Bone turnover markers in serum and periodontal microenvironments

An injectable photopolymerizable chitosan hydrogel doped anti-inflammatory peptide for long-lasting periodontal pocket delivery and periodontitis therapy

Periodontitis is a common chronic inflammatory disease caused by plaque that leads to alveolar bone resorption and tooth loss. Inflammation control and achieving better tissue repair are the key to periodontitis treatment. In this study, human β-Defensin 1 short motif Pep-B with inflammation inhibition and differentiation regulation properties, is firstly used in the treatment of periodontitis, and an injectable photopolymerizable Pep-B/chitosan methacryloyl composite hydrogel (CMSA/Pep-B) is constructed. We confirm that Pep-B improves inflammation, and restores osteogenic behavior and function of injured stem cells. CMSA/Pep-B has good injectability, fluidity and photopolymerizability, and can sustainably release Pep-B to maintain drug concentration in periodontal pockets. Furthermore, animal experiments showed that CMSA/Pep-B significantly ameliorated the inflammation of the periodontium and reduced the alveolar bone loss by decreasing inflammatory infiltration, osteoclast formation and collagen destruction. In conclusion, CMSA/Pep-B is envisaged to be a novel bioactive material or therapeutic drug for treating periodontitis.

Calprotectin and N-telopeptide of Type I Collagen (NTx) as Gingival Crevicular Fluid (GCF) Biomarker in Peri-Implantitis Patients

Introduction: Formulation of various preventive and therapeutic strategies is possible only by a better understanding of the immune-inflammatory profile of peri-implant diseases. For understanding the changes and turnover of bone, various markers have been used in the past literature, out of which, N-telopeptide of Type I Collagen (NTx) is acknowledged to be the most reliable marker.

Aims and objectives: Assessment of calprotectin and NTx concentration in gingival crevicular fluid (GCF) around the implant sites in subjects suffering from peri-implantitis.

Materials and methods: In total, 70 healthy individuals were included in the present study. These patients had opted for dental implants within the last decade. After collecting the peri-implant crevicular fluid (PICF) and GCF, various examinations were carried out. PICF samples were obtained with the help of sterile paper available in the form of strips. The enzyme-linked immunosorbent assay (ELISA) technique was used for measuring the calprotectin and NTx. All the readings were obtained in nanograms per microliter of PICF. All the results were recorded and analyzed.

Results: The overall mean calprotectin and NTx values were observed to be in a significantly higher range within the sites suffering from peri-implantitis when compared with healthy locations. The calprotectin values and NTx levels were positively correlated with the mean values of periodontal parameters observed clinically.

Conclusion: Both calprotectin and NTx could be used as a biomarker signifying the presence of inflammation as well as bone resorption in patients suffering from peri-implantitis.

Evaluation of Osteocalcin Levels in Saliva of Periodontitis Patients and Their Correlation with the Disease Severity: A Cross-Sectional Study

OBJECTIVES

 The present study aimed to investigate osteocalcin levels in saliva of healthy and periodontitis patients and correlate these levels with periodontitis severity.

MATERIALS AND METHODS

 This cross-sectional study was conducted in a hospital setup. A total of 95 individuals participated in the study with 46 subjects in group I (healthy individuals) and 49 subjects in group II (mild, moderate, and severe chronic periodontitis patients). A detailed assessment of clinical periodontal parameters and alveolar bone loss was made. Unstimulated saliva samples were collected from all study subjects and osteocalcin levels were quantitatively analyzed by sandwich enzyme-linked immunosorbent essay technique.

STATISTICAL ANALYSIS

 One-way analysis of variance, Spearman's correlation test, and Pearson's chi-squared test were applied at a significance level of 95%. p-Values less than 0.05 were considered statistically significant.

