Hyaluronic acid: Perspectives in dentistry. A systematic review

Histologic Evaluation of Early Papilla Healing after Augmentation with Injectable Hyaluronic Acid-A Proof of Concept

Objectives: This human histological study's purpose was to histologically evaluate papillae's healing after hyaluronic acid (HA) gel augmentation at three healing time points after one injection with hyaDENT BG®. Methods: Fifteen papillae from two patients with stage III, grade B periodontitis have been selected for this study. Every week for three weeks, five papillae were injected once with HA gel, and during the fourth week, the papillae were surgically removed as part of step 3 of the periodontal treatment. The histological analysis was performed on fifteen papillae, with five papillae corresponding to every timepoint of healing (weeks 1, 2, and 3). The primary outcome was considered to be the newly formed collagen fibers. The presence of residual HA, the integrity of epithelium or the presence of erosions/ulcerations, the presence and characteristics of inflammatory infiltrate, the presence of granulomatous reactions, and interstitial edema were considered to be secondary outcomes. Results: From the first to the third week, newly formed connective tissue begins to appear, while the observed HA pools (vesicles) content decreases. The density of inflammatory infiltrate was higher in the first week after injection, decreasing considerably by week 3; however, it was still visible throughout the healing time points. A granulomatous reaction was present in only three samples, while no signs of ulceration or necrosis could be observed; however, epithelial erosions could be observed on some samples after the first week. Conclusions: Papila augmentation with hyaluronic acid promotes new collagen formation from the second week of healing despite some foreign body granulomatous reactions.

Histological evaluation of different concentrations of hyaluronic-acid-added zinc oxide eugenol on rat molar pulp

Hyaluronic acid (HA), known for diverse properties, was investigated for its potential in dental pulp therapy. This study investigated the potential of HA in dental pulp therapy by examining the physical properties and effects of zinc oxide eugenol (ZOE) pulpotomy materials containing varying HA concentrations on rat molar teeth. In vitro tests assessed compressive strength and hardness of ZOE materials blended with HA (0.5%, 1%, 3%) and HA gels (0.54%, 0.8%). 120 samples, encompassing the control group, underwent compressive strength testing, while 60 samples were designated for hardness assessment. In vivo experiments on rat molars studied histological effects of HA-containing ZOE on dental pulp over 1 week and 1 month. Gels with HA concentrations of 0.5%, 1%, and 0.54% were used in pulpotomy on 22 rats. Each rat underwent the procedure on four teeth, with one tooth serving as a control, totaling 88 teeth subjected to the intervention. In the analyses, SPSS 22.0 was used and the significance level was set at P = 0.05. Findings showed that HA at 0.5% maintained compressive strength, but higher concentrations decreased mechanical properties significantly (P = 0.001). Histological assessments indicated better outcomes with lower HA concentrations in terms of odontoblast layer continuity (P = 0.005 at 1 month) and pulp vitality (P = 0.001 at 1 week and P = 0.018 at 1 month). The study suggests HA holds promise for pulpotomy and regenerative endodontic treatments, but further research is needed to understand long-term clinical implications.

Hyaluronidase inhibits TGF-β-mediated rat periodontal ligament fibroblast expression of collagen and myofibroblast markers: An in vitro exploration of periodontal tissue remodeling

OBJECTIVE

To determine the effect of hyaluronic acid (HA) degradation by hyaluronidase (HYAL) in inhibiting collagen fiber production by rat periodontal ligament cells (rPDLCs).

DESIGN

Primary rPDLCs were isolated from the euthanized rats and used for in vitro experiments. The appropriate HYAL concentration was determined through CCK-8 testing for cytotoxicity detection and Alizarin red staining for mineralization detection. RT-qPCR and western blot assays were conducted to assess the effect of HYAL, with or without TGF-β, on generation of collagen fiber constituents and expression of actin alpha 2, smooth muscle (ACTA2) of rPDLCs.

RESULTS

Neither cell proliferation nor mineralization were significantly affected by treatment with 4 U/mL HYAL. HYAL (4 U/mL) alone downregulated type I collagen fiber (Col1a1 and Col1a2) and Acta2 mRNA expression; however, ACTA2 and COL1 protein levels were only downregulated by HYAL treatment after TGF-β induction.

CONCLUSIONS

Treatment of rPDLCs with HYAL can inhibit TGF-β-induced collagen matrix formation and myofibroblast transformation.

Bidirectional Association between Periodontitis and Thyroid Disease: A Scoping Review

Periodontitis is a chronic inflammatory disease of the tissues surrounding and supporting the teeth. Due to the development of chronic inflammation, periodontitis can contribute to the development of several systemic diseases, including thyroid disease. Thyroid pathology includes benign, malignant, and autoimmune conditions leading to hypothyroidism, hyperthyroidism, or euthyroidism. Alterations in thyroid hormones, especially hypothyroidism, can reveal significant oral manifestations, including periodontitis. This scoping review aims to explore the probable causal relationship between periodontitis and thyroid disease, in terms of epidemiology, pathogenesis, and treatment. The search strategy follows the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, and Cochrane were searched from January 2014 to January 2024, entering the MESH terms "periodontitis" and "thyroid". Of 153 initial records, 20 articles were selected and discussed. There is a high prevalence of periodontitis among patients with thyroid disease, including thyroid cancer. The causes at the basis of this association are genetic factors, the oral microbiome, and proinflammatory cytokines. Periodontal treatment, specifically scaling and root planning, can ameliorate thyroid parameters. Although there are a few randomized controlled studies in the literature, this review lays the foundation for a bidirectional relationship between periodontitis and thyroid disease, the link to which is, once again, systemic inflammation.

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.

Application of hydrogel microneedles in the oral cavity

Microneedles are a transdermal drug delivery system in which the needle punctures the epithelium to deliver the drug directly to deep tissues, thus avoiding the influence of the first-pass effect of the gastrointestinal tract and minimizing the likelihood of pain induction. Hydrogel microneedles are microneedles prepared from hydrogels that have good biocompatibility, controllable mechanical properties, and controllable drug release and can be modified to achieve environmental control of drug release in vivo. The large epithelial tissue in the oral cavity is an ideal site for drug delivery via microneedles. Hydrogel microneedles can overcome mucosal hindrances to delivering drugs to deep tissues; this prevents humidity and a highly dynamic environment in the oral cavity from influencing the efficacy of the drugs and enables them to obtain better therapeutic effects. This article analyzes the materials and advantages of common hydrogel microneedles and reviews the application of hydrogel microneedles in the oral cavity.

Hyaluronic acid-based gels for oral application: Comparison of in vitro effects on gingival cells and bacteria

Purpose

This study aimed to evaluate the cytotoxic effects of different topical hyaluronic acid-based gels on human gingival fibroblasts and oral bacteria.

Methods

Four different hyaluronate gels - Bexident® Aftas (BA), GUM® AftaClear (AfC), Gengigel®(G), Aloclair® Plus (AlC) and a chlorhexidine gel - Bexident®Gums(BG) were selected. Human gingival fibroblasts (HGF) were seeded in 48-well plates with different gel/culture medium concentrations (v/v%) and cell viability was evaluated at 1 and 3 days of culture. Cell morphology was assessed, and alterations graded according to ISO 10993-5:2009(E). Streptococcus oralis CECT 907T colony was, seed on 48-well plate or spread onto the blood agar plates and exposed to the different gel's concentration. The optical density (OD) was assessed, and the diameter of the inhibition zone was measured (mm).

Results

BA and G elicited reduced HGF cytotoxicity, followed by AfC. AlC and BG were cytotoxic at concentrations up to 3% for all exposure times. PCM images of HGF showed moderate-to-severe alterations for AlC and BG and slight to mild changes, for BA, AfC and G. The highest antibacterial activity against S.oralis was observed on AlC and AfC, and no antibacterial activity was observed for BA and G. Inhibitory effect in sessile colonies was only observed in AlC and BG.

Conclusions

AlC demonstrated superior antibacterial activities against S.oralis but a higher cytotoxic potential in HGF. BA and G presented the lowest cytotoxicity with little to no antibacterial effect. AfC demonstrated bacteriostatic effects and low cytotoxicity on HGF.

The Efficacy of Three Different Oral Hygiene Regimens in Preventing Chemotherapy-Induced Oral Mucositis in Pediatric Patients Receiving Hematopoietic Stem Cell Transplantation

BACKGROUND

Oral mucositis is one of the side effects developed post-hematopoietic stem cell transplant. This retrospective study aimed to assess the efficacy of a mouthwash mixture (lidocaine, sodium alginate, sucralfate, pheniramine) versus hyaluronic acid and a solution of sodium bicarbonate in terms of healing time and weight gain in the treatment of oral mucositis in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation with hemato-oncological malignancies.

