Lemongrass-Incorporated Tissue Conditioner with Adjustable Inhibitory Effect Against Candida albicans: An In Vitro Study.

PURPOSE: To develop and assess lemongrass-incorporated tissue conditioners (LG-TCs) with a potent and long-lasting inhibitory effect against Candida albicans cultures to control the accumulation of fungi. MATERIALS AND METHODS: LG essential oil with concentrations of 7.17%, 3.56%, 1.77%, and 0.89% (w/w) or nystatin were mixed with the liquid part of the TC before being added to the powder part to form 486 TC samples of 6-mm diameter x 2-mm thickness (n = 81 samples for each group of LG-/nystatin-incorporated or unmodified TCs). After being immersed in 37°C water for 1, 2, 3, 5, 7, 9, 12, or 14 days, these TC samples were removed, blotted with sterile filter paper, and then exposed to fungal suspension (1 × 105 CFU/mL). The TC samples were evaluated for their capacity to inhibit fungal growth by 99.9%. RESULTS: The anti-Candida effect of the unmodified TCs was reduced significantly after the samples were immersed in water. Interestingly, a long-lasting anti-Candida effect was observed in the TCs incorporated with LG essential oil. After being immersed in water for at least 14 days, the TCs with 1.77% LG oil were still able to inhibit fungal growth substantially. In contrast, a shorter-lasting (5 days) anti-Candida effect was found in the TCs with 0.89% (w/w) LG oil. Additionally, the TCs incorporated with LG oil at concentrations of 3.56% (w/w) or more inhibited the growth of the fungus by 99.99%, and its anti-Candida effect lasted for 14 days. CONCLUSION: LG-TCs showed an impressive and long-lasting inhibitory effect against C. albicans.

Antimicrobial Properties of Ocimum Species: An In Vitro Study.

Objective: This study aimed to determine the antimicrobial activity of ethanol-extracts obtained from Ocimum gratissimum L. (clove or African basil, Lamiaceae) and O. santum L. (holy basil) against some microorganisms present in oral cavity related to either medical or dental disease. Materials and Methods: Antimicrobial properties of both ethanol-extracts of Ocimum species against Streptococcus mutans KPSK2, S. pyogenes ATCC 19615, Staphylococcus aureus ATCC 16794, and Candida albicans ATCC 10231 were primarily determined by agar disk diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal or fungicidal concentration (MBC or MFC) of these herbal extracts were further determined by broth micro-dilution method. Results: Ethanol-extracts of O. sanctum L. and O. gratissimum L. inhibited the growth of all tested microorganisms in various degrees ranging from the strongest antimicrobial activity of O. sanctum against S. pyogenes [MIC at 0.19% (w/v); MBC at 0.78% (w/v)] to the least inhibitory activity of O. gratissimum against C. albicans [MIC at 12.5% (w/v); undetectable MFC]. The ethanol-extract of O. sanctum showed stronger antimicrobial property against the tested bacteria and fungus than O. gratissimum. The ethanol-extracts of both Ocimum species showed stronger antibacterial than antifungal activity. However, the ethanol-extract of O. gratissimum even at a high concentration of 50% (w/v) was unable to eliminate the tested fungus. Conclusion: Ethanol-extracts of Ocimum species contain effective antibacterial and antifungal properties that may be beneficial for further development of antimicrobial agents in medical and dental fields.

Fungicidal and inhibitory efficacy of cinnamon and lemongrass essential oils on Candida albicans biofilm established on acrylic resin: An in vitro study.

