Local Delivery of Hyaluronan as an Adjunct to Scaling and Root Planing in the Treatment of Chronic Periodontitis

Adjunctive use of hyaluronic acid in the treatment of gingival recessions: a systematic review and meta-analysis

OBJECTIVES

To explore the efficacy of Hyaluronic acid as an adjunctive in treatment of gingival recessions (GR).

MATERIALS AND METHODS

A systematic literature search was performed in several electronic databases, including Medline/ PubMed, Embase, CENTRAL and LILACS. Recession improvement was evaluated through multiple outcome variables. The Cochrane Risk of Bias tool and the ROBINS-I tool were used to assess the quality of the included trials. Weighted Mean Differences (WMDs) and 95% confidence intervals (CIs) between test and control sites were estimated through meta-analysis using a random-effect model for the amount of Relative Root Coverage (RRC).

RESULTS

A total of 3 randomised studies were deemed as eligible for inclusion. Their data were also used for pooling the effect estimates. Overall analysis of RRC (3 studies) presented a WMD of 7.49% (p = 0.42; 95% CIs -10.88, 25.86) in favour of adjunctive use of hyaluronic acid during Coronally Advanced Flap (CAF) technique, although statistical significance was not reached. Statistical heterogeneity was found to be high (I2 = 80%).

CONCLUSIONS

Within their limitations, the present data indicate that the local application of Hyaluronic acid does not lead to additional clinical benefits when used as an adjunctive to the treatment of GR with CAF. However, due to the high heterogeneity among the studies, additional well-designed RCTs are needed to provide further evidence on this clinical indication for the use of Hyaluronic acid.

CLINICAL RELEVANCE

In the frame of the current review, the adjunctive use of Hyaluronic acid does not additionally improve the clinical outcomes obtained during treatment of GR with CAF.

Healing of Periodontal Suprabony Defects following Treatment with Open Flap Debridement with or without Hyaluronic Acid (HA) Application

Background and Objectives: This randomized, double-arm, multicentric clinical trial aims to compare the clinical outcomes following the treatment of suprabony periodontal defects using open flap debridement (OFD) with or without the application of hyaluronic acid (HA). Materials and Methods: Sixty systemically healthy patients with at least two teeth presenting suprabony periodontal defects were randomly assigned with a 1:1 allocation ratio using computer-generated tables into a test (OFD + HA) or control group (OFD). The main outcome variable was clinical attachment level (CAL). The secondary outcome variables were changes in mean probing pocket depth (PPD), gingival recession (GR), full-mouth plaque score (FMPS), and full-mouth bleeding score (FMBS). All clinical measurements were carried out at baseline and 12 months. Results: Sixty patients, thirty in each group, were available for statistical analysis. The mean CAL gain was statistically significantly different (p < 0.001) in the test group compared with the control group (3.06 ± 1.13 mm vs. 1.44 ± 1.07 mm). PPD reduction of test group measurements (3.28 ± 1.14 mm) versus the control group measurements (2.61 ± 1.22 mm) were statistically significant (p = 0.032). GR changes were statistically significant only in the test group 0.74 ± 1.03 mm (p < 0.001). FMBS and FMPS revealed a statistically significant improvement mostly in the test group. Conclusions: Suprabony periodontal defects could benefit from the additional application of HA in conjunction with OFD in terms of improvement of the clinical parameters compared with OFD alone.

Effects of topically administered 0.6% hyaluronic acid on the healing of labial frenectomy in conventional and 940-nm indium gallium arsenide phosphide (InGaAsP) diode laser techniques in pediatric patients: a randomized, placebo-controlled clinical study

This study aimed to investigate the effects of 0.6% hyaluronic acid (HA) gel on the healing process and postoperative pain levels after diode laser-assisted labial frenectomy in pediatric patients. Ninety-six pediatric patients (females, 50 and males, 46) aged 8-14 years were randomly divided into four groups as follows: (1) conventional frenectomy with 0.6% topically administered HA (CFH, n = 24); (2) conventional frenectomy with placebo gel (CFP, n = 24); (3) frenectomy performed by diode laser with 0.6% topically administered HA (DLH, n = 24); and (4) frenectomy performed by diode laser with placebo gel (DLP, n = 24). HA application was continued for 1 week thrice daily after the frenectomy. Visual analog scale forms were collected from patients 1 week after the operation. In addition, the plaque index, gingival index, periodontal probing depth, and keratinized tissue width and thickness were recorded. This process was repeated 1 and 3 months after the first visit. The DLH group revealed significant differences in the probing depth, bleeding on probing, keratinized gingiva width, and attached gingiva width according to dual comparisons of the initial, first, and third-month values (p = 0.010, p = 0.007, p<0.001, and p = 0.001, respectively). Significant differences were observed between the CFP and CFH groups according to the initial and initial third-month values with regard to the bleeding on probing (p=0.019 and p = 0.019, respectively). The attached gingival thickness revealed significant differences between the CFP and CFH groups for the initial and initial-third-month comparisons (p = 0.005 and p = 0.007, respectively). The mean values of the initial and initial-third-month differences were significantly higher in the CFH group than those in the CFP group. HA- and laser-assisted labial frenectomies revealed better outcomes in terms of the probing depth, attached gingiva width, keratinized gingiva width, healing process, and postoperative comfort.

Clinical evaluation of sodium hypochlorite/amino acids and cross-linked hyaluronic acid adjunctive to non-surgical periodontal treatment: a randomized controlled clinical trial

OBJECTIVES

To compare the clinical outcomes obtained with either mechanical subgingival debridement in conjunction with a sodium hypochlorite and amino acids containing gel followed by subsequent application of a cross-linked hyaluronic acid gel (xHyA) gel, or with mechanical debridement alone.

MATERIALS AND METHODS

Fourty-eight patients diagnosed with stages II-III (Grades A/B) generalised periodontitis were randomly treated with either scaling and root planing (SRP) (control) or SRP plus adjunctive sodium hypochlorite/amino acid and xHyA gels (test). The primary outcome variable was reduction of probing depth (PD), while changes in clinical attachment level (CAL), bleeding on probing (BOP) and plaque index (PI) were secondary outcomes. The outcomes were assessed at baseline, at 3 and 6 months following therapy.

RESULTS

All patients completed the 6 months evaluation. At 6 months, the test group showed statistically significantly better results in terms of mean PD reduction (2.9 ± 0.4 vs 1.8 ± 0.6 mm, p < 0.001). Similarly, mean CAL gain was statistically higher in the test group compared to the control one (test: 2.6 ± 0.5 vs control: 1.6 ± 0.6 mm, p < 0.001). Mean BOP decreased from 81.8 ± 16.2% to 48.9 ± 14.5% in control (p < 0.001) and from 83.2 ± 15.5% to 17.6 ± 11.5% in test (p < 0.001) groups with a statistically significant difference favouring the test group (p < 0.001). Mean PI scores were reduced statistically significantly in both groups (from 38.8 ± 26% to 26.5 ± 20.5% in control (p = 0.039) and from 60.6 ± 10.9% to 12.7 ± 8.9% in test group (p < 0.001)), with a statistically significant difference between the groups (p < 0.001). The number of moderate pockets (4-6 mm) were reduced from 1518 (41.2%) to 803 (22.6%) in the control and from 1803 (48.6%) to 234 (7.7%) in the test group with a statistically significant difference between the groups (p < 0.001), while the number of deep pockets (≥ 7 mm) changed from 277 (7.6%) to 35 (1.0%) in the control and from 298 (8.7%) to 4 (0.1%) in test group (p = 0.003).

