Searched for: person:msw300
Experimental and finite element study of residual thermal stresses in veneered Y-TZP structures
Tanaka, Carina B; Harisha, Hossam; Baldassarri, Marta; Wolff, Mark S; Tong, Hui; Meira, Josete B C; Zhang, Yu
The main complications of zirconia-based laminated systems are chipping and delamination of veneering porcelain, which has been found to be directly associated with the development of residual thermal stresses in the porcelain layer. This study investigates the effects of cooling rate and specimen geometry on the residual stress states in porcelain-veneered zirconia structures. Bilayers of three different shapes (bars, semi-cylindrical shells, and arch-cubic structures) with 1.5 mm and 0.7 mm thickness of dentin porcelain and zirconia framework, respectively, were subjected to two cooling protocols: slow cooling (SC) at 32 degrees C/min and extremely-slow cooling (XSC) at 2 degrees C/min. The residual thermal stresses were determined using the Vickers indentation method and validated by finite element analysis. The residual stress profiles were similar among geometries in the same cooling protocol. XSC groups presented significantly higher tensile stresses (p = 0.000), especially for curved interfaces. XSC is a time-consuming process that showed no beneficial effect regarding residual stresses compared to the manufacturer recommended slow cooling rate.
PMCID:4831075
PMID: 27087734
ISSN: 0272-8842
CID: 2080312
A pilot study of dentists' assessment of caries detection and staging systems applied to early caries: PEARL Network findings
Thompson, Van P; Schenkel, Andrew B; Penugonda, Bapanaiah; Wolff, Mark S; Zeller, Gregory G; Wu, Hongyu; Vena, Don; Grill, Ashley C; Curro, Frederick A
The International Caries Detection and Assessment System (ICDAS II) and the Caries Classification System (CCS) are caries stage description systems proposed for adoption into clinical practice. This pilot study investigated clinicians' training in and use of these systems for detection of early caries and recommendations for individual tooth treatment. Patient participants (N = 8) with a range of noncavitated lesions (CCS ranks 2 and 4 and ICDAS II ranks 2-4) identified by a team of calibrated examiners were recruited from the New York University College of Dentistry clinic. Eighteen dentists-8 from the Practitioners Engaged in Applied Research and Learning (PEARL) Network and 10 recruited from the Academy of General Dentistry-were randomly assigned to 1 of 3 groups: 5 dentists used only visual-tactile (VT) examination, 7 were trained in the ICDAS II, and 6 were trained in the CCS. Lesion stage for each tooth was determined by the ICDAS II and CCS groups, and recommended treatment was decided by all groups. Teeth were assessed both with and without radiographs. Caries was detected in 92.7% (95% CI, 88%-96%) of the teeth by dentists with CCS training, 88.8% (95% CI, 84%-92%) of the teeth by those with ICDAS II training, and 62.3% (95% CI, 55%-69%) of teeth by the VT group. Web-based training was acceptable to all dentists in the CCS group (6 of 6) but fewer of the dentists in the ICDAS II group (5 of 7). The modified CCS translated clinically to more accurate caries detection, particularly compared to detection by untrained dentists (VT group). Moreover, the CCS was more accepted than was the ICDAS II, but dentists in both groups were open to the application of these systems. Agreement on caries staging requires additional training prior to a larger validation study.
PMID: 27148652
ISSN: 0363-6771
CID: 2228602
A Novel Chemically Modified Curcumin "Normalizes" Wound-Healing in Rats with Experimentally Induced Type I Diabetes: Initial Studies
Zhang, Yazhou; McClain, Steve A; Lee, Hsi-Ming; Elburki, Muna S; Yu, Huiwen; Gu, Ying; Zhang, Yu; Wolff, Mark; Johnson, Francis; Golub, Lorne M
Introduction. Impaired wound-healing in diabetics can lead to life-threatening complications, such as limb amputation, associated in part with excessive matrix metalloproteinase- (MMP-) mediated degradation of collagen and other matrix constituents. In the current study, a novel triketonic chemically modified curcumin, CMC2.24, was tested for efficacy in healing of standardized skin wounds in streptozotocin-induced diabetic rats. Initially, CMC2.24 was daily applied topically at 1% or 3% concentrations or administered systemically (oral intubation; 30 mg/kg); controls received vehicle treatment only. Over 7 days, the diabetics exhibited impaired wound closure, assessed by gross and histologic measurements, compared to the nondiabetic controls. All drug treatments significantly improved wound closure with efficacy ratings as follows: 1% 2.24 > systemic 2.24 > 3% 2.24 with no effect on the severe hyperglycemia. In subsequent experiments, 1% CMC2.24 "normalized" wound-healing in the diabetics, whereas 1% curcumin was no more effective than 0.25% CMC2.24, and the latter remained 34% worse than normal. MMP-8 was increased 10-fold in the diabetic wounds and topically applied 1% (but not 0.25%) CMC2.24 significantly reduced this excessive collagenase-2; MMP-13/collagenase-3 did not show significant changes. Additional studies indicated efficacy of 1% CMC2.24 over more prolonged periods of time up to 30 days.
