Objectives: This study evaluated the marginal gaps on several surfaces of onlays created with the Cerec 3D system using one intraoral and two extraoral optical impression methods.
Methods: A human molar (#19) was mounted with its adjacent teeth on a typodont (Frasaco) and prepared for a MODL onlay. The typodont was assembled in the mannequin head in order to simulate clinical conditions. The same operator took 36 individual optical impressions using a CEREC 3D camera. For group 1 (IP), a thin layer of titanium dioxide powder (CEREC powder-VITA) was applied directly onto the surface of the preparation for imaging (n = 12). For group 2 (EP), a sectional impression was taken with hydrocolloid Identic Syringable (Dux Dental), a die made with polyvinylsiloxane KwikkModel Scan (R-dental Dentalerzeugnisse GmbH) and powdered with titanium dioxide for imaging (n = 12). For group 3 (ES), a sectional impression was taken with PVS and a sectional stock tray, a die fabricated in stone (Diamond die- HI-TEC Dental Products) and the die being imaged without powdering (n = 12). One operator designed and machined the onlays in VitaBlocks Mark II for Cerec (VITA) using a CEREC 3D. The marginal gaps (microm) were measured with an optical microscope (50x) at 12 points, three on each surface of the MODL. The results were analyzed by two-way ANOVA/ Tukey's (p = 0.05).
Results: The overall mean marginal gaps (microm) for the three methods were: IP = 111.6 (+/- 34.0); EP = 161.4 (+/- 37.6) and ES = 116.8 (+/- 42.3). IP and ES were equal, but both were significantly less than EP. The pooled mean marginal gaps (microm) for the occlusal = 110.5 (+/- 39) and lingual = 111.5 (+/- 30.5) surfaces were equivalent and significantly less than the distal = 136.5 (+/- 42.5) and mesial = 161.1 (+/- 43.3).
Conclusion: The marginal gap of CEREC 3D onlay restorations was not different when the optical impression was taken intraorally vs extraorally using a stone cast that does not require powdering. The lingual and occlusal surfaces showed the lowest gaps.
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http://dx.doi.org/10.2341/09-178-L | DOI Listing |
J Conserv Dent Endod
November 2024
Department of Conservative Dentistry and Endodontics, GITAM Dental College and Hospital, Visakhapatnam, Andhra Pradesh, India.
Background: Long-term durability of a restoration relies on the marginal integrity and its ability to withstand the occlusal forces. Fiber-reinforced composites (FRCs) exhibited superior properties in terms of fracture toughness, flexural strength, and wear resistance.
Aim: The aim of this study was to assess and compare marginal adaptation and microtensile bond strength (µTBS) of posterior FRCs comparing with a condensable composite.
Introduction: Anal Lymphoma (AL) is a rare presentation of extranodal lymphomas, characterized by occurrence in the anal area and largely understudied due to its infrequency. This study aims to address gaps in knowledge about AL's demographic and clinical profiles, treatments, and survival outcomes, leveraging data from the SEER program.
Methods: We conducted a retrospective analysis of 79 AL cases identified in the SEER database from 2000 to 2022; 36 stage I AL were identified and defined as localized primary anal lymphoma (L-PAL).
J Am Pharm Assoc (2003)
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Vanderbilt University Medical Center, Department of Biomedical Informatics.
Background: Policy changes during the COVID-19 pandemic allowed buprenorphine to be prescribed for opioid use disorder (OUD) via telemedicine without an in-person visit. A recently proposed change will limit buprenorphine access to 30 days without an in-person visit. Given that people living in rural areas may be disproportionally impacted by this change, we sought to better understand how buprenorphine adherence may be impacted by requiring in-person visits.
View Article and Find Full Text PDFBMC Oral Health
December 2024
Faculty of Odonto-Stomatology, University of Health Sciences, Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam.
Background: The success of a restoration largely depends on the quality of its fit. This study aimed to investigate the fit quality of monolithic zirconia veneers (MZVs) produced through traditional and digital workflows.
Methods: A typodont maxillary right central incisor was prepared.
Biomimetics (Basel)
November 2024
Department of Dental Laboratory Science, College of Health Science, Catholic University of Pusan, 57 Oryundae-ro, Geumjeong-gu, Busan 46252, Republic of Korea.
DLP printing is a new method for producing zirconia laminates that ensure clinically acceptable gaps in the internal, marginal, and incisal regions. A typical model of a central maxillary incisor was prepped by a dentist and scanned. The laminate was designed using CAD software version 2023.
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