Evaluation of the efficacy of green tea catechins as an adjunct to scaling and root planing in the management of chronic periodontitis using PCR analysis: A clinical and microbiological study

Application of Natural Medicinal Plants Active Ingredients in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant cancer of the head and neck, with high morbidity and mortality, ranking as the sixth most common cancer in the world. The treatment of OSCC is mainly radiotherapy, chemotherapy and surgery, however, the prognosis of patients is still poor and the recurrence rate is high. This paper reviews the range of effects of natural medicinal plant active ingredients (NMPAIs) on OSCC cancer, including the types of NMPAIs, anti-cancer mechanisms, involved signaling pathways, and clinical trials. The NMPAIs include terpenoids, phenols, flavonoids, glycosides, alkaloids, coumarins, and volatile oils. These active ingredients inhibit proliferation, induce apoptosis and autophagy, inhibit migration and invasion of OSCC cells, and regulate cancer immunity to exert anti-cancer effects. The mechanism involves signaling pathways such as mitogen-activated protein kinase, phosphatidylinositol 3 kinase/protein kinase B, nuclear factor kappa B, miR-22/WNT1/β-catenin and Nrf2/Keap1. Clinically, NMPAIs can inhibit the growth of OSCC, and the combined drug is more effective. Natural medicinal plants are promising candidates for the treatment of OSCC.

Phytotherapy in periodontics as an effective and sustainable supplemental treatment: a narrative review

PURPOSE

Periodontal disease is a chronic condition caused by microbial infection and mediated by the host's immune response. Phytotherapy is a therapeutic approach that utilizes a renewable resource capable of supplying less expensive medicines for the world's growing population. This review aimed to present clinical evidence on the use of complementary medicinal herbs in the treatment of periodontal diseases.

METHODS

Different databases were searched using the terms "herbal" and "periodontitis." All included studies were examined with a focus on herbal indications, type, and prescription length. Dentists' therapeutic and prophylactic herbal prescribing habits were also assessed.

RESULTS

Various herbs such as turmeric, neem, aloe-vera, pomegranate, catechu, tulsi, cloves, lemon grass, green tea, tea tree oil, peppermint, garlic, pineapple, oak bark, babul, bakul, sage, coriander, moringa, amla, guava, and grape seed extract have been used in the treatment of periodontitis. These herbs have been reported to exhibit a range of therapeutic effects, including anti-inflammatory, antiplaque, antihalitosis, antiresorptive, antioxidant, antibacterial, antifungal, antiviral, and antimicrobial properties. These components can be utilized in various forms such as mouth rinse, gel, oil, toothpaste, aqueous extract, mouthwash, or tooth powder.

CONCLUSIONS

Several readily available herbal formulations are now available on the market and have been shown to be effective as supplemental periodontal phytotherapy. However, these should be used under the supervision of a dental professional to ensure optimal benefits and effectiveness. Therefore, it is necessary to improve the understanding of suggested herbal prescription practices among dental professionals.

Antioxidant, anti-inflammatory and antimicrobial activity of natural products in periodontal disease: a comprehensive review

Periodontal diseases (PD) are common chronic inflammatory oral pathologies that are strongly linked to others not found in the mouth cavity. The immune system mediates the host response, which includes the upregulation of proinflammatory cytokines, metalloproteinases, and reactive oxygen species (ROS); the latter may play an important role in the establishment and progression of inflammatory diseases, particularly periodontal disease, via the development of oxidative stress (OS). Natural antioxidants have powerful anti-inflammatory properties, and some can reduce serum levels of key PD indicators such tumor necrosis factor (TNF) and interleukin IL-1. This review compiles, through a thorough literature analysis, the antioxidant, anti-inflammatory, and antibacterial effects of a variety of natural products, as well as their therapeutic potential in the treatment of PD.

Green Alternatives as Antimicrobial Agents in Mitigating Periodontal Diseases: A Narrative Review

Periodontal diseases and dental caries are the most common infectious oral diseases impacting oral health globally. Oral cavity health is crucial for enhancing life quality since it serves as the entranceway to general health. The oral microbiome and oral infectious diseases are strongly correlated. Gram-negative anaerobic bacteria have been associated with periodontal diseases. Due to the shortcomings of several antimicrobial medications frequently applied in dentistry, the lack of resources in developing countries, the prevalence of oral inflammatory conditions, and the rise in bacterial antibiotic resistance, there is a need for reliable, efficient, and affordable alternative solutions for the prevention and treatment of periodontal diseases. Several accessible chemical agents can alter the oral microbiota, although these substances also have unfavorable symptoms such as vomiting, diarrhea, and tooth discoloration. Natural phytochemicals generated from plants that have historically been used as medicines are categorized as prospective alternatives due to the ongoing quest for substitute products. This review concentrated on phytochemicals or herbal extracts that impact periodontal diseases by decreasing the formation of dental biofilms and plaques, preventing the proliferation of oral pathogens, and inhibiting bacterial adhesion to surfaces. Investigations examining the effectiveness and safety of plant-based medicines have also been presented, including those conducted over the past decade.

