In situ shell technique for edentulous ridge augmentation.

BACKGROUND: The novel two-stage technique presented in this study is based on guided bone regeneration for three-dimensional bone augmentation. METHODS AND RESULTS: The proposed technique was performed to augment an atrophic alveolar ridge in the maxilla and mandible. This method is based on using an autogenous bone plate, a mixture of allogeneic bone graft and injectable -platelet-rich fibrin, and a bioresorbable barrier membrane. Based on the cases presented in this study, sufficient osseous regeneration was achieved to place dental implants in an ideal position. CONCLUSION: Within the limitations of the present study, it seems that in situ shell technique could be a beneficial method to augment the extremely atrophied ridges with less morbidity and shorter operative time. KEY POINTS: Why is this case new information? The cases presented a new technique using in situ autogenous plates for ridge augmentation. What are the keys to the successful management of this case? The keys to the successful management of these cases are proper flap management and less traumatic bony plate preparation. What are the primary limitations to success in this case? The primary limitation to success in this technique would be a need for high surgical skills to conduct the procedure accurately.

Evaluation of bioactivity and biodegradability of a biomimetic soft tissue scaffold for clinical use: An in vitro study.

Background: Autogenous soft-tissue graft is the gold-standard approach to augment oral soft tissues. However, tissue engineering is increasingly surveyed to overcome its substantial drawbacks, including the secondary site of operation, patient's pain and discomfort, limited tissue of donor site, and so on. Chitosan and gelatin have been utilized in this field over the years due to their great biological virtues. Zeolite, another remarkable candidate for tissue engineering, possesses outstanding biological and mechanical properties, thanks to its nanostructure. Therefore, this study aimed to investigate the biodegradability and DNA content of seeded human gingival fibroblasts on a New Chitosan-Gelatin-Zeolite Scaffold for the perspective of oral and mucosal soft tissue augmentation. Materials and Methods: DNA contents of the human gingival fibroblast cell line (HGF.1) seeded on the chitosan-gelatin (CG) and CGZ scaffolds were evaluated by propidium iodide staining on days 1, 5, and 8. Scaffolds' biodegradations were investigated on days 1, 7, 14, 28, 42, and 60. Results: Although both scaffolds provided appropriate substrates for HGF.1 growth, significantly higher DNA contents were recorded for the CGZ scaffold. Among experimental groups, the highest mean value was recorded in the CGZ on day 8. CGZ showed a significantly lower biodegradation percentage at all time points. Conclusions: The incorporation of zeolite into the CG scaffold at a ratio of 1:10 improved the cell proliferation and stability of the composite scaffold. CGZ scaffold may offer a promising alternative to soft-tissue grafts due to its suitable biological features.

Sterility and bioactivity evaluation of two types of bone graft substitutes after removing the original packaging.

Background: Xenograft and allograft bone substitutes are widely used to replace the missing bone in defects. Since removing the packaging of these grafts can nullify their sterilization, this study aimed to evaluate the sterility and bioactivity changes of an allograft and a xenograft following uncapping/recap. Methods: Two types of commercial allograft and xenograft vials were unpacked and further exposed to operating room air, where implant surgery was performed for one second, ten minutes, and one hour. After three repetitions, samples were analyzed using microbiological tests and scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDX) for sterility and bioactivity evaluation. Results: None of the bone graft samples showed microbial growth or bioactivity-negative changes after seven days of unpacking the vials. Conclusion: Despite the positive results of this study, future studies and more analysis considering influential factors are required. Also, disinfection and air exchange must still be observed during biomaterial application and bone grafting procedures.

Microbiological Study of Periodontal Disease in Populations with HIV: a Systematic Review and Meta-Analysis.

