Gouri
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1) The document discusses a study on incorporating visible light activated titanium dioxide (TiO2) nanoparticles into denture base resin to improve oral health. 2) In vitro tests found that denture base resin containing 3-5% TiO2 nanoparticles exposed to visible light significantly reduced colony forming units of common oral pathogens over time. 3) Preliminary in vivo tests also saw reduced bacterial plaque buildup on dentures containing TiO2 after 6 months of use, suggesting the nanoparticles maintain antimicrobial activity long-term.
Gouri
- 1. Received financial grants in aid from ICMR for the period 2010 - 2013 ANTIMICORBIAL ACTIVITY OF VISIBLE LIGHT ACTIVATED TiO2 PHOTOCATALYTIC NANOPARTICLES UPON INCORPORATION IN DENTURE BASE RESIN DR GOURI V ANEHOSUR PROFESSOR DEPARTMENT OF PROSTHODONTICS SDM COLLEGE OF DENTAL SCIENCES AND HOSPITAL DHARWAD, INDIA
- 2. Received financial grants in aid from ICMR for the period 2010 - 2013 2 Studies have shown that majority of denture wearing population are failing to maintain their denture hygiene which is an important etiologic factor for denture induced stomatitis (DIS) which manifests as erythematous, edematous mucosa confined to denture bearing area. These changes with denture wearing increase the prevalence of S.aureus, L.acidophilus, Candida albicans and A. viscosus. Candida albicans is associated with stomatitis and disseminated fungal infections especially candida induced aspiration pneumonia, which is known to be fatal in the elderly. Various researches have added antifungal and antiseptic agents to acrylic denture base resins, which were rapidly released from them. In addition, routine use of denture cleansers may be unaffordably prohibitive in cost, especially among geriatric and handicapped denture wearers. Therefore, to improve oral health of denture wearers, it is necessary to develop simple and effective method to remove denture plaque. INTRODUCTION
- 3. Received financial grants in aid from ICMR for the period 2010 - 2013 3 PHOTOCATALYSIS •Photocatalysis is a technique wherein UV rays activate the photocatalyst. •TiO2 is chemically stable, biocompatible and non-toxic and is one of the prevailing materials in the field of photocatalysis. However, there were no identified reports on the antimicrobial activity of visible light activated photocatalytic TiO2 nanoparticles upon incorporation in PMMA denture base resins Commercially available TiO2 had negligible visible light photocatalytic activity since it contains high concentrations of defects which cause rapid recombination of photo generated electron-hole pairs Therefore to establish a clean and safe photocatalytic reaction using solar and/or visible light, it was vital to develop titanium dioxide photocatalyst that can absorb visible light and operate with high efficiency. Therefore, TiO2 was prepared by nitrogen doping with TiN as a precursor
- 4. Received financial grants in aid from ICMR for the period 2010 - 2013 4 Need based study effects at community level - especially for the geriatric, physically and economically handicapped patients. Control and prevention of oro-pharyngeal infections - microbial load will be reduced on the denture NEED FOR THE STUDY
- 5. Received financial grants in aid from ICMR for the period 2010 - 2013 5 a. Synthesis and control of “nano-particle-morphology” of visible light activated TiO2 b. To determine the minimum photo exposure period to achieve satisfactory reduction in colony forming units (CFU) c. To have qualitative assessment of antimicrobial activity of TiO2 d. To have quantitative assessment of antimicrobial activity of TiO2 e. Periodic assessment of TiO2 incorporated in denture base material over a predetermined time frame • In-vitro • In-vivo f. To asses the chemical and micro structural changes of TiO2 incorporated denture base material by spectroscopic studies – SEM, FTIR etc. OBJECTIVES
- 6. Received financial grants in aid from ICMR for the period 2010 - 2013 Commercially available 6 TiN – peroxide based technique Amorphous Anatase METHODOLOGY
- 7. Received financial grants in aid from ICMR for the period 2010 - 2013 7 ANATASE FORM OF TiO2 XRD SEM & EDAX XRD and SEM – EDAX proved that TiO2 obtained could be activated by visible light SEM –EDAX confirmed that the particles obtained were 30 nm.
