Theunis Oberholzer

Awareness of complications of oral piercing in a group of adolescents and young South African adults

OBJECTIVES Intraoral piercing as a body art has been gaining popularity amongst adolescents and young adults; however there is limited data on the awareness to complications associated with it. This study investigated the awareness of complications of oral piercing among a group of adolescents and young South African adults with intraoral piercings. STUDY DESIGN A total of 250 patients with intraoral piercing were asked to complete a questionnaire on the awareness of complications of oral piercing and were then examined by two calibrated dentists to determine oral complications caused by the pierced ornament. RESULTS Data revealed that 59.4% of the respondents were not aware of any complications in oral piercing. 24% of the respondents had intraoral piercing in the last 12 months, with a combined total of 17.2% having the procedure performed 5 to 7 years before. CONCLUSIONS The general lack of awareness of complications related to oral piercing needs to be addressed by the dental community.

Chitosan and gelatin based prototype delivery systems for the treatment of oral mucositis: from material to performance in vitro.

In this study we developed and evaluated a prototype of an effective occlusive mucoadhesive system for prophylaxis and/or treatment of oral mucositis based on chitosan and gelatine models together with nystatin as a prophylactic agent incorporated into the formulation and investigated drug release in-vitro. Results of in vitro studies showed that chitosan and gelatine based gels posses properties that makes them excellent candidates for treatment of oral mucositis. These properties include not only the palliative effects of an occlusive dressing but also the potential for delivering therapeutic compounds with chitosan gels providing drug concentrations above their minimum inhibition concentration and extending the retention time in the oral cavity due to their bioadhesive properties. Chitosan also offers an advantage over suspensions because of its inherent antimicrobial properties. The performance of gelatin-based gels highlights the novel, non-toxic, in situ forming gelatine based hydrogel. The results of in vitro drug release experiments demonstrated that all the hydrogel showed sustained release properties.

Towards Development of Novel Chitosan Based Drug Delivery Prototypes: Devices for Targeted Delivery Drug Therapy at the Molecular Level in Aqueous Media

We recently showed that chitosan containing hydrogel isare capable of displaying antioxidant activity and prevents formation of oxidative DNA damage in vitro [9]. In this short communication we report our investigations towards developing two alternative novel simple flexible and effective drug delivery systems that provide optimal dosage of drugs precisely where and when needed and therefore achieve and sustain a complex delivery profile. Two topics of a. free radical generation in biocompatible media and b. supramolecular host-guest recognition through miniaturizing and multi-functionalizing molecular carriers for improved drug delivery in disease-specific manner are combined with the aim of harnessing free radical reactivity within the laboratory and developing alternative and effective treatments for disease states mediated by free radicals.

Insights into Functional Erythromycin/Antioxidant Containing Chitosan Hydrogels as Potential Bio-active Restorative Materials: Structure, Function and Antimicrobial Activity

Substantial data are available in the literature on the role of Reactive Oxygen Opecies (ROS) and antioxidants in disorders such as the inflammatory and in chronic immune mediated conditions such as rheumatoid arthritis. However, remarkably little information is available on the periodontal diseases, which show many of the pathological features of other chronic inflammatory diseases. The periodontal tissues also provide an ideal medium within which to study mechanisms of ROS mediated tissue damage and of antioxidant defense in response to bacterial colonization, through the non-invasive collection of GCF. Bio-adhesive polymers appear to be particularly attractive for the development of alternative etches free dentin bonding system with an added advantage of additional therapeutic delivery systems to improve intradental administration of therapeutic and prophylactic agents if necessary. Chitosan, which is a biologically safe biopolymer, has been proposed as a bio-adhesive polymer and are of continuous interest to us due to their unique properties and flexibility in broad range of oral applications reported by others and us recently. The objectives of this study is to evaluate the novel chitosan based functional drug delivery systems which can be successfully incorporated into “dual action bioactive restorative materials” containing common antibiotic such as erythromycin, krill oil, aloe and aspirin as commonly used antioxidant species. Methods: The novel hydrogels will be investigated with respect to the antioxidant capacity and drug release capacity of the tetracycline as well as erythromycin from the designer drug delivery system, the use of SEM imaging for the characterization of the surfaces and reactive features of novel materials with antimicrobial potential as well asuse of the newly designed materials as an effective adhesive restorative materials. Results: A continuous release of erythromycin, while maintaining antibiotic effects against the tested bacteria,for at least 24 hours was shown from designer chitosan-antioxidant hydrogels. The increase antioxidant capacityof the designer material, significant antimicrobial capacity as well as adhesive dentine bond strength make thechitosan-containing restorative materials suitable and potentially advantageous materials for restorative andperiodontal applications in-vitro. The addition of antioxidants to the functionalized restorative material acts as aalternative free radical defense mechanism and therefor increases the shear bond strength teeth by managing theexcess of free radicals produced during common restorative procedure. Future investigations are necessary tovalidate this hypothesis.