METHODS

A total of 171 patients that received chemotherapy for the hematopoietic stem cell transplant were divided into three groups; group 1, treated with a mixed mouthwash of lidocaine, sodium alginate, sucralfate, and pheniramine; group 2, treated with hyaluronic acid; and group 3, treated with an aqueous solution of 5% sodium bicarbonate. Weight and mucositis scale scores derived from medical records of patients.

RESULTS

There was a statistically significant difference in the mucositis scale scores between the groups on the transplant day and days 5, 10, 15 and 20 after the transplantation. At these measurement points, Group 2 (receiving hyaluronic acid) had a lower score, and Group 3 (who received sodium bicarbonate) had a higher score, especially on days 5 and 10 after the transplantation.

CONCLUSION

The results suggest that hyaluronic acid is a more effective treatment option than the other oral care solutions that are frequently used for prophylaxis and treatment of oral mucositis.

From Basic Science to Clinical Practice: A Review of Current Periodontal/Mucogingival Regenerative Biomaterials

Periodontitis is a dysbiosis-driven inflammatory disease affecting the tooth-supporting tissues, characterized by their progressive resorption, which can ultimately lead to tooth loss. A step-wise therapeutic approach is employed for periodontitis. After an initial behavioral and non-surgical phase, intra-bony or furcation defects may be amenable to regenerative procedures. This review discusses the regenerative technologies employed for periodontal regeneration, highlighting the current limitations and future research areas. The search, performed on the MEDLINE database, has identified the available biomaterials, including biologicals (autologous platelet concentrates, hydrogels), bone grafts (pure or putty), and membranes. Biologicals and bone grafts have been critically analyzed in terms of composition, mechanism of action, and clinical applications. Although a certain degree of periodontal regeneration is predictable in intra-bony and class II furcation defects, complete defect closure is hardly achieved. Moreover, treating class III furcation defects remains challenging. The key properties required for functional regeneration are discussed, and none of the commercially available biomaterials possess all the ideal characteristics. Therefore, research is needed to promote the advancement of more effective and targeted regenerative therapies for periodontitis. Lastly, improving the design and reporting of clinical studies is suggested by strictly adhering to the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement.

Chronic Traumatic Ulcer: A Case Report

Chronic traumatic ulcers (CTUs) of the oral cavity are frequently brought on by repeated mechanical stress, such as biting or friction from dental appliances, or sharp or broken carious teeth. Although they are frequently disregarded, patients with nonhealing ulcers in the mouth should have CTUs taken into consideration. This report highlights the significance of differential diagnosis and suitable treatment options by discussing a case of a CTU that persisted on the tongue's right lateral border.

The response of human osteoblasts on bovine xenografts with and without hyaluronate used in bone augmentation

The aim of the in vitro study was to asses the effect of hyaluronate in conjunction with bovine derived xenografts on the viability, proliferation on day 4, 7 and 10, expression of early osteogenic differentiation marker Alkaline phosphatase on day 14 and 21, collagen, calcium deposition on day 14, 21 and 28 and cellular characteristics, as assessed through live cell image analysis, confocal laser scanning microscopy and scanning electron microscopy, in primary human osteoblasts compared to three bovine xenografts without hyaluronate. All experiments were performed in triplicates. Data were compared between groups and timepoints using one-way analysis of variance (ANOVA). Bonferroni post hoc test were further used for multiple comparison between groups (p < .05) An increase in cell viability (p < .05) and enhanced ALP activity was observed in all xenografts. Specimens containing hyaluronate showed a highest significant difference (23755 ± 29953, p < .0001). The highest levels of calcium (1.60 ± 0.30) and collagen (1.92 ± 0.09, p < .0001) deposition were also observed with hyaluronate loaded groups. The osteoblasts were well attached and spread on all xenograft groups. However, a higher number of cells were observed with hyaluronate functionalized xenograft (76.27 ± 15.11, (p < .0001) in live cell image analysis and they migrated towards the graft boundaries. The biofunctionalization of xenografts with hyaluronate improves their in vitro performance on human osteoblasts. This suggests that hyaluronate might be able to improve the bone regeneration when using such xenografts.

Green tea and hyaluronic acid gel enhance fibroblast activation and improves the gingival healing post-third molar extraction

This study evaluates the effects of a green tea (Camellia sinensis) and hyaluronic acid gel on fibroblast activity and alveolar bone repair following third molar extractions. By examining the gene expression related to cell survival, proliferation, and angiogenesis, the study bridges in vitro findings with clinical outcomes in a split-mouth randomized trial. Human fibroblasts were exposed to the treatment gel, analysing gene expression through RT-qPCR. Twenty participants undergoing bilateral third molar extractions received the test gel on one side and a placebo on the other. Assessments included patient-reported outcomes, professional evaluations, and radiographic analyses at multiple postoperative intervals. The test gel significantly enhanced AKT, CDKs, and VEGF gene expressions, indicating a positive effect on angiogenesis and cell proliferation. Clinically, it resulted in reduced exudate, swelling, and secondary interventions, with radiographs showing improved alveolar bone density after 90 days. The green tea and hyaluronic acid gel significantly improves soft tissue and bone healing post-extraction, offering a promising adjunctive therapy for enhancing postoperative recovery. This gel represents a novel adjuvant treatment option for facilitating improved healing outcomes after third molar extractions, highlighting its potential utility in clinical dental practice.

Hyaluronic acid in Dentoalveolar regeneration: Biological rationale and clinical applications

Background

Hyaluronic acid (HA) is found in different locations in the periodontium, including mineralized tissues (i.e., cementum and alveolar bone) and non-mineralized tissues (i.e., gingiva and periodontal ligament). In addition, it seems to play an essential part in regulating the underlying mechanisms involved in tissue inflammatory reactions and wound healing. HA has the potential to regulate periodontal tissue regeneration and treat periodontal disease.

Aim

The current review of the literature was conducted to assess how HA plays its part in periodontal therapy and examine the contemporary literature's viewpoint on its use in periodontal regeneration.

Conclusion

HA has a multifunctional character in periodontal regeneration, and healing and appears to provide promising outcomes in different periodontal regenerative applications.

Hyaluronic acid enhances cell migration, viability, and mineralized tissue-specific genes in cementoblasts

BACKGROUND/OBJECTIVES

It has been repeatedly demonstrated that cementum formation is a crucial step in periodontal regeneration. Hyaluronic acid (HA) is an important component of the extracellular matrix which regulates cells functions and cell-cell communication. Hyaluronic acid/derivatives have been used in regenerative periodontal therapy, but the cellular effects of HA are still unknown. To investigate the effects of HA on cementoblast functions, cell viability, migration, mineralization, differentiation, and mineralized tissue-associated genes and cementoblast-specific markers of the cementoblasts were tested.

MATERIALS AND METHODS

Cementoblasts (OCCM-30) were treated with various dilutions (0, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, 1:128) of HA and examined for cell viability, migration, mineralization, and gene expressions. The mRNA expressions of osteocalcin (OCN), runt-related transcription factor 2 (Runx2), bone sialoprotein (BSP), collagen type I (COL-I), alkaline phosphatase (ALP), cementum protein-1 (CEMP-1), cementum attachment protein (CAP), and small mothers against decapentaplegic (Smad) -1, 2, 3, 6, 7, β-catenin (Ctnnb1) were performed with real-time polymerase chain reaction (RT-PCR). Total RNA was isolated on days 3 and 8, and cell viability was determined using MTT assay on days 1 and 3. The cell mineralization was evaluated by von Kossa staining on day 8. Cell migration was assessed 2, 4, 6, and 24 hours following exposure to HA dilutions using an in vitro wound healing assay (0, 1:2, 1:4, 1:8).

RESULTS

At dilution of 1:2 to 1:128, HA importantly increased cell viability (p < .01). HA at a dilution of 1/2 increased wound healing rates after 4 h compared to the other dilutions and the untreated control group. Increased numbers of mineralized nodules were determined at dilutions of 1:2, 1:4, and 1:8 compared with control group. mRNA expressions of mineralized tissue marker including COL-I, BSP, RunX2, ALP, and OCN significantly improved by HA treatments compared with control group both on 3 days and on 8 days (p < .01). Smad 2, Smad 3, Smad 7, and β-catenin (Ctnnb1) mRNAs were up-regulated, while Smad1 and Smad 6 were not affected by HA administration. Additionally, HA at dilutions of 1:2, 1:4, and 1:8 remarkably enhanced CEMP-1 and CAP expressions in a dilution- and time-dependent manner (p < .01).