RESULTS

 The results showed a significant association of qualification with group II (p < 0.02). Bone loss scores were also significantly associated with periodontitis severity (p < 0.01). However, no statistically significant difference was observed between group I and group II in terms of mean salivary osteocalcin levels (p = 0.68). Also, an insignificant correlation was also observed between osteocalcin levels and periodontitis severity (p = 0.13).

CONCLUSION

 The overall study results showed that there was no significant difference between saliva osteocalcin levels of healthy and periodontitis patients. Also, there was a nonsignificant correlation between osteocalcin levels and periodontitis severity. The findings of the present study support the hypothesis that low osteocalcin levels in saliva might be considered as a poor indicator of periodontal disease progression and severity.

Guided tissue regeneration of intrabony defects with perforated barrier membranes, simvastatin, and EDTA root surface modification: A clinical and biochemical study

BACKGROUND

Perforated barrier membranes (PBM) were suggested to enhance periodontal regeneration by allowing positive charity of wanted elements from the gingival tissue side. The present study was designed to evaluate clinically and biochemically the use of PBM combined with simvastatin (SMV) gel with and without an associated EDTA gel root surface etching as a suggested option that could improve SMV availability and clinical outcomes of PBM.

METHODS

Forty patients having moderate-to-severe chronic periodontitis with 40 intrabony defects were randomly divided into four treatment groups (10 sites each). Patients in group 1 received 1.2% SMV gel and covering the defect with occlusive membrane (OM). Patients in group 2 received 1.2% SMV gel and covering the defect with PBM. Group 3 received 24% EDTA root surface etching, 1.2% SMV gel, and defect coverage with OM (eOM). Patients in group 4 were treated as in group 3 but the defect was covered with PBM (ePBM). Clinical parameters were recorded at baseline before surgical procedures and were reassessed at 6 and 9 months after therapy. The mean concentration of SMV in gingival crevicular fluid (GCF) was estimated by reverse-phase high-performance liquid chromatography at days 1, 7, 14, 21, and 30.

RESULTS

At 6- and 9-month observation periods, groups 3 and 4 showed a statistically significant improvement in PD reduction and CAL gain compared with groups 1 and 2. Group 4 showed a statistically significant more defect fill compared with groups 1, 2, and 3 (P ≤ .05). Group 2 showed statistically significant higher defect fill compared with group 1 and group 3 (P < .05). Bone density was significantly increased with no significant difference between the four groups at 6- and 9-month observation periods. SMV-GCF concentration in group 4 showed the highest mean concentration with no significant difference than that of group 3.

CONCLUSION

The use of perforated barrier membranes in association with SMV enhances the clinical hard tissue parameters compared with occlusive ones in treating intrabony periodontal defects. Moreover, EDTA root surface treatment could enhance SMV availability in the defect area.

Calprotectin and cross-linked N-telopeptides of type I collagen levels in crevicular fluid from implant sites with peri-implant diseases: a pilot study

BACKGROUND

Peri-implant crevicular fluid (PICF) contains calprotectin and NTx, which are markers for inflammation and bone resorption, respectively. The aims of this pilot study were to compare calprotectin and NTx levels in PICF from implant sites with or without peri-implant diseases and to evaluate the usefulness of calprotectin and NTx as diagnostic markers for peri-implant diseases.

METHODS

Thirty-five patients with dental implants participated in this pilot study. PICF samples were collected from peri-implant disease sites (n = 40) and non-diseased (healthy) sites (n = 34) after clinical indicators including probing depth (PD), bleeding on probing (BOP), gingival index (GI), and bone loss (BL) rate were investigated. Calprotectin and NTx amounts in PICF were measured using their respective ELISA kits and then compared between diseased and healthy samples. The relationship between PICF calprotectin or NTx levels and clinical indicator levels was investigated. A receiver operating characteristic (ROC) curve analysis of calprotectin and NTx was performed to predict peri-implant diseases.