CONCLUSION

Within their limits the present data indicate that: a) both treatments resulted in statistically significant improvements in all evaluated clinical parameters, and b) the adjunctive subgingival application of sodium hypochlorite/amino acid and xHyA to SRP yielded statistically significantly higher improvements compared to SRP alone.

CLINICAL RELEVANCE

The combination of sodium hypochlorite/amino acid and xHyA gels to subgingival mechanical debridement appears to represent a valuable approach to additionally improve the outcomes of non-surgical periodontal treatment. Clinical Trial Registration Number NCT04662216 (ClinicalTrials.gov).

Supra and subgingival application of antiseptics or antibiotics during periodontal therapy

Periodontal diseases (gingivitis and periodontitis) are characterized by inflammatory processes which arise as a result of disruption of the balance in the oral ecosystem. According to the current S3 level clinical practice guidelines, therapy of patients with periodontitis involves a stepwise approach that includes the control of the patient's risk factors and the debridement of supra and subgingival biofilm. This debridement can be performed with or without the use of some adjuvant therapies, including physical or chemical agents, host modulating agents, subgingivally locally delivered antimicrobials, or systemic antimicrobials. Therefore, the main aim of this article is to review in a narrative manner the existing literature regarding the adjuvant application of local agents, either subgingivally delivered antibiotics and antiseptics or supragingivally applied rinses and dentifrices, during the different steps in periodontal therapy performed in Europe.

The Effect of Hyaluronic Acid Gel on Periodontal Parameters, Pro-Inflammatory Cytokines and Biochemical Markers in Periodontitis Patients

Hyaluronic acid in its various forms shows bacteriostatic, fungistatic, anti-inflammatory, anti-edematous, osteoinductive, and pro-angiogenetic properties. This study aimed to evaluate the effect of subgingival delivery of 0.8% hyaluronic acid (HA) gel on clinical periodontal parameters, pro-inflammatory cytokines (IL-1 beta and TNF-alpha) and biochemical markers of inflammation (C-reactive protein (CRP) and alkaline phosphatase (ALP) enzymes) in patients with periodontitis. Seventy-five patients with chronic periodontitis were divided randomly into three groups (25 in each group): group I received scaling and surface root debridement (SRD) + HA gel; group II received SRD + chlorhexidine gel; and group III received surface root debridement alone. Clinical periodontal parameter measurements and blood samples were collected to estimate pro-inflammatory and biochemical parameters at the baseline before therapy and after two months of therapy. The results show that HA gel has a significant effect on the reduction in clinical periodontal parameters (PI, GI, BOP, PPD, and CAL), IL-1 beta, TNF-alpha, CRP, and ALP after 2 months of therapy as compared to the baseline (p < 0.05) with nonsignificant differences from the CHX group (p > 0.05), except GI (p < 0.05), and significant differences from the SRD group (p < 0.05). Moreover, significant differences were found between the three groups regarding the mean improvements of GI, BOP, PPD, IL-1β, CRP, and ALP. It can be concluded that HA gel has a positive effect on clinical periodontal parameters and improvements in inflammatory mediators similar to chlorhexidine. Therefore, HA gel can be used as an adjuvant to SRD in the treatment of periodontitis.

Oxygen-Releasing Hyaluronic Acid-Based Dispersion with Controlled Oxygen Delivery for Enhanced Periodontal Tissue Engineering

Periodontitis is a chronic biofilm-associated inflammatory disease of the tooth-supporting tissues that causes tooth loss. It is strongly associated with anaerobic bacterial colonization and represents a substantial global health burden. Due to a local hypoxic environment, tissue regeneration is impaired. Oxygen therapy has shown promising results as a potential treatment of periodontitis, but so far, local oxygen delivery remains a key technical challenge. An oxygen (O₂)-releasing hyaluronic acid (HA)-based dispersion with a controlled oxygen delivery was developed. Cell viability of primary human fibroblasts, osteoblasts, and HUVECs was demonstrated, and biocompatibility was tested using a chorioallantoic membrane assay (CAM assay). Suppression of anaerobic growth of Porphyromonas gingivalis was shown using the broth microdilution assay. In vitro assays showed that the O₂-releasing HA was not cytotoxic towards human primary fibroblasts, osteoblasts, and HUVECs. In vivo, angiogenesis was enhanced in a CAM assay, although not to a statistically significant degree. Growth of P. gingivalis was inhibited by CaO₂ concentrations higher than 256 mg/L. Taken together, the results of this study demonstrate the biocompatibility and selective antimicrobial activity against P. gingivalis for the developed O₂-releasing HA-based dispersion and the potential of O₂-releasing biomaterials for periodontal tissue regeneration.

A thermosensitive gel with an active hyaluronic acid ingredient that contains an octenidine preservation system as an adjunct to scaling and root planning: a randomized prospective clinical study

OBJECTIVES

To evaluate the adjunctive effect of a thermosensitive gel formulation that contains 0.8% oligo hyaluronic acid (HA) combined with a preservation system of octenidine HCl 0.625% and phenoxyethanol to scaling and root planing (SRP) as compared with SRP alone in the treatment of residual pockets of patients with stage 3 periodontitis.

MATERIALS AND METHODS

Thirty-four patients (21 males and 13 females) aged 29-78 years (51.3 ± 13.1) with stage 3 periodontitis were recruited to participate in the present split-mouth study. None of the patients has been previously treated for periodontitis. Plaque index (PI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were evaluated at baseline and at 3 and 6 months post treatment. Full-mouth SRP was performed in all residual pockets ≥ 5 mm. Treatment was performed by means of ultrasonic and hand instruments and lasted 45-60 min. The gel was applied subgingivally in the test sites immediately after SRP (baseline) and 1 month later. The paired t-test for two means was applied to test the statistical significance of the change from baseline within each arm and determine the difference between groups. The level of significance was set at 0.05 for all tests.

RESULTS

Mean PD reductions between baseline and 3 and 6 months were 1.98 mm and 2.79 mm for the test and 1.22 mm and 1.50 mm for the control group, respectively. Comparisons between the test and control groups revealed that SRP + gel yielded statistically significantly higher PD reductions compared to SRP alone (p < 0.0001). Compared to baseline, CAL and BOP values improved statistically significantly in both groups, although the test group presented statistically significantly higher CAL gains and BOP reductions than the control group (P < 0.0001).

CONCLUSION

In residual pockets of stage 3 periodontitis patients, the local application of a thermosensitive gel with an active HA ingredient and a preservation system of octenidine HCl 0.625% in conjunction with SRP may additionally improve the clinical outcomes obtained with SRP alone.

CLINICAL RELEVANCE

A novel HA and octenidine containing thermosensitive gel effectively improved the clinical parameters in stage 3 periodontitis patients over a 6-month period.

Coronally advanced flap with and without hyaluronic acid (HYALOSS) for the treatment of gingival recession – a randomized clinical trial

Objectives: To compare and evaluate the surgical outcome of gingival recession treatment using CAF alone or in conjunction with hyaluronic acid (HA) on Miller's Class I and class II gingival recession defects. Materials and methods: After randomisation, the control group (15 patients) received CAF alone and the test group (15 patients) received HA as an adjunct to CAF technique for an isolated gingival recession accompanied by an adequate width of keratinized gingiva on maxillary canines and premolars. All patients were evaluated at 7, 15, 30, 60 and 90 days interval post-operatively. Data obtained was subjected to statistical analysis and p value <0.05 was considered as statistically significant. Results: At 90 days interval statistically highly significant root coverage was obtained with mean gain of 66.1% in control group and 86.6% in test group. Statistically significant reduction in depth of gingival recession and gain in clinical attachment level was found for control and the test groups, and intergroup comparison showed statistically significant differences for root coverage and clinical attachment level between the groups (p = 0.000), however no significant differences were found for width of attached gingiva, keratinized gingiva and gingival thickness between the groups at 90 days (p > 005). Conclusion: HA has proven to be beneficial in the field of regenerative therapy. Our analysis suggested that HA can be used as a promising adjunct with CAF for root coverage, however further studies are required to imply the results on larger population.