CONCLUSIONS

The present results have demonstrated that HA affected the expression of both mineralized tissue markers and cementoblast-specific genes. Positive effects of HA on the cementoblast functions demonstrated that HA application may play a key role in cementum regeneration.

Injectable platelet rich fibrin versus hyaluronic acid with bovine derived xenograft for alveolar ridge preservation. A randomized controlled clinical trial with histomorphometric analysis

BACKGROUND

Alveolar ridge preservation (ARP) is a technique that aims to maintain bone volume and minimize resorption after tooth extraction.

OBJECTIVE

This study aimed to compare the effectiveness of injectable platelet-rich fibrin (I-PRF) versus hyaluronic acid (HA) in combination with xenografts for ARP.

METHODS

This randomized controlled trial included 36 patients (20 females and 16 males) who required implant placement in the upper arch. The patients were randomly allocated to one of three groups (n = 12 each): I-PRF with xenografts, HA with xenografts, or xenografts alone. All patients underwent ARP, and the extraction sockets were sealed with a free gingival graft harvested from the palate, a total of 36 implants were inserted. Cone-beam CT scans were performed before and 4 months postoperatively to measure radiographic bone gain as the primary outcome. Clinical parameters, including soft tissue thickness and clinical bone width, were evaluated preoperatively, and at 4 months and 1 year postoperatively. Additionally, histological assessment of core bone biopsies was performed 4 months postoperatively using histomorphometric analysis to determine the percentages of newly formed bone, mature bone, and residual grafts.

RESULTS

Regarding the radiographic bone gain 4 months postoperative the HA group exhibited the highest value (9.78 ± 0.87), which was significantly greater than the values observed in the I-PRF and control groups (8.60 ± 1.27 and 7.99 ± 0.89, respectively) (one-way ANOVA, p = 0.007). Crestal bone loss was significantly higher in the control group (-0.98 ± 0.18) than in the I-PRF group (-0.53 ± 0.11) and HA group (-0.33 ± 0.15) groups (one-way ANOVA, p < 0.001). In the histomorphometric analysis, the mean area fraction of newly formed bone trabeculae was significantly higher in the HA group (56.66 ± 7.35) than in the I-PRF group (28.74 ± 5.15) and the control group (24.05 ± 3.64) (repeated measures ANOVA, p < 0.001). Additionally, the mean area fraction of residual graft material was higher in the I-PRF group (6.76 ± 2.59), followed by the control group (2.71 ± 1.24), while the HA group had the lowest value (2.63 ± 1.27) (Repeated measures ANOVA, p < 0.001).

CONCLUSION

The combination of HA with xenografts yielded better radiographic and histological outcomes in terms of new bone formation and degree of bone maturation than the I-PRF and control groups. Furthermore, I-PRF improved soft tissue thickness. Please note that clinical trial registration was not completed prior to participant recruitment and randomization. The registration link for this trial is https://clinicaltrials.gov/ct2/show/NCT05781529.

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.

The Association of High-Molecular-Weight Hyaluronic Acid (HMWHA), Alpha Lipoic Acid (ALA), Magnesium, Vitamin B6, and Vitamin D Improves Subchorionic Hematoma Resorption in Women with Threatened Miscarriage: A Pilot Clinical Study

Background-We evaluated whether the oral intake of high-molecular-weight hyaluronic acid (HMWHA) in association with alpha lipoic acid (ALA), magnesium, vitamin B6, and vitamin D can improve the resorption of subchorionic hematoma in cases of threatened miscarriage. Methods-In this study, we enrolled 56 pregnant women with threatened miscarriage (i.e., subchorionic hematomas, pelvic pain/uterine contractions, and/or vaginal bleeding) between the 6th and the 13th week of gestation. They were treated with vaginal progesterone (200 mg/twice a day) (control group; n = 25) or vaginal progesterone plus oral 200 mg HMWHA, 100 mg ALA, 450 mg magnesium, 2.6 mg vitamin B6, and 50 mcg vitamin D (treatment group; n = 31; DAV®-HA, LoLi Pharma srl, Rome, Italy). An ultrasound scan was performed at the first visit (T0) and after 7 days (T1) and 14 days (T2) until hematoma resorption. Results-At the ultrasound scan, the treatment group showed faster resorption of the subchorionic hematoma compared with the control group, both at T1 (control group 140 (112-180), treated group 84 (40-112), p < 0.0031), and T2 (control group: 72 (48-112), treated group: 0 (0-0), p < 0.0001). Moreover, subjective symptoms, such as vaginal bleeding, abdominal pain, and uterine contractions, showed a faster decrease in the treatment group than in the control group. Conclusions-The association may more rapidly improve the resolution of threatened miscarriage and related symptoms compared to the standard local protocol.

Exploring the anti-inflammatory potential of topical hyaluronic acid for vocal fold injury in a rat model

PURPOSE

Vocal fold injuries are associated with fibrosis and dysphonia, which is a major obstacle to surgical treatment. The aim of this study is to evaluate the effect of topical hyaluronic acid with or without diclofenac on the inflammatory phase of vocal fold wound healing.

METHODS

Forty-one male Sprague-Dawley rats were randomly assigned to four groups: an uninjured control group, an injured control group without any treatment, and two intervention groups in which hyaluronic acid with or without diclofenac was applied to the injured vocal fold. Gene expression of inflammatory markers and ECM-related molecules were examined.

RESULTS

Vocal fold injury resulted in a significant upregulation of inflammatory parameters [Ptgs2, Il1b and Il10] and Has1. Tgfb1, Has3 and Eln gene expression were significantly downregulated by the topical application of hyaluronic acid. The combination of hyaluronic acid and diclofenac did not result in any significant changes.

CONCLUSIONS

Vocal fold wound healing was significantly improved by a single post-operative topical application of hyaluronic acid. The addition of diclofenac may provide no additional benefit.

Fibroblast Viability Through Mechanical and Chemical Root Surface Modifications in Periodontal Healing: An In Vitro Comparative Study

BACKGROUND

The wound-healing process incorporates a spectrum of periodontal therapeutic interventions that strive to restore the health and function of the periodontium. Fibroblasts play pivotal roles in tissue repair and regeneration. Extensive research has been focused on mechanical and chemical root surface modifications to enhance fibroblast adhesion, which is crucial for successful wound healing.

PURPOSE

This study aimed to assess the combined efficacy of mechanical and chemical root surface modifications in promoting fibroblast viability to root surfaces affected by periodontitis in comparison to chemical modifications alone.

MATERIALS AND METHODS

Root samples were collected from healthy individuals and those with advanced periodontitis. The specimens were prepared, and the experimental groups were categorized based on the type of surface modification with mechanical and/or chemical materials, including hyaluronic acid (HA), ethylenediaminetetraacetic acid (EDTA), enamel matrix derivatives (EMD), and EDTA/EMD. Fibroblasts were seeded onto previously treated root samples. Cell adhesion was assessed using a viability assay.

RESULTS

Fibroblast viability was significantly higher on root surfaces treated with chemical agents than on those treated with mechanical and chemical modifications. Long-duration EDTA and short-duration EMD treatments were significantly effective in enhancing cell viability. EDTA/EMD surface treatments resulted in significantly higher cell viability in all groups compared to the periodontitis root surfaces.

CONCLUSION

EDTA, EMD, and their combined application can potentially ameliorate periodontitis-induced surface structural impairments. Mechanical surface debridement can significantly affect the effectiveness of EDTA and EMD root conditioning agents.

Could Hyaluronic Acid Be Considered as a Senomorphic Agent in Knee Osteoarthritis? A Systematic Review

BACKGROUND

Knee osteoarthritis (KOA) is one of the most common causes of disability in elderly patients and tends to be a major burden on social and health care spending. Despite its severe socioeconomic impact, KOA remains, to date, an incurable disease. Due to its proper characteristics, KOA represents a favorable disease model for experimenting with senotherapeutics, a group of treatments that counteract the development of age-related disorders and chronic diseases. In recent years, the use of intra-articular hyaluronic acid (IAHA) in the treatment of diseases related to the wear and tear of the articular cartilage has been gaining popularity. Given its ability in joint lubrification, shock absorption, and cell signaling, our aim is to investigate, through the existing scientific literature, its potential role as a senomorphic agent, emphasizing its crucial function in KOA patients. Indeed, senomorphics are a particular group of senotherapeutics capable of modulating the functions and morphology of senescent cells to those of young cells or delaying the progression of young cells to senescent cells in tissues.

METHODS

A search in the scientific literature (PubMed, Cochrane Library, and Google Scholar) was carried out from 2019 to 2023, thus the last 5 years.

