Effect of Periodontal Ligament Stem Cells-Derived Conditioned Medium on Gene Expression and Differentiation of Tumor Necrosis Factor-α-Challenged Osteoblasts.

OBJECTIVES: Tumor necrosis factor-α (TNF-α) causes bone resorption in periodontitis. It induces the production of receptor activator of NF-κB ligand (RANKL) from osteoblasts, leading to the disturbance of bone homeostasis through RANKL, RANK, and osteoprotegerin (OPG) axis. This study aimed to explore the effect of periodontal ligament stem cells-derived conditioned medium (PDLSCs-CM) on gene expression related to bone homeostasis and the differentiation of TNF-α-challenged osteoblasts. MATERIALS AND METHODS: Human osteoblasts were cultured with 50 ng/mL of TNF-α and 0, 1, 10, and 100 µg/ mL of PDLSCs-CM. Osteoblasts cultured without TNF-α and PDLSCs-CM were served as control. Gene expression of RANKL, OPG, and interleukin-1ß (IL-1ß) was evaluated by reverse transcription quantitative polymerase chain reaction at 48 hours. The early-stage and late-stage differentiation of TNF-α-challenged osteoblasts without or with PDLSCs-CM was explored by alkaline phosphatase (ALP) activity and alizarin red staining, respectively, at day 1, 3, 6, 9, and 12. STATISTICAL ANALYSIS: Mann-Whitney U test was used to analyze the differences in gene expression of TNF-α-challenged osteoblasts at 24 and 48 hours, and Kruskal-Wallis test was used to analyze the effect of PDLSCs-CM on gene expression and ALP activity among all experimental groups using SPSS software version 21.0. Statistical significance was considered with p-value less than 0.05. RESULTS: Expression of RANKL, OPG and IL-1ß was significantly upregulated in TNF-α-challenged osteoblasts compared to the untreated control. The PDLSCs-CM at 1 and 10 µg/mL downregulated gene expression of TNF-α-challenged osteoblasts compared to the group without PDLSCs-CM, but the difference did not reach statistical significance. The ALP activity was decreased in TNF-α-challenged osteoblasts. The addition of PDLSCs-CM did not alter ALP activity of TNF-α-challenged osteoblasts. Alizarin red staining was comparable in the TNF-α-challenged osteoblasts cultured without or with PDLSCs-CM. CONCLUSIONS: The PDLSCs-CM did not alter gene expression involved in bone homeostasis and differentiation of TNF-α-challenged osteoblasts.

Effect of Vitamin C as an Adjunct in Nonsurgical Periodontal Therapy in Uncontrolled Type 2 Diabetes Mellitus Patients.

OBJECTIVE: The main purpose of this article is to evaluate periodontal parameters of chronic periodontitis patients with uncontrolled type 2 diabetes mellitus after initial periodontal therapy plus vitamin C. MATERIALS AND METHODS: A double-blind, placebo-controlled, clinical trial was conducted. Subjects received initial periodontal therapy plus 500 mg/day vitamin C for 2 months (n = 15) or placebo (n = 16). Fasting blood sugar (FBS), hemoglobin A1c (HbA1C), and plasma vitamin C level were assessed at baseline and 2 months post-treatment. Plaque Index, Sulcus Bleeding Index, Gingival Index, pocket depth, and clinical attachment level were measured at baseline, 1 month, and 2 months post-treatment. RESULTS: Almost all subjects had low level of plasma vitamin C at baseline. In the test group, plasma vitamin C was significantly increased to an adequate level at the end of 2 months. After periodontal treatment, FBS and HbA1c were not significantly different compared with baseline in the test group. In the control group, FBS was significantly decreased from baseline. However, no significant difference between groups was found either in FBS or HbA1c. All periodontal parameters were significantly improved from baseline in both groups. However, no significant difference was found between groups. CONCLUSION: Supplementation of 500 mg/day vitamin C did not give an additional benefit in promoting periodontal status in periodontitis patients with uncontrolled type 2 diabetes mellitus.

In vitro effect of diode laser against biofilm of Aggregatibacter actinomycetemcomitans.

OBJECTIVE: The main objective is to investigate the antibacterial effect of diode laser against Aggregatibacter actinomycetemcomitans biofilm. MATERIALS AND METHODS: Biofilms of A. actinomycetemcomitans plus Streptococcus sanguinis grown on bovine root surfaces were treated with an 810-nm diode laser using a noncontact pulsed mode with a pulse interval and pulse length of 20 ms. Four protocols, that is, one episode of 1.5 or 2.5 W for 30 s and three episodes of 1.5 or 2.5 W for 30 s were tested. No treatment and 0.2% chlorhexidine treatment served as negative and positive controls, respectively. Viable bacterial number was determined by colony counting. RESULTS: Treatment with chlorhexidine and all laser protocols except that using single episode of 1.5 W reduced the number of A. actinomycetemcomitans in either single-species or dual-species biofilm compared to negative control. A higher percentage of A. actinomycetemcomitans reduction was demonstrated after increasing the power output or repeating the irradiation. CONCLUSIONS: The laser protocols used in this study could reduce the number of viable bacteria but not eradicate A. actinomycetemcomitans biofilm.