BACKGROUND: No systematic review/meta-analysis has been conducted on the microbiological profile associated with the occurrence of periodontitis in patients with HIV. The aim of this study was to evaluate the prevalence of identified bacteria in HIV-infected patients with periodontal disease. METHODS: Three English electronic databases (MEDLINE (via PubMed), SCOPUS, and Web of Science) were searched systematically from the beginning to February 13, 2021. The frequency of each identified bacteria in HIV-infected patients with periodontal disease was extracted. All meta-analysis methods were performed using STATA software. RESULTS: Twenty-two articles met inclusion criteria and were enrolled into the systematic review. This review analyzed a total of 965 HIV-infected patients with periodontitis. The prevalence of periodontitis was higher in HIV-infected male patients (83% (CI 95%: 76 - 88%)) compared to females (28% (CI 95%: 17 - 39%)). In our study, the pooled prevalence of necrotizing ulcerative periodontitis and necrotizing ulcerative gingivitis in patients with HIV infection was 67% (CI 95%: 52 - 82%) and 60% (CI 95%: 45 - 74%), while a lower prevalence of linear gingivitis erythema was reported (11% (CI 95%: 5 - 18%)). More than 140 bacterial species were identified from HIV-infected patients with periodontal disease. High prevalence of Tannerella forsythia (51% (CI 95%: 5 - 96%)), Fusobacterium nucleatum (50% (CI 95%: 21 - 78%)), Prevotella intermedia (50% (CI 95%: 32 - 68%)), Peptostreptococcus micros (44% (CI 95%: 25 - 65%)), Campylobacter rectus (35% (CI 95%: 25 - 45%)), and Fusobacterium spp. (35% (CI 95%: 3 - 78%)) in HIV-infected patients with periodontal disease was found. CONCLUSIONS: Our study demonstrated that the prevalence of the red and orange complex of bacteria in HIV patients with periodontal disease is relatively high.

Assessing the Surface Modifications of Contaminated Sandblasted and Acid-Etched Implants Through Diode Lasers of Different Wavelengths: An In Vitro Study.

Objective: The present study was conducted to compare the effects of 810 nm, 980 nm, and dual (810: 50%-980: 50%) diode lasers on the surface modifications of implants contaminated by a standard strain of Escherichia coli. Methods: Based on the operation on their surface, the implants were divided into six groups: "Group 1" was the positive control group undergoing no specific procedures. "Groups 2, 3, 4, 5, and 6" were contaminated by a standard strain of E. coli; "Group 2" was also set as the negative control group. "Groups 3, 4, and 5" were irradiated by 810 nm, 980 nm, and dual lasers (810: 50%-980: 50%; 1.5W, 320 µm fiber) for 30 sec, respectively. "Group 6" was treated using standard titanium brushes. All groups were examined to evaluate the surface modifications by the X-ray diffraction analysis, scanning electron microscope, and atomic force microscopy. Results: The values of carbon, oxygen, aluminum, titanium, and vanadium were significantly different in the surface composition of the contaminated implants from the control groups (p = 0.010, 0.033, 0.044, 0.016, and 0.037, respectively). In all target areas, there were significant differences in surface roughness (p < 0.0001); the same was also true about the pairwise comparison of the study groups (p < 0.0001). "Group 5" demonstrated lower morphological surface changes and roughness degrees. Conclusions: Overall, laser irradiation could alter the surfaces of the contaminated implants. Titanium brushes and 810/980 nm lasers resulted in similar morphological alterations. Dual lasers enjoyed the least degree of morphological alterations and surface roughness.

Evaluation of UV photofunctionalization effect on ultrastructural properties of SLA titanium disks: An in vitro study.

Background: The success rate of dental implants diminishes over time; the lack of osseointegration and infection are the major causes of most implant failures. One of the effective methods to improve the surface properties is to irradiate ultraviolet (UV) light. This study investigated the effect of UV photofunctionalization on the ultrasuperficial properties of sandblasted, large-grit, acid-etched (SLA) titanium discs. Methods: In this in vitro study, 24 sandblasted and acid-etched titanium discs, with a lifespan of more than four weeks, were categorized into three groups (n=8): control, ultraviolet C (UVC), and ultraviolet B (UVB). Then, they were exposed to a UV light source for 48 hours at a 1-cm distance. In addition to measuring the contact angle between the liquid and the disc surface in each of the three groups, the atomic concentrations of carbon, oxygen, and nitrogen atoms were measured at three different sites on each disc. One-way ANOVA and post hoc Tukey tests were used to analyze data. Results: The mean concentration of carbon atoms significantly differed in the control, UVC, and UVB groups (P<0.001). The mean concentrations of nitrogen atoms differed significantly between the three groups (P<0.001). However, the mean concentrations of oxygen atoms were not significantly different between the three groups. In examining the contact angle, wettability was higher in the UVC group than in the UVB group and higher in the UBV group than in the control group. Conclusion: Photofunctionalization with UV light significantly decreased carbon and nitrogen concentrations on the surface of titanium implants, indicating that the implant's superficial hydrocarbons were eliminated. It was observed that UVC photofunctionalization was more effective than UVB photofunctionalization in reducing superficial contamination and improving wettability.