RESULTS

Calprotectin and NTx levels in PICF were significantly higher from peri-implant disease sites than from healthy sites. PICF calprotectin amounts correlated with PD, and its levels were significantly higher in the GI-1 and GI-2 groups than in the GI-0 group. PICF NTx amounts correlated with PD and the BL rate. ROC curves indicated that PICF calprotectin and NTx are useful biomarkers for peri-implant diseases.

CONCLUSIONS

Calprotectin and NTx in PICF have potential as biomarkers for the diagnosis of peri-implant diseases.

Biomarkers of alveolar bone resorption in gingival crevicular fluid: A systematic review

BACKGROUND

Periodontitis is a prevalent oral disease with bone loss being it's hallmark. Clinical parameters used to measure periodontitis are retrospective and do not indicate active inflammation nor prognosis. GCF can be easily collected chairside and bone turnover biomarkers found in GCF can be evaluated to check for active inflammation and disease progression. This systematic review aims to evaluate the literature for association and predictive value of bone turnover biomarkers in GCF during periodontal disease.

MATERIALS AND METHODS

This review was conducted and reported according to the PRISMA guidelines. The online databases Google Scholar and PubMed were used for data search. MeSH terms were used for PubMed search. All original studies from 1990 to 2017 conducted on human subjects in the English language were included in the review. Studies on non-human subjects, reviews and studies conducted in languages other than English were not considered. Reference lists of qualified articles were also searched.

RESULTS

The search generated 2300 results whose titles were screened and 1571 articles were retreived. 23 articles were accepted in the review and full texts were accessed. These included 1 randomized controlled trial, 12 cross-sectional studies, five pre-post interventional studies, 4 longitudinal and 1 in-vitro in-vivo experimental study. The studies were conducted on patients of both genders ranging from 10 to 81 years in age. A total of 37 biomarkers were evalueted in the studies included in this review. Majority of the studies reported interleukin-1β (IL-1β) while receptor activated nuclear factor-kappa B ligand (RANKL) and matrix metalloproteinase-8 (MMP-8) were the other frequently reported biomarkers. Most of the studies evaluated more than two biomarkers. ELISA was the most commonly used biochemical test used for detection.

CONCLUSION

A wide range of biomarkers have been established as indicators of alveolar bone resorption. Few of the biomarkers have also shown positive correlation with disease progression and outcome of periodontal therapies thus underscoring their predictive value in periodontal diagnosis and prognosis. Not one single biomarker has been reported to have a predictive advantage over another and a combination of two or more biomarkers along with clinical evaluation is recommended.

Plasma levels of N-telopeptide of Type I collagen in periodontal health, disease and after treatment

Background:

To determine plasma concentrations of bone resorption marker cross-linked N-terminal telopeptide (NTx) of Type I collagen in periodontal health, disease and after nonsurgical periodontal therapy in chronic periodontitis group. In addition, to know the association between plasma NTx levels and the different clinical parameters.

Materials and Methods:

Thirty subjects were divided on the basis of their periodontal status and were categorized as Group I: Healthy, Group II: Gingivitis, and Group III: Chronic periodontitis. Group III subjects were treated with scaling and root planing, 6-8 weeks later blood samples were analyzed, and they constituted Group IV. NTx levels in plasma were analyzed by competitive - enzyme-linked immunosorbent assay. All data were analyzed using statistical software (SPSS) (α = 0.05).

Results:

All the samples tested positive for the presence of NTx. The mean NTx concentration was highest in Group III (18.77 nanomole Bone Collagen Equivalent [nm BCE]) and the lowest in Group IV (16.02 nm BCE). The values of Group I and Group II fell between the highest and the lowest values (16.23 nm BCE and 16.70 nm BCE, respectively). The difference in mean NTx levels in Group III and Group IV were statistically significant. NTx levels in all the groups positively correlated with the clinical parameters. All data were analyzed using statistical software (SPSS) (α = 0.05).

Conclusion:

Within the limits of this study, it may be suggested that plasma NTx levels may provide distinguishing data between periodontally healthy diseased sites and after nonsurgical therapy of diseased sites.

