickness were recorded. Linear mixed model regression analysis and generalized estimating equations with Bonferroni adjustments were conducted for repeated measures. RESULTS: Twenty-five patients (49 ± 4 years; 13 males; nine NGG) completed the study. Soft tissue closure was slower in GG (P < 0.01). Differential response in WF/GCF protein concentrations was detected for ACTH (increased in GG only) and insulin, leptin, osteocalcin (decreased in NGG only) at day 6 (P ≤0.04), with no inter-group differences at any time(P > 0.05). Blood perfusion rate decreased immediately postoperatively (P < 0.01, GG) followed by 3-day hyperemia (P > 0.05 both groups). The recovery to baseline values was almost complete for NGG whereas GG stayed ischemic even at 4 months (P = 0.05). Buccal bone thickness changes were significant in GG sites (P ≤ 0.05). CONCLUSION: History of bone grafting alters the clinical, physiological, and molecular healing response of overlying soft tissues after implant placement surgery.

Soft tissue healing around platform-switching and platform-matching single implants: A randomized clinical trial.

BACKGROUND: Implants with platform-switching (PS) design have been demonstrated to reduce marginal bone loss. However, the influence on peri-implant soft tissue healing is unclear. This study was designed to investigate its effect on peri-implant soft tissue healing after implant uncovery. METHODS: Non-smokers needing two implants in different quadrants were recruited in this study. For each individual, one PS and one platform-matching (PM) implants were placed using two-stage protocol. Following 2 to 8 months of healing, all implants were uncovered and connected to the corresponding healing abutments. Clinical measurements and peri-implant crevicular fluid (PICF) were taken at 1-, 2-, 4-, and 6-week after 2nd stage surgery. The cytokine concentrations in PICF were analyzed. Peri-implant mucosa (1 × 2 × 2 mm) was harvested around the healing abutment for the analysis of gene expression at uncovery and 6-week post-uncovery. RESULTS: Eighteen participants (nine males; 51.7 ± 14.9 years) were recruited. Compared to PM, PS showed significantly lower probing depth (PD) at 1- and 2-week as well as modified sulcus bleeding index (mSBI) at 1-, 4-, and 6-week (P < 0.05). Over time, a decrease in osteoprotegerin and interleukin-1ß concentrations in PICF along with an increase in receptor activator of unclear factor kappa-B ligand, periostin, and peroxidasin gene expressions in peri-implant mucosa were noted within both groups (P < 0.05) without significant intergroup differences. CONCLUSION: Within the limits, implants with PS design rendered significant benefits over PM design in PD and mSBI reduction during a 6-week healing. However, molecular changes within PICF and peri-implant mucosa as a response to PM and PS appear negligible.

Ferutinin directs dental pulp-derived stem cells towards the osteogenic lineage by epigenetically regulating canonical Wnt signaling.

Osteoporosis is a silent systemic disease that causes bone deterioration, and affects over 10 million people in the US alone. This study was undertaken to develop a potential stem cell therapy for osteoporosis. We have isolated and expanded human dental pulp-derived stem cells (DPSCs), characterized them, and confirmed their multipotential differentiation abilities. Stem cells often remain quiescent and require activation to differentiate and function. Herein, we show that ferutinin activates DPSCs by modulating the Wnt/ß-catenin signaling pathway and key osteoblast-secreted proteins osteocalcin and collagen 1A1 both mRNA and protein levels. To confirm that ferutinin modulates the Wnt pathway, we inhibited glycogen synthase kinase 3 (GSK3) and found that protein expression patterns were similar to those found in ferutinin-treated DPSCs. To evaluate the role of ferutinin in epigenetic regulation of canonical Wnt signaling, the pathway molecules Wnt3a and Dvl3 were analyzed using chromatin immunoprecipitation (ChIP)-quantitative PCR approaches. We confirmed that active marks of both H3K9 acetylation and H3K4 trimethylation were significantly enhanced in the promoter sites of the WNT3A and DVL3 genes in DPSCs after addition of ferutinin. These data provide evidence that ferutinin activates and promotes osteogenic differentiation of DPSCs, and could be used as an inducer as a potentially effective stem cell therapy for osteoporosis.

Salivary detection of periodontopathic bacteria and periodontal health status in dental students.

OBJECTIVE: Saliva may become a potential source of contamination through vertical and horizontal transmissions as well as cross-infections. This study aims to use saliva as a screening tool to detect putative periodontal pathogens in a young population with fairly good oral hygiene. MATERIALS AND METHODS: Stimulated saliva samples were obtained from 134 dental students (20.5+/-1 years, range 18-22 years). Among those, 77 subjects also completed a periodontal examination including attachment loss, modified dental, gingival and plaque indices (AL, mDI, GI and PI). The test bacteria were identified using a 16S rRNA-based PCR detection method. RESULTS: One or more of the test bacteria was found in 67% of the subjects. Prevotella nigrescens was detected as single bacterium in 16% of the subjects followed by Treponema denticola (4%), Porphyromonas gingivalis (2%), Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans (1%) and Tannerella forsythia (1%). Two or more pathogens were detected in 42% of the subjects. Clinical examination revealed health with no attachment loss (AL) in 84% of the students. In no AL group, 38% of the students were pathogen free while this was 25% for students in localized AL group (p>0.05). There was a statistically significant association between the detection of salivary periodontal pathogen in general and higher PI (p=0.018) and GI (p=0.043). CONCLUSION: Within the limits of this study, it is possible to detect all six periodontal pathogens in the saliva of dental students. Although a correlation can be observed between the presence of salivary periodontal pathogen and clinical signs of inflammation such as plaque accumulation and gingival bleeding, detection of specific bacteria in saliva is not related to the presence of localized AL based on the presented study population.

Early wound healing following one-stage dental implant placement with and without antibiotic prophylaxis: a pilot study.

BACKGROUND: One-stage implant placement has clinically acceptable treatment outcomes. Among other advantages, it may allow investigation of early wound healing. The purpose of this pilot study was to determine whether peri-implant crevicular fluid (PICF) can be used to detect early changes around implants placed with one-stage surgical protocol following 1 week of healing. METHODS: Twenty subjects (11 males and nine females; aged 22 to 72 years; two smokers) were included. Exclusion criteria were allergies to amoxicillin and systemic conditions that may affect healing. Subjects had a healthy periodontium and needed a single implant; eight received antibiotic prophylaxis, and 12 served as controls. Clinical healing was evaluated with plaque and gingival indices (PI and GI, respectively). Gingival crevicular fluid (GCF) from the surgical site was obtained prior to the surgery, whereas PICF was collected at the 1-week visit. Enzyme-linked immunosorbent assay was used to determine GCF/PICF interleukin (IL)-1beta and -8 concentrations. Peripheral blood and GCF antibiotic levels were measured by high-performance liquid chromatography. RESULTS: Postoperative PI and GI were slightly increased. Total GCF and PICF volumes did not show a significant difference between appointments. There was an increase in PICF IL-1beta and -8 levels at 1 week postoperatively. Mean amoxicillin serum concentration was 5.1 +/- 2 microg/ml at 1 to 4 hours following the initial dose, whereas GCF amoxicillin levels were below the limit of detection. Antibiotic prophylaxis had a modest effect on clinical indices (PI and GI) and no appreciable effect on biomarkers. CONCLUSIONS: PICF content can be studied as early as 1 week following one-stage implant placement. The results raise doubts regarding the clinical usefulness of amoxicillin prophylaxis.