Effect of Green Tea on the Level of Salivary Interleukin-1 Beta in Patients with Chronic Periodontitis: A Randomized Clinical Trial

Aim

Interleukin-1 beta (IL-1β) is one of the major biomarkers involved in the pathogenesis of chronic periodontitis. The aim of this study was to evaluate the changes in salivary IL-1β concentration in patients with chronic periodontitis following daily consumption of green tea.

Methods and Materials

Thirty patients with an average age of 45.8 years suffering from chronic periodontitis were randomly assigned into 2 groups (i.e., experimental and control groups). Besides receiving phase 1 periodontal treatment (scaling and root planning (SRP)), the experimental group drank green tea for a period of 6 weeks. To measure the concentration of salivary IL-1β, saliva samples were taken from both groups at 2 time points, i.e., prior to SRP (time point 1 (T0)) and after 6 weeks (time point 2 (T1)). The nonparametric Wilcoxon test was used to examine and compare the changes in the concentration of salivary IL-1β in each group relevant to the 2 time points (T0 and T1). Data were submitted to statistical analysis.

Results

At the end of the study period, a significant reduction (P=0.0001) in the concentration of salivary IL-1β was observed in the experimental group (A). As for the control group (B), however, there was no significant change (P=0.307) in the concentration of salivary IL-1β after 6 weeks following phase 1 periodontal treatment.

Conclusion

Green tea supplementation, in addition to SRP, may reduce salivary IL-1β levels in patients with chronic periodontitis for a period of 6 weeks.

The effect of (-)-epigallocatechin gallate as an adjunct to non-surgical periodontal treatment: a randomized clinical trial

Background

EGCG is proven to be of good effect to relieve periodontal inflammation, but it has not been applied as a local delivery medicine in patients with periodontitis widely. The aim of this clinical trial was to evaluate the adjunctive effect of (-)-epigallocatechin gallate (EGCG) aqueous solution as a coolant during scaling and root planing in the management of chronic periodontitis.

Methods

A double-blind, randomized controlled study was performed on 15 patients with moderate to severe chronic periodontitis. The bilateral maxillary teeth were randomly divided into the test side and the control side on every individual. On the control side, the periodontal therapy was routinely performed. And on the test side, in the process of periodontal therapy, the distilled water in the ultrasonic scaler was replaced with a 5-mg/mL EGCG solution. The probing depth (PPD), clinical attachment level (CAL), bleeding index (BI), gingival index (GI), and plaque index (PI) were recorded at baseline and 6 and 12 weeks after the treatment.

Results

PPD, CAL, BI, GI, and PI generally improved after treatment in both groups. At the sixth week and the twelfth week of review, PPD, CAL, GI, and PI had no statistical difference (p >0.05) between the two groups. At the review of the twelfth week, BI on the test side decreased significantly (p <0.05).

Conclusions

Using EGCG solution as the irrigant instead of water has an additional benefit on the bleeding index at the 12-week review. However, the rest clinical parameters had no additional benefit.

Trial registration

ClinicalTrials.gov ChiCTR2000029831, date of registration: Feb 15, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06298-6.

Impact of Green Tea (Camellia Sinensis) on periodontitis and caries. Systematic review and meta-analysis

Background

The oral health-promoting effects of green tea are attributed to its polyphenol components. Aim of this work was to systematically review the literature in search for clinical trials assessing green tea for managing periodontitis and caries.

Methods

Randomized clinical trials comparing the efficacy of green tea versus control groups in oral hygiene and gingival health; periodontitis; caries; periodontal pathogens number; Streptococcus mutans, Lactobacillus spp. Meta-analysis and meta-regression analysis were performed.

Literature searches were carried out using MedLine (PubMed), Scopus, and the Cochrane Library. Eighteen studies (870 subjects) were included.