Local delivery of hyaluronic acid as an adjunct to scaling and root planing in the treatment of chronic periodontitis in smokers and non-smokers: A clinical and microbiological study

Objective:

The objective of the study is to assess the effects of adjunctive use of hyaluronic acid (HA), clinically and microbiologically in smokers and nonsmokers, in the management of chronic periodontitis.

Material and Methods:

48 sites from 24 chronic periodontitis patients, including smokers and nonsmokers with probing depth >5 mm, were selected for the study. A split-mouth design was followed. Scaling and root planing (SRP) was performed for all the patients. The test sites received 0.8% HA gel whereas the control site received placebo gel. The clinical parameters plaque, gingival and bleeding indices, Pocket Probing Depth (PPD), and clinical attachment level (CAL) were evaluated at baseline, 1 and 3 months. Microbiological parameters were evaluated at baseline and 1 month.

Results:

The results showed reduction in PPD and gain in CAL in both smokers and nonsmokers at the end of 3^rd month. The improvements in the test sites were statistically significant when compared with that of control sites. The microbiological analysis showed a significant reduction in Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis at the test sites when compared to the controls in both the groups.

Conclusion:

The findings in both groups suggest that the use of locally delivered 0.8% HA gel may be valuable as an adjunct to SRP in the treatment of chronic periodontitis.

A randomized controlled trial evaluating hyaluronic acid gel as wound healing agent in alveolar ridge preservation

AIM

To compare the results of administration of hyaluronic acid (HA) gel to no gel administration following alveolar ridge preservation (ARP) in terms of changes in wound dimensions over time.

MATERIALS AND METHODS

Systemically healthy patients scheduled for ARP at one or two sites in the incisor, cuspid, or premolar area with at least one neighbouring tooth and >50% buccal bone present following extraction were included. ARP consisted of socket grafting with collagen-enriched, deproteinized bovine bone mineral and socket sealing by means of a collagen matrix. Following surgical therapy, sites were randomly allocated to the control group (no gel application) or the test group (0.8% HA gel applied onto the collagen matrix three times per day for 7 days). Bucco-lingual and mesio-distal wound dimensions were registered at T0 (immediately post operation), T1 (1 week), and T2 (3 weeks). Patient-reported outcomes, clinical outcomes, and hard and soft tissue changes were recorded up to 4 months (T3).

RESULTS

In the control group, 20 patients (7 males, 13 females; mean age 53.30) with 23 sites, and in the test group 18 patients (9 males, 9 females; mean age 52.56) with 23 sites, were included. There were no significant differences between the groups in the changes in wound dimensions from T0 to T2 (bucco-lingual aspect: p = .340; mesio-distal aspect: p = .883). Three sites (13%) in the control group and six (26%) in the test group demonstrated complete wound resolution at T2 (p = .259). HA failed to show any effect on the number of analgesics taken (p = .175), patient-reported outcomes (p ≥ .263), alveolitis (p = .136), socket healing (p ≥ .424), soft tissue changes (p ≥ .064), or mucosal scarring (p = .548). However, significantly more horizontal bone loss at the coronal aspect was found in the test group (p ≤ .025).

CONCLUSION

HA failed to promote wound resolution on a collagen matrix. This study was registered in ClinicalTrials.gov (NCT04467736).

Biomolecules in Dental Applications: Randomized, Controlled Clinical Trial Evaluating the Influence of Hyaluronic Acid Adjunctive Therapy on Clinical Parameters of Moderate Periodontitis

The biological activity of hyaluronic acid (HA) has been well-researched during the past decades; however, there are few randomized, controlled trials of its clinical effects in periodontal therapy. The purpose of this study was to evaluate the effect of hyaluronic acid on the principal parameters of periodontal healing. A specific, commercially available formulation designed and registered for professional dental application, composed of 16 mg/mL of cross-linked and 2 mg/mL of non-cross-linked HA, was used as an adjunctive to non-surgical periodontal therapy, and clinical parameters were evaluated after 3 months. The addition of HA to periodontal therapy demonstrated more favorable clinical results regarding reduction in inflammation, measured by bleeding on probing (-6% compared to the control group) and gain in periodontal attachment (1 mm more than control group), while it had no effect on probing depth reduction. No side effects were reported. Our study demonstrated that HA is a safe and easy-to-use biological agent; due to its wide array of properties, it may significantly improve the results of periodontal therapy. However, more long-term studies are needed to investigate whether these favorable effects remain over time.

Clinical and radiographic evaluation of 0.8% hyaluronic acid as an adjunct to open flap debridement in the treatment of periodontal intrabony defects: randomized controlled clinical trial

OBJECTIVES

Present study aimed to evaluate and compare the clinical and radiographic efficacy of 0.8% hyaluronic acid (HA) gel as an adjunct to open flap debridement (OFD) versus open flap debridement (OFD) alone in the treatment of periodontal intrabony defects.

MATERIALS AND METHODS

This randomized, controlled, split-mouth, clinical trial included 20 chronic periodontitis (stage II or III (grades A to B)) patients, having at least two contralateral intrabony defects. Forty bilateral intrabony defects (20 in each group) were randomly divided into test (0.8% HA gel + OFD) and control (OFD + placebo) groups. Clinical parameters evaluated at baseline, 6-months, and 12-months were plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and gingival recession (GR). Using cone beam computed tomography (CBCT), radiographic parameters were evaluated at baseline and 12 months. This included bone defect fill (DF), alveolar crest changes (ACC), and defect resolution (DR). CAL served as the primary outcome variable.

RESULTS

After 12 months, the test group showed significantly greater CAL gain (5.1 ± 1.2 versus 4.05 ± 1.19 mm) and bone defect fill (DF) (5.67 ± 2.01 versus 4.49 ± 1.78 mm) compared to the control group. Mean PD reduction in the test group (5.3 ± 1.2 versus 4.35 ± 0.81 mm) was statistically significant compared to the control group at 12-month period. The control group showed statistically significant increase in GR (1.2 ± 0.76 versus 0.7 ± 0.73 mm) compared to the test group after 12 months.

CONCLUSION

Application of hyaluronic acid gel in conjunction with open flap debridement resulted in enhanced clinical and radiographic outcomes compared to open flap debridement alone.

CLINICAL RELEVANCE

Adjunctive application of HA gel in open flap debridement may improve clinical and radiographic outcomes.

CLINICAL TRIAL REGISTERED NUMBER

CTRI/2018/03/012334.

Healing of intrabony defects following regenerative surgery by means of single-flap approach in conjunction with either hyaluronic acid or an enamel matrix derivative: a 24-month randomized controlled clinical trial

Objectives

The aim of this randomized controlled clinical trial was to compare the clinical outcomes obtained in intrabony defects following regenerative periodontal surgery using the single-flap approach (SFA) in conjunction with either hyaluronic acid (HA) or enamel matrix derivative (EMD).

Materials and methods

Thirty-two intrabony defects in 32 healthy subjects were randomly assigned: HA (test group) or EMD (control group). Clinical attachment level (CAL), probing depth (PD), gingival recession (REC), and bleeding on probing (BOP) were recorded at baseline,12, 18, and 24 months after surgery.