RESULTS

One hundred thirty-eight articles were found concerning the role of hyaluronic acid injections in KOA patients. In these studies, its therapeutic efficacy, its anti-inflammatory properties, and its low risk of side effects emerged.

CONCLUSION

IAHA injections are a valuable treatment option for KOA while they can provide pain relief, improve joint function, and slow the progression of joint degeneration. The inhibitory effect of HA on MMP13 and its action as a senomorphic agent suggests that it may have additional benefits beyond its lubricating and shock-absorbing properties. In order to clarify its mechanisms of action and to optimize its clinical use, further studies are definitely needed.

Hyaluronic Acid: Exploring Its Versatile Applications in Dentistry

Hyaluronic acid (HA) a polysaccharide present in many areas of the body like the synovium of synovial joints, and connective tissues which have high regenerative and biocompatible properties has been an area of interest since recent times in dentistry. Several research papers and review articles were studied in the Pubmed database to formulate this review article. The main aim of this article is to demonstrate various applications of HA in different branches of dentistry. The PubMed database was searched for keywords "Hyaluronic acid AND periodontics," "Hyaluronic acid AND oral and maxillofacial surgery," "Hyaluronic acid AND oral medicine," "Hyaluronic acid AND orthodontics," "Hyaluronic acid AND endodontics," and "Hyaluronic acid AND aesthetic dentistry" which resulted in six, 296, 83, 86, 40, and 49 articles, respectively. The most relevant and informative articles were selected and studied for this review article. This review article will also help people to gain knowledge about the future aspects of the use of HA in dentistry and also motivate clinicians and new-generation dentists to inculcate the HA's use in their respective practice in dentistry.

Advances in haemostatic sponges: Characteristics and the underlying mechanisms for rapid haemostasis

In traumatized patients, the primary cause of mortality is uncontrollable continuous bleeding and unexpected intraoperative bleeding which is likely to increase the risk of complications and surgical failure. High expansion sponges are effective clinical practice for the treatment of wound bleeding (irregular/deep/narrow) that are caused by capillaries, veins and even arterioles as they possess a high liquid absorption ratio so can absorb blood platelets easily in comparison with traditional haemostasis treatments, which involve compression, ligation, or electrical coagulation etc. When in contact with blood, haemostatic sponges can cause platelet adhesion, aggregation, and thrombosis, preventing blood from flowing out from wounds, triggering the release of coagulation factors, causing the blood to form a stable polymerized fibre protein, forming blood clots, and achieving the goal of wound bleeding control. Haemostatic sponges are found in a variety of shapes and sizes. The aim of this review is to facilitate an overview of recent research around haemostatic sponge materials, products, and technology. This paper reviews the synthesis, properties, and characteristics of haemostatic sponges, together with the haemostasis mechanisms of haemostatic sponges (composite materials), such as chitosan, cellulose, gelatin, starch, graphene oxide, hyaluronic acid, alginate, polyethylene glycol, silk fibroin, synthetic polymers silver nanoparticles, zinc oxide nanoparticles, mesoporous silica nanoparticles, and silica nanoparticles. Also, this paper reviews commercial sponges and their properties. In addition to this, we discuss various in-vitro/in-vivo approaches for the evaluation of the effect of sponges on haemostasis.

Traumatic ulcer of the tongue mimicking a malignant lesion: Case report

INTRODUCTION AND IMPORTANCE

The most prevalent oral ulcers are those caused by trauma, and their etiopathogenesis has been frequently obvious. Yet, oral ulcers can be misdiagnosed and managed incorrectly.

CASE PRESENTATION

A 25-year-old patient presented to our service with a painful lesion on the right lateral border of the tongue that had evolved for one week. A possible traumatic factor was identified. The ulcer completely recovered once the trauma's cause was removed. An accurate diagnosis was achieved by combining a precise physical examination with clinical follow-up.

CLINICAL DISCUSSION

Single oral ulcers have various clinical presentations that can be confusing. Some of them may mimic oral squamous cell carcinoma (OSCC), especially when accompanied by any induration. Determining the cause of oral ulceration requires a careful medical history and a clinical examination with inspection and palpation, which may be combined with other accessory investigations if necessary.

CONCLUSION

This clinical case reinforces the importance of investigating local causes before moving on to systemic ones. We present differential diagnosis and management algorithm of single oral ulcers.

New medical device coating mouth gel for temporary relief of teething symptoms: a pilot randomized, open-label, controlled study

BACKGROUND

This study verified the feasibility of the monthly recruitment rate, tested the Face, Legs, Activity, Cry and Consolability Pain Assessment Tool (FLACC) for pain in infants and collected preliminary efficacy and safety data of a new proprietary oral gel formulation of high-molecular-weight hyaluronan (HMWHA) for the relief of teething. Results will support the design a future main trial vs. local anesthetic, that is currently the only clinically proven pain reliever.

METHODS

This was a pilot, randomized, controlled, multicenter, open-label, and parallel-group trial. It was performed in two Romanian clinics recruiting infants from 3 to 36 months. Teething diagnosis was based on a minimum of three symptoms such as: local pain, swelling, erythema, hyper-salivation, and depth characteristics of unerupted tooth. Absence of subcutaneous mucosal laceration was also required. The children were assigned either to HMWHA (HABPX V 3.3, Bioplax Ltd, Wallington, UK), or to standard drug (Dentinox^®-Gel N; Dentinox, Berlin, Germany) and treated for 7 consecutive days. Investigators recorded the primary endpoints: swelling, redness and pain (by FLACC method), on days 0, 3 and 7. Changes in crying, mouth spasms, salivation, local pain, swelling, and redness were the secondary endpoints, recorded daily by the parents, on diary cards. Tolerability was assessed on day 14, too.

RESULTS

Twenty-seven Infants were allocated in HMWHA, and 30 in standard drug. Enrolment rate was 9 patients/month/site. A significant reduction for HMWHA group was evidenced in pain, swelling (from day 0 to 7, P=0.034 between groups), redness (from day 0 to 3, P=0.045 and from day 0 to 7, P<0.001 between groups) and confirmed by the parents' diary records. Pain measurements obtained by FLACC method are consistent with the data belonging to other parameters. Investigator's global assessment of performance was in favor of the HMWHA (P<0.005). Only two patients, both belonging to standard drug group, experienced adverse events (fever, not related to treatment) and dropped out of the study.

CONCLUSIONS

The results solve the feasibility questions and clearly evidence the performance of HABPX V 3.3 in teething symptoms, exceeding the objectives of a simple pilot trial to some extent. Coating oral gels containing HMWHA could be a therapeutic solution for both parents and physicians in managing the irritation and pain resulting from tooth eruption in children.

Evaluation between Biodegradable Magnesium Metal GBR Membrane and Bovine Graft with or without Hyaluronate

Bone substitutes and barrier membranes are widely used in dental regeneration procedures. New materials are constantly being developed to provide the most optimal surgical outcomes. One of these developments is the addition of hyaluronate (HA) to the bovine bone graft, which has beneficial wound healing and handling properties. However, an acidic environment that is potentially produced by the HA is known to increase the degradation of magnesium metal. The aim of this study was to evaluate the potential risk for the addition of HA to the bovine bone graft on the degradation rate and hence the efficacy of a new biodegradable magnesium metal GBR membrane. pH and conductivity measurements were made in vitro for samples placed in phosphate-buffered solutions. These in vitro tests showed that the combination of the bovine graft with HA resulted in an alkaline environment for the concentrations that were used. The combination was also tested in a clinical setting. The use of the magnesium metal membrane in combination with the tested grafting materials achieved successful treatment in these patients and no adverse effects were observed in vivo for regenerative treatments with or without HA. Magnesium based biodegradable GBR membranes can be safely used in combination with bovine graft with or without hyaluronate.

Clinical, histological, immunohistochemical, and biomolecular analysis of hyaluronic acid in early wound healing of human gingival tissues: A randomized, split-mouth trial

BACKGROUND

Hyaluronic acid (HA) exerts a fundamental role in tissue repair. In vitro and animal studies demonstrated its ability to enhance wound healing. Nevertheless, in vivo human studies evaluating mechanisms involved in oral soft tissue repair are lacking. The aim of this study was to evaluate the in vivo effect of HA on early wound healing of human gingival (G) tissues.

METHODS

In the present randomized, split-mouth, double-blind, clinical trial, G biopsies were obtained in eight patients 24 h post-surgery after HA application (HA group) and compared with those obtained from the same patients without HA application (no treatment; NT group). Clinical response was evaluated through the Early Wound Healing Score (EHS). Microvascular density (MVD), collagen content and cellular proliferation were evaluated through sirius red and Masson trichrome staining, and Ki-67 immunohistochemistry, respectively. To assess collagen turnover, MMP-1, MMP-2, MMP-9, TGF-β1 protein levels and LOX, MMP1, TIMP1, TGFB1 gene expression were analyzed by western blot and real time polymerase chain reaction.