Results

Green tea treatment had medium positive effect size in reducing GI (SMD: 0.50; 95%CI: −0.02/1.01); PI (SMD: 0.54; 95%CI: 0.14/0.95); GBI (SMD: 0.58; 95%CI: −0.41/1.56) and BOP (SMD: 0.52; 95%CI: −0.57/1.60) in respect to the control group. Splitting to subgroups, green tea showed a small negative effect in the chlorhexidine control groups. Green tea treatment had medium positive effect size in reducing CAL (SMD 0.58; 95%CI: −0.49/1.65) and large positive effect size in reducing PPD (SMD:1.02; 95%CI: 0.45/1.59).

Conclusion

Even if the results are encouraging, there is insufficient evidence to recommend the use of green tea formulation as first choice treatment for gingivitis, periodontitis and caries.

Different applications forms of green tea (Camellia sinensis (L.) Kuntze) for the treatment of periodontitis: a systematic review and meta-analysis

BACKGROUND

Scaling and root planning (SRP) is the gold standard for non-surgical periodontal treatment. Green tea as a supporting alternative in non-surgical periodontal treatment has been suggested as a therapeutic option in the treatment of periodontitis.

OBJECTIVE

To analyse the comparative effectiveness of green tea (Camellia sinensis) in its different forms and applications for the treatment of periodontitis.

METHODS

We included randomized clinical trials evaluating green tea as an adjuvant therapeutic agent to scaling and root planning (SRP) in the treatment of periodontitis. For the meta-analysis, we calculated standardized mean difference (SMD) and 95%CI comparing green tea and control (only SRP). We subgrouped by types of application forms of green tea. The certainty of the evidence was assessed through GRADE.

RESULTS

Nine studies were included. The follow-up time of treatments varied from 21 days to 6 months. The subgroup meta-analysis showed that the green tea as sachet reduced probing bleeding (SMD = -0.71; 95%CI) and the gingival index (SMD = -0.78; 95%CI) compared to SRP with very low certainty of evidence. The sachet (SMD = -0.29; 95%CI) and dentifrice (SMD = -1.31; 95%CI) reduced plaque index with very low certainty compared to the control. All forms of application of green tea showed very low certainty of evidence (SMD = -0.27; 95% CI) in reducing the probing depth, as well as for the loss of clinical insertion (SMD = -0.42; 95% CI) with low certainty of evidence.

CONCLUSION

There was not a difference in the effectiveness of green tea isolated or in combination with SRP to reduce probing depth. Green tea adjunct to periodontal therapy showed very low certainty of effectiveness for the treatment of periodontal disease.

Assessment of benzyl isothiocyanate as an adjunct to conventional periodontal therapy

Background:

Conventional nonsurgical periodontal therapy eliminates the pathogenic microbes, yet residual deposits promote the recurrence of the disease. As antimicrobials may pose undesirable effects, alternate therapies are probed.

Aim:

The aim of the study is to evaluate the efficacy of locally delivered benzyl isothiocyanate (BITC) as an adjunct to scaling and root planing to treat patients with chronic periodontitis.

Materials and Methods:

The study included 30 patients diagnosed with chronic periodontitis. Test (scaling and root planing along with BITC intervention) and control (scaling and root planing) sites were randomly assigned to each patient. These sites were in the contralateral quadrants, having a probing depth of 4–6 mm. The plaque index (PI), gingival index (GI), pocket probing depth (PPD), clinical attachment level (CAL), and microbial load (colony forming unit [CFU]) were assessed at baseline, 1-week, and 6-week time interval. Data were analyzed by ANOVA/Friedman test, Mann–Whitney U-test, pairwise paired t-test, and Wilcoxon test, with P ≤ 0.05 set as statistically significant.

Results:

The scores of PI, GI, PPD, and CAL from baseline to 6-week follow-up within both the test and control sites were noted to be statistically significant (P < 0.0001). The CFU showed a significant reduction (P = 0.0229) within the test site at varying time intervals. The change in the mean PI score from baseline to 6-week time interval between the test and control site was noted to be statistically significant (P = 0.0039).

Conclusion:

The local application of BITC chips effectively reduced the PI, GI, PPD, and CFU, subsequently with the gain in CAL, and improved the tissue integrity and thereby oral hygiene.

Efficacy of (-)-epigallocatechin gallate delivered by a new-type scaler tip during scaling and root planing on chronic periodontitis: a split-mouth, randomized clinical trial

Background

(−)-Epigallocatechin Gallate (EGCG) as green tea catechins possessed antibacterial and anti-inflammatory effects on periodontal disease. This study was designed to evaluate the clinical and microbiological efficacy of scaling and root planing (SRP) using EGCG aqueous solution as coolants through a new-type ultrasonic scaler tip on chronic periodontitis.