Nasopalatine duct cyst as a delayed consequence of dental implant placement in the anterior maxilla: A case report.

Dental implants are now the best treatment method to replace missing teeth. However, complications may necessitate further therapeutic interventions because of anatomic limitations and mistakes during surgical procedures. In this case report, a nasopalatine duct cyst (NPDC) due to implant placement was studied. After clinical and radiographic evaluation, unilocular radiolucency with disturbance to the nasopalatine canal was observed. Following that, flap elevation was performed. Subsequently, the cyst was enucleated, and the bone defect was filled with xenograft and further covered with a resorbable membrane. Histopathology results confirmed NPDC as the definite diagnosis. After six months, the defect was completely resolved.

Effect of Implant Design on Stress Distribution: A Finite Element Study.

Implant design and biomaterial composition are contributing factors in stress distribution throughout the implant body and the surrounding bone. The aim of this study was to evaluate the pattern of stress distribution using four different implant systems based on finite element analysis. This study was conducted using a cone beam computed tomography scan and four implant systems (ITI, SPI, 3i, and IDCAM); mandibular and implant models were constructed by a computer-aided design software (CATIA). Stress distribution under axial, mesio-distal, and combination static loading was assessed using finite element analysis in ABAQUS. The maximum von Mises stress value in dental implants was recorded for IDCAMs and IDCAMm implants considering all types of loading directions; however, these implant models showed the least stress distribution in the surrounding bone. The maximum stress occurred using combination followed by axial and mesio-distal loading. The stress distribution was concentrated, in all designs, at the level of the most coronal portion of the cortical bone. Within the limitations of the present study, it could be assumed that implant design may affect the distribution of stress in the implant body, and it could be used as a strategy to reduce stress concentration in the surrounding bone.

Vaccine-associated complications: a comparative multicenter evaluation among dental practitioners and dental students-which candidate vaccine is more safe in SARS COV II, Gam-COVID-Vac (Sputnik V), ChAdOx1 nCoV-19 (AstraZeneca), BBV152 (Covaxin), or BBIBP-CorV(Sinopharm)?

BACKGROUND: The rapidly developed vaccines against the severe acute respiratory syndrome coronavirus 2 carry a risk of provoking side effects. This study aimed to evaluate current vaccination non-serious/serious side effects. METHODS: A multicenter electronic questionnaire via an online platform was conducted over a 1-week period among vaccinated dental staff and dental students inquiring whether they experienced vaccine-related side-effects after vaccine administration. RESULTS: A total of 1205 respondents with a mean age of 39 (SD: 12) were retained for the analyses. The following vaccines were reported; Gam-COVID-Vac (Sputnik V), ChAdOx1 nCoV-19 (AstraZeneca), BBV152 (Covaxin), or BBIBP-CorV (Sinopharm). The majority of respondents received ChAdOx1 nCoV-19 (51.1%) and Gam-COVID-Vac (37.6%). The symptoms most frequently reported after vaccination were fatigue (79%), local pain in the injection site (77.4%), malaise (73%), and body pain (71.1%). Enrollees reported more onset of reactions on 0-12 h (44.1%) and 12-24 h (29.0%) after vaccine administration (p value <0.001). In 75.7%, the side effects last for up to 3 days. Merely 5.5% of cases reported the presence of side effects after the first week. Individuals with a history of SARSCoV-2 and other infections (MERS, influenza, and EBV) were more likely to report a number of unserious systemic side effects. CONCLUSION: The commonly reported adverse events were in line with similar studies. We have concerns with the frequency of serious adverse effects. This work necessitates the need for further clinical assessments with larger sample sizes.

The detection of SARS-CoV-2 RNA in indoor air of dental clinics during the COVID-19 pandemic.

In the indoor environment of dental clinics, dental personnel and patients are exposed to a risk of infection because of the transmission of SARS-CoV-2 via particles or droplets. This study investigated the presence of SARS-CoV-2 RNA in indoor air of dental clinics in Tehran, Iran. Air sampling was done (n = 36) collecting particulate samples on PTFE filters at flow rates of 30 to 58 L/min. The samples were analyzed with novel coronavirus nucleic acid diagnostic real-time PCR kits. Only 13 out of 36 samples were positive for SARS-CoV-2 RNA. Logistic regression showed that sampling site's volume, PM2.5 concentration, number of people, and number of active patient treatment units were significantly positively related with the presence of SARS-CoV-2 RNA. Thus, strategies to control the spread of COVID-19 should include reducing the number of infected people in dental clinics, adding filtration systems, and/or improving ventilation conditions.