Results

At 24 months, both treatments resulted in statistically significant clinical improvements evidenced by PD-reduction and CAL-gain (p<0.001). The mean CAL-gain was 2.19±1.11 mm in the test and 2.94±1.12 mm in the control sites (p=0.067). PD-reduction was statistically significantly higher for the control group (4.5±0.97 mm) than the test group (3.31±0.70 mm), (p=0.001). CAL-gain ≤ 3 mm was observed in 87.5% and in 62.5% of the test and control sites, respectively. Test sites showed slightly lower REC values than the control sites. No statistically significant differences were found for BOP between treatments.

Conclusions

The present findings indicate that both treatments led to statistically significant clinical improvements compared to baseline, although the application of EMD resulted in statistically significantly higher PD-reduction compared to the use of HA.

Clinical relevance

The use of HA in conjunction with a SFA resulted in significant PD-reduction and CAL-gain, pointing to the potential clinical relevance of this material in regenerative periodontal surgery.

Comparative Evaluation of Two Hyaluronic Acid Gel Products for the Treatment of Interdental Papillary Defects

Objectives

The aim was to investigate the efficacy of single injections of two different hyaluronic acid products, Flex Barrier and Revident, in reducing the size of black triangles to treat Nordland-Tarnow Class I and II recessions.

Materials and Methods

Forty adult patients were recruited with at least two upper and two lower interdental papilla defects in the front region between canine teeth. According to the Nordland-Tarnow classification of papillary defects, both Class I and Class II recessions were included in the investigation. Patients were randomly assigned to experimental groups to receive single injections of two different hyaluronic acid products, either Flex Barrier or Revident. The untreated sites served as controls. Photographs were taken before and immediately after the treatment, and again after one week and one month. To determine the size of the black triangles, Image J software was used. For statistical analysis, a mixed-design ANOVA was applied.

Results

Both Flex Barrier and Revident significantly decreased the size of the treated defects immediately after the treatment and also one week later (p<0.001). The beneficial effect of Revident lasted longer than Flex Barrier as it remained significant even after one month in Revident-treated patients, however, not in the Flex Barrier-treated group. Furthermore, Nordland-Tarnow Class I lesions generally showed a greater improvement than Class II lesions.

Conclusion

In this proof-of-concept, randomized clinical trial we have demonstrated the clinical applicability of both Flex Barrier and Revident, although Revident gave longer-lasting improvements than Flex Barrier. Further trials are needed to optimize multiple-application protocols for treating gingival black triangles.

Evaluation of biochemical and clinical effects of hyaluronic acid on non-surgical periodontal treatment: a randomized controlled trial

BACKGROUND

Recent studies reported that hyaluronic acid (HA) has anti-inflammatory, anti-edematous, and anti-bacterial activities in dentistry, particularly in gingival disorders caused by subgingival plaque microorganisms.

AIMS

This study aimed to evaluate the early term effects of HA as an adjunct to scaling and root planing (SRP) on clinical parameters, periodontal inflamed surface area (PISA), and adenosine deaminase (ADA), catalase (CAT), and glutathione (GSH) levels in gingival crevicular fluid (GCF) in periodontitis.

METHODS

A total of 24 periodontitis patients per group were included in this randomized-controlled study. The study population was divided into four groups: in Group 1: SRP+ saline; in Group 2: SRP + HA gel; in Group 3: SRP+ HA mouth rinse; and in Group 4: SRP + HA mouth rinse + HA gingival gel were applied. At baseline and week 4, clinical parameters and PISA were calculated. Also, biochemicals' (ADA, CAT, and GSH) levels were determined by spectrophotometric analysis.

RESULTS

There was a statistically significant improvement in clinical parameters and PISA in all four groups in control sessions (p < 0.05). There was a significant decrease in ADA in GCF and significant increases in CAT and GSH levels after SRP (p < 0.05) in all four groups. The groups that were administered only gel (2nd and 4th) were different from other groups in terms of ADA, CAT, and GSH levels at 1st week (p < 0.05).

CONCLUSION

HA application as an adjunct to SRP did not affect the clinical results, although, in the control sessions following the application, the results were favorable for the biochemical data in gel-applied groups.

TRIAL REGISTRATION

ClinicalTrials.gov.tr (NCT03754010).

Evaluation of the Bactericidal Activity of a Hyaluronic Acid-Vehicled Clarithromycin Antibiotic Mixture by Confocal Laser Scanning Microscopy

Confocal laser scanning microscopy (CLSM) was used to evaluate the antibacterial effect and depth of action of a novel clarithromycin-containing triple antibiotic mixture, which was proposed for root canal disinfection in dental pulp regeneration. A previous study reported that this mixture had no tooth discoloration effects in vitro. After infection with Enterococcus faecalis for 3 weeks, the dentinal tubules in the cylindrical root specimens were exposed to different antibiotic mixtures: ciprofloxacin, metronidazole and minocycline (3-MIX); ciprofloxacin, metronidazole and clarithromycin (3-MIXC) and ciprofloxacin and metronidazole (2-MIX). Each antibiotic formulation was mixed with macrogol (MG) or hyaluronic acid (HA) vehicles. CLSM and viability staining were used to quantitatively analyze the mean depth of the antibacterial effect and the proportions of dead and live bacteria inside the dentinal tubules. The 3-MIX and 3-MIXC demonstrated a similar depth of action. The mean proportion of dead bacteria was similar in the 3-MIX and 3-MIXC groups, and both were statistically higher than that of 2-MIX (p = 0.014). Each antibiotic mixture showed a higher bactericidal efficacy if conveyed with HA, compared to MG (3-MIX, p = 0.019; 3-MIXC, p = 0.013 and 2-MIX, p = 0.0125). The depth of action and the antibacterial efficacy of 3-MIXC seemed comparable with 3-MIX.

Single application of 0.8% hyaluronic acid as a coadjuvant of nonsurgical treatment in nonsmoking patients with periodontitis: A split-mouth, randomized, controlled pilot clinical trial

Background:

Topical coadjuvants might be indicated to increase the results of nonsurgical periodontal treatment and overcome some of its limitations. The aim of this study was to evaluate the clinical benefits of a single topical application of 0.8% hyaluronic acid (HA) as a coadjuvant to scaling and root planing (SRP) in periodontal patients.

Materials and Methods:

Sixteen patients diagnosed with periodontitis were recruited to participate in this split-mouth randomized controlled trial. At baseline, oral hygiene instructions, prophylaxis, and SRP were performed in both sides; additionally, a subgingival application of HA at 0.8% was made in the test side. Several clinical parameters were assessed at baseline, 6, and 12 weeks later: full mouth plaque score, gingival score, bleeding on probing (BoP), probing depth (PD), and clinical attachment level (CAL).

Results:

At the end of 12 weeks, there was a overall improvement in all periodontal parameters in both sides (P < 0.05). Test sides showed less BoP when compared to the control sides (9.4 ± 4.0 vs. 14.9 ± 8.9, P < 0.05). Other periodontal parameters such as PD and CAL showed a slight improvement in comparison with the control sides, but the difference was not statistically significant (P > 0.05).

Conclusion:

Results from this study indicate that a single subgingival application of 0.8% HA seems to reduce gingival inflammation and improve clinical parameters, particularly BoP. Further studies are needed to evaluate the effect of repeated application of HA and long-term results.

Hyaluronic acid as adjunctive to non-surgical and surgical periodontal therapy: a systematic review and meta-analysis

OBJECTIVES

To evaluate the potential added benefit of the topical application of hyaluronic acid (HA) on the clinical outcomes following non-surgical or surgical periodontal therapy.