Methods

This split-mouth, randomized clinical trial included 20 patients (2 drop-outs) with chronic periodontitis and the maxillary contra-lateral sides were allocated into test and control groups randomly. Through the new-type scaler tip, 762 sites with probing depth (PD) ≥ 4 mm were treated by SRP using EGCG solution or distilled water as coolants respectively. Clinical parameters and red complex pathogens in subgingival microbiome were evaluated at baseline, 3 and 6 months after treatments.

Results

During 6 months, the SRP plus EGCG medication contributed to additional PD reduction as 0.33 mm and gain of clinical attachment level as 0.3 mm compared with SRP alone, and approximate 8% more sites obtained PD reduction ≥ 2 mm (p < 0.05). Meanwhile, the mean relative abundance of Tannerella forsythia was significantly lower in the combined treatment group (p < 0.05).

Conclusion

The purified EGCG showed the potential to improve the outcome of periodontal non-surgical treatment and the new-type scaler tip provided an alternative vehicle for subgingival medication.

Trial registration The trial was registered in Chinese Clinical Trial Registry on 15 February 2020 (No.: ChiCTR2000029831, retrospectively registered). http://www.chictr.org.cn/showprojen.aspx?proj=49441.

[Research progress on the regulation of phenolic compounds of traditional Chinese herbs on oral microbes]

Phenolic compounds are widely found in natural Chinese medicinal plants and have excellent pharmacological properties, such as antioxidation and anti-inflammation. They are the main pharmacological components of many medicinal Chinese herbs. Oral microbiota, especially its composition and metabolism, is highly related to the balance of oral microecology and plays a key role in the occurrence and development of oral diseases. Recent studies have shown that phenolic compounds of traditional Chinese herbs can prevent and treat oral diseases, such as caries, periodontal disease, and oral mucosal infection, by regulating the composition, metabolites, and virulence of oral microorganisms. This review will summarize and discuss the regulation of phenolic compounds on oral microbes.

Influence of adjuvant therapy with green tea extract in the treatment of experimental periodontitis

AIM

This study evaluated the effects of topical green tea extract solution (GTE) as adjuvant therapy to mechanical debridement for the treatment of experimental periodontitis (EP).

MATERIAL AND METHODS

We used 120 male rats (Rattus norvegicus albinus - Wistar), divided into the following four groups: NEP (sham) (n = 30): no experimental periodontitis (NEP), only simulation of EP by installation and removal of a ligature; EP (n = 30): EP induction by ligature; SRP (n = 30): EP, scaling and root planing (SRP), and irrigation with physiological saline solution; SRP/GT (n = 30): EP, SRP, and irrigation with GTE. Histologic analysis and immunohistochemistry were performed for detection of interleukin (IL)1ß, tumor necrosis factor-alpha (TNF-α), IL-10, and anti-tartrate resistant acid phosphatase (TRAP) in the furcation area. The percentage of bone in the furcation (PBF) was considered the primary variable and evaluated at 14, 22, and 37 days. The data from the histological analysis and the IL- 1B, TNF- A, and IL-10 were submitted to a Kruskal-Wallis variance test and Dunn's posttest (p ≤ 0.05). The histometric data and TRAP were submitted to analysis of variance (ANOVA) and Tukey's posttest (p ≤ 0.05).

RESULTS

The SRP/GT group showed lower inflammatory process, lower immunolabeling pattern of IL-1ß and TNF-α, and greater immunolabeling pattern of IL-10 compared with the EP and SRP groups at 22 days. Fewer TRAP-positive multinucleated osteoclasts were observed in all periods in the SRP/GT group (5.22 ± 0.65; 7.33 ± 0.80; 8.55 ± 1.15) compared with the SRP group (30.67 ± 8.55; 13.22 ± 0.77; 13.87 ± 0.77). Higher PBF was observed in all periods in the SRP/GT group (74.65 ± 7.14; 76.61 ± 5.36; 79.24 ± 3.75) compared with the SRP group (61.60 ± 9.48; 54.84 ± 9.06; 53.25 ± 9.66).

CONCLUSION

GTE adjuvant to SRP reduced inflammation, osteoclastic activity, and alveolar bone loss in EP.

The effect of green tea as an adjunct to scaling and root planing in non-surgical periodontitis therapy: a systematic review

OBJECTIVE

To provide a systematic overview on the efficacy of green tea catechin as an adjunct to scaling and root planing (SRP) in terms of probing pocket depth (PPD).