Role of prostaglandin pathway and alendronate-based carriers to enhance statin-induced bone

This study investigated the role of the prostaglandin (PG) pathway in locally applied, simvastatin-induced oral bone growth. The possibility of enhancing long-term bone augmentation with an alendronate-based carrier was initiated. Mandibles of 44 mature female rats were treated bilaterally with the following combinations: 2 mg of simvastatin in ethanol (SIM-EtOH), EtOH, 2 mg of simvastatin acid complexed with alendronate-beta-cyclodextrin conjugate (SIM/ALN-CD), ALN-CD, or ALN. Bone wash technology (injection of PBS and re-collection by suction) was used to sample injection sites at baseline (day 0), and 3, 7, 14, and 21 days post-treatment. After 21-24 or 48 days, histomorphometric analysis was done. The amount of PGE(2) in bone wash fluid was measured by ELISA, normalized by total protein, and compared between high and low bone growth groups (ANOVA) and correlated with subsequent bone histology at 21 days (Spearman). SIM-stimulated PGE(2) synthase and EP4 receptor mRNA in murine osteoblast and fibroblast cell lines were evaluated with real-time PCR. Single injections of 2 mg of SIM-EtOH induced significantly more new bone than control side after 21 days. PGE(2)/protein ratios peaked at day 7 and were correlated with the subsequent 21-day new bone width. The correlations at day 14 between PGE(2) and new bone width changed to a negative relationship in the test group. SIM-stimulated osteoblasts expressed increased mRNA levels of PGE receptor EP4, while SIM activated PGE synthesis in fibroblasts. SIM/ALN-CD tended to preserve bone long-term. Findings suggest that PGE pathway activation and higher levels of PGE(2) during the first week following SIM-induced bone growth are desirable, and alendronate-beta-cyclodextrin conjugates not only act as tissue-specific carriers, but preserve new bone.

Calprotectin and cross-linked N-terminal telopeptides in peri-implant and gingival crevicular fluid

In a previous study on guided bone augmentation, a new collagen membrane was compared with an e-PTFE one on 28 partially edentulous patients who received 50 dental implants at stage 2 surgery. After implant integration and subsequent loading, we were able to recruit 22 patients with 22 implants and their contra-lateral corresponding teeth for longitudinal observation. Clinical parameters probing depth (PD), bleeding on probing (BoP), plaque index (PI), assessment of gingival crevicular fluid (GCF) and peri-implant crevicular fluid (PCF) volumes and periapical radiographs were performed at 2- and 3-year control appointments. Calprotectin (MRP 8/14) and cross-linked N-terminal telopeptide (NTx) levels in both crevicular fluids were determined by ELISA. PD was significantly reduced from years 2 to 3 appointments at implant sites as at teeth sites. At the 3-year appointment in both compartments, fluid volumes were significantly increased, which corresponded well with ascending NTx levels. The total amount of calprotectin decreased non-significantly in both GCF and PCF samples. Periapical radiographs revealed stable bone conditions around implants without significant changes from years 2 to 3 examinations. Clinical peri-implant parameters were considered as stable as the periodontal parameters of their corresponding teeth. A parallel increase in NTx levels in both GCF and PCF at 3-year appointment is not clearly understood; it may reflect an upregulation in the overall bone turnover rate.

Relationship between gelatinases and bone turnover in the healing bone defect

PURPOSE

The aim of this pilot study was to determine the relationship between gelatinase (MMP-9 and MMP-2) markers of soft tissue inflammation/turnover at the bone/soft tissue interface and bone turnover (osteocalcin [OC], pyridinoline cross-linked carboxyl-terminal telopeptide of type 1 collagen [ICTP], and bone fill) during healing of an alveolar bone defect.