MATERIALS AND METHODS

A systematic search was performed in Medline, Embase, Cochrane, Web of Science, Scopus and Grey literature databases. The literature search was preformed according to PRISMA guidelines. The Cochrane risk of bias tool was used in order to assess the methodology of the included trials. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) between the treatment and controls were estimated using the random-effect model for amount of bleeding on probing (BOP), probing depth (PD) reduction and clinical attachment level (CAL) gain. In order to minimize the bias and to perform meta-analysis, only randomized clinical studies (RCTs) were selected.

RESULTS

Thirteen RCTs were included: 11 on non-surgical periodontal treatment and two on surgical periodontal treatment. Overall analysis of PD reduction, CAL gain and BOP reduction in non-surgical therapy with adjunctive HA presented WMD of - 0.36 mm (95% CI - 0.54 to - 0.19 mm; p < 0.0001), 0.73 mm (95% CI 0.28 to 1.17 mm; p < 0.0001) and - 15% (95% CI - 22 to - 8%; p < 0.001) respectively, favouring the application of HA. The overall analysis on PD and CAL gain in surgical therapy with adjunctive HA presented WMD of - 0.89 mm (95% CI - 1.42 to - 0.36 mm; p < 0.0001) for PD reduction and 0.85 mm (95% CI 0.08 to 1.62 mm; p < 0.0001) for CAL gain after 6-24 months favouring the treatment with HA. However, comparison presented considerable heterogeneity between the non-surgical studies and a high risk of bias in general.

CONCLUSIONS

Within their limits, the present data indicate that the topical application of HA may lead to additional clinical benefits when used as an adjunctive to non-surgical and surgical periodontal therapy. However, due to the high risk of bias and heterogeneity, there is a need for further well-designed RCTs to evaluate this material in various clinical scenarios.

CLINICAL RELEVANCE

The adjunctive use of HA may improve the clinical outcomes when used in conjunction with non-surgical and surgical periodontal therapy.

BDNF/HMW-HA complex as an adjunct to nonsurgical periodontal treatment of ligature-induced periodontitis in dogs

BACKGROUND

Recently, brain-derived neurotrophic factor (BDNF)/high molecular weight hyaluronic acid (HMW-HA) complex with flap surgery has been shown to promote periodontal tissue regeneration. The objective of this study was to evaluate the effects of local subgingival application of BDNF/HMW-HA complex adjunctive to scaling and root planning (SRP) on ligature-induced periodontitis in dogs.

METHODS

The dogs were divided into four treatment groups: no treatment (control), SRP alone, SRP followed by local application of HMW-HA (SRP+HMW-HA), and SRP followed by local application of BDNF (500 μg/ml)/ HMW-HA complex (SRP+BDNF/HMW-HA). HMW-HA or BDNF/HMW-HA complex was topically applied to periodontal pockets using a syringe without surgery. Two weeks after treatment, clinical parameters (gingival index, clinical attachment level, periodontal pocket depth and bleeding on probing) were recorded and specimens were collected from anesthetized animals for histological analysis.

RESULTS

The SRP+BDNF/HMW-HA group showed significant improvement in all clinical parameters compared to other treatment groups. Histologic analysis showed greater suppression of apical migration of epithelial tissue and milder inflammatory cell infiltration in the SRP+BDNF/HMW-HA group than in the other treatment groups. Furthermore, new cementum and alveolar bone were regenerated, and collagen fibers were inserted into them in the SRP+BDNF/HMW-HA group.

CONCLUSION

BDNF/HMW-HA complex as an adjunct to nonsurgical periodontal treatment has the potential to reduce excess inflammation. Further investigation will be needed to clarify periodontal tissue regenerative effects of BDNF/HMW-HA complex in a nonsurgical setting.

Effectiveness of adjunctive hyaluronic acid application in coronally advanced flap in Miller class I single gingival recession sites: a randomized controlled clinical trial

OBJECTIVES

The aim of this randomized controlled clinical trial was to evaluate the possible advantages of adjunctive hyaluronic acid (HA) application in the coronally advanced flap (CAF) procedure in single Miller class I/recession type 1 (RT1) gingival recession treatment.

MATERIAL AND METHODS

Thirty patients with one recession were enrolled; 15 were randomly assigned CAF + HA and 15 to CAF alone. The recession reduction (RecRed), clinical attachment level gain (CAL-gain), changes in probing pocket depth (PPD) and in the width of keratinized tissue (KT), complete root coverage (CRC), and mean root coverage (MRC) were calculated after 18 months. Post-operative morbidity (pain intensity, discomfort, and swelling) was recorded 7 days after treatment using visual analogue scale (VAS).

RESULTS

After 18 months, RecRed was statistically significantly higher in the test group (2.7 mm [1.0]) than in the control group (1.9 mm [1.0]; p = 0.007). PPD were found to be slightly but statistically significantly increased in both groups. No statistically significant difference was found for KT gain between treatments. CRC was 80% for test and 33.3% for control sites (p < 0.05). A MRC of 93.8 ± 13.0% for test and 73.1 ± 20.8% for control sites was calculated (p < 0.05). The test group reported lower swelling and discomfort values 7-days post-surgery (p < 0.05). Statistically significant difference was not found for pain intensity.

CONCLUSIONS

The adjunctive use of HA was effective in obtaining CRC for single Miller class I/RT1 gingival recession sites.

CLINICAL RELEVANCE

Adjunctive application of HA in the coronally advanced flap procedure may improve the reduction of the recessions and increase the probability of CRC in Miller class I recessions.

Local icariin application enhanced periodontal tissue regeneration and relieved local inflammation in a minipig model of periodontitis

Periodontitis is an inflammatory autoimmune disease. Treatment should alleviate inflammation, regulate the immune reaction and promote periodontal tissue regeneration. Icariin is the main active ingredient of Epimedii Folium, and it is a promising compound for the enhancement of mesenchymal stem cell function, promotion of bone formation, inhibition of bone resorption, alleviation of inflammation and regulation of immunity. The study investigated the effect of icariin on periodontal tissue regeneration in a minipig model of periodontitis. The minipig model of periodontitis was established. Icariin was injected locally. The periodontal clinical assessment index, a computed tomography (CT) scan, histopathology and enzyme-linked immune sorbent assay (ELISA) were used to evaluate the effects of icariin. Quantitative analysis results 12 weeks post-injection demonstrated that probing depth, gingival recession, attachment loss and alveolar bone regeneration values were (3.72 ± 1.18) mm vs. (6.56 ± 1.47) mm, (1.67 ± 0.59) mm vs. (2.38 ± 0.61) mm, (5.56 ± 1.29) mm vs. (8.61 ± 1.72) mm, and (25.65 ± 5.13) mm³ vs. (9.48 ± 1.78) mm³ in the icariin group and 0.9% NaCl group, respectively. The clinical assessment, CT scan, and histopathology results demonstrated significant enhancement of periodontal tissue regeneration in the icariin group compared to the 0.9% NaCl group. The ELISA results suggested that the concentration of interleukin-1 beta (IL-1β) in the icariin group was downregulated compared to the 0.9% NaCl group, which indicates that local injection of icariin relieved local inflammation in a minipig model of periodontitis. Local injection of icariin promoted periodontal tissue regeneration and exerted anti-inflammatory and immunomodulatory function. These results support the application of icariin for the clinical treatment of periodontitis.