RESULTS

Twenty-four hours after surgery, the EHS was significantly higher in the HA group. MVD, collagen content, and cell proliferation were not affected. LOX mRNA, MMP-1 protein, and TIMP1 gene expression were significantly upregulated in the HA compared to the NT group.

CONCLUSIONS

The additional use of 0.8% HA gel does not modify new blood vessel growth in the early phase of gingival wound healing. Concerning the secondary outcomes, HA seems to enhance extracellular matrix remodeling and collagen maturation, which could drive early wound healing of G tissues to improve clinical parameters.

Dental Materials Applied to 3D and 4D Printing Technologies: A Review

As computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have matured, three-dimensional (3D) printing materials suitable for dentistry have attracted considerable research interest, owing to their high efficiency and low cost for clinical treatment. Three-dimensional printing technology, also known as additive manufacturing, has developed rapidly over the last forty years, with gradual application in various fields from industry to dental sciences. Four-dimensional (4D) printing, defined as the fabrication of complex spontaneous structures that change over time in response to external stimuli in expected ways, includes the increasingly popular bioprinting. Existing 3D printing materials have varied characteristics and scopes of application; therefore, categorization is required. This review aims to classify, summarize, and discuss dental materials for 3D printing and 4D printing from a clinical perspective. Based on these, this review describes four major materials, i.e., polymers, metals, ceramics, and biomaterials. The manufacturing process of 3D printing and 4D printing materials, their characteristics, applicable printing technologies, and clinical application scope are described in detail. Furthermore, the development of composite materials for 3D printing is the main focus of future research, as combining multiple materials can improve the materials' properties. Updates in material sciences play important roles in dentistry; hence, the emergence of newer materials are expected to promote further innovations in dentistry.

Efficacy of Hyaluronic Acid in Relieving Post-implantation Pain: A Split-Mouth Randomized Controlled Trial

Background

Many patients suffer from some degree of pain following the surgical procedures of dental implantation. The fear of pain may be one reason for postponing such prosthodontic treatments. Many procedures have been suggested to control post-implantation pain. This trial evaluated the effectiveness of using hyaluronic acid (HA) during dental implantation on patients’ perceived pain during the postsurgical soft-tissue healing period.

Methodology

A split-mouth randomized controlled trial (RCT) was conducted. The trial sample consisted of 22 dental implants in 11 patients (five males and six females). Patients were selected from those attending the Department of Oral Medicine at the Faculty of Dentistry, University of Damascus between February 2021 and May 2022. The implants were performed in similar bone quality and density for each patient as the implants were inserted in the same jaw on both sides to ensure the same physiological conditions. The study sample was divided into two groups. The first group (the experimental group) consisted of 11 implants in which the implant site was drilled, following which HA was placed inside the implant site and on the surrounding bone before the flap was returned and sutured. The second group (the control group) comprised 11 implants following the conventional procedure without applying any material to the implant socket. The main outcome measure was pain perception which was assessed using the visual analog scale (VAS). Patients were asked to record their perceived pain on the first, third, and tenth days. Two-sample t-tests were used to detect significant differences.

Results

There were statistically significant differences in the mean pain intensity between the experimental and control groups on the first, third, and tenth days (p < 0.05). The mean values of perceived pain in the control group were 5.68, 1.72, and 0.56 on the first, third, and tenth days, respectively. In comparison, the mean values of perceived pain in the experimental group were 4.52, 1.14, and 0.18 on the first, third, and tenth days, respectively. The maximum perceived pain in the control group was 7.5 on the first day following implantation, whereas the maximum value recorded in the experimental group was 6.5. At the third assessment time (i.e., 10 days following the surgical intervention), the mean values were in the very mild category of pain intensity.

Conclusions

This study showed that applying HA in the implant cavity and on the surrounding bone effectively reduced pain after dental implant surgery in comparison with the control group. Patients had lower mean pain scores at one, three, and ten days following surgery compared to the conventional method. HA is suggested to be an adjunctive method to control postsurgical pain after dental implantation.

Analysis of the response to two pharmacological protocols in patients with oral lichen planus: A randomized clinical trial

OBJECTIVE

To evaluate the effectiveness of two different therapies on oral lichen planus (OLP) treatment through the analysis of OLP symptoms and signs and to analyze the risk of side effects related to the adopted protocols.

METHODS

Thirty-eight patients with OLP were selected according to van der Meij and van der Waal clinical and histopathological criteria. Through a randomized design, 19 patients received Tacrolimus 0.1% ointment (T group) and 19 an anti-inflammatory mouthwash (M group) composed of calcium hydroxide 10%, hyaluronic acid 0.3%, umbelliferone, and oligomeric proanthocyanidins. The patients were examined on a regular basis for OLP symptoms, signs, and disease severity score changes over a 3-month follow-up period.

RESULTS

Both treatments were effective in the reduction of OLP signs and symptoms. However, at 3 months (T3), in comparison with the M group, T group patients showed significantly lower mean values of OLP signs (p = 0.035), symptoms (p = 0.045), and disease severity scores (p = 0.041). Moreover, the Spearman test showed that there was a significant correlation between OLP signs and symptoms at each follow-up session in all patients.

CONCLUSIONS

Both treatments demonstrated a significant approach to control OLP. However, tacrolimus determined a more effective improvement in OLP signs and symptoms compared to anti-inflammatory mouthwash at 3-month follow-up.

Effectiveness of Hyaluronic Acid Gel Injection with and without PRGF for Management of Interdental Papillary Loss: A Randomized Clinical Trial

BACKGROUND

To evaluate the effectiveness of hyaluronic acid (HA) gel injection with and without plasma rich in growth factors (PRGF) for the management of interdental papillary loss.

METHODS

A single blinded randomized clinical trial was carried out on 21 subjects with 34 sites. Patients within the age group 18-45 years who had Class I and II papillary recession in the maxillary anterior region were selected. The sites involved were randomly assigned to Group HA alone and Group HA + PRGF. The patients were recalled 4 weeks after receiving supragingival and subgingival instrumentation. HA or HA + PRGF was injected into the defective papilla at baseline and at 3 and 6 weeks. Image based measurements of Papillary Width (PW), Papillary Deficient Height (PDH), Deficient Area (DA), Deficient Volume (DV) were registered at baseline, 3 weeks, 6 weeks and 12 weeks. A vernier caliper was used to measure the papillary depth in the impression made using additional silicone impression material pre- and post-intervention.

RESULTS

There was a significant improvement in the within-group comparison of PW, PDH, DA and DV in both the groups. Group HA + PRGF showed significantly greater improvement in comparison to Group HA alone in terms of PDH, DA and DV at 6 and 12 weeks.

CONCLUSIONS

Even though HA gel has already been established as a promising injectable agent in the minimally invasive treatment of interdental papillary deficiency, PRGF may also have a significant adjuvant effect when used along with HA. Further clinical studies with longer follow up duration, larger sample size and standardization of the tooth shape are required for a better understanding of the adjuvant effect of PRGF when used along with HA.

Clinical efficacy of hyaluronic acid in the treatment of periodontal intrabony defect: a systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to evaluate the effects of hyaluronic acid (HA) alone or in combination with any bone substitute for the treatment of intrabony defects (IBDs).

MATERIAL AND METHODS

Six databases were searched up to April 2022 to find randomized clinical trials comparing the clinical effects of open flap debridement (OFD) + HA versus OFD alone (first group) or OFD + HA + bone substitutes versus OFD + bone substitutes (second group) in the treatment of IBDs with a follow-up of at least 3 months. Random effects models of mean differences were used to determine the clinical attachment level (CAL) gain, probing depth (PD) reduction, and radiographic bone fill (RBF).

RESULTS

Of the 276 studies identified, 6 were included in the qualitative synthesis, and 5 in the meta-analyses. The meta-analyses in the first group showed a statistically significant differences for CAL gain (mean difference [MD]:1.00; 95% confidence interval [CI]:0.65 - 1.35; n = 2) and PD reduction (MD: 0.76; 95%CI: 0.34 - 1.17; n = 2) favoring HA + OFD at 6 months. However, in the second group, the meta-analyses did no show additional effect of HA in association with bone substitute was demonstrated for either CAL gain (MD: 0.57; 95%CI: - 0.30 - 1.43; n = 2) or PD reduction (MD: 1.05; 95%CI: - 0.38 - 2.47; n = 2) but did show significant differences for RBF (MD: 0.57; 95%CI: 0.15 - 0.99; n = 2) at 12 months.