Reopening of dental clinics during SARS-CoV-2 pandemic: an evidence-based review of literature for clinical interventions.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes serious acute respiratory diseases including pneumonia and bronchitis with approximately 2.3% fatality occurrence. MAIN BODY: This study argues the main concepts that need to be considered for the gradual reopening of dental offices include treatment planning approaches, fundamental elements needed to prevent transmission of SARS-CoV-2 virus in dental healthcare settings, personal protection equipment (PPE) for dental health care providers, environmental measures, adjunctive measures, and rapid point of care tests in dental offices. CONCLUSION: This article seeks to provide an overview of existing scientific evidence to suggest a guideline for reopening dental offices.

Fear control and danger control amid COVID-19 dental crisis: Application of the Extended Parallel Process Model.

OBJECTIVES: There is high risk of contamination with COVID-19 virus during routine dental procedures and infection control is crucial. The aim of this study was to determine the factors associated with Covid-19 preventive behaviors among oral health care providers using an extended parallel process model (EPPM). METHODS: In a cross-sectional study, short text message invite surveys were sent to 870 oral health care providers in west part of Iran. Data were collected through validated self-report EPPM questionnaires. Descriptive statistics, Chi-square and Fishers exact tests were used for data analysis. RESULTS: In total, 300 completed questionnaires were received and the mean age of respondents was 29.89 ± 11.17 years (range: 20-75 years). Among the study population, 284 (94.67%) perceived the threat of infection highly. Washing hands frequently with water and soap and use of hand sanitizer was reported by 93.33%, of participants. Age (P = 0.010), sex (P = 0.002) and occupation field (P = 0.010) were significantly associated with danger control responses. Data identified that those oral health care providers that were on the danger control response adopted preventive behaviors more strictly than those on fear control response. CONCLUSION: The results of this study showed how degrees of perceived threat and perceived efficacy influenced oral health providers' willingness to perform recommended health behaviors. These findings can assist public health agencies in developing educational programs specifically designed for promoting preventive behaviors among oral health providers in pandemic situations.

Chitosan Coating of TiO2 Nanotube Arrays for Improved Metformin Release and Osteoblast Differentiation.

BACKGROUND: Ineffective integration has been recognized as one of the major causes of early orthopedic failure of titanium-based implants. One strategy to address this problem is to develop modified titanium surfaces that promote osteoblast differentiation. This study explored titanium surfaces modified with TiO2 nanotubes (TiO2 NTs) capable of localized drug delivery into bone and enhanced osteoblast cell differentiation. MATERIALS AND METHODS: Briefly, TiO2 NTs were subjected to anodic oxidation and loaded with Metformin, a widely used diabetes drug. To create surfaces with sustainable drug-eluting characteristics, TiO2 NTs were spin coated with a thin layer of chitosan. The surfaces were characterized via scanning electron microscopy, atomic force microscopy, and contact angle measurements. The surfaces were then exposed to mesenchymal bone marrow stem cells (MSCs) to evaluate cell adhesion, growth, differentiation, and morphology on the modified surfaces. RESULTS: A noticeable increase in drug release time (3 days vs 20 days) and a decrease in burst release characteristics (85% to 7%) was observed in coated samples as compared to uncoated samples, respectively. Chitosan-coated TiO2 NTs exhibited a considerable enhancement in cell adhesion, proliferation, and genetic expression of type I collagen, and alkaline phosphatase activity as compared to uncoated TiO2 NTs. CONCLUSION: TiO2 NT surfaces with a chitosan coating are capable of delivering Metformin to a bone site over a sustained period of time with the potential to enhance MSCs cell attachment, proliferation, and differentiation.

The lncRNA ANRIL is down-regulated in peripheral blood of patients with periodontitis.