MATERIALS AND METHODS

Ten subjects undergoing oral surgery had a 5 x 5-mm trephine defect created on an edentulous ridge and were sampled at the bone/soft tissue interface at baseline (prior to flap reflection), 2 weeks and 12 weeks postsurgery, using a novel bone wash device. Recovered irrigants were analyzed for MMP-9 and MMP-2 by gelatin zymography, OC and ICTP with radioimmunoassays, and albumin (ALB; to normalize markers for blood content) with a sandwich enzyme-linked immunosorbent assay. Bone fill at 12 weeks was analyzed by radiographic absorptiometry.

RESULTS

All markers of enzymatic activity and bone turnover varied significantly across time (P < or = .03), with bone turnover markers OC and ICTP decreasing between baseline and 2 weeks, and MMP-9 and MMP-2 increased. Measures generally returned to near baseline levels after 12 weeks. MMP-9 versus MMP-2 (r = 0.97, P < .0001) and OC versus ICTP (r = 0.38, P = .048) were correlated with each other, while MMP-9 and MMP-2 were negatively correlated with ICTP (r = -0.48, P = .011 and r = -0.62, P = .006, respectively). MMP-9 was negatively correlated with subsequent bone fill (r = -0.63, P = .07).

CONCLUSIONS

Bone wash sampling showed that gelatinase activity at 2 weeks following creation of an alveolar defect appeared to decrease bone turnover and eventual bone fill, suggesting benefits for anti-MMP therapy during wound healing.

The effect of a mouth rinse containing phenolic compounds on plaque formation and developing gingivitis

BACKGROUND

The clinical effect of Listerine, a mouth rinse containing a mixture of phenolic compounds, is ascribed to its bactericidal properties. However, phenolic compounds are also known to interfere with the inflammatory process.

OBJECTIVE

The purpose of this clinical trial was to evaluate the effect of regular mouth rinsing with Listerine on plaque and gingivitis during a 2-week period of no mechanical oral hygiene.

MATERIAL AND METHODS

Twenty-one subjects were recruited for the study. On Day 0 of each 2-week experimental period, the participants were told to abstain from all mechanical plaque-control measures but to rinse twice a day with 10 ml of the assigned solution (test: Listerine, positive control:0.1% chlorhexidine (CHX), negative control: saline) for 60 s. Each experimental period was preceded by a 2-week period including oral hygiene instruction, scaling and professional mechanical tooth cleaning. Examinations included assessments of plaque and gingivitis (Days 0 and 14), sampling of plaque and collection of gingival crevicular fluid (GCF) (Days 0, 7 and 14). From the supragingival plaque samples, six different morphotypes of bacteria were counted using dark-field microscopy. The GCF collected was analysed with respect to the content of lactoferrin and albumin.

RESULTS

During the experimental periods, it was observed that significantly less plaque formed and less gingivitis developed when the participants rinsed with the Listerine mouthwash than with saline solution. However, significantly more plaque formed during the Listerine than during the CHX rinse period, while there was no significant difference in the development of gingival bleeding between the Listerine and the CHX rinse regimens. Significantly smaller proportions of motile rods and fusiforms were found in the List and CHX groups than in the control (Ctrl) group. The increase of the lactoferrin/albumin ratio in the List group was significantly smaller than that in the Ctrl group but significantly larger than in the CHX group.

CONCLUSION

It was suggested that the effect of Listerine on gingivitis is more pronounced than on plaque formation. This indicates that the phenolic compound may have anti-inflammatory effects.

Serum, Saliva, and Gingival Crevicular Fluid Osteocalcin: Their Relation to Periodontal Status and Bone Mineral Density in Postmenopausal Women

BACKGROUND

Periodontitis and osteoporosis are characterized by the loss of bone mass. Osteocalcin levels have been postulated as a marker of inhibition of bone formation. The aim of the present study was to assess plasma, saliva, and gingival crevicular fluid (GCF) levels of osteocalcin and correlate them with periodontitis and osteoporosis.