STATEMENT OF PROBLEM: It is unclear whether cinnamon and lemongrass essential oils can effectively reduce the Candida-biofilm frequently formed on dental devices made from heat-polymerized polymethyl methacrylate (PMMA) resin that contributes to the development of mild oropharyngeal as well as life-threatening candidiasis in patients wearing the devices. PURPOSE: The purpose of this in vitro study was to determine the efficacy of cinnamon and lemongrass essential oils in eradicating Candida albicans biofilm on heat-polymerized PMMA specimens and to determine whether they retard the formation of fungal biofilm. MATERIAL AND METHODS: The antifungal effect of cinnamon and lemongrass essential oils was determined by using agar disk diffusion and broth microdilution methods to obtain minimum inhibitory concentrations. The mature C albicans biofilm (48 hours) was pre-established on PMMA specimens before being individually treated with various concentrations (½, 1, 2, 4, 8, 16 times minimum inhibitory concentration) of each tested oil for different exposure times (1, 2, 4, 8, and 24 hours). In another experiment, fungal biofilm was established on the PMMA specimens that were primed individually with various concentrations of the tested oils for different times. The 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)-reduction assay was used to quantitate biofilm viability in both experiments. Statistical analysis was performed by using the 1-sample Kolmogorov-Smirnov test and 2-way ANOVA followed by the Tukey multiple comparison test (α=.05). RESULTS: Minimum inhibitory concentration values of cinnamon and lemongrass essential oils against planktonic C albicans were 0.1 µL/mL (0.01% v/v) and 0.4 µL/mL (0.04% v/v). At 8 times the minimum inhibitory concentration, cinnamon oil (0.8 µL/mL or 0.08% v/v) and lemongrass oil (3.2 µL/mL or 0.32% v/v) eradicated the pre-established fungal biofilm by 99.0% in an exposure time of 1 hour. In contrast, high concentrations of 8 and 16 times the minimum inhibitory concentration of cinnamon oil (0.8 µL/mL or 0.08% v/v) and lemongrass oil (6.4 µL/mL or 0.64% v/v) coated on PMMA specimens for 24 hours were only able to inhibit the formation of fungal biofilm by approximately 70.0%. CONCLUSIONS: Cinnamon and lemongrass essential oils can eliminate pre-established C albicans biofilm and restrain the formation of fungal biofilm on heat-polymerized PMMA specimens. Both effects of the tested essential oils depended on dose and exposure or priming time.

In Vitro Anti-Cariogenic Plaque Effects of Essential Oils Extracted from Culinary Herbs.

INTRODUCTION: Cariogenic bacteria including mutans streptococci and lactobacilli are partly but significantly involved in dental caries development. An effective prevention strategy against dental caries is to decrease the accumulation of this microbiota either in planktonic or in biofilm form. AIM: To examine the antimicrobial and anti-plaque effects of some culinary herbs (spices), so the herbs are plausibly used as alternative and effective herbal plaque control supplements to promote good oral health. MATERIALS AND METHODS: Essential oils extracted from sweet basil (Ocimum basilicum), cinnamon bark (Cinnamomum zeylanicum), sweet fennel (Foeniculum vulgare), kaffir lime (Citrus hystrix), black pepper (Piper nigrum), peppermint (Mentha piperita), and spearmint (Mentha spicata) were primarily examined for their antimicrobial activities against the cariogenic bacteria (Streptococcus mutans KPSK2 and Lactobacillus casei) using the agar disk diffusion and broth microdilution methods, respectively. These essential oils were then analysed for anti-plaque effects (retardation of S. mutans biofilm formation and reduction of the in vitro established biofilm). This experimental study was performed at the Department of Oral Microbiology, Faculty of Dentistry, Mahidol University during June 2015 till August 2016. RESULTS: All selected essential oils showed different degrees of antimicrobial activity against the planktonic form of both cariogenic bacteria. Cinnamon bark essential oil expressed the strongest inhibitory effect against S. mutans {MIC of 0.08% (v/v)} and L. casei {MIC of 0.16% (v/v)}, whereas the weakest effect was found in kaffir lime essential oil {MIC values of 2.5% and 5.0% (v/v) for S. mutans and L. casei, respectively}. Up to 80% of S. mutans biofilm was retarded to form on the substratum primed with these spice essential oils, especially cinnamon oil. The preventive effect of these oils was in dose- and exposure time-dependent manners. For reductive effect against the 24-hour pre-established S. mutans biofilm, at least 50% of the biofilm mass was reduced when the biofilm was treated with each essential oil at the MIC for an hour. The reductive effect against the in vitro established S. mutans biofilm of these culinary herb essential oils only depended on the exposure time. CONCLUSION: Cinnamon and sweet basil essential oils with impressive in vitro anti-cariogenic bacteria and anti-plaque effects may be proposed as alternative and effective supplements to promote oral health status.