Novel Melatonin-chitosan Hydrogels as Suitable Oral Bio-drug Delivery Systems to Fight Oral Mucositis: Synergy of Antioxidants and Bioactives in Action

Oral mucositis is a consequence of the toxic effects of chemotherapeutic agents and irradiation on oral mucosa cells. It is estimated that oral mucositis is a complication in 40% of patients receiving chemotherapy, more than 90% of those irradiated for head and neck cancer. This condition is frequently associated with severe pain and inflammation and can cause malnutrition, systemic infections, and low quality of life, as well as limiting chemotherapy doses. The pineal hormone melatonin inhibits the production of free radicals that mediate the toxicity of chemotherapy. The main objectives of this study is to develop and evaluate a novel occlusive bioadhesive system for prophylaxis and/or treatment of oral mucositis based on chitosan and melatonin in order to exploit natural biomaterials as functional biocompatible gels and evaluate the performance of the alternative drug delivery system towards in-vitro generated free-radical mediated inflammation response as a model system for oral mucosatis.

Cyclodextrins as Oral Drug Carrier Molecular Devices: Origins, Reasons and In-vitro Model Applications

Cyclodextrins are cyclic oligomers of glucose that can form water-soluble inclusion complexes with small molecules and por- tions of large compounds. These biocompatible, cyclic oligosaccharides do not elicit immune responses and have low toxicities in ani- mals and humans. Cyclodextrins are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current cyclodextrin-based therapeutics are described and possible future applications discussed with particular focus on oral drug administration. This article focuses on development of in vitro reliable and simple prototypes for oral drug delivery by combing chemical, structural and pharmacological knowledge available to date in order to create an optimal oral drug delivery system based on modified cyclodextrins. Practical in vitro model is also demonstrated.

Insights into functional tea infused-chitosan hydrogels as potential bio-active restorative materials

Introduction: We described novel chitosan hydrogels (chitosan-H) containing tea infusions (green, red and black) as functional additive prototypes with special focus on the design and functionality of dual action composite restorative materials. Their intended uses include remineralizing bases/liners, therapeutically active restorative materials and/or functional additives as well as functional prototype of the drug delivery system. Materials and Methods: The above mentioned hydrogels were prepared by dispersion of the corresponding component in glycerol and acetic acid with the addition of chitosan gelling agent. The surface morphology scanning electron microscope (SEM), release behavior (physiological pH as well as acidic conditions), stability of the hydrogels as well as antioxidant capacity of the tea infused hydrogels was evaluated. Results: It was found that all the anti-oxidant chitosan-H hydrogels treated dentine gave significantly (P < 0.05; Non-parametric ANOVA test) higher shear bond strength values than dentine treated or not treated with phosphoric acid. Overall, there was a small relapse in the shear bond strength after 6 months. The SEM is employed to observe the surface of the newly made functional restorative materials. The anti-oxidant capacity of various black, red and green tea infusions was investigated and demonstrated increased antioxidant stability of the newly prepared material stability. Conclusion: We have developed and evaluated several functional chitosan hydrogels with several targets as therapeutic restorative materials, the added benefits of their unique functionality involve increased dentin adhesive bond strengths (after 24 h and after 6 month), concept of using functional materials as carriers for pro-drugs as well as display certain degree of defense mechanism for a free radical damage.

Development of Novel Drug Delivery Prototypes Devices for Targeted Delivery Drug Therapy at the Molecular Level in Aqueous Media

A novel approach in target specific molecular prototype drug delivery system concerns the attempt to employ radical affording substances (RAS) or radical quenching substances (RQS) as prodrugs able to produce irreversible damage on the desired target and therefore to stimulate cellular apoptosis. However, radical species generated can react quickly within the chemical environment prior to reaching its proper site of action. In this short communication, we report our investigations towards developing two alternative novel, simple, flexible and effective drug delivery systems that provide optimal dosage of drugs precisely where and when needed and therefore achieve and sustain a complex delivery profile. We have demonstrated the application of two effective molecular prototype delivery systems able to harness free radical reactivity within the laboratory where biological processes can be studied and controlled, leading to the prevention of disease and the development of new treatments for disease states mediated by free radicals.