CONCLUSION

Compared with OFD alone, local application of HA in the treatment of IBDs provided a significant CAL gain and PD reduction at 6 months. However, its combination with bone substitutes showed no statistically significant differences at 12 months.

CLINICAL RELEVANCE

The use of OFD + HA improves the CAL and PD in the treatment of IBDs compared to OFD only after 6 months of follow-up. These results are not maintained after 12 months.

Clinical Performance Evaluation of a Hyaluronic Acid Dental Gel for the Treatment of Traumatic Ulcers in Patients with Fixed Orthodontic Appliances: A Randomized Controlled Trial

BACKGROUND

A newly available gel containing hyaluronic acid (HA) and polyvinylpyrrolidone was tested for efficacy on traumatic oral ulcers (TOU) caused by fixed orthodontic appliances.

METHODS

A double-blind RCT was conducted to test the new gel versus a placebo. According to the sample size calculation, a total of 60 patients were considered sufficient and randomly allocated to one of the two groups out of a pool of 100 total patients who initially agreed to participate in the study. A VAS scale test and lesion measurements at T0, T1, and T2 were performed on the patients.

RESULTS

A total of 70 patients developed TOU, with 8 drop-outs; the intergroup comparison showed a statistically significant greater dimension of the lesion in the control group at T2 when compared to the test group. The pain experienced by the patients belonging to the test group was significantly lower than the pain in the patients in the control group Conclusions: Under the limitations of the study, the new formula might provide faster healing with less pain experienced by the patient when compared to a placebo.

Effectiveness of hyaluronic acid in the management of oral lichen planus: a systematic review and meta-analysis

Oral lichen planus (OLP) is a chronic inflammatory immune-mediated condition that has been identified as a potentially malignant oral disorder. Various therapies have been proposed for its management as alternative to corticosteroids. However, no definitive treatment has been identified that can result in complete remission or minimal recurrence. Hyaluronic acid has recently been used as an alternative therapy for the management of OLP. This study aimed to systematically review the effectiveness of Hyaluronic acid in the management of symptomatic OLP. Online electronic databases and manual searches were performed for randomized controlled trials (RCTs) published in English between January 2010 and April 2022. RCTs were identified that compared the efficacy of hyaluronic acid and other interventional therapies at baseline and during follow-up. The Cochrane Risk of Bias tool was used to assess the quality of the included studies. Visual analog scale (VAS) scores, Thongprasom sign scores, lesion size, degree of erythema, clinical severity, and disease severity were assessed both quantitatively and qualitatively. Seven studies were analyzed. Five studies reported a high risk of bias while the remaining two studies reported an unclear risk of bias. The overall quantitative assessment of size, symptoms, degree of erythema, and sign score in OLP lesions treated with HA was not statistically significant compared to that in the control group (P > 0.05). In addition, subgroup analysis comparing HA with placebo or corticosteroids did not yield statistically significant (P > 0.05) results. Qualitatively, both HA and tacrolimus resulted in an effective reduction in signs and symptoms. Clinical/disease severity index/scores were inconsistent. A high degree of heterogeneity was observed among the included studies. None of the included studies reported the side effects of HA. These findings suggest that corticosteroids, tacrolimus, placebo, and HA could be equally effective in OLP management. The clinical/disease severity index or score reduction cannot be determined with certainty. Thus, OLP can be treated with HA as an alternative therapy. Owing to limited clinical trials on HA, high heterogeneity, and high risk of bias in the included studies, definitive conclusions cannot be derived.

Prolyl-hydroxylase inhibitor-induced regeneration of alveolar bone and soft tissue in a mouse model of periodontitis through metabolic reprogramming

Bone injuries and fractures reliably heal through a process of regeneration with restoration to original structure and function when the gap between adjacent sides of a fracture site is small. However, when there is significant volumetric loss of bone, bone regeneration usually does not occur. In the present studies, we explore a particular case of volumetric bone loss in a mouse model of human periodontal disease (PD) in which alveolar bone surrounding teeth is permanently lost and not replaced. This model employs the placement a ligature around the upper second molar for 10 days leading to inflammation and bone breakdown and faithfully replicates the bacterially-induced inflammatory etiology of human PD to induce bone degeneration. After ligature removal, mice are treated with a timed-release formulation of a small molecule inhibitor of prolylhydroxylases (PHDi; 1,4-DPCA) previously shown to induce epimorphic regeneration of soft tissue in non-regenerating mice. This PHDi induces high expression of HIF-1α and is able to shift the metabolic state from OXPHOS to aerobic glycolysis, an energetic state used by stem cells and embryonic tissue. This regenerative response was completely blocked by siHIF1a. In these studies, we show that timed-release 1,4-DPCA rapidly and completely restores PD-affected bone and soft tissue with normal anatomic fidelity and with increased stem cell markers due to site-specific stem cell migration and/or de-differentiation of local tissue, periodontal ligament (PDL) cell proliferation, and increased vascularization. In-vitro studies using gingival tissue show that 1,4-DPCA indeed induces de-differentiation and the expression of stem cell markers but does not exclude the role of migrating stem cells. Evidence of metabolic reprogramming is seen by the expression of not only HIF-1a, its gene targets, and resultant de-differentiation markers, but also the metabolic genes Glut-1, Gapdh, Pdk1, Pgk1 and Ldh-a in jaw periodontal tissue.

Chitosan as a Functional Carrier for the Local Delivery Anti-Inflammatory Systems Containing Scutellariae baicalensis radix Extract

The aim of the study was to establish the influence of chitosan on the preparation of systems containing Scutellariae baicalensis radix extract and to demonstrate the potential of anti-inflammatory action for the treatment of periodontitis. In the first stage, the impact of the variables (extraction mixture composition, temperature, and the number of extraction cycles) on the extracted samples' biological characteristics was analyzed using the Design of Experiments (DoE) approach. The best conditions for baicalin, baicalein, and wogonin extraction from Scutellariae baicalensis radix were 80% methanol in the extraction mixture, 70 °C, and 4 cycles per 60 min. The DoE approach can be used to choose the best chitosan system parameters with equal success. An increase in the deacetylation degree of chitosan used in the system improved the potential for reducing free radicals and inhibiting the hyaluronidase enzyme. Also, increasing the degree of chitosan deacetylation results in increased resistance of the carrier to biodegradation and an extended baicalin release profile, which is also associated with an increase in the viscosity of the chitosan-based system. In total, the system of a freeze-dried extract with chitosan 90/500 in the ratio of 2:1 (system S9) turns out to be the one with the best physicochemical (high percentage of baicalin release and the highest viscosity conditioning the prolonged stay at the site of administration) and biological properties (the highest antioxidant and anti-inflammatory activities), resulting in the highest potential for use in the treatment of oral inflammatory diseases.

Grafted Microparticles Based on Glycidyl Methacrylate, Hydroxyethyl Methacrylate and Sodium Hyaluronate: Synthesis, Characterization, Adsorption and Release Studies of Metronidazole

Three types of precursor microparticles based on glycidyl methacrylate, hydroxyethyl methacrylate and one of the following three crosslinking agents (mono-, di- or triethylene glycol dimethacrylate) were prepared using the suspension polymerization technique. The precursor microparticles were subsequently used to obtain three types of hybrid microparticles. Their synthesis took place by grafting sodium hyaluronate, in a basic medium, to the epoxy groups located on the surface of the precursor microparticles. Both types of the microparticles were characterized by: FTIR spectroscopy, epoxy groups content, thermogravimetric analysis, dimensional analysis, grafting degree of sodium hyaluronate, SEM and AFM analyses, and specific parameters of porous structures (specific surface area, pore volume, porosity). The results showed that the hybrid microparticles present higher specific surface areas, higher swelling capacities as well as higher adsorption capacities of antimicrobial drugs (metronidazole). To examine the interactions between metronidazole and the precursor/hybrid microparticles the adsorption equilibrium, kinetic and thermodynamic studies were carried out. Thus, it was determined the performance of the polymer systems in order to select a polymer-drug system with a high efficiency. The release kinetics reflect that the release mechanism of metronidazole in the case of hybrid microparticles is a complex mechanism characteristic of anomalous or non-Fickian diffusion.