A Chinese herbal supplement could treat an inflammatory autoimmune disease of the tissues surrounding the teeth. Zhipeng Fan and colleagues at Capital Medical University in Beijing, China found reduced inflammation and improved tissue regeneration in induced periodontitis in miniature pigs, three months following local injections with the Chinese herbal extract icariin. Periodontitis is an overactive immune response to bacterial invasion in the gums, leading to the breakdown of supportive tissue and bone, and potential tooth loss. Clinical assessment, CT scans and microscopic examination showed icariin injections promoted gum and bone regeneration, possibly by stimulating local stem cells. It also reduced signs of inflammation, including significantly decreasing the expression of IL-1β, an immune response mediator. Further studies are needed to confirm icariin’s mode of action and optimal dosage for potential clinical use.

In vitro effects of hyaluronic acid on human periodontal ligament cells

Background

Hyaluronic acid (HA) has been reported to have a positive effect on periodontal wound healing following nonsurgical and surgical therapy. However, to date, a few basic in vitro studies have been reported to investigating the potential of HA on human periodontal ligament (PDL) cell regeneration. Therefore, the aim of this study was to investigate the effect of HA on PDL cell compatibility, proliferation, and differentiation in vitro.

Methods

Either non-cross-linked (HA_ncl) or cross-linked (HA_cl) HA was investigated. Human PDL cells were seeded in 7 conditions as follows (1) Control tissue culture plastic (TCP) (2) dilution of HA_ncl (1:100), (3) dilution of HA_ncl (1:10), 4) HA_ncl directly coated onto TCP, (5) dilution of HA_cl (1:100), 6) dilution of HA_cl (1:10) and (7) HA_cl directly coated onto TCP. Samples were then investigated for cell viability using a live/dead assay, an inflammatory reaction using real-time PCR and ELISA for MMP2, IL-1 and cell proliferation via an MTS assay. Furthermore, the osteogenic potential of PDL cells was assessed by alkaline phosphatase(ALP) activity, collagen1(COL1) and osteocalcin(OCN) immunostaining, alizarin red staining, and real-time PCR for genes encoding Runx2, COL1, ALP, and OCN.

Results

Both HA_ncl and HA_cl showed high PDL cell viability (greater than 90%) irrespective of the culturing conditions. Furthermore, no significant difference in both mRNA and protein levels of proinflammatory cytokines, including MMP2 and IL-1 expression was observed. Both diluted HA_ncl and HA_cl significantly increased cell numbers compared to the controlled TCP samples at 3 and 5 days. HA_ncl and HA_cl in standard cell growth media significantly decreased ALP staining, COL1 immunostaining and down-regulated early osteogenic differentiation, including Runx2, COL1, and OCN mRNA levels when compared to control samples. When osteogenic differentiation medium (ODM) was added, interestingly, the expression of early osteogenic markers increased by demonstrating higher levels of COL1 and ALP expression; especially in HA 1:10 diluted condition. Late stage osteogenic markers remained inhibited.

Conclusions

Both non-cross-linked and cross-linked HA maintained high PDL cell viability, increased proliferation, and early osteogenic differentiation. However, HA was consistently associated with a significant decrease in late osteogenic differentiation of primary human PDL cells. Future in vitro and animal research is necessary to further characterize the effect of HA on periodontal regeneration.

Hyaluronic Acid and Its Composites as a Local Antimicrobial/Antiadhesive Barrier

Living in biofilms is probably the most common condition for bacteria and fungi and biofilm-related infections account for the majority of bacterial infectious diseases worldwide. Among others biofilm-related infections, those associated with implanted biomaterials have an enormous and still largely underestimated impact in orthopaedics and trauma, cardio-surgery and several other surgical disciplines. Given the limited efficacy of existing antibiotics in the prevention and treatment of bacterial biofilms, new strategies are needed to protect implants and host tissues, overcoming the striking ability of the microorganisms to adhere on different surfaces and to immediately protect themselves by forming the biofilm matrix. Adhesion is a necessary first step in microbial colonization and pathogenesis and provides a potential target for new preventive and treatment approach. Among various polymers, tested as antibacterial coatings, hyaluronic acid and some of its composites do offer a well-established long-term safety profile and a proven ability to reduce bacterial adhesion and biofilm formation. Aim of the present review is to summarize the available evidence concerning the antiadhesion/antibiofilm activity of hyaluronic acid and some of its derivatives to reduce/prevent bacterial adhesion and biofilm formation in various experimental and clinical settings.

Hyaluronic acid: Perspectives in dentistry. A systematic review

To date, topical therapies guarantee a better delivery of high concentrations of pharmacologic agents to the soft periodontal tissue, gingiva, and periodontal ligament as well as to the hard tissue such as alveolar bone and cementum. Topical hyaluronic acid (HA) has recently been recognized as an adjuvant treatment for chronic inflammatory disease in addition to its use to improve healing after dental procedures. The aim of our work was to systematically review the published literature about potential effects of HA as an adjuvant treatment for chronic inflammatory disease, in addition to its use to improve healing after common dental procedures. Relevant published studies were found in PubMed, Google Scholar, and Ovid using a combined keyword search or medical subject headings. At the end of our study selection process, 25 relevant publications were included, three of them regarding gingivitis, 13 of them relating to chronic periodontitis, seven of them relating to dental surgery, including implant and sinus lift procedures, and the remaining three articles describing oral ulcers. Not only does topical administration of HA play a pivotal key role in the postoperative care of patients undergoing dental procedures, but positive results were also generally observed in all patients with chronic inflammatory gingival and periodontal disease and in patients with oral ulcers.

Evaluation of effectiveness of hyaluronic acid in combination with bioresorbable membrane (poly lactic acid-poly glycolic acid) for the treatment of infrabony defects in humans: A clinical and radiographic study

Background:

The combination of biomaterials, bone graft substitutes along with guided tissue regeneration (GTR) has been shown to be an effective modality of periodontal regenerative therapy for infrabony defects. Therefore, the present randomized controlled clinical study was undertaken to evaluate the effectiveness of hyaluronic acid (HA) in combination with bioresorbable membrane for the treatment of human infrabony defects.

Materials and Methods:

Twenty four infrabony defects in 20 systemically healthy patients were randomly assigned to test (HA in combination with bioresorbable membrane) and control (bioresorbable membrane alone) treatment groups. Probing pocket depth (PPD), relative attachment level, and relative gingival margin level were measured with a computerized Florida disc probe at baseline and at 6 months follow-up. Radiographic measurements were also evaluated at baseline and at 6 months of postsurgery.

Results:

At 6 months, the mean reduction in PPD in test group and control group was 4.52 mm and 2.97 mm, respectively. Significantly higher clinical attachment level with a gain of 2.20 mm was found in the test group as compared to control group. In addition, statistically significant greater reduction of radiographic defect depth was observed in the test group.

Conclusion:

Regenerative approach using hyaloss in combination with GTR for the treatment of human infrabony defects resulted in a significant added benefit in terms of CAL gains, PPD reductions and radiographic defect fill, as well as LBG, compared to the GTR alone.

To compare the effect of the local delivery of hyaluronan as an adjunct to scaling and root planing versus scaling and root planing alone in the treatment of chronic periodontitis

Background:

Hyaluronan is a critical component of the extracellular matrix and contributes significantly to tissue hydrodynamics and cell migration and proliferation. Studies have demonstrated its anti-inflammatory, antibacterial, and regenerative effects. The present study aimed to assess the clinical effects of the subgingival application of 0.8% hyaluronic acid gel as an adjunct to scaling and root planing (SRP) in the treatment of generalized chronic periodontitis.

