In vivo efficacy of low-level laser therapy on bone regeneration.

PURPOSE: In clinical use of low-level laser therapy for bone regeneration (LLLT), application protocol (dose, duration, and repetitions) has not been established. This study aimed to depict a reliable dosage of LLLT by evaluating the efficacy of different dosing of LLLT (diode) on the healing of rabbit cranial defects. METHODS: Critical size defects were prepared in calvarias of 26 New Zealand White Rabbits in such each animal containing both test and control groups. Test groups were irradiated with 4 Joule/cm2 (j/cm2), 6 j/cm2, and 8 j/cm2. The rabbits were subjected to six times of laser treatments in 10 days. At the end of the second week, 5 rabbits were sacrificed for histopathological and immunohistochemical analyses. At the 4th and 8th weeks, 20 rabbits (10 each) were sacrificed for micro-CT and histopathological analyses. RESULTS: Micro-CT evaluation revealed improved new bone formation in all test groups compared to the control group. 6 j/cm2 group demonstrated the highest bone formation. The highest bone morphogenic protein -2 levels were found in the 4 j/cm2 group. Osteocalcin expression was significantly higher in 4 j/cm2 group. CONCLUSIONS: Our findings indicate that LLLT have a positive effect on new bone formation. The high efficacy of doses of 4 j/cm2 and 6 j/cm2 is promising to promote early bone healing.

An Unusual Case of Early Dental Implant Failure in an Otherwise-Healthy Patient due to Actinomycosis.

Actinomyces species are members of normal oral flora that may give rise to a rare disease-oral actinomycosis. Presented herein is a case of early implant failure associated with actinomycosis in an otherwise healthy 43-year-old female and the treatment adopted after explantation. Clinically, 1 month after the implant placement, the peri-implant soft tissues were hyperplastic and associated with an excessive tissue reaction, bleeding, suppuration, deep probing depth, and implant mobility of #19 and #20 implants. Both implants were removed and all granulomatous tissues were thoroughly debrided. Histopathological examination revealed signs of acute ulcerative inflammatory reaction and Actinomyces colonies. The patient was prescribed short-term oral penicillins. Six months after explantation, the deficient bone was augmented using a combination of absorbable collagen membrane, autogenous block bone, and xenograft. The patient was followed for 1 year; and subsequently, 2 implants were re-inserted at the same positions. The patient was followed and no recurrences were observed. Implant failure due to actinomycosis is an extremely rare condition, and a definitive diagnosis is therefore essential for successful treatment.

Evaluation of GCF IL-17, IL-10, TWEAK, and sclerostin levels after scaling and root planing and adjunctive use of diode laser application in patients with periodontitis.

BACKGROUND: The aim of the present study was to evaluate the clinical efficacy of the diode laser as an adjunct to scaling and root planing (SRP) and also determine the biochemical profile by evaluating the gingival crevicular fluid (GCF) levels of interleukin (IL)-17, IL-10, tumor necrosis factor-related weak inducer of apoptosis (TWEAK), and sclerostin. METHODS: A total of 40 systemically healthy, patients with Stage III periodontitis were included in this randomized controlled study. Participants were randomly divided into two groups as SRP + diode laser (L) (0.80W power, 940 nm wavelength and 0.80J/s energy level) and only SRP group. Recording of periodontal parameters and collecting GCF samples were performed at baseline, first and 3rd months. Biomarker levels in GCF were measured with ELISA RESULTS: At baseline, no significant difference was detected between groups in terms of both clinical and biochemical parameters. All biochemical parameters (except for IL-10 in control group), presented a statistically significant difference for 3 months study period in both groups. When laser and control groups were compared, significant differences were not observed, except the lower GCF IL-17 levels (P = 0.025), bleeding on probing (P = 0.028), and clinical attachment level (CAL) (P = 0.0002) values in laser group at third, first, and third months, respectively. Statistically significant correlations were also noted between biochemical parameters and clinical parameters. CONCLUSIONS: The GCF IL-17, TWEAK, and sclerostin levels may be useful for monitoring response to SRP+L therapy. However, long-term studies on higher populations are needed to evaluate the effectiveness of adjunctive use of diode laser application to SRP.