Combination prosthetic design providing a superior retention for mid-facial defect rehabilitation: A Case Report.

Large maxillofacial defects from malignant tumor treatment are rarely rehabilitated by surgical reconstruction alone. Ameloblastic carcinoma, a rare aggressive odontogenic malignant tumor, requires wide surgical excision to gain a tumor-free margin. In the post-surgical defect, prosthetic rehabilitation is the treatment of choice to restore function and esthetics. Moreover, an intra-oral prosthesis such as an obturator restores speech, mastication and deglutition. Retention of the obturator is a major problem while rehabilitating large defects. The existing anatomical structures from the defect with the help of magnet attachments are suitable to enhance retention, stability and support of the prostheses. This case report presents a patient with an intraoral and extra-oral combination defect following surgical resection of ameloblastic carcinoma and describes the prosthetic techniques and design considerations for a magnet-retained obturator and mid-facial prosthesis. An implant-retained mid-facial prosthesis was fabricated. The retention of combined prostheses was obtained from the remaining right posterior teeth only. The patient had an unfavorable defect due to the large size and presence of scar contracture that vertically tends to dislodge the obturator. Magnet attachments were used to combine the facial and oral prosthesis, minimize the vertical dislodging forces and enhance retention. In addition, the retention was also gained from the scar band at lower border of mid-facial defect that avoided the need for more implants surgery. Magnet attachment with anatomical structure of the mid-facial defect provides an acceptable means of retention in large extraoral-intraoral combinations defects, improving the function, esthetic and the patients' quality of life. Key words:Mid-facial prosthesis, obturator, magnet attachment, maxillectomy.

Evaluation of Stress Distribution on Implant-Retained Auricular Prostheses: The Finite Element Method.

PURPOSE: The purpose of this study was to evaluate stress distribution around two craniofacial implants in an auricular prosthesis according to the removal forces. Three attachment combinations were used to evaluate the stress distribution under removal forces of 45 and 90 degrees. MATERIALS AND METHODS: Three attachment designs were examined: (1) a Hader bar with three clips; (2) a Hader bar with one clip and two extracoronal resilient attachments (ERAs); and (3) a Hader bar with one clip and two Locators. The removal force was determined by means of an Instron universal testing machine with a crosshead speed of 10 mm/minute. All three designs were created in three dimensions using SolidWorks. The applied removal force and the models were then introduced to finite element software to analyze the stress distribution. RESULTS: The angle of removal force greatly affected the magnitude and direction of stress distribution on the implants. The magnitude of stress under the 45-degree removal force was higher than the stress at 90 degrees. The combination of the 1,000-g retention clip and 2,268-g retention Locator exhibited the highest stress on the implant flange when the removal force was applied at 45 degrees. CONCLUSION: The removal angle greatly influences the amount of force and stress on the implants. Prosthodontists are encouraged to inform patients to remove the prosthesis at 90 degrees and, if possible, use a low-retentive attachment to reduce stress.

Effect of essential oils prepared from Thai culinary herbs on sessile Candida albicans cultures.

