Inflammatory and bone remodelling related biomarkers following periodontal transplantation of the tissue engineered biocomplex.

OBJECTIVES: To assess gingival crevicular fluid (GCF) levels of inflammatory and bone remodelling related biomarkers following transplantation of a tissue-engineered biocomplex into intrabony defects at several time-points over 12-months. MATERIALS AND METHODS: Group-A (n = 9) received the Minimal Access Flap (MAF) surgical technique combined with a biocomplex of autologous clinical-grade alveolar bone-marrow mesenchymal stem cells in collagen scaffolds enriched with an autologous fibrin/platelet lysate (aFPL). Group-B (n = 10) received the MAF surgery, with collagen scaffolds enriched with aFPL and Group-C (n = 8) received the MAF surgery alone. GCF was collected from the osseous defects of subjects via paper strips/30 sec at baseline, 6-weeks, 3-, 6-, 9-, 12-months post-surgery. Levels of inflammatory and bone remodelling-related biomarkers in GCF were determined by ELISA. RESULTS: Group-A demonstrated significantly higher GCF levels of BMP-7 at 6-9 months than baseline, with gradually decreasing levels of pro-inflammatory and pro-osteoclastogenic markers (TNF-α, RANKL) over the study-period; and an overall decrease in the RANKL/OPG ratio at 9-12 months than baseline (all p < 0.001). In comparison, only modest interim changes were observed in Groups-B and -C. CONCLUSIONS: At the protein level, the approach of MAF and biocomplex transplantation provided greater tissue regeneration potential as cell-based therapy appeared to modulate inflammation and bone remodelling in residual periodontal defects. CLINICAL RELEVANCE: Transplantation of a tissue engineered construct into periodontal intrabony defects demonstrated a biochemical pattern for inflammatory control and tissue regeneration over 12-months compared to the control treatments. Understanding the biological healing events of stem cell transplantation may facilitate the design of novel treatment strategies. CLINICAL DATABASE REGISTRATION: ClinicalTrials.gov ID: NCT02449005.

A tissue-engineered biocomplex for periodontal reconstruction. A proof-of-principle randomized clinical study.

AIM: To assess the safety/efficacy of a tissue-engineered biocomplex in periodontal reconstruction. METHODS: Twenty-seven intrabony defects were block-randomized across three treatment groups: Group-A (NA  = 9) received autologous clinical-grade alveolar bone marrow mesenchymal stem cells (a-BMMSCs), seeded into collagen scaffolds, enriched with autologous fibrin/platelet lysate (aFPL). In Group-B (NB  = 10), the collagen scaffold/aFPL devoid of a-BMMSCs filled the osseous defect. Group-C (NC  = 8) received Minimal Access Flap surgery retaining the soft tissue wall of defects identically with Groups-A/-B. Subjects were clinically/radiographically assessed before anaesthesia (baseline) and repeatedly over 12 months. RESULTS: Quality controls were satisfied before biocomplex transplantation. There were no adverse healing events. All approaches led to significant clinical improvements (p < .001) with no inter-group differences. At 12 months, the estimated marginal means for all groups were as follows: 3.0 (95% CI: 1.9-4.1) mm for attachment gain; 3.7 (2.7-4.8) mm for probing pocket depth reduction; 0.7 (0.2-1.3) mm increase in recession. An overall greater mean reduction in the radiographic Cemento-Enamel Junction to Bottom Defect (CEJ-BD) distance was found for Groups-A/-C over Group-B (p < .023). CONCLUSION: Radiographic evidence of bone fill was less pronounced in Group-B, although clinical improvements were similar across groups. All approaches aimed to trigger the innate healing potential of tissues. Cell-based therapy is justified for periodontal reconstruction and remains promising in selected cases.

Interim tissue changes following connective tissue grafting and two-stage implant placement. A randomized clinical trial.