MATERIALS AND METHODS

A systematic literature search was performed using electronic databases in PubMed, Scopus, Medline, Cochrane, CINAHL, and Web of Science on randomized clinical trials up to January 2017. The research question was posed in accordance with PRISMA guidelines.

RESULTS

The search provided 234 studies. After analyzing the full texts, five studies were included, with four studies qualifying for meta-analysis. Mean PPD reduction was significantly higher (α = 0.05) when green tea catechin was used as an adjunct to SRP (test group) than with SRP alone (control group). The difference in the reduction was 0.74 mm [0.35-1.13; 95% CI].

CONCLUSION

The local application of green tea catechin as an adjunct to SRP may result in a beneficial reduction in PPD. Due to the highly heterogeneous data and some risk of bias, however, this data still needs to be interpreted with caution.

CLINICAL RELEVANCE

The finding suggests that green tea catechin may be a topical adjunct to SRP without negative side effects.

The Effect of Ultrasound, Oxygen and Sunlight on the Stability of (-)-Epigallocatechin Gallate

(-)-Epigallocatechin gallate (EGCG), is the main catechin found in green tea, and has several beneficial effects. This study investigated the stability of EGCG aqueous solution under different stored and ultrasonic conditions to determine whether it can be used with an ultrasonic dental scaler to treat periodontal infection. Four concentrations (0.05, 0.1, 0.15, 2 mg/mL) of EGCG aqueous solution were prepared and stored under four different conditions (A: Exposed to neither sunlight nor air, B: Exposed to sunlight, but not air, C: Not exposed to sunlight, but air, D: Exposed to sunlight and air) for two days. The degradation rate of EGCG was measured by high performance liquid chromatography (HPLC). On the other hand, an ultrasonic dental scaler was used to atomize the EGCG solution under four different conditions (a: Exposed to neither air nor sunlight, b: Not exposed to air, but sunlight, c: Not exposed to sunlight, but air, d: Exposed to air and sunlight), the degradation of EGCG was measured by HPLC. We found that the stability of EGCG was concentration-dependent in water at room temperature. Both sunlight and oxygen influenced the stability of EGCG, and oxygen had a more pronounced effect on stability of EGCG than sunlight. The most important conclusion was that the ultrasound may accelerate the degradation of EGCG due to the presence of oxygen and sunlight, but not because of the ultrasonic vibration. Thus, EGCG aqueous solution has the potential to be used through an ultrasonic dental scaler to treat periodontal infection in the future.

Impact of green tea intake on clinical improvement in chronic periodontitis: A randomized clinical trial

PURPOSE

To investigate the effects of daily consuming of green tea on clinical criteria in Periodontitis.

METHODS

Thirty patients with chronic periodontitis were randomly divided into control and experimental groups after scaling and root planning (SRP). Experimental group consumed green tea herbal for 6 weeks and the control group received no intervention. Clinical indices were measured before and 6 weeks after the intervention, and compared for each groups by non-parametric Wilcoxon test and between two groups by Man-Witheny test. Significance level of the test was considered at 95%.

RESULTS

The results showed that probing depth (PD) and bleeding index (BI) reduced significantly in both groups before and after SRP, this reduction in the intervention group was higher than the control group (P=0.003 and 0.031, respectively). On the other hand, reducing the amount of plaque index (PI) despite being significant in each group, was not significant between the two groups (P=0.135).

CONCLUSIONS

According to the results of this study, daily consumption of green tea herbal can have a positive impact on the treatment of periodontal diseases and can be applied as a supplement for improving the effects of phase I periodontal therapy.

Effect of Green Tea Varnish on Depth of Root Caries

AIM

Root caries is a common, debilitating condition particularly in the elderly population, which can lead to tooth loss. Evidence shows that green tea has cariostatic effects. Considering the gap of information on green tea varnish, this study aimed to assess the efficacy of green tea varnish in the prevention of root caries.

MATERIALS AND METHODS

This in vitro experimental study was performed on 42 sound premolars. Two layers of acid-resistant nail varnish were applied on root surfaces except for a window of 1 × 4 mm. The teeth were randomly divided into three groups (n = 14). Group I (control) received no intervention. Group II received green tea varnish applied on the roots every 48 hours for 21 days. Group III received green tea varnish every 24 hours for 21 days. Sections of 40 μ thickness were prepared from the center of the window, and the depth of carious lesion was measured in three points with 500 μ distance from each other using polarized light microscope. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 16 and non-parametric Kruskal-Wallis and Mann-Whitney U tests (α = 0.05).