Evaluation of gingival crevicular fluid and peri-implant crevicular fluid levels of sclerostin, TWEAK, RANKL and OPG.

BACKGROUND: The combination of local and systemic factors play role in the pathogenesis of periodontal and peri-implant diseases. Host-derived enzymes, cytokines and other proinflammatory mediators play an integral role in this destruction. The aim of this study is to evaluate gingival crevicular fluid (GCF) and peri-implant crevicular (PICF) fluid levels of sclerostin, TNF-related weak inducer of apoptosis (TWEAK), receptor activator of nuclear factor kappa-beta ligand (RANKL) and osteoprotegerin OPG in periodontal and peri-implant tissues in disease and health conditions and also to assess the potential for use as biomarkers. MATERIALS AND METHODS: The study population was consisted of 50 women and 41 men, in the total of 91 individuals, with a mean age of 51.84 ±â€¯14.05. Periodontitis (n = 22), periodontal health (n = 17), peri-implantitis (n = 27) and peri-implant health (n = 25) groups were established according to clinical and radiographic examination results of 39 teeth and 52 implants restored with fixed prosthetic restorations. In all groups, periodontal and peri-implant parameters (probing depth, gingival recession, gingival bleeding time index, gingival index, and plaque index) were recorded and GCF and PICF samples were also collected. Sclerostin, TWEAK, RANKL and OPG levels in GCF and PICF were measured with ELISA tests. RESULTS: Peri-implantitis group presented significantly higher levels of Sclerostin (p = 0.002), TWEAK(p < 0.0001), RANKL(p < 0.0001), and OPG (p = 0.037) compared to peri-implant health group. Similarly, significantly higher levels of TWEAK (p = 0.001), RANKL(p < 0.0001), and OPG(p = 0.025) were detected in periodontitis group when compared to periodontal health group. Statistically significant correlations were also noted between biochemical parameters and clinical parameters. CONCLUSION: Findings of this study evaluating four different bone metabolism related proteins at the same time, suggests levels of sclerostin may be a biomarker for peri-implant disease presenting significantly higher levels in the peri-implantitis group than in the peri-implant health group. Moreover, levels of TWEAK can be a good indicator for both periodontal and peri-implant disease, due to the correlations with periodontal clinical parameters and the higher levels of TWEAK in diseased sites compared to the healthy sites for both dental implants and teeth.

Evaluation of gingival crevicular fluid and peri-implant sulcus fluid levels of periostin: A preliminary report.

BACKGROUND: Periostin is a protein present in alveolar bone and periodontal ligament whose function is related to response to external forces. The aims of this study are to detect levels of periostin in peri-implant sulcular fluid (PISF) and gingival crevicular fluid (GCF) and to evaluate the relationship between periostin, pyridinoline cross-linked carboxyterminal telopeptide of Type I collagen (ICTP), and C-terminal cross-linked telopeptide of Type I collagen (CTX) levels and clinical inflammatory symptoms and duration of functional loading. METHODS: The study population comprised nine women and four men with mean age 43.23 ± 12.48. Twenty "bone-level designed" dental implants (DIs) placed in molar or premolar sites, without any signs of peri-implant bone loss and with a restoration in function for at least 12 months, were included in the study with 20 contralateral natural teeth (NT) as controls. Clinical parameters and restoration dates of the implants were recorded. PISF, GCF, ICTP, CTX, and periostin levels were evaluated using enzyme-linked immunosorbent assay. RESULTS: ICTP, CTX, and periostin levels were similar between DI and NT groups. There were no statistically significant differences between PISF and GCF values. When implants were grouped as healthy (gingival index [GI] = 0) and inflamed (GI ≥0), ICTP levels and PISF volume were lower in healthy implants compared with the inflamed group. Both periostin and CTX levels were negatively correlated with functioning time, suggesting less bone remodeling around DIs at later stages of functioning. CONCLUSION: Findings of this study suggest collagen breakdown products may be used as markers to evaluate peri-implant metabolism.