Platelet-rich plasma stimulated proliferation, migration, and attachment of cultured periodontal ligament cells.

OBJECTIVE: The aim of this study is to evaluate the effects of platelet-rich plasma (PRP) on the proliferation, migration, and attachment of cultured periodontal ligament (PDL) cells. MATERIALS AND METHODS: 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess number of PDL cells cultured in medium with or without PRP. Cell migration toward medium with or without PRP was assessed using the Boyden chamber. Cell attachment was assessed by counting cells on PRP or non-PRP coated dentin specimens. Group differences were analyzed using two-way ANOVA at 0.05 significance level. RESULTS: In the MTT and cell migration assay, the number of cells in 5% and 10% PRP-treated groups were significantly higher than that in the non-PRP-treated group (P < 0.05). In the attachment assay, the number of cells on the dentin specimens in 10% PRP-treated group was significantly higher than that in the non-PRP treated group (P < 0.05). CONCLUSION: PRP could stimulate proliferation, migration, and attachment of PDL cells.

Long-term outcome following regenerative periodontal treatment of intrabony defects.

This study aimed to evaluate the long-term outcome of the regenerative periodontal therapy of an intrabony defect in terms of tooth survival and clinical attachment level (CAL) stability. The association between failure and patient as well as tooth variables was assessed. Treatment records of the patients who received regenerative surgery and re-evaluation at 1-year post-surgery were screened. Patient and tooth variables, defect characteristics, and types of treatments were collected. Periodontal parameters were retrieved before regenerative surgery (baseline), 1-year post-surgery, and every visits of supportive periodontal treatment (SPT) until failure, including tooth loss or CAL loss ≥2 mm was found. In this study, treatment records from 89 patients were included. These patients continued SPT from 0.5-11.16 years. Of these patients, 92.1 % survived from tooth loss, while 61.8 % survived from CAL loss ≥2 mm compared to 1-year post-surgery. At the sites with residual pocket depth <5 mm, patients attending SPT >80 % had a significantly less percentage of teeth with CAL loss ≥2 mm compared to 1-year post-surgery than those attending SPT <80 %. However, at the sites with residual pocket depth ≥5 mm, no significant difference in the percentage of teeth with CAL loss ≥2 mm was found between patients attending SPT >80 % or <80 %. Smoking, patient's compliance, and residual pocket depth after regenerative surgery were significantly associated with tooth loss. However, these factors were not significantly associated with CAL loss compared to baseline or 1-year post-surgery.

Clinical effect of locally delivered gel containing green tea extract as an adjunct to non-surgical periodontal treatment.

UNLABELLED: Green tea catechins had an in vitro antibacterial effect against periodontopathic bacteria and were able to inhibit destruction of the periodontal tissue. In this study, we aimed to evaluate the effect of locally delivered gel containing green tea extract as an adjunct to non-surgical periodontal treatment. Forty-eight subjects who had teeth with probing pocket depth of 5-10 mm were randomly allocated into the test or control group. Probing pocket depth, clinical attachment level, gingival index (GI), bleeding on probing (BOP) and full mouth plaque score were measured at baseline. Subjects received oral hygiene instruction, single episode of scaling and root planing and subgingival application of the green tea gel (test group) or the placebo gel (control group). The gel was repeatedly applied at 1 and 2 weeks later. The parameters were recorded again at the 1st, 3rd and 6th month after the last gel application. The results showed that all parameters were improved in both groups compared to baseline. The test group exhibited significantly higher reduction in BOP at the 3rd month (p = 0.003) and significantly lower GI at the 1st month (p < 0.001) and 3rd month (p < 0.001) when compared with the control group. Thus, green tea gel could provide a superior benefit in reducing bleeding on probing and gingival inflammation when used as an adjunct to non-surgical periodontal treatment. ( TRIAL REGISTRATION: MU-IRB 2008/153.0511, ClinicalTrials.gov NCT00918060).

Effect of green tea mouthwash on oral malodor.

This study aimed to determine the effect of green tea mouthwash on oral malodor, plaque, and gingival inflammation. Gingivitis subjects who had over 80 parts per billion of volatile sulfur compounds (VSC) in the morning breath were randomly assigned into green tea or placebo mouthwash group. At baseline, VSC, Plaque Index (PI) and Papillary Bleeding Index (PBI) were recorded. Participants were rinsed with the assigned mouthwash, and VSC level was remeasured at 30 minutes and 3 hours postrinsing. For the following 4 weeks, participants were asked to rinse with the assigned mouthwash twice daily. VSC, PI and PBI were remeasured at day 28. It was found that, at 30 minutes and 3 hours postrinsing, VSC was reduced by 36.76% and 33.18% in the green tea group and 19.83% and 9.17% in the placebo group, respectively. At day 28, VSC was reduced by 38.61% in the green tea group and 10.86% in the placebo group. VSC level in the green tea group was significantly different when compared to the placebo. PI and PBI were significantly reduced in both groups. However, no significant difference was found between groups. In conclusion, green tea mouthwash could significantly reduce VSC level in gingivitis subjects after rinsing for 4 weeks.