Long non-coding RNAs (lncRNAs) have crucial roles in lncRNAs in periodontal development and disorders of this tissue. A number of lncRNAs especially those regulating immune responses contribute in the pathophysiology of periodontitis. In the current case-control study, we assessed expression levels of two immune response-related lncRNAs namely the antisense non-coding RNA in the INK4 locus (ANRIL) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in gingival tissues and blood samples of patients with periodontitis and healthy subjects. Expression of ANRIL was significantly lower in peripheral blood of patients compared with controls (Posterior Beta RE = -1.734, P value = 0.035). However, when diving study participants based on their gender, no significant difference was found between patients and sex-matched controls. Expression of this lncRNA was not different between periodontitis tissues and normal tissues. Expression of MALAT1 was not different between samples obtained from cases and controls. Tissue or blood expressions of ANRIL or MALAT1 were not correlated with age of either patients or controls. There were significant correlations between expression levels of ANRIL and MALAT1 in gingival tissues both in cases (r = 0.62, P < 0.0001) and in controls (r = 0.37, P < 0.0001). However, blood levels of these lncRNAs were not correlated with each other either in cases or in controls. Most notably, there was no significant correlation between expression levels of these lncRNAs in gingival tissues and in the blood of study participants. The current study indicates dysregulation of ANRIL in the peripheral blood of patients with periodontitis in spite of its normal levels in gingival tissues which might reflect disturbance in systemic immune responses in these patients.

Biomaterial selection for bone augmentation in implant dentistry: A systematic review.

In the present study, a systematic review was conducted to evaluate the biomaterials and their effectiveness for bone augmentation in implant dentistry. The databases of Cochrane Library, Google Scholar, PubMed (National Center for Biotechnology Information), and Scopus were searched for published studies between 2006 and March 30, 2018. We only included clinical studies in this research. Due to a lack of quantitative evidence and the vast heterogeneity of the biomaterials, implant surgery sites, implant types, follow-up periods, and various implant placement techniques (1-stage or 2-stage), we could not manage to do a meta-analysis on the 13 included studies. Several techniques can result in vertical bone augmentation. Complications can be seen in vertical bone augmentation and especially in the autogenous bone grafting; however, some biomaterials showed promising results to be practical substitutes for autogenous bone. Bio-Oss and beta-tricalcium phosphate are our second-level candidates for vertical bone augmentation due to their promising clinical results with the least infection and immunologic response risk. The gold standard, however, remains the autogenous bone graft. Further clinical studies in the future with exact report of bone measures are needed to develop new comparisons and quantitative analyses.

The Effect of Bio-Conditioning of Titanium Implants for Enhancing Osteogenic Activity.

Early and effective integration of titanium-based materials into bone tissue is of vital importance for long-term stability of implants. Surface modification is commonly used to enhance cell-substrate interactions for improving cell adhesion, proliferation, and activity. Here, the surface of titanium substrates and commercial implants were coated with blood (TiB), fetal bovine serum (TiF), and phosphate-buffered saline (TiP) solution using a spin coating process. Surface roughness and wettability of samples were measured using contact angle measurements and atomic force microscopy. The samples were then exposed to human osteoblast-like MG63 cells in order to evaluate adhesion, growth, differentiation, and morphology on the surface of modified samples. Untreated titanium disks were used as controls. The lowest roughness and wettability values were found in unmodified titanium samples followed by TiP, TiF, and TiB. The percentage of cellular attachment and proliferation for each sample was measured using an MTT (3-[4,5-dimethylthiazol-2yl] 2,5diphenyl-2H-tetrazoliumbromide) assay. Cell adhesion and proliferation were most improved on TiB followed closely by TiF. The results of this study revealed an increased expression of the osteogenic marker protein alkaline phosphatase on TiB and the coated commercial titanium implants. These results suggested that precoating titanium samples with blood may improve cellular response by successfully mimicking a physiological environment that could be beneficial for clinical implant procedures.

Development of a PCL/gelatin/chitosan/ß-TCP electrospun composite for guided bone regeneration.

Many approaches have been developed to regenerate biological substitutes for repairing damaged tissues. Guided bone/tissue regeneration (GBR/GTR) that employs a barrier membrane has received much attention in recent years. Regardless of substantial efforts for treatment of damaged tissue in recent years, an effective therapeutic strategy is still a challenge for tissue engineering researchers. The aim of the current study is to fabricate a GBR membrane consisting of polycaprolactone (PCL)/gelatin/chitosan which is modified with different percentages of ß-tricalcium phosphate (ß-TCP) for improved biocompatibility, mechanical properties, and antibacterial activity. The membranes are examined for their mechanical properties, surface roughness, hydrophilicity, biodegradability and biological response. The mechanical properties, wettability and roughness of the membranes are improved with increases in ß-TCP content. An increase in the elastic modulus of the substrates is obtained as the amount of ß-TCP increases to 5% (145-200 MPa). After 5 h, the number of attached cells is enhanced by 30%, 40% and 50% on membranes having 1%, 3% and 5% ß-TCP, respectively. The cell growth on a membrane with 3% of ß-TCP is also 50% and 20% higher than those without ß-TCP and 5% ß-TCP, respectively. Expression of type I collagen is increased with addition of ß-TCP by 3%, while there is no difference in ALP activity. The results indicated that a composite having (3%) ß-TCP has a potential application for guided bone tissue regeneration.