Although medicinal herbs with fungicidal effects have been ubiquitously employed in traditional medicine, such effects of culinary herbs and spices still have to be elucidated. Therefore, it is noteworthy to determine the antifungal efficacy of some edible herbs used in Thai cuisine against sessile Candida albicans cultures, and to inquire if they can be further utilized as naturally-derived antifungals. Fourteen essential oils extracted from Thai culinary herbs and spices were tested for their antifungal activity against C. albicans using the agar disk diffusion method followed by broth micro-dilution method for the determination of minimum inhibitory concentration (MIC) and minimum fungicidal concentration. The oils with potent antifungal effects against planktonic fungi were then assessed for their effect against sessile fungus (adherent organisms and established biofilm culture). MIC of the oils against sessile C. albicans was evaluated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide reduction assay. All selected culinary herbs and spices, except galangal, garlic, and turmeric, exhibited inhibitory effects on planktonic yeast cells. Cinnamon bark and sweet basil leaf essential oils exhibited potent fungicidal effect on planktonic and sessile fungus. Sessile MICs were 8-16 times higher than planktonic MICs. Consequently, both cinnamon bark and sweet basil leaf herbal oils seem to be highly effective anti-Candida choices. (J Oral Sci 58, 365-371, 2016).

Prosthodontic rehabilitation of congenital auricular defect: a clinical report.

This clinical report presents the prosthetic rehabilitation of a congenital auricular defect. The rehabilitation was initially performed with an adhesive retained silicone prosthesis. After careful evaluation of the patient's retentive needs, two endo-osseous craniofacial implants were placed in the mastoid region. After integration, an implant-retained silicone prosthesis was fabricated using a Hader bar with two ERA attachments, which restored the defect with good aesthetic and functional outcome. Prosthetic rehabilitation is a viable treatment option for restoring auricular defects and can be indicated in situations where surgical reconstruction may not be feasible.

Lemongrass-Incorporated Tissue Conditioner Against Candida albicans Culture.

BACKGROUND: Tissue conditioner is applied popularly with dental prosthesis during wound healing process but it becomes a reservoir of oral microbiota, especially Candida species after long-term usage. Several antifungal drugs have been mixed with this material to control fungal level. In this study, lemongrass essential oil was added into COE-COMFORT tissue conditioner before being determined for anti-Candida efficacy. MATERIALS AND METHODS: Lemongrass (Cymbopogon citratus) essential oil was primarily determined for antifungal activity against C. albicans American type culture collection (ATCC) 10231 and MIC (minimum inhibitory concentration) value by agar disk diffusion and broth microdilution methods, respectively. COE-COMFORT tissue conditioner was prepared as recommended by the manufacturer after a fixed volume of the oil at its MIC or higher concentrations were mixed thoroughly in its liquid part. Antifungal efficacy of the tissue conditioner with/without herb was finally analyzed. RESULTS: Lemongrass essential oil displayed potent antifungal activity against C. albicans ATCC 10231and its MIC value was 0.06% (v/v). Dissimilarly, the tissue conditioner containing the oil at MIC level did not cease the growth of the tested fungus. Both reference and clinical isolates of C. albicans were completely inhibited after exposed to the tissue conditioner containing at least 0.25% (v/v) of the oil (approximately 4-time MIC). The tissue conditioner without herb or with nystatin was employed as negative or positive control, respectively. CONCLUSION: COE-COMFORT tissue conditioner supplemented with lemongrass essential oil obviously demonstrated another desirable property as in vitro anti-Candida efficacy to minimize the risk of getting Candidal infection.

Prosthetic rehabilitation of an ocular defect with post-enucleation socket syndrome: A case report.

Ocular trauma can be caused by road traffic accidents, falls, assaults, or work-related accidents. Enucleation is often indicated after ocular injury or for the treatment of intraocular tumors, severe ocular infections, and painful blind eyes. Rehabilitation of an enucleated socket without an intraocular implant or with an inappropriately sized implant can result in superior sulcus deepening, enophthalmos, ptosis, ectropion, and lower lid laxity, which are collectively known as post-enucleation socket syndrome. This clinical report describes the rehabilitation of post-enucleation socket syndrome with a modified ocular prosthesis. Modifications to the ocular prosthesis were performed to correct the ptosis, superior sulcus deepening, and enophthalmos. The rehabilitation procedure produced satisfactory results.

In vitro effects of Salvia officinalis L. essential oil on Candida albicans.