RESULTS

The mean (and standard deviation) depth of carious lesion was 54.30 ± 28.64 (μm), 0, and 0 in groups I, II, and III respectively. Control group showed the highest depth of caries. Groups II and III were not significantly different in this respect, but significant differences were noted in depth of caries between groups I and II and also groups I and III (p < 0.001).

CONCLUSION

Based on the results, the green tea varnish may possess anticariogenic effects on root caries when applied every 24 or 48 hours over a 21-day period. Application of green tea varnish every 24 or 48 hours for 21 days may prevent root caries.

CLINICAL SIGNIFICANCE

Application of green tea varnish can prevent root caries.

Clinical Evaluation of Effects of Local Application of Aloe vera Gel as an Adjunct to Scaling and Root Planning in Patients with Chronic Periodontitis

STATEMENT OF THE PROBLEM

Aloe vera gel contains various components with antibiotic and anti-inflammatory characteristics, which may have potential advantages to treat periodontal diseases.

PURPOSE

The aim of this study was to evaluate the effects of local application of aloe vera gel as an adjunct to scaling and root planning in the treatment of patients with chronic periodontitis.

MATERIALS AND METHOD

This single-blind clinical trial, performed in a split mouth design, was conducted on 20 patients with moderate to severe chronic periodontitis. Following a baseline examination at first day which included the assessments of plaque index (PI), gingival index (GI), and probing depth (PD); patients randomly received either SRP in one quadrant (control group), or SRP combined with aloe vera gel in another quadrant (experimental group). All cases were examined again, assessing PI, GI, and PD at 30^th and 60^th day.

RESULTS

There was no significant difference in PI in the three stages between control and experimental groups. In all patients, there was a significant improvement in the three stages in GI and PD for both quadrants treated only with SRP or combination of SRP and aloe vera. However, experimental group presented significantly lower GI (p= 0.0001) and PD (p= 0.009) than the control group at the end of study period.

CONCLUSION

This study revealed that local application of aloe vera gel could be considered as an adjunctive treatment with scaling and root planning for chronic periodontitis.

Excessive Consumption of Green Tea as a Risk Factor for Periodontal Disease among Korean Adults

This study was performed to assess the relationship between the amount of green tea that is consumed and periodontitis. It is based on data obtained from the Korea National Health and Nutrition Examination Survey, conducted between 2008 and 2010. A community periodontal index equal to code 3 was defined as moderate periodontitis, and code 4 was defined as severe periodontitis (n = 16,726). Consumption of green tea less than one cup per day was associated with a decreased prevalence of periodontal disease among Korean adults. The association between the consumption of green tea and periodontal disease was independent of various potential confounding factors, such as age, sex, body mass index, smoking, drinking, exercise, metabolic syndrome, frequency of tooth brushing per day, use of secondary oral products, the number of dental examination per year, diabetes, hypertension, and white blood cell count. Adjusted odds ratio and 95% confidence interval of no consumption was 1.360 (1.156, 1.601) when participants with consumption of two times per week ≤ x < 7 times per week was considered as a reference. However, consumption of one or more cups per day increased the prevalence of moderate and severe periodontitis. In conclusion, excessive consumption of green tea may be considered as a risk factor for periodontal disease among Korean adults.

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

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).

Strategies for the inhibition of gingipains for the potential treatment of periodontitis and associated systemic diseases

Gingipains are the major virulence factors of Porphyromonas gingivalis, the main periodontopathogen. It is expected that inhibition of gingipain activity in vivo could prevent or slow down the progression of adult periodontitis. To date, several classes of gingipain inhibitors have been recognized. These include gingipain N-terminal prodomains, synthetic compounds, inhibitors from natural sources, antibiotics, antiseptics, antibodies, and bacteria. Several synthetic compounds are potent gingipain inhibitors but inhibit a broad spectrum of host proteases and have undesirable side effects. Synthetic compounds with high specificity for gingipains have unknown toxicity effects, making natural inhibitors more promising as therapeutic gingipain blockers. Cranberry and rice extracts interfere with gingipain activity and prevent the growth and biofilm formation of periodontopathogens. Although the ideal gingipain inhibitor has yet to be discovered, gingipain inhibition represents a novel approach to treat and prevent periodontitis. Gingipain inhibitors may also help treat systemic disorders that are associated with periodontitis, including cardiovascular disease, rheumatoid arthritis, aspiration pneumonia, pre-term birth, and low birth weight.