Materials and Methods:

Patients with chronic periodontitis were recruited to participate in a study with a split-mouth design and provided informed consent. One hundred sites were included in the study and divided into fifty test sites and fifty control sites. These were assessed for plaque index (PI), gingival index (GI), pocket probing depths, and relative attachment level (RAL) at-pretreatment (baseline), 4, and 12 weeks posttreatment. The patients received full-mouth SRP. A 0.8% hyaluronan gel was administered subgingivally in the test sites at baseline and after 1 week. Significant differences between test and control were evaluated using the t-test, analysis of variance (test) followed by Bonferroni post hoc test.

Results:

A significant reduction in PI and GI was observed in both groups at 12 weeks (P < 0.05). Significant reduction in the pocket probing depths and gain RAL was observed in both the groups as compared to baseline (P < 0.05). The hyaluronan group compared to control at 12 weeks showed statistically significant reduction in the probing pocket depth and gain in RAL (P < 0.05).

Conclusion:

The subgingival application of 0.8% hyaluronan gel in conjunction with SRP may have a beneficial effect on periodontal health in patients with chronic periodontitis.

A chitosan-hyaluronic acid hydrogel scaffold for periodontal tissue engineering

The current challenge in treating periodontitis is regenerating the periodontium. This motivates tissue-engineering researchers to develop scaffolds as artificial matrices that give mechanical support for osteoblasts, cementoblasts, gingival and periodontal ligament fibroblast cells. In this study, modified hyaluronic acid (HA) and chitosan (CS) were employed to create a hybrid CS-HA hydrogel scaffold for periodontal regeneration. CS, HA, and CS-HA scaffolds were obtained by freeze-drying technique, resulting in porous structures suitable for use in tissue engineering. Scaffolds were submitted to gamma and UV-sterilization without significant morphology changes. The ATR-FTIR spectra of CS-HA hydrogels showed peaks at 377 cm^-1 , 1566 cm^-1 , and 1614 cm^-1 , representing secondary amide, primary amine, and carboxyl acid respectively, and it was also observed the emergence of peaks at 886 cm^-1 , which probably represents the Schiff base formed in the case of hybrid CS-HA hydrogels. The scaffolds presented a high rate of PBS uptake, reaching values higher than 95%. Thermal degradation of HA scaffolds was around 225°C and CS was around 285°C. The ATR-FTIR spectra and swelling degree were slightly disturbed mainly after gamma sterilization, but degradation temperature did not change after sterilization. The performance of the CS-HA hydrogel scaffolds for in vitro cell culture was tested using NIH3T3 and MG63 cell lines. The Alamar Blue test showed a significant increase in cellular viability and high CD44 expression, suggesting that the cells migrated more when seeded onto the scaffolds. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1691-1702, 2016.

Local delivery of hyaluronan 0.8% as an adjunct to scaling and root planing in the treatment of chronic periodontitis: A clinical and microbiological study

BACKGROUND

The purpose of this study was to assess the clinical and microbiological effects of the local and sub-gingival application of a hyaluronan gel on scaling and root planing (SRP) in the treatment of moderate generalized chronic periodontitis.

MATERIALS AND METHODS

In this split mouth study, 72 teeth in 18 patients with generalized chronic periodontitis with moderate severity were chosen for the study. Plaque samples were obtained by paper points at required intervals. Contra-lateral pairs of premolars and canine teeth in the maxilla or the mandible were selected to receive test treatment or serve as controls. Experimental jaw quadrants received sub-gingival administration of 0.2-ml 0.8% hyaluronan gel into selected sites following SRP and 1-week later. Clinical parameters were assessed at baseline, 1(st), 4(th), and 12(th) week. Colony-forming units (CFU) per milliliter were assessed at baseline, after SRP and after 2 weeks of drug insertion Student t-test and repeated measure ANOVA (RMANOVA) were used in this study. RMANOVA was used to find the significance in bleeding on probing (BOP) and plaque index (PI) and t-test for probing pocket depth (PPD) and clinical attachment level (CAL).

RESULTS

The results revealed that there was a significant reduction in BOP (P < 0.001) PI (P < 0.001), PPD (P < 0.001) and CAL (P < 0.001) were also observed in experimental jaw quadrant following SRP and insertion of 0.8% hyaluronan when compared with the control group. A statistically significant reduction of CFUs was also found (P < 0.001) in the experimental site when compared with the control site.

CONCLUSION

Sub-gingival placement of 0.2-ml of 0.8% hyaluronan along with SRP resulted in a significant improvement in both clinical and microbiological parameters when compared with the control site.

Efficacy of hyaluronic acid (hyaluronan) in root coverage procedures as an adjunct to coronally advanced flap in Millers Class I recession: A clinical study

Background:

The purpose of this study was to assess the efficacy of hyaluronic acid (HA) in root coverage procedures as an adjunct to coronally advanced flap (CAF) procedure.

Materials and Methods:

This was a randomized clinical trial with split mouth design, where 10 patients with 20 sites of Millers Class I recession were treated and followed-up for a period of 6 months. CAF procedure was performed, HA was applied onto the experimental sites before suturing the flap. Recession depth (RD) was measured regularly at baseline 1, 3, 6, 12, and 24 weeks postoperatively. Probing pocket depth (PPD) and clinical attachment level (CAL) were also measured along with RD at baseline and 12 and 24 weeks.

Results:

There was a significant change in RD, PPD, CAL, and percentage of root coverage in both groups when compared to the baseline values. There was no statistically significant difference between experimental and control group in terms of RD (P = 0.917), PPD (P = 0.917) and CAL (P = 0.761). RD was 3.2 mm ± 0.78 mm in experimental site and control sites 2.9 mm ± 0.73 mm reduced to 1.1 mm ± 0.99 mm in experimental sites and 1.0 mm ± 0.66 mm in control sites. Though, there is no statistically significant difference root coverage in the experimental group appeared to be clinically more stable compared with the control group after 24 weeks.

Conclusions:

This study suggests that use of HA may improve the clinical outcome of root coverage with CAF procedure.

Genome-wide association study of periodontal health measured by probing depth in adults ages 18-49 years

The etiology of chronic periodontitis clearly includes a heritable component. Our purpose was to perform a small exploratory genome-wide association study in adults ages 18–49 years to nominate genes associated with periodontal disease−related phenotypes for future consideration. Full-mouth periodontal pocket depth probing was performed on participants (N = 673), with affected status defined as two or more sextants with probing depths of 5.5 mm or greater. Two variations of this phenotype that differed in how missing teeth were treated were used in analysis. More than 1.2 million genetic markers across the genome were genotyped or imputed and tested for genetic association. We identified ten suggestive loci (p-value ≤ 1E-5), including genes/loci that have been previously implicated in chronic periodontitis: LAMA2, HAS2, CDH2, ESR1, and the genomic region on chromosome 14q21-22 between SOS2 and NIN. Moreover, we nominated novel loci not previously implicated in chronic periodontitis or related pathways, including the regions 3p22 near OSBPL10 (a lipid receptor implicated in hyperlipidemia), 4p15 near HSP90AB2P (a heat shock pseudogene), 11p15 near GVINP1 (a GTPase pseudogene), 14q31 near SEL1L (an intracellular transporter), and 18q12 in FHOD3 (an actin cytoskeleton regulator). Replication of these results in additional samples is needed. This is one of the first research efforts to identify genetic polymorphisms associated with chronic periodontitis-related phenotypes by the genome-wide association study approach. Though small, efforts such this are needed in order to nominate novel genes and generate new hypotheses for exploration and testing in future studies.

Comparative analysis of hyaluronan gel and xanthan-based chlorhexidine gel, as adjunct to scaling and root planing with scaling and root planing alone in the treatment of chronic periodontitis: A preliminary study

AIM

The aim of this study was to evaluate the effects of hyaluronan (HA) and chlorhexidine (CHX) gels as adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis.