AIM: To determine tissue changes at implants placed either conventionally or in combination with a connective tissue graft (CTG). MATERIALS AND METHODS: Forty-eight partially edentulous subjects were randomized into two treatment Groups, and 46 completed the study. Group-A (NA  = 23) received crestal implant placement. In Group-B (NB  = 23), a CTG harvested from the palate was stabilized over the implant neck. At the time of implant placement (T0), Groups were categorized as having thin mucosa ≤ 2.5 mm at the surgical site (NSubgroup-AI  = 12, NSubgroup-BI  = 11) or thick mucosa > 2.5 mm (NSubgroup-AII  = 11, NSubgroup-BII  = 12). Mucosa thickness, width of keratinized tissue (WKT), crestal bone levels and relative bone thickness were determined at T0 and at the two-stage surgery (T1). RESULTS: At T1, on the alveolar crest, mucosa thickness significantly decreased in the thick mucosa Subgroups (-AII/-BII, both p = 0.001), but increased at thin mucosa grafted sites (p = 0.049). No significant changes were noted in the WKT for either group. Thin mucosa grafted Subgroups (-AI/-BI) demonstrated significant decreases in crestal bone levels (both p ≤ 0.008). Crestal relative bone thickness decreased in all Subgroups (p ≤ 0.027 for significant changes). CONCLUSIONS: Connective tissue grafting resulted in smaller reductions of mucosa thickness on the alveolar crest and appeared to have the greater effects at sites with initially thin mucosa.

Clinical associations between acetylcholine levels and cholinesterase activity in saliva and gingival crevicular fluid and periodontal diseases.

AIM: The oral mucosa possesses a non-neuronal cholinergic system. This study aimed to determine clinical evidence for a role of cholinergic mechanisms in the pathogenesis of periodontal diseases. MATERIALS AND METHODS: Fifty healthy participants, 52 patients with gingivitis and 49 with periodontitis were recruited. Full periodontal parameters were recorded and saliva and gingival crevicular fluid (GCF) collected. Levels of acetylcholine and inflammatory mediators were quantified using commercially available assay kits. Acetylcholinesterase and butyrylcholinesterase activities were measured using a published biochemical assay. RESULTS: Acetylcholine levels are significantly elevated in saliva and GCF, whereas GCF levels of butyrylcholinesterase activity are significantly decreased, in patients with periodontal diseases. Acetylcholine levels in saliva and GCF correlated positively with clinical markers of disease severity and with increased levels of IL-17A and IL-17F. In contrast, butyrylcholinesterase activity levels in GCF showed significant negative correlations with clinical markers of disease severity and IL-17A and IL-17F levels. None of the findings were due to smoking. CONCLUSIONS: Elevated acetylcholine levels and reduced butyrylcholinesterase activity are clinically associated with periodontal diseases and elevated levels of IL-17A and IL-17F. Therefore, non-neuronal cholinergic mechanisms may influence IL-17 biology and the aetiopathogenesis of periodontal diseases and therefore are possible therapeutic targets.

Comparison of enamel matrix derivative (Emdogain) and subepithelial connective tissue graft for root coverage in patients with multiple gingival recession defects: A randomized controlled clinical study.

OBJECTIVE: The purpose of the present study was to compare the clinical efficiency of enamel matrix derivative (EMD) placed under a coronally advanced flap (CAF; test group), to a connective tissue graft (CTG) placed under a CAF (control group), in patients with multiple recession defects. METHOD AND MATERIALS: Twelve patients with multiple Miller's Class I or II gingival recessions in contralateral quadrants of the maxilla were selected. The primary outcome variable was the change in depth of the buccal recession (REC), at 6 months (T6) after surgery. The secondary outcome parameters included the clinical attachment level (CAL), the probing pocket depth (PPD), and the width of keratinized gingiva (WKT) apical to the recession. Recession defects were randomly divided to the test or control group by using a computer-generated randomization list. Data were analyzed within the frame of Mixed Linear Models with the ANOVA method. RESULTS: There were no statistically significantly differences observed between test and control groups in regards with the depth of buccal recession with a mean REC of 1.82 mm (CTG) and 1.72 mm (EMD) respectively. Similarly the mean PPD value was 1.3 mm for both groups at T6, while the respective value for CAL was 1.7 mm (EMD) and 1.8 mm (CTG). Statistically significant differences were observed only for the WKT, which were 3.0 mm and 3.6 mm for the test and control groups respectively (P < .001) at T6. CONCLUSION: The use of EMD in conjunction with a CAF resulted in similar results as compared to the CTG plus CAF.

Control of dentin/root sensitivity during non-surgical and surgical periodontal treatment.