METHODS

Seventy-three postmenopausal women, over 35 years old, were recruited for the study. Serum, saliva, and GCF osteocalcin were measured. Vertebral bone mineral density was measured by dual-energy x-ray absorptiometry. Differences between groups were assessed by analysis of variance (ANOVA), chi-square test, and non-parametric Kruskal-Wallis test.

RESULTS

Thirty-four (46.6%) were classified in the normal healthy bone group, 11 women (15.1%) in the osteopenic group, and 28 women (38.4%) in the osteoporotic group. No statistically significant differences between these densitometric groups were observed in probing depth (P = 0.24); clinical attachment level (P = 0.11); or mean osteocalcin concentrations in serum, saliva, and GCF. Twenty-seven (37.0%) of the women were classified without periodontitis (NPG) and 63.0% (N = 46) with periodontal disease (PG). There were no statistical differences in serum and saliva osteocalcin concentrations between these two groups. GCF osteocalcin concentrations were significantly higher in the PG women than in the NPG group (P = 0.008). Mean probing depth correlated significantly with GCF osteocalcin concentrations (r = 0.35; P = 0.002).

CONCLUSION

The results further support the concept that osteocalcin levels in GCF correlates with periodontal but not with osteoporosis status.

Advances in periodontal disease markers

A computer-assisted medline search was conducted to find the relevant articles concerning the periodontal disease markers in gingival crevicular fluid (GCF) and saliva published during the 10-year period from 1993 to July 2003. This review suggests that certain diagnostic uses of saliva and GCF show promise. Although both fluids have been used to evaluate the risk for an individual to develop periodontal disease and to monitor of the host response to periodontal therapy, GCF has the chance of being closely approximated to the periodontal tissues where periodontal disease begins. The enzymes contributed to extracellular matrix (ECM) molecules and non-ECM molecules degradation and markers for polymorphonuclear leukocytes (PMN) activity and influx into the gingival tissue seem to provide valuable information regarding the periodontal disease diagnosis and prognosis. There is also an increasing evidence implicating reactive oxygen species and nitric oxide pathway in the pathogenesis of periodontal diseases. Although promising results have been achieved with the assays evaluating the markers in assessment of periodontal disease status, up to now, none of these tests are used routinely. Further, one commercially available genetic test has been reported to have the potential to be used to predict the periodontal disease, but there are controversial reports on this genetic susceptibility test.

Local biochemical markers of bone turnover: relationship to subsequent density of healing alveolar bone defects

OBJECTIVES

This pilot study was designed to test whether biochemical markers of bone turnover in washes of periosteal or trabecular alveolar bone surfaces could be correlated with increases in bone density of an adjacent healing implant socket.

METHODS

Ten subjects had a canula inserted into the alveolar crest and sterile phosphate-buffered saline was washed over the periosteal and trabecular surfaces and collected. Surgical flaps were reflected, 5 mm diameter bone cores were removed from the bone wash site, and standardized radiographs were taken. The sites were allowed to heal for 12 weeks, and radiographs were repeated. Bone washes of the healing sites were also collected after 2 and 12 weeks. Washes were analysed for bone turnover markers osteocalcin (OC; radioimmunoassay) and C-terminal telopeptide of Type 1 collagen (ICTP; enzyme-linked immunosorbent assay (ELISA)), and blood component albumin (ALB; ELISA). Changes in bone density during healing were determined by radiographic absorptiometry.

RESULTS

OC/ALB and ICTP/ALB ratios were higher for trabecular than periosteal washes at baseline (p<or=0.01). Trabecular OC/ALB and ICTP/ALB were inversely correlated with increasing bone density of the healing bone core socket (r=-0.72, p=0.03; Pearson's correlation coefficient).

CONCLUSIONS

Biochemical markers of bone turnover in bone washes of specific alveolar bone sites may prove helpful in predicting how the bone density will increase around healing dental implants.