MATERIALS AND METHODS

Sixty patients within the age group of 30-65 years recruited to participate in the study were randomly equally divided into three groups. Complete SRP and subgingival debridement were performed within 6 h in all the patients. For control (Group I) patients, SRP was the only treatment modality given; for Group II and III patients, at least 8 teeth with 4-8 mm probing pocket depth (PPD) were selected for subgingival application of HA gel and CHX gel, respectively. Clinical periodontal parameters such as gingival index, PPD, and clinical attachment level (CAL) were recorded at baseline and 3 months, whereas plaque index was recorded at baseline, 1 month, and 3 months. For measuring systemic/hematological parameters, blood samples for laboratory tests for total leucocyte count (TLC), differential leucocyte count (DLC), and C-reactive protein (CRP) were obtained using standard 2-mL syringe from each subject in all the three groups at baseline, 24 h, and on the 1 month and 3 months post-baseline.

RESULTS

In all the three groups, a significant reduction in PPD and gain in CAL were observed between baseline and 3 months follow-up (P< 0.05); however, at 3 months, change in PPD and CAL was more in Group II than Group III, but the difference was non-significant, and Group I (control) showed less changes in PPD and CAL than both experimental groups. Only one patient revealed positive value for CRP at baseline only, and hence could not be statistically analyzed. In all the three groups, the peak values for TLC count were observed at 24 h. At 1-month and 3-month intervals, a significant improvement in TLC and DLC counts was observed among the experimental (HA gel/SRP and Xan-CHX gel) groups as compared to control group (SRP alone).

Hyaluronic Acid: a boon in periodontal therapy

Hyaluronic acid is a naturally occurring linear polysaccharide of the extracellular matrix of connective tissue, synovial fluid, and other tissues. Its use in the treatment of the inflammatory process is established in medical areas such as orthopedics, dermatology, and ophthalmology. The Pubmed/Medline database was searched for keywords “Hyaluronic acid and periodontal disease” and “Hyaluronic acid and gingivitis” which resulted in 89 and 22 articles respectively. Only highly relevant articles from electronic and manual search in English literature were selected for the present review article. In the field of dentistry, hyaluronic acid has shown anti-inflammatory and anti-bacterial effects in the treatment of periodontal diseases. Due to its tissue healing properties, it could be used as an adjunct to mechanical therapy in the treatment of periodontitis. Further studies are required to determine the clinical efficacy of hyaluronic acid in healing of periodontal lesion. The aim of the present review, article is to discuss the role of hyaluronic acid in periodontal therapy.

Expression of interferon-γ, interferon-α and related genes in individuals with Down syndrome and periodontitis

BACKGROUND

Recently, attenuation of anti-inflammatory and increase of pro-inflammatory mediators was demonstrated in individuals with Down syndrome (DS) in comparison with euploid patients during periodontal disease (PD), suggesting a shift to a more aggressive inflammation in DS.

AIM

To determine the influence of DS in the modulation of interferons (IFNs) signaling pathway in PD.

MATERIALS AND METHODS

Clinical periodontal assessment was performed and gingival tissue samples obtained from a total of 51 subjects, including 19 DS individuals with PD, 20 euploid individuals with PD and 12 euploid individuals without PD. Expression levels of interferon-gamma (IFNG) and interferon-alpha (IFNA), and their receptors IFNGR1, IFNGR2, IFNAR1 and IFNAR2, the signaling intermediates Janus kinase 1 (JAK1), signal transducer and activator of transcription 1 (STAT1) and interferon regulatory factor 1 (IRF1) were determined using real time quantitative polymerase chain reaction (qPCR).

RESULTS

Clinical signs of periodontal disease were markedly more severe in DS and euploid patients with PD in comparison to euploid and periodontally healthy patients. There was no difference on mRNA levels of IFNA, IFNG, INFGR2, IFNAR1 and IFNAR2 between DS and euploid individuals, even though some of these genes are located on chromosome 21. STAT1 and IRF1 mRNA levels were significantly lower in DS patients in comparison with euploid individuals with PD. In euploid individuals, PD was associated with an increased expression of IFNGR1, IFNGR2, IFNAR1, STAT1 and IRF1.

CONCLUSIONS

Reduced expression of STAT1 and IRF1 genes indicate an impaired activation of IFNs signaling in individuals with DS and PD. Expression of IFNA, IFNG and IFN receptors was not altered in DS patients, indicating that indirect mechanisms are involved in the reduced activation of IFN signaling.

Multiple applications of flurbiprofen and chlorhexidine chips in patients with chronic periodontitis: a randomized, double blind, parallel, 2-arms clinical trial

AIM

The aim of the present randomized, double blind, parallel, 2-arm clinical study was to examine the safety and efficacy of frequent applications of chlorhexidine chip (CHX) and flurbiprofen chip (FBP) in patients with chronic periodontitis.

METHODS

Sixty patients were randomized into CHX and FBP groups. Following OHI and scaling and root planing (SRP), baseline pocket depth (PD) measurements, gingival recession and bleeding on probing (BOP) were performed and repeated at week 4 and 8. The assigned chip was placed at weeks 0, 1, 2, 3, 5, 7.

RESULTS

Mean PD reduction in the CHX group was 2.08 mm (7.17 to 5.09, p < 0.0001). Mean PD reduction in the FBP group was 2.27 mm (6.72 to 4.45, p < 0.0001). Ninety-seven percentage and 95% of these sites exhibited PD reduction ≥1 mm, while 38% and 34% of the sites exhibited PD ≥3 mm (FBP and CHX, respectively). Clinical attachment level gain (1.66 and 1.95 mm, respectively) was statistically significant (p < 0.0001). Baseline BOP dropped from 98% and 100% to 24% and 30% for the CHX and FBP groups, respectively (p < 0.0001).

CONCLUSION

Frequent applications of CHX and FBP chips resulted in a significant improvement in the periodontal condition in these sites. Furthermore studies will be required to compare this new treatment regimen to SRP or SRP with single chip application.

Chitosan hydrogel for localized gene silencing

OBJECTIVE

To achieve effective delivery of siRNA into target cells in vivo, we have developed a novel approach of siRNA delivery by using local drug delivery systems.

RESULTS

The chitosan hydrogel (CH-HG) displayed a liquid-solid phase transition in a temperature-dependent manner and formed an endothermic hydrogel in tumor tissue after intra-tumoral injection. Additionally, we tested the extent of in vivo delivery following a single intra-tumoral injection of Alexa555 siRNA/CH-HG into A375SM-bearing mice. The Alexa555 siRNA demonstrated higher localization into tumor cells compared to control. The Alexa555 siRNA delivery extends to tumor cells outside of CH-HG and some tumor cells also infiltrated into CH-HG. For therapeutic proof-of-concept studies, CH-HG including TG2-targeted siRNA significantly inhibited tumor growth in melanoma (A375SM) and breast (MDA-MB231) tumor models compared to control (A375SM: 72% reduction and MDA-MB231: 92% reduction, p < 0.001).

EXPERIMENTAL DESIGN

we prepared a CH-HG system loaded with siRNA to enhance localized therapeutic efficacy without risk for systemic side effects. Delivery of siRNA into CH-HG was confirmed by fluorescence microscopy. Antitumor efficacy was examined in mouse models of melanoma (A375SM) and breast (MDA-MD231) cancer.

CONCLUSIONS

This study developed a novel local delivery method for siRNA therapy using the CH-HG system. This approach could have broad applications for multiple localized diseases.