AIM: To determine the efficacy of a desensitizing regimen compared to a control in preventing the occurrence and/or alleviating dentin/root sensitivity (DRS) following non-surgical (NSPT) and surgical periodontal treatment (SPT). METHODS: Seventy-four chronic-periodontitis patients (CPP) were randomized into a test group (n = 38) using an in-office prophylaxis paste and a toothpaste at home both containing 8% arginine and calcium carbonate (Pro-Argin(™) Technology) or into a control group (n = 36) receiving a fluoride-free prophylaxis paste and a fluoride toothpaste. The examiner applied the assigned paste onto selected teeth for 3 s following NSPT and for 60 s before flap closure. Patients brushed with the assigned toothpaste twice daily throughout the study. DRS to air stimulus was assessed by the Schiff scale (0-3) and the Visual Analog Scale (VAS: 0-100 mm) six times over 17 weeks. RESULTS: In the test group, VAS scores significantly decreased at 8, 11 and 17 weeks from baseline (p ≤ 0.003) and Schiff scores at 8 and 11 weeks from baseline (p ≤ 0.014). The control group exhibited significant increases in VAS and Schiff during the study period (p ≤ 0.006). Marked inter-group differences were noted at all time points (p < 0.001). CONCLUSIONS: The combined use of desensitizing products (8% arginine and calcium carbonate) in-office and at-home prevented DRS development and maintained this effect for 17 weeks following NSPT and SPT.

The utilization of a diode laser in the surgical treatment of peri-implantitis. A randomized clinical trial.

OBJECTIVES: A comparison of different treatment modalities of peri-implantitis can lead to the development and application of more effective and efficient methods of therapy in clinical practice. This study compares the effectiveness of open flap debridement used alone, with an approach employing the additional use of a diode laser for the treatment of peri-implantitis. MATERIALS AND METHODS: Nineteen patients were divided into two groups and treated for peri-implantitis. In the control group (C group), the therapy utilized access flaps, plastic curettes, and sterilized gauzes soaked in saline. The test group (L group) was treated similarly but with additional irradiation using a diode laser. The parameters studied were pocket depth (PD) as the primary outcome variable, clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI) as secondary variables. Measurements were performed at three different time points, baseline (BSL), 3 months, and 6 months after treatment. Three months after treatment, a mean PD reduction of 1.19 mm for the control group and 1.38 mm for the laser group was recorded. The corresponding BOP changes were 72.9 and 66.7%, respectively. These changes were significant and remained at the same levels at the 6-month examination (p < 0.05). CAL was reduced significantly only in group L from 5.25 mm at baseline to 4.54 mm at 3 months, remaining at this level at 6 months (p < 0.05). PI was reduced significantly in group C at 3 months from 37.5 to 6.3%. The 6-month data showed no statistically significant difference (p < 0.05) from the 3-month measurements. RESULTS: The two methods of therapy for peri-implantitis examined seemed to be equally efficient in the reduction of the PD and BOP 3 months after surgery, with the results sustained at the same levels after 6 months. CAL significantly improved only in the test group after 3 months. PI was reduced and maintained at low levels in both groups. CONCLUSIONS: Surgical treatment of peri-implantitis by access flaps leads to improvement of all clinical parameters studied while the additional use of diode laser does not seem to have an extra beneficiary effect. CLINICAL RELEVANCE: The additional use of a diode laser in the surgical treatment of peri-implantitis offers a limited clinical benefit.

Effects of local application of simvastatin on bone regeneration in femoral bone defects in rabbit.

Simvastatin (SIM), which is widely used in hyperlipidemia treatment, has also attracted attention due to its anabolic effects on bones. This study is designed to investigate the effectiveness of 2 mg SIM combined with 3 different carriers as delivery systems. Bone defects were surgically created in the femoral bones of 14 New Zealand white rabbits. The carriers used were the inorganic bovine bone graft (BOS), the hydroxyapatite combined with calcium sulfate (HACS), and the collagen sponge (COS). The bone defects were divided for each time period into 7 groups, as follows: passive control group (CONT), active control groups (BOS), (HACS) and (COS) (no simvastatin), and groups (BOS + SIM), (HACS + SIM) (carrier and simvastatin combination). Animal were sacrificed at 4 and 8 weeks postoperatively, and bone defects areas were prepared for histological examination and histomorphometric evaluation. Analysis of variance demonstrated statistically significant differences between groups depending on the carrier used. At 4 weeks, the BOS + SIM group presented higher rates of new bone formation, whereas at 8 weeks more new bone formation was noted for the HACS + SIM group. This study suggests that local application of simvastatin, combined with an appropriate carrier, can promote new bone formation.