OBJECTIVE: To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. METHODS: Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons. RESULTS: S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). CONCLUSIONS: S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis.

Late effects of orbital enucleation and radiation on maxillofacial prosthetic rehabilitation: A clinical report.

The retinoblastoma is one of the most common tumors of the eye diagnosed in childhood. The treatment for patients with retinoblastoma includes surgical removal of the lesion along with adjunctive chemotherapy and radiotherapy. If the tumor is controlled, these treatments can have secondary adverse effects pertaining to the growth and development of orofacial structures in young patients. This clinical report describes the prosthetic rehabilitation of a patient who underwent enucleation followed by radiation therapy and adjunctive chemotherapy to treat the primary diagnosis of retinoblastoma. This therapy resulted in a combination of dental and facial growth and developmental abnormalities.

In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants

<p><b>OBJECTIVE</b>To determine the antimicrobial effects of grape seed on peri-implantitis microflora.</p><p><b>METHODS</b>The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Candida albicans (C. albicans) and clinical strains of S. aureus, Klebsiella pneumonia (K. pneumonia) and Candida parapsilosis (C. parapsilosis) by disk diffusion test. Minimum inhibitory concentrations (MIC) and minimum cidal concentrations (MCC) were determined using modified agar dilution millpore method. The extract was further combined with polyethylene glycol and propylene glycol, and was tested for antimicrobial effects.</p><p><b>RESULTS</b>Grape seed extract showed positive inhibitory effects with S. aureus at MIC of 0.625 mg/mL and MCC of 1.25 mg/mL respectively. However the extracts showed minimal or no reactivity against strains of E. coli, K. pneumonia, C. parapsilosis and C. albicans. The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S. aureus.</p><p><b>CONCLUSIONS</b>The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skin-abutment interface of craniofacial implants.</p>

Oral colonization of Candida species in patients receiving radiotherapy in the head and neck area.

OBJECTIVE: To investigate oral Candida strain diversity in patients receiving radiation therapy for head and neck cancer compared to controls by conventional procedures, including cultivation of imprint samples on chromogenic medium and subsequent identification using Analytical Profile Index testing. METHOD AND MATERIALS: Twenty-two irradiated patients aged 18 to 55 years were recruited from the Maxillofacial Prosthetic Service, Mahidol University. Concomitantly, 22 healthy individuals whose age and sex matched that of the patient group were selected for a control group. RESULTS: All patients studied were Candida carriers and were predominantly infected with Candida albicans (86.36%). Besides C albicans, other yeasts colonizing the oral cavity of these patients were C glabrata, C krusei, and C tropicalis. Candida carriage was found relatively less frequently (45.45%) in control subjects. However, C albicans was still the predominant species detected. No C dubliniensis was found in either group. CONCLUSION: Head and neck cancer patients who had received radiotherapy had a high prevalence of Candida colonization in the oral cavity. Consequently, prophylaxis to reduce Candida infection in these patients is required. This may improve the quality of life for patients who receive irradiation treatment for malignant cancer.

Determination of oral microflora in irradiated ocular deformed children.

Children with a retinoblastoma usually have enucleation of eye contents and undergo radiation therapy. In this group of children a slight deformation in facial growth is exhibited on the operated side. The radiation affects the oral microflora. This study was conducted to investigate the oral microflora in this group of patients compared to normal children. Nineteen children, ages 4-15 years, were tested for oral microflora by culture. A control group was comprised of 20 normal healthy children from a primary school in Bangkok, Thailand. Paraffin-stimulated whole saliva was collected and cultured for the presence of mutans streptococci, lactobacilli and Candida species. The isolation frequencies and abundances of lactobacilli and Candida species in saliva samples of irradiated children were significantly greater than healthy children. The mutans streptococci counts were significantly different from healthy controls. Radiation therapy may have had some influence on the oral ecology of these patients, so had a higher risk of caries and candidiasis than the healthy controls. Therefore, comprehensive preventive measures should be taken in these children.