PMCID:4846750
PMID: 27190999
ISSN: 2314-6753
CID: 2111832
Nationwide 2.5-Year School-Based Public Health Intervention Program Designed to Reduce the Incidence of Caries in Children of Grenada
Wolff, Mark S; Hill, Rachel; Wilson-Genderson, Maureen; Hirsch, Stuart; Dasanayake, Ananda P
This paper describes an innovative public health intervention, called 'Smile Grenada', targeting the oral health of children in Grenada utilizing the resources of a US dental school, several oral health care companies, local governmental and public health authorities, and Grenadian school personnel. METHODS: Preintervention visual/tactile caries examinations were collected from 1,092 schoolchildren (mean age 9.9 years, standard deviation, SD = 3.7) in 2010. The intervention included: (1) classroom-based toothbrushing with fluoridated toothpaste, (2) fluoride varnish applied by trained dental students, teachers and local providers 3 times a year and (3) glass ionomer sealants placed on first permanent molars in children aged 6-8 years. Postintervention data were collected in May, 2013 (n = 2,301, mean age 9.8 years, SD = 3.7). Decayed and demineralized surfaces were examined for the whole sample and decay/demineralization and sealant retention on 6-year molars were examined separately (ages 6-8 in 2013 cohort). RESULTS: The number of decayed/demineralized surfaces declined across all age groups. The average number of decayed surfaces dropped from 9 at baseline to just over 6 (F1, 3,393 = 69.8, p < 0.0001) and the average number of demineralized surfaces dropped from 6 to less than 2 (1.8 surfaces; F1, 3,393 = 819.0, p < 0.0001). For children aged 6-8 years, there were statistically significantly fewer decayed surfaces (t1, 2,086 = 12.40, p < 0.0001; mean baseline 0.93, SD = 1.75; mean follow-up 0.23, SD = 0.83) and demineralized surfaces (t1, 2,086 = 19.7, p < 0.0001; mean baseline 2.11, SD = 2.74; mean follow-up 0.50, SD = 0.97) on 6-year molars. The Smile Grenada program successfully demonstrated a locally sustainable model for improving oral health in children in a developing country.
PMID: 27100682
ISSN: 1421-976x
CID: 2080342
The Public Health Reach of High Fluoride Vehicles: Examples of Innovative Approaches
Tellez, Marisol; Wolff, Mark S
Fluorides and sealants have been shown to reduce caries in populations, making fluoride interventions a large part of the dental public health effort. Although public health programs have traditionally focused on fluoride vehicles delivering less than 1,000 ppm of fluoride, more recent efforts have shifted toward the use of high fluoride vehicles such as varnishes and prescription toothpastes. In the USA, states are developing innovative strategies to increase access to dental services by using primary care medical providers to deliver early preventive services as part of well-child care visits. Currently, Medicaid programs in 43 states reimburse medical providers for preventive services including varnish application. Still, there is uncertainty about the cost-effectiveness of such interventions. In many resource-strained environments, with shortages of dental health care providers, lack of fluoridated water and lower dental awareness, it is necessary to develop sustainable programs utilizing already established programs, like primary school education, where caries prevention may be set as a priority. Dental caries among the elderly is an ongoing complex problem. The 5,000-ppm F toothpaste may be a reasonable approach for developing public health programs where root caries control is the main concern. Fluoride varnish and high concentration fluoride toothpaste are attractive because they can easily be incorporated into well-child visits and community-based geriatric programs. Additional research on the effectiveness and costs associated with population-based programs of this nature for high risk groups is needed, especially in areas where a community-based fluoride delivery program is not available.
PMID: 27099929
ISSN: 1421-976x
CID: 2118662
Integrated case presentation -- establishing inter-professional teams to facilitate team based learning
Chapter by: De Bartolo, Angela; Rodriguez-Cardenas, MP; Sherwin, G; Wolff, MS
in: RSE : Research Scholarship Expo by
[S.l. : NYU College of Dentistry], 2016
pp. 043-044
ISBN: n/a
CID: 2889722
Interfaces in fixed dental prostheses: Challenges and opportunities
Chapter by: Zhang, Y; Chughtai, A; Wolff, MS; Trushkowsky, R; Chai, H
in: Material-Tissue Interfacial Phenomena: Contributions from Dental and Craniofacial Reconstructions by
pp. 67-83
ISBN: 9780081003411
CID: 2452512
Dental Fear and Avoidance in Treatment Seekers at a Large, Urban Dental Clinic
Heyman, Richard E; Slep, Amy M Smith; White-Ajmani, Mandi; Bulling, Lisanne; Zickgraf, Hana F; Franklin, Martin E; Wolff, Mark S
PURPOSE: The prevalence and correlates of dental fear have been studied in representative population studies, but not in patients presenting for dental treatment. We hypothesized that dental fear among patients presenting at a large, urban college of dentistry would be similar to that of the population (e.g. 11% high dental fear, 17% to 35% moderate or higher fear) and that fear would be associated with avoidance of routine dental care, increased use of urgent dental care and poor oral health. MATERIALS AND METHODS: Participants were 1070 consecutive patients at a large, urban dental care center. All patients completed a clinical interview, including demographics, medical history, dental history and presenting concerns, and behavioral health history. Patients were also asked to rate their dental anxiety/fear on a 1 (none) to 10 (high) scale. RESULTS: Over 20% of patients reported elevated anxiety/fear, of which 12.30% reported moderate and 8.75% high fear. Severity of dental anxiety/fear was strongly related to the likelihood of avoiding dental services in the past and related to myriad presenting problems. CONCLUSIONS: As hypothesized, the prevalence of moderate or higher fear in dental patients was considerable and closely matched that found in general population surveys. Thus, the 'dental home' is an ideal location to treat clinically significant dental anxiety/fear.
PMID: 27351733
ISSN: 1602-1622
CID: 2257202
Integrated case presentation : establishing interprofessional teams to facilitate team-based learning [Meeting Abstract]
De Bartolo, Angela; Rodriguez, Maria P; Sherwin, Gene; Wolff, Mark S
ORIGINAL:0011895
ISSN: 1930-7837
CID: 2536682
Modern Concepts in Aesthetic Dentistry and Multidisciplined Reconstructive Grand Rounds [Editorial]
Calamia, John R; Trushkowsky, Richard D; David, Steven B; Wolff, Mark S
PMID: 26140979
ISSN: 1558-0512
CID: 1649672