Immunological and microbiological findings after the application of two periodontal surgical techniques: a randomized, controlled clinical trial.

AIM: To examine microbiological and immunological alterations following two periodontal surgical techniques, over a 6-month period. MATERIALS AND METHODS: A total of 30 chronic periodontitis patients participated in the present randomized controlled clinical trial and were randomized in two groups. Modified Widman flap (MWF) was applied in the control group and apically positioned flap (APF), without intervention to the bone, in the experimental group. Gingival crevicular fluid samples and subgingival plaque samples from the operated sites were collected at baseline, 6th, 12th and 24th post-operative week. RESULTS: No major differences were noticed in immunological and microbiological profile of patients receiving either modified MWF or APF, for a period of 6 months. CONCLUSIONS: The choice of the periodontal surgical procedure does not seem to affect the immunological and the microbiological profile of patients with chronic periodontitis.

Clinical, radiographic, microbiological, and immunological outcomes of flapped vs. flapless dental implants: a prospective randomized controlled clinical trial.

OBJECTIVES: The objective of this study was to compare the placement of flapped vs. flapless dental implants utilizing clinical, radiographic, microbiological, and immunological parameters. MATERIAL AND METHODS: A total of 20 patients received 30 dental implants following a one-stage protocol. The patients were randomly assigned into two study groups: control group with 15 flapped implants and test group with 15 flapless implants. Follow-up examinations were carried out after 1, 2, 6, and 12 weeks. Clinical recordings, sulcular fluid sampling, microbiological analysis, and digital subtraction radiography were utilized to compare the two surgical approaches. RESULTS: Peri-implant sulcus depth was significantly greater in flapped implants at both 6 and 12 postsurgical weeks (P < 0.001). Flapped implants showed crestal bone loss (0.29 ± 0.06 mm), whereas no bone resorption was detected around flapless implants. Matrix metalloproteinase-8 values were higher to a statistically significant level in the control group at 1 (P = 0.003) and 6 weeks (P = 0.007) after placement. In the test group, the presence of Porphyromonas gingivalis was significantly higher at the 2nd postoperative week (P = 0.005), whereas the counts of Tannerella forsythia were significantly elevated at the 1st (P = 0.005), 2nd (P = 0.001), and 12th (P = 0.002) postoperative weeks, possibly indicating an earlier formation and maturation of the peri-implant sulcus. Patients reported more pain after flapped implant placement. CONCLUSIONS: Flapless implant placement yielded improved clinical, radiographic, and immunological outcomes compared with flapped implantation. In addition, patients seem to better withstand flapless implant placement.

Cigarette smoking associated with advanced periodontal destruction in a Greek sample population of patients with periodontal disease.

OBJECTIVES: The objective of this study was to evaluate the possible risk factor related to the severity of periodontal destruction in an adult Greek population and to determine possible risk factors of chronic periodontal disease. METHODS: The 115 participants (mean age 47.5, range 28-74 years) were referred for periodontal treatment in two high-standard therapeutic centers. All individuals were clinically examined and answered a detailed questionnaire. The sociodemographic characteristics and periodontal findings were recorded and statistically analyzed. RESULTS: The prevalence of periodontal destruction was significantly high, as 91.3% of the participants had at least one tooth with attachment loss > or = 7 mm and 73% presented with mean loss of attachment > 4 mm. In this subject cohort, 31.3% had never smoked, 15.7% had quit smoking, and 53% were currently smokers (heavy, moderate, or occasional). Heavy smokers exhibited worse periodontal tissue breakdown and less bleeding tendency compared to moderate, infrequent, or never smokers. Among the other investigated parameters, age and customary oral hygiene practices were correlated with periodontal pocket formation and clinical attachment loss. CONCLUSIONS: The results of this study suggest that smoking appears to be a major environmental factor associated with accelerated periodontal destruction in an adult urban Greek population with regular oral hygiene habits.

Free soluble receptor activator of nuclear factor-kappab ligand in gingival crevicular fluid correlates with distinct pathogens in periodontitis patients.