Increased cancer risk in patients with periodontitis.

BACKGROUND: Previous studies have noted a possible association between periodontal diseases and the risk of various cancers. We assessed cancer risk in a cohort of patients with moderate to severe periodontitis. METHODS: Patients diagnosed with moderate to severe periodontitis by a periodontist between 2001 and 2010 were identified from the hospital registry. Patients younger than 35 years of age or with a prior cancer diagnosis were excluded. The age- and gender-standardized incidence rates (SIR) were calculated by dividing the number of observed cases by the number of expected cases from Turkish National Cancer Registry 2013 data. RESULTS: A total of 280 patients were included (median age 49.6, 54% female). Median follow-up was 12 years. Twenty-five new cancer cases were observed. Patients with periodontitis had 77% increased risk of cancer (SIR 1.77, 95% CI 1.17-2.58, p = .004). Women with periodontitis had significantly higher risk of breast cancer (SIR 2.40, 95% CI 0.88-5.33) and men with periodontitis had significantly higher risk of prostate cancer (SIR 3.75, 95% CI 0.95-10.21) and hematological cancers (SIR 6.97, 95% CI 1.77-18.98). CONCLUSION: Although showing a causal association necessitates further investigation, our results support the idea that periodontitis might be associated with increased cancer risk, particularly with hematological, breast and prostate cancers.

Platelet-rich plasma-loaded chitosan scaffolds: preparation and growth factor release kinetics.

The aim of this study is to compare the effects of different platelet-rich plasma (PRP) preparation methods on platelet activity and to investigate the growth factor (GF) release kinetics from PRP-loaded chitosan scaffolds for tissue engineering applications. Flow cytometry analysis showed that centrifugation processes used for PRP preparation did not cause significant effect on platelet activation levels by means of markers investigated. Two different methods were used to prepare PRP-loaded chitosan scaffolds: (i) PRP was added to chitosan gel before freeze-drying to prepare scaffolds called as "GEL" and (ii) PRP was embedded to freeze-dried chitosan scaffolds to prepare scaffolds called as "SPONGE." In addition, nonactivated PRP and PRP activated with type-I collagen were used as control groups. Scanning electron microscopy images demonstrated that, in GEL group, there is no deterioration on the scaffolds porous, 3D, and interconnected structure. GF release kinetics was determined by enzyme-linked immunosorbent assay for platelet-derived GF-BB, transforming GF-ß1, and insulin-like GF-1. A sustained release of GFs was achieved in GEL group while a sharp burst release was observed for all the GFs from the SPONGE groups. Moreover, platelet-derived GF-BB, insulin-like GF-1, and transforming GF-ß1 releases were prolonged to 20 days in GEL groups, and the biological activities of all GFs released from GEL and SPONGE scaffolds were preserved. This study demonstrated that chitosan scaffold that was called GEL could be an appropriate carrier for PRP applications by providing sustained release of GFs.

Effect of inflammation on cytokine levels and bone remodelling markers in peri-implant sulcus fluid: a preliminary report.

OBJECTIVES: Since ingredients of peri-implant sulcus fluid (PISF) may be related to the bony structure surrounding dental implants, analyze of specific markers related to bone resorption in PISF seems to be suitable for long term monitoring of peri-implant health. It is suggested that analysis of PISF may serve for detection of inflammation. The aim of this study is to analyze PISF interleukin-1 beta (IL-1ß), IL-10, osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B ligand (RANKL) levels to determine whether the diagnostic value of PISF can be used to evaluate early changes around implants. MATERIALS AND METHODS: A total of 47 dental implants either healthy/non-inflamed (n=20) (Group I), or gingivitis/inflamed (n=27) (Group II), were classified. Peri-implant status has been evaluated by clinical evaluation (plaque index, gingival index, probing depth and gingival bleeding time index) were recorded and PISF samples were also obtained. PISF IL-1ß, IL-10, RANKL, and OPG levels were measured by enzyme-linked immunosorbent assay. Potential volumetric changes in PISF were also evaluated. RESULTS: All clinical parameters and volume of PISF were higher in Group II and these differences were statistically significant except volume values. IL-1ß, IL-10 and OPG levels in PISF were significantly higher in Group II. Although the PISF RANKL level in Group II was higher than the level of Group I, the difference between groups did not reach the statistically significant level. CONCLUSIONS: These data suggest that a balance of inflammatory- and osteoclastogenesis related molecules locally produced may play an important role in the development of inflammatory peri-implant lesions.