Effect of metformin on dental pulp stem cells attachment, proliferation and differentiation cultured on biphasic bone substitutes.

OBJECTIVE: To evaluate to the effect of metformin on attachment of human dental pulp stem cells (hDPSCs) and their proliferation and osteogenic differentiation on biphasic hydroxyapatite/beta-tricalcium phosphate granules of macro-porous biphasic calcium phosphate (MBCP). MATERIALS AND METHODS: This in vitro study included four groups: A:hDPSCs + MBCP + Metfromin, B:hDPSCs + MBCP, C:hDPSCs + Metformin and D:hDPSCs (control). Attachment of hDPSCs to bone granules in groups A and B was observed by scanning electron microscopy on days 1 and 7 of cultivation. Cell viability was assessed by MTT assay on days 1, 3, and 7 after cell seeding. Differentiation of the hDPSCs was assessed by measurement of alkaline phosphatase activity on days 3, 7, 14 and 21 after cell culturing in standard and osteogenic media. The data was analyzed by two-way ANOVA at a significance level of p = 0.05. RESULTS: The hDPSCs had firmly attached to the surface of MBCP granules, especially in group A. The MTT values increased in all groups from day 1 to day 7 (p < 0.001). The highest MTT values were observed in group C followed by the control group and groups A and B (p < 0.001). Alkaline phosphatase activity also increased in all groups between days 3 to 21 (p < 0.001) except between days 7 and 14 in standard media (p = 0.094). In standard media, groups with MBCP granules (A and B) showed higher activity (p < 0.05). In osteogenic media, the groups with metformin (A and C) showed higher alkaline phosphatase activity (p < 0.05). CONCLUSION: This in vitro study showed that 100 Mol/L metformin increased attachment and proliferation of hDPSCs on biphasic granules. Osteogenic differentiation of hDPSCs also increased in the presence of metformin.

Cell Toxicity and inhibitory effects of Cyperus rotundus extract on Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans.

Periodontitis and tooth decay are common dental diseases. There are some bacterial risk factors such as Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans complications, tubers of Cyperus rotundus was used to determine the antimicrobial effect of fungi. Considering the increasing resistance of bacteria and fungi to antibiotics and their alcoholic and aqueous extracts and essential oil on Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans, as well as an examination cytotoxicity on gingival fibroblast cells. Alcoholic and aqueous extracts and essential oil prepared from tubers of Cyperus rotundus. After bacterial and fungal cultures, the inhibition zone, Minimum inhibitory concentrations (MIC), and Minimum Bactericidal Concentration (MBC), were studied. Cytotoxicity was also evaluated using the Methyl tetrazolium test (MTT).The results showed that Cyperus rotundus alcoholic extract had the greatest effect on inhibition of growth and death of Streptococcus mutans, Aggregatibacter actinomycetemcomitans. According to the present study, Cyperus rotundus extract can be considered as a suitable candidate for the treatment and prevention of periodontitis and tooth decay.

Development of chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis.

The aim of this research was to develop chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis, which was fabricated through an environmental friendly process. Mucoadhesive films increase the advantage of higher efficiency and drug localization in the affected region. In this research, mucoadhesive films, for the release of hydrocortisone sodium succinate, were prepared using different ratios of chitosan, gelatin and keratin. In the first step, chitosan and gelatin proportions were optimized after evaluating the mechanical properties, swelling capacity, water uptake, stability, and biodegradation of the films. Then, keratin was added at different percentages to the optimum composite of chitosan and gelatin together with the drug. The results of surface pH showed that none of the samples were harmful to the buccal cavity. FTIR analysis confirmed the influence of keratin on the structure of the composite. The presence of a higher amount of keratin in the composite films resulted in high mechanical, mucoadhesive properties and stability, low water uptake and biodegradation in phosphate buffer saline (pH = 7.4) containing 104 U/ml lysozyme. The release profile of the films ascertained that keratin is a rate controller in the release of the hydrocortisone sodium succinate. Finally, chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate can be employed in dental applications.