Minor Recurrent Aphthous Ulcer Management with Hyaluronic Acid Gel in an Italian Cohort: A Double-Blind Randomized Clinical Trial

Background. Recurrent aphthous ulcer is a common mucosal disease and encompasses diverse interventions for its management of symptoms like pain and discomfort. Since new therapies keep evolving with better outcomes as compared to traditional interventions, one such therapy using hyaluronic acid has been recently explored using clinical studies based on advances in dental therapeutics. Therefore, we designed this clinical study which is double blinded and randomized using minor recurrent aphthous cases. Objective. To evaluate the efficacy of hyaluronic acid topical oral gel in the treatment of minor RAS ulcers, with regard to pain relief and reduction in ulcer size. Design. A double-blind randomized controlled clinical trial was designed to conduct an experimental research at IRCCS Fondazione Ca’ Granda, Ospedale Maggiore Policlinico, Milan. The participants were recruited from the unit of oral maxillofacial surgery and randomly assigned to test (hyaluronic acid gel) and control groups (placebo gel). 1 : 1 computer-generated random sequence was prepared, and opaque closed envelopes were used for allocation concealment. Participants and clinical investigators were blinded. The outcome measures included ulcer size (mm) and the visual analogue scale for pain and healing as a secondary outcome measure (efficacy index). Results. The mean baseline score for ulcer size for the test group was $1.85\pm 1$ and the placebo group was $1.85\pm 1.2$ . At day 7, the test group was $1\pm 1.5$ and the placebo group was $2\pm 1.5$ ( $p<0.001$ ). There was significant reduction in ulcer size as compared to the placebo group. In addition, there was significant improvement in pain levels ( $p<0.01$ ) in the test group as compared to the control group. Conclusion. In conclusion, there was significant decrease in the size of the ulcer in the test group as compared to the placebo group. Hyaluronic acid seems to have promising effects on the ulcer size and pain relief associated with minor aphthous ulcers. Trial Registration. The protocol of this clinical trial was registered with the Clinical Trial Registry of ISRCTN with study ID ISRCTN16509838, registered 30 June 2020. It can be accessed on this URL: 10.1186/ISRCTN16509838

Cells and material-based strategies for regenerative endodontics

<p class = "Abstract" style = "margin: 0 cm; line-height: 32px; font-size: 12 pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); "><span lang = "EN-US">The carious process leads to inflammation of pulp tissue. Current care options include root canal treatment or apexification. These procedures, however, result in the loss of tooth vitality, sensitivity, and healing. Pulp capping and dental pulp regeneration are continually evolving techniques to regenerate pulp tissue, avoiding necrosis and loss of vitality. Many studies have successfully employed stem/progenitor cell populations, revascularization approaches, scaffolds or material-based strategies for pulp regeneration. Here we outline advantages and disadvantages of different methods and techniques which are currently being used in the field of regenerative endodontics. We also summarize recent findings on efficacious peptide-based materials which target the dental niche.<o:p></o:p></span></p>

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Pulp infection necessitates removal of necrotic, inflamed and infected tissue.

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Materials used clinically are inert (such as gutta percha, mineral trioxide aggregate).

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Recent developments in materials (angiogenic hydrogels, stem cell composites) have tuneable bioactivity.

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Dental pulp regeneration may now be possible through the use of bioactive systems, that guide regeneration.

A randomized clinical trial of hyaluronic acid gel pulpotomy in primary molars with 1 year follow-up

OBJECTIVE

This randomized clinical study aimed to evaluate the success of hyaluronic acid (HA) as a pulpotomy medicament of human primary molars and to compare it with formocresol (FC) and ferric sulphate (FS) pulpotomy treatments up to 12 months.

MATERIALS AND METHODS

The study was conducted with 130 primary molars of 44 children. The ethical approval and registration to clinical trials (No: NCT04115358) were completed. After the removal of all the coronal pulp tissue, a 0.5% HA gel, or a FC, or a 20% FS solution were applied randomly to the radicular pulp tissues of the primary molars. Then, the pulp chambers were filled with a zinc oxide eugenol cement and restored either with a composite filling material or with a stainless-steel crown. The treatment success rates of the 3 groups were followed and compared clinically and radiographically at 1st-, 3rd-, 6th- and 12th-months.

RESULTS

Primary molars treated with FC, FS and HA dressings were clinically successful 77.5%, 86.8% and 87.5% respectively after 12th-month follow-up (p > .05). Radiographic successes of FC, FS and HA groups were lower than clinical successes (57.6%, 68.8%, 57.9% respectively at the 12th-month) but the difference between the groups was not statistically significant (p > .05). Equivalence analysis assuming not more than 10% difference between the materials suggested that HA was not inferior to FC or FS.

CONCLUSIONS

Within the limitations of this study, our randomized clinical trial shows that HA is a promising pulpotomy medicament in primary molars. However, further studies are justified to further improve the HA material success.

Efficiency of Hyaluronic Acid in Infrabony Defects: A Systematic Review of Human Clinical Trials

Background and objectives: The aim of this systematic review was to assess the electronic literature about the benefits of using hyaluronic acid (HA) in the surgical periodontal treatment of infrabony defects. Materials and methods: This review was conducted under the PRISMA guidelines. The electronic search was conducted on PubMed, Scopus, Web of Science, and Cochrane databases until February 2022. The inclusion criteria consisted of human clinical trials that reported the use of HA in open-flap debridement (OFD) for infrabony defects. The assessment of risk of bias was performed using the Cochrane risk of bias tool. Statistical analysis was performed using Review Manager. Results: Overall, three RCTs were found eligible for the statistical analysis. Probing depth (PD) reduction and clinical attachment level (CAL) gain in the HA test group presented WMs of −1.11 mm (95% CI −2.38 to 0.16 mm; p = 0.09) and −1.38 mm (95% CI −2.26 to −0.49 mm; p = 0.002), respectively. However, the heterogeneity of the RCTs was high, and the risk of bias, in general, was low. Conclusions: The use of hyaluronic acid seems to have beneficial effects in periodontal surgery using OFD, in terms of PD and CAL. To draw a clear conclusion, more adapted and well-designed clinical trials are needed to assess the advantage of this product in comparison with other products.

Orodispersible hyaluronic acid film delivery for oral wound healing in rats

Background/purpose

Oral wound healing undergoes a dynamic process of oral environment. This study aimed to investigate the effects of hyaluronic acid (HA) film on oral wound healing in a rat model.

Materials and methods

A total of 60 rats with tongue wounds (5 mm in diameter) were randomly divided into control (n = 20), HA gel (n = 20), and HA film groups (n = 20). The animals were sacrificed on either 3 or 7 days after the experiment. Clinical, histological, and quantitative reverse transcriptase-polymerase chain reaction analysis were performed to evaluate the healing rate, inflammation, re-epithelialization, and gene expression of wound healing biomarkers.

Results

The healing rates of HA gel (84.4 ± 9.2%) and HA film (74.0 ± 15.0%) were significantly higher than that of the control (51.7 ± 16.9%) on day 7 (P < 0.001 and P = 0.002, respectively). Histological analysis revealed no significant differences between the groups on day 3. On day 7, only the HA film showed significant improvement in inflammation (P = 0.038) and re-epithelialization (P = 0.011) compared to the control. Regarding wound healing biomarkers, both HA gel and HA film groups showed lower level of COL1α1 expression on day 3 compared to the control.

Conclusion

Within the limits of this study, HA film was found to be effective for oral wound healing, particularly for re-epithelialization. This finding suggests that HA film delivery can be beneficial not only for clinical convenience but also for promoting oral wound healing.

A Fresh Look at Mouthwashes-What Is Inside and What Is It For?

Mouthwashes are a very popular additional oral hygiene element and there are plenty of individual products, whose compositions are in a state of flux. The aim of our study was to investigate the compositions of mouthwashes and their functions, as well as to discuss their effectiveness in preventing and curing oral diseases and side effects. We searched for mouthwashes available on the market in Poland. We identified 241 individual mouthwash products. The extraction of compositions was performed and functions of the ingredients were assessed. Then, analysis was performed. The evaluation revealed that there are plenty of ingredients, but a typical mouthwash is a water–glycerine mixture and consists of additional sweetener, surfactant, preservative, and some colourant and flavouring agent, as well as usually having two oral health substances, anticaries sodium fluoride and antimicrobial essential oils. The effectiveness or side effects of several substances of mouthwashes were thoroughly discussed. We recommend not multiplying individual mouthwash products and their ingredients beyond medical or pharmaceutical necessity, especially without scientific proof.

Endosseous Dental Implant Materials and Clinical Outcomes of Different Alloys: A Systematic Review

In recent years, implantology has made significant progress, as it has now become a safe and predictable practice. The development of new geometries, primary and secondary, of new surfaces and alloys, has made this possible. The purpose of this review is to analyze the different alloys present on the market, such as that in zirconia, and evaluate their clinical differences with those most commonly used, such as those in grade IV titanium. The review, conducted on major scientific databases such as Scopus, PubMed, Web of Science and MDPI yielded a startling number of 305 results. After the application of the filters and the evaluation of the results in the review, only 10 Randomized Clinical Trials (RCTs) were included. Multiple outcomes were considered, such as Marginal Bone Level (MBL), Bleeding on Probing (BoP), Survival Rate, Success Rate and parameters related to aesthetic and prosthetic factors. There are currently no statistically significant differences between the use of zirconia implants and titanium implants, neither for fixed prosthetic restorations nor for overdenture restorations. Only the cases reported complain about the rigidity and, therefore, the possibility of fracture of the zirconium. Certainly the continuous improvement in these materials will ensure that they could be used safely while maintaining their high aesthetic performance.