Bone morphogenetic protein-6-loaded chitosan scaffolds enhance the osteoblastic characteristics of MC3T3-E1 cells.

The purpose of this study is to investigate the convenience of bone morphogenetic protein-6 (BMP-6)-loaded chitosan scaffolds with preosteoblastic cells for bone tissue engineering. MC3T3-E1 cells were seeded into three different groups: chitosan scaffolds, BMP-6-loaded chitosan scaffolds, and chitosan scaffolds with free BMP-6 in culture medium. Tissue-engineered constructs were characterized by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay, scanning electron microscopy (SEM), mineralization assay (von Kossa), alkaline phosphatase (ALP) activity, and osteocalcin (OCN) assays. BMP-6-loaded chitosan scaffolds supported proliferation of the MC3T3-E1 mouse osteogenic cells in a similar pattern as the unloaded chitosan scaffolds group and as the chitosan scaffolds with free BMP-6 group. SEM images of the cell-seeded scaffolds revealed significant acceleration of extracellular matrix synthesis in BMP-6-loaded chitosan scaffolds. Both levels of ALP and OCN were higher in BMP-6-loaded chitosan scaffold group compared with the other two groups. In addition, BMP-6-loaded scaffolds showed strong staining in mineralization assays. These findings suggest that BMP-6-loaded chitosan scaffold supports cellular functions of the osteoblastic cells; therefore, this scaffold is considered as a new promising vehicle for bone tissue engineering applications.

bFGF-loaded HA-chitosan: a promising scaffold for periodontal tissue engineering.

A scaffold containing growth factors promoting regeneration may be a useful device to maintain periodontal regeneration when applied with appropriate cells. The aim of this study is to evaluate the convenience of chitosan and hydroxyapatite (HA)-chitosan scaffolds loaded with basic fibroblast growth factor (bFGF) for periodontal tissue engineering applications. Scaffolds were fabricated by freeze-drying technique using 2 and 3% chitosan gel in the absence or presence of HA particles. Addition of HA beads to chitosan gels produced a novel scaffold in which the pore sizes and interconnectivity were preserved. The scaffolds were loaded with 100 ng bFGF by embedding technique. HA-chitosan scaffolds provide better controlled release kinetics for bFGF compared with chitosan scaffolds and total release continued up to 168 h. Cell culture studies were carried out with periodontal ligament (PDL) cells and cementoblasts. Both 3-[4,5-dimethylthiazol-2-yl]-diphenyltetrazolium bromide (MTT) assay and confocal laser scanning microscope analysis revealed cells proliferating inside the scaffolds. The results demonstrated that bFGF-loaded HA-chitosan scaffolds provide a suitable three-dimensional environment supporting the cellular structure, proliferation, and mineralization.

In vitro release of dexamethasone or bFGF from chitosan/hydroxyapatite scaffolds.