AIM: The aim of the experiment was to investigate the levels of free soluble receptor activator of nuclear factor-kb ligand (sRANKL) in periodontal health and disease and their correlations to clinical parameters and important periodontal pathogens. MATERIAL AND METHODS: Chronic periodontitis (n=35) and periodontally healthy (n=38) subjects participated in the present study. Pocket depth, recession and bleeding index were recorded at a total of 221 sites. Subgingival plaque samples from these sites were analysed for the levels of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola. Gingival crevicular fluid samples were analysed with ELISA for levels of free sRANKL. Comparisons between groups were performed by applying non-parametric tests (Mann-Whitney) and correlations among parameters were sought for with Spearman's r coefficient. RESULTS: Mean levels of free sRANKL were higher in periodontitis subjects and correlated significantly with mean counts of T. denticola on the subject level and P. gingivalis, T. denticola on the site level (Spearman's r coefficient, p<0.05), but not with clinical parameters. No correlations were found between the levels of free sRANKL and investigated parameters in periodontally healthy individuals. No effect of smoking was found on investigated parameters and correlations (univariate analysis of variance and pairwise comparisons). CONCLUSIONS: Findings from the present study suggest a correlation of levels of sRANKL with important pathogens in periodontitis patients.

Real-time polymerase chain reaction quantification of Epstein--Barr virus in chronic periodontitis patients.

BACKGROUND: Although herpes viruses have been implicated in the pathogenesis of chronic and aggressive periodontitis, few data in the literature refer to quantification of these viruses in periodontal sites, especially in relation to serological findings. OBJECTIVE: The aim of the present study was to compare Epstein--Barr virus (EBV) DNA load in subgingival specimens from chronic periodontitis patients and in periodontally healthy subjects, in relation to serologic testing of IgM and IgG antibodies to EBV. METHODS: A total of 22 chronic periodontitis patients and 13 controls participated in the present study. Seventy-nine subgingival specimens (one pooled, one from a deep and one from a shallow site), sampled with paper points, were analysed with real-time polymerase chain reaction for EBV. Subjects were also examined for anti-EBV IgG and IgM levels in serum, using an enzyme-linked immunosorbent assay. RESULTS: One subject was seronegative for EBV. Three subjects (one patient and two controls) displayed anti-EBV IgM. Their data were excluded from further analysis. All three displayed EBV in their subgingival samples. Nine out of the remaining 20 chronic periodontitis patients and 10 out of 11 controls did not display EBV subgingivally. A statistically significant difference in viral load was observed between pooled and shallow-pocket samples from periodontitis patients but not between samples from deep and shallow pockets (Kruskall--Wallis anova, Dunn's multiple comparisons test). CONCLUSIONS: Data from the present study do not strongly support the pathogenetic significance of EBV in chronic periodontitis lesions. The data do, however, suggest that parallel serological assessments provide a useful insight into the association of viruses with periodontal disease.

Guided tissue regeneration in intrabony periodontal defects following treatment with two bioabsorbable membranes in combination with bovine bone mineral graft. A clinical and radiographic study.

AIM: Comparison of two bioabsorbable barriers (collagen and polylactic acid (PLA) membranes) combined with a bovine bone mineral (BBM) graft, with an access flap procedure (AFP) alone for treating intrabony defects. MATERIAL AND METHODS: Thirty-four subjects participated in this prospective, controlled clinical trial. Baseline clinical examination (probing depth (PD), clinical attachment level (CAL)) of selected sites was performed 2 months after completion of conservative treatment in conjunction with hard-tissue measurements to ascertain the depth of the defect (cementoenamel junction to the bottom of the defects). After randomly dividing patients into three groups (two membrane groups, one control group), full thickness flaps were elevated and exposed root surfaces planed before filling defects with bone graft and positioning a barrier membrane covering the defect. The control group was treated identically except for the barrier and bone graft placement. Clinical treatment outcomes were finally evaluated 12 months after surgery for changes of PD and CAL. Radiographs at baseline and 12 months were compared using non-standardized digital radiography. RESULTS: A mean reduction in PD value of 5.08 mm and mean CAL gain of 4.39 mm occurred in the collagen-BBM group. Corresponding values for the PLA-BBM group were 4.72 and 3.71 mm, while access flap procedure (AFP) sites produced values of 2.50 and 2.43 mm. All improvements in clinical parameters were statistically significant (p<0.001) within groups for all variables. Both membranes produced statistically greater PD reduction and CAL gain compared with AFP treatment (p<0.05). Comparison between barrier groups failed to reveal any statistically significant difference in probing pocket depth reduction (p=0.56) or in CAL gain (p=0.34). CONCLUSION: Placement of the two barrier membranes used in the present study in combination with BBM graft significantly improved clinical and radiographic parameters of deep intrabony pockets and proved superior to access flap alone.