General Characteristics, Biomedical and Dental Application, and Usage of Chitosan in the Treatment of Temporomandibular Joint Disorders: A Narrative Review

The aim of this narrative review was to present research investigating chitosan, including its general characteristics, properties, and medical and dental applications, and finally to present the current state of knowledge regarding the efficacy of chitosan in the treatment of temporomandibular disorders (TMDs) based on the literature. The PICO approach was used for the literature search strategy. The PubMed database was analyzed with the following keywords: (“chitosan”[MeSH Terms] OR “chitosan”[All Fields] OR “chitosans”[All Fields] OR “chitosan s”[All Fields] OR “chitosane”[All Fields]) AND (“temporomandibular joint”[MeSH Terms] OR (“tem-poromandibular”[All Fields] AND “joint”[All Fields]) OR “temporomandibular joint”[All Fields] OR (“temporomandibular”[All Fields] AND “joints”[All Fields]) OR “temporo-mandibular joints”[All Fields]). After screening 8 results, 5 studies were included in this review. Chitosan presents many biological properties and therefore it can be widely used in several branches of medicine and dentistry. Chitosan promotes wound healing, helps to control bleeding, and is used in wound dressings, such as sutures and artificial skin. Apart from its antibacterial property, chitosan has many other properties, such as antifungal, mucoadhesive, anti-inflammatory, analgesic, antioxidant, antihyperglycemic, and antitumoral properties. Further clinical studies assessing the efficacy of chitosan in the treatment of TMD are required. According to only one clinical study, chitosan was effective in the treatment of TMD; however, better clinical results were obtained with platelet-rich plasma.

[Clinical and microbiological evaluation of hyaluronic acid and chlorhexidine mouthwash in the treatment of peri-implant mucositis]

OBJECTIVE

The aim of this study was to evaluate the effectiveness of hyaluronic acid and chlorhexidine mouthwash in the treatment of peri-implant mucositis.

MATERIAL AND METHODS

Clinical and microbiological studies were conducted before and 14 days, 1, 3 and 6 months after the periodontal treatment in 46 patients (144 implants with fixed dentures) with peri-implant mucositis. The patients were divided into 3 groups: test, comparison and control. Basic periodontal therapy in all groups included professional cleaning and individual oral hygiene training. Test group (15 patients) received basic periodontal therapy plus 0.20% chlorhexidine with hyaluronic acid mouthwash, the comparison group (15 patients) - basic periodontal therapy +0.05% chlorhexidine mouthwash. In control group (16 patients), treatment was limited to basic periodontal therapy only.

RESULTS

At the initial stages of observations, there was a statistically significant improvement in the clinical indices in all treatment groups (p<0.001). The use of 0.20% chlorhexidine with hyaluronic acid mouthwash revealed a higher quality of treatment. After 6 months of observation, the clinical features in patients of the control group was almost similar to the state before treatment. The patients of the test group had a more pronounced elimination of facultative and periodontal pathogens in comparison with other groups.

CONCLUSION

The use of 0.20% chlorhexidine with hyaluronic acid containing mouthwash allows the clinician to achieve a better results in the treatment of peri-implant mucositis. The evaluation the oral microflora in patients with peri-implant mucositis can be used as a prognostic criterion for the outcomes of rehabilitation.

Association of hyaluronic acid with a deproteinized bovine graft improves bone repair and increases bone formation in critical-size bone defects

BACKGROUND

This study is designed to evaluate the potential of different formulations of hyaluronic acid (HA) to improve new bone formation in critical-size calvaria defect (CSD) when combined with a deproteinized bovine graft (DBG) material.

METHODS

Thirty male rats were used. A 5-mm-diameter CSD was created and three experimental groups (n = 10) were randomly assigned based on the treatments performed. Group DBG: CSD filled with a DBG; group DBG/LV: CSD filled by the combination of DBG and HA in a low-viscosity crosslinking agent; group DBG/HV: CSD filled by the combination of DBG and HA in a high-viscosity crosslinking agent. Animals were euthanized 30 days postoperatively. Histological, histometric (percentage of newly formed bone [PNFB], percentage of remaining graft particles, histochemical, and immunohistochemical (bone morphogenetic protein 2/4 [BMP2/4], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analyses were performed.

RESULTS

The highest PNFB was observed in DBG/HV when compared with the other groups (P ≤0.05). DBG/LV and DBG/HV presented almost no inflammatory cells. In contrast, inflammation was observed in group DBG. Extensive resorption of graft particles was observed in group DBG, which was not present in DBG/LV and DBG/HV as confirmed by the larger size of the particles (P ≤0.05). BMP2/4 and OCN immunolabeling were higher in DBG/HV when compared with group DBG (P ≤0.05). Increased number of TRAP-positive cells was observed in DBG/LV and DBG/HV (P ≤0.05). Lower percentage of mature collagen fibers was observed in DBG/HV (P ≤0.05).

CONCLUSION

The combination of HA in a high-viscosity crosslinking agent with DBG improves the bone repair process and increases the amount of newly formed bone towards CSDs in rat calvaria.

Hyaluronic Acid: A Key Ingredient in the Therapy of Inflammation

Hyaluronic acid (HA) is a natural polymer, produced endogenously by the human body, which has unique physicochemical and biological properties, exhibiting desirable biocompatibility and biodegradability. Therefore, it has been widely studied for possible applications in the area of inflammatory diseases. Although exogenous HA has been described as unable to restore or replace the properties and activities of endogenous HA, it can still provide satisfactory pain relief. This review aims to discuss the advances that have been achieved in the treatment of inflammatory diseases using hyaluronic acid as a key ingredient, essentially focusing on studies carried out between the years 2017 and 2021.

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.

Local application of hyaluronic acid in conjunction with free gingival graft: a randomized clinical trial

OBJECTIVES

To assess the effect of the application of hyaluronic acid (HA) in conjunction with free gingival graft (FGG) on postoperative patient discomfort and wound healing.

MATERIALS AND METHODS

A total of 24 healthy non-smoker patients requiring FGG were recruited for the study. Subjects were randomly assigned into study groups, local application of HA on both donor and recipient sites and control group, application of normal saline. The FGG dimensions were evaluated using digital photographs. Post-operative pain was evaluated for 14 days. Color matching and patient satisfaction were evaluated at 6 months.

RESULTS

In this randomized clinical trial, 21 patients (mean age 23 years, (15 females and 6 males) completed the study. Baseline characteristics were comparable across treatment groups. Pain scores in donor sites were statistically significant and higher in control group than study group until day 7 (p < 0.05). Mean of the surface area of the graft at baseline in study vs control group were (169 ± 21), (183 ± 22) (2 mm), respectively. While at 6 months, were (147 ± 30) and (139 ± 32) (2 mm), in study and control group, respectively (p > 0.05). Color match showed no statistical significance difference.

CONCLUSIONS

Topical application of HA may exhibit significant improvement of postoperative pain and no significant difference in graft dimensions and patients' satisfaction.

CLINICAL RELEVANCE

Topical application of HA is recommended as a dressing material in FGG surgeries to reduce postoperative pain and accelerate healing.

Polysaccharide-Based Micro- and Nanosized Drug Delivery Systems for Potential Application in the Pediatric Dentistry

The intensive development of micro- and nanotechnologies in recent years has offered a wide horizon of new possibilities for drug delivery in dentistry. The use of polymeric drug carriers turned out to be a very successful technique for formulating micro- and nanoparticles with controlled or targeted drug release in the oral cavity. Such innovative strategies have the potential to provide an improved therapeutic approach to prevention and treatment of various oral diseases not only for adults, but also in the pediatric dental practice. Due to their biocompatibility, biotolerance and biodegradability, naturally occurring polysaccharides like chitosan, alginate, pectin, dextran, starch, etc., are among the most preferred materials for preparation of micro- and nano-devices for drug delivery, offering simple particle-forming characteristics and easily tunable properties of the formulated structures. Their low immunogenicity and low toxicity provide an advantage over most synthetic polymers for the development of pediatric formulations. This review is focused on micro- and nanoscale polysaccharide biomaterials as dental drug carriers, with an emphasis on their potential application in pediatric dentistry.