- 8. Received financial grants in aid from ICMR for the period 2010 - 2013 8 In vitro PMMA DBM with 3% and 5% TiO2 Exposed to visible light spectrum – 450nm to 1000nm Time duration – 3,4,5 hours Candida albicans, Streptococcus mutans, Staphylococcus aureus, Actinomyces , Lactobacillus Time periods – 1d, 1w, 1m, 3m, 6m CFU in all micro organisms had decreased substantially In vivo tests were started
- 9. Received financial grants in aid from ICMR for the period 2010 - 2013 • Ethical clearance • Informed consent • Pilot study (n=10) • The sample size at an alpha error of 5% and a precision of 20% with 80% power worked out to a sample size of 8.3 per group. Allowing for 20% loss of samples the optimum sample size works out to be 10 subjects per group. • An experimental observational study design was used where every case had a matched control. • A total of 26 (n=13) were recruited for the study yielded a total of 112 samples over a period ranging from 1 d to 6m 9 In vivo
- 10. Received financial grants in aid from ICMR for the period 2010 - 2013 10 The Study group and controls were compared by combining all the colony counts with respect to each time duration. A two way ANOVA was performed to compare the overall colony counts across time duration and also to look for any interaction between the factors. There was no observed difference as the F =0.57 with p=0.70 and a partial eta square of only 0.36. However the contrast between study group and control was much more marked with F=0.39 (dF =1,4) with p=0.12 and partial eta square of 0.494. This indicates that nearly half of the difference in variances is explained by the difference in study group vs control. The two way ANOVA table of between subject defects is explained. Statistical analysis: Tests of Between-Subjects Effects Dependent Variable: COLONY SUMS Source Type III Sum of Squares df Mean Square F Sig. Partial Eta Squared Model 75893165.400a 6 12648860.900 15.257 .010 .958 DURATION 1890820.400 4 472705.100 .570 .700 .363 TYPE 3241024.900 1 3241024.900 3.909 .119 .494 Error 3316305.600 4 829076.400 Total 79209471.000 10 RESULTS
- 11. Received financial grants in aid from ICMR for the period 2010 - 2013 11 CLINCAL OUTCOME PHYSICAL – CHEMICAL PROPERTIES COST FACTOR DISCUSSION • Dentures were carrying less load plaque and oral pathogenic micro organisms • Justified as antimicrobial activity was present over a period of 6 months • As XRD, SEM-EDAX also shows nano TiO2 BIOCOMPATIBLE CLINCAL OUTCOME
- 12. Received financial grants in aid from ICMR for the period 2010 - 2013 12 PHYSICAL CHEMICAL PROPERTIES FTIR Nature of bonding , degree of polymerisation XRD size of nanoparticles as 31nm EDAX Presence of nano particles in PMMA SEM Surface morphology of nano particles and composites Unaffordably prohibitive - physically and economically handicapped denture wearers Oral health care vs. General health care COST FACTOR Denture cleansers INR. 300/- to Rs. 500/- Note: only if used daily TiO2 containing dentures – lab charges + maximum INR.450/- (one time investment)
- 13. Received financial grants in aid from ICMR for the period 2010 - 2013 13 Oral health takes backstage to general health in developing nations Oral health directly affects systemic health especially respiratory infection It is difficult in economically and physically handicapped , mentally challenged maintenance of denture hygiene is a must Additionally it does not affect polymerisation of acrylic and its mechanical properties Visible Light activated synthesized by peroxide based technique using TiN as precursor Therefore, use of economical and effective anatase form on TiO2 is recommended Ample and freely available sunlight in tropical region CONCLUSIONTHANK YOU
Editor's Notes
- #11: Ten cases were recruited randomly by applying inclusion exclusion criteria. Similarly ten matched controls were also recruited by matching for age, gender and diabetic status. To accommodate for any unexpected loss of in vivo data the test group size was increased to 13.
- #13: XRD -Chemical nature of the absorbants on TiO2 nano particles FTIR- Nature of bonding = catalytic particles and microbes SEM - Surface morphology of nano particles and composites surface roughness is comparable to polished PMMA DBM In accordance with Cheng et al in 2008 EDAX - Presence of tio in pmma