Topical application of Garcinia mangostana L. pericarp gel as an adjunct to periodontal treatment.

OBJECTIVE: To evaluate the effects of gel containing Garcinia mangostana L. pericarp extract (GM gel) applied topically as an adjunct to periodontal treatment. DESIGN: Subjects who had periodontal pockets on their single-rooted teeth were randomized into the test or control group. Subjects in the test group received periodontal treatment consisting of scaling, root planing and subgingival application of GM gel while those in the control group received scaling and root planing without GM gel application. SETTING: Mahidol University, Faculty of Dentistry, Thailand. MAIN OUTCOME MEASURES: Clinical parameters included probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), Gingival Index (GI) and Plaque Index (PI). Microbiological parameter included subgingival microbial composition as examined by phase contrast microscopy. RESULTS: Clinical improvement compared to baseline was found in both groups (P < 0.05). The test group exhibited significantly higher reduction in mean PPD, GI and BOP than the control group at the 3rd month after treatment (P < 0.05). Subgingival microbial composition changed from diseased state to that compatible with health after treatment in both groups. However, significant differences between groups were found only in the mean percentage of cocci at the 1st and 3rd month after treatment (P < 0.05). CONCLUSIONS: GM gel could enhance the clinical effects of periodontal treatment.

Effects of herbal mouthwash containing the pericarp extract of Garcinia mangostana L on halitosis, plaque and papillary bleeding index.

OBJECTIVES: To determine the effects of herbal mouthwash containing the pericarp extract of Carcinia mangostana L on volatile sulfur compound (VSC) levels, plaque index (PI) and papillary bleeding index (PBI) in gingivitis subjects and the recurrence of these parameters after periodontal treatment. METHODS: Sixty subjects who were diagnosed as having mild or moderate chronic gingivitis were randomly distributed into herbal or placebo mouthwash groups. On day 1, all parameters were recorded. Subjects rinsed with the assigned mouthwash and VSC was measured at 30 min and 3 h post-rinsing. For the following 2 weeks, subjects practiced their usual oral hygiene and rinsed with the assigned mouthwash twice daily after tooth brushing. On day 15, parameters were recorded. In the 4-week washout period that followed, subjects received scaling and polishing. After another baseline examination, they were re-randomized into the herbal or placebo group and rinsed with mouthwash for 2 weeks. All parameters were re-evaluated on day 15. RESULTS: All parameters were significantly different compared to baseline in both groups at 30 min, 3 h and day 15 (p < 0.05). When compared between groups, VSC was significantly different at day 15 (p < 0.05). After scaling, poloshing and rinsing with mouthwash for 2 weeks, PI and PBI were significantly different compared to baseline (p < 0.05) while VSC was not (p > 0.05). When compared between groups, VSC was significantly different (p < 0.05). CONCLUSION: Herbal mouthwash containing the pericarp extract of G. mangostana may be used as an adjunct in treating oral malodor.

Invasion of Porphyromonas gingivalis into human gingival fibroblasts in vitro.

Porphyromonas gingivalis, one of the important periodontal pathogens, exhibits many virulence properties. Among these, the adhesion to and invasion into host tissues are crucial for the initiation and progression of periodontal diseases. While evidence indicating the ability of this organism to adhere to and invade into epithelial cells as well as endothelial cells has accumulated, that involving the gingival fibroblasts is very limited. Therefore, this study aimed to determine the ability of P. gingivalis to invade primary cultures of human gingival fibroblasts using the antibiotic protection assay. In addition, interactions between P. gingivalis and the gingival fibroblasts were investigated using electron microscopy. The results demonstrated that P. gingivalis 381 could invade human gingival fibroblasts with an invasion efficiency of 0.17%. Using the scanning electron microscopic study, numerous filopodia were seen on the surfaces of gingival fibroblasts after P. gingivalis adhesion. The transmission electron microscopy revealed the presence of an intracellular bacterium. After 90 min incubation, the bacterium was found in the cytoplasm of the gingival fibroblasts, without membrane surrounding. Some fibroblasts contained a number of vacuoles and dilated rough endoplasmic reticulum even when bacteria were not found intracellularly. Thus, the invasion of this organism into the gingival fibroblasts may play a direct role in the destruction of the periodontal tissues and may also relate to the difficulties of eradicating the bacteria from periodontitis lesions.