Chitosan scaffolds containing dexamethasone (Dex) or basic fibroblast growth factor (bFGF) were developed to create alternative drug-delivery systems for possible tissue-engineering applications such as periodontal bone regeneration. Chitosan solutions (2% and 3% (w/v) in acetic acid) were prepared from chitosan flakes with high deacetylation degree (>85%), then these solutions were freeze-dried at -80 degrees C to obtain scaffolds with interconnected pore structures. Dex and bFGF were incorporated into scaffolds by embedding method (solvent sorption method). The initial loading amounts were varied as 300, 600 and 900 ng Dex per dry scaffold (average dry weight is 3 mg) and 50 or 100 ng bFGF per dry scaffold to a range of deliverable doses. Release studies which were conducted in Dulbecco's phosphate-buffered saline (DPBS) showed that 900 ng Dex loaded chitosan scaffolds in both compositions released total Dex during a 5-day period at a nearly constant rate after the initial burst. However, bFGF release from all scaffolds with both loading amounts (50 ng or 100 ng) was completed in 10 or 20 h. In order to prolong the release period of bFGF, composite scaffolds were fabricated in the presence of hydroxyapatite (HA) beads with average particle size of 40 mum. Sustained release of bFGF up to 7 days was achieved due to the electrostatic interactions between HA and bFGF molecules. These results suggested that chitosan scaffolds can be suitable for Dex release; however, the presence of HA in the chitosan scaffold is necessary to achieve the desired release period for bFGF.

Analysis of the inflammatory process around endosseous dental implants and natural teeth: myeloperoxidase level and nitric oxide metabolism.

PURPOSE: The aim of the present study was to analyze the 2 molecular measures of inflammation: (1) the nitrite, an end metabolite of nitric oxide (NO) oxidation and (2) myeloperoxidase (MPO). Both are found in peri-implant sulcus fluid (PISF) of implants and gingival crevicular fluid (GCF) of natural teeth in healthy or diseased states. MATERIALS AND METHODS: A total of 109 tooth or dental implant sites, either healthy/noninflamed, inflamed (Gingival Index [GI] > 0), or affected by periodontitis, were classified, and GCF/PISF samples were obtained. GCF/PISF MPO and nitrite levels were spectrophotometrically determined. For comparison of clinical parameters and PISF/GCF nitrite and MPO levels, Kruskal-Wallis analysis followed by Mann-Whitney test with Bonferroni correction was performed. Healthy/noninflamed, slightly inflamed, moderate/severely inflamed sites were also analyzed using the Kruskal-Wallis test followed by the Mann-Whitney test with Bonferroni correction. The correlation between nitrite and MPO levels and clinical inflammatory status were analyzed with Spearman's correlation coefficient. RESULTS: Clinical parameters, including both the GCF and PISF volumes, demonstrated gradual increases with the presence of gingival/peri-implant inflammation (P < .05). Despite the higher PISF than GCF volume at healthy sites (P = .001), there were no volumetric differences at inflamed sites (P = .771). PISF from inflamed sites (P = .025) and GCF from gingivitis and periodontitis sites presented higher total MPO levels (P < .05) than samples from noninflamed sites. Despite the relatively stable GCF nitrite levels at healthy and diseased sites, PISF from inflamed sites had higher nitrite content than noninflamed sites (P < .05). CONCLUSIONS: The present study demonstrated the volumetric similarities of PISF and GCF in terms of response to inflammation. However, some differences between the 2 biochemical measures of inflammation and their presence in PISF and GCF were also observed. PISF is likely to have a considerable diagnostic potential for reflecting the biologic changes around load-bearing endosseous dental implants. (Cohort Study) (More than 50 references.)

Necrosis of gingiva and alveolar bone caused by acid etching and its treatment with subepithelial connective tissue graft.

The misuse of various chemicals in dentistry may cause damage to gingiva and alveolar bone. In this case report, we describe necrosis of the gingiva and alveolar bone caused by acid etching. A patient whose caries on the cervical third of the root of his mandibular right first molar were treated 2 days earlier presented to our clinic with severe pain and discomfort in the treated area. Intraoral examination revealed a spreading gingival ulceration and exposed alveolar bone. The patient was followed and a week later, when the gingival inflammation had decreased, periodontal surgery was performed. A full-thickness flap was raised and necrotic gingiva and bone were removed. As a result, only a narrow band of keratinized gingiva remained. To treat the gingival recession and protect the underlying bone, a subepithelial connective tissue graft was placed during the same session. After the operation, the patient"s complaints resolved. Subepithelial connective tissue graft can be an important treatment approach in cases of necrosis and gingival recession caused by the misuse of various chemicals.