PMID- 33846018 OWN - NLM STAT- MEDLINE DCOM- 20210629 LR - 20220730 IS - 1879-0097 (Electronic) IS - 0109-5641 (Linking) VI - 37 IP - 7 DP - 2021 Jul TI - Characterization and toxicity evaluation of air-borne particles released by grinding from two dental resin composites in vitro. PG - 1121-1133 LID - S0109-5641(21)00114-7 [pii] LID - 10.1016/j.dental.2021.03.011 [doi] AB - OBJECTIVE: The project aims to evaluate whether inhalation of particles released upon grinding of dental composites may pose a health hazard to dentists. The main objective of the study was to characterize the dust from polymer-based dental composites ground with different grain sized burs and investigate particle uptake and the potential cytotoxic effects in human bronchial cells. METHODS: Polymerized blocks of two dental composites, Filtek Z250 and Filtek Z500 from 3M ESPE, were ground with super coarse (black) and fine (red) burs inside a glass chamber. Ultrafine airborne dust concentration and particle size distribution was measured real-time during grinding with a scanning mobility particle sizer (SMPS). Filter-collected airborne particles were characterized with dynamic light scattering (DLS) and scanning electron microscopy (SEM). Human bronchial epithelial cells (HBEC-3KT) were exposed to the dusts in dose-effect experiments. Toxicity was measured with lactate dehydrogenase (LDH) assay and cell counting kit-8 (CCK8). Cellular uptake was observed with transmission electron microscopy (TEM). RESULTS: Airborne ultrafine particles showed that most particles were in the size range 15-35 nm (SMPS). SEM analysis proved that more than 80% of the particles have a minimum Feret diameter less than 1 mum. In solution (DLS), the particles have larger diameters and tend to agglomerate. Cell toxicity (LDH, CCK8) is shown after 48 h and 72 h exposure times and at the highest doses. TEM showed presence of the particles within the cell cytoplasm. SIGNIFICANCE: Prolonged and frequent exposure through inhalation may have negative health implications for dentists. CI - Copyright (c) 2021. Published by Elsevier Inc. FAU - Camassa, L M A AU - Camassa LMA AD - National Institute of Occupational Health, Oslo, Norway. FAU - Ervik, T K AU - Ervik TK AD - National Institute of Occupational Health, Oslo, Norway. FAU - Zegeye, F D AU - Zegeye FD AD - National Institute of Occupational Health, Oslo, Norway. FAU - Mdala, I AU - Mdala I AD - Institute of Health and Society, University of Oslo, Oslo, Norway; Oral Health Centres of Expertise in Eastern Norway, Oslo, Norway. FAU - Valen, H AU - Valen H AD - Nordic Institute of Dental Materials, Oslo, Norway. FAU - Ansteinsson, V AU - Ansteinsson V AD - Oral Health Centres of Expertise in Eastern Norway, Oslo, Norway. FAU - Zienolddiny, S AU - Zienolddiny S AD - National Institute of Occupational Health, Oslo, Norway. Electronic address: shan.zienolddiny@stami.no. LA - eng PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20210410 PL - England TA - Dent Mater JT - Dental materials : official publication of the Academy of Dental Materials JID - 8508040 RN - 0 (Dust) RN - 0 (Resins, Synthetic) EIN - Dent Mater. 2022 Sep;38(9):1564. PMID: 35907752 MH - *Dust MH - Humans MH - Microscopy, Electron, Scanning MH - Microscopy, Electron, Transmission MH - Particle Size MH - *Resins, Synthetic OTO - NOTNLM OT - Characterization OT - Dental composites OT - Diamond burs OT - Toxicity EDAT- 2021/04/14 06:00 MHDA- 2021/06/30 06:00 CRDT- 2021/04/13 05:44 PHST- 2020/10/01 00:00 [received] PHST- 2021/03/29 00:00 [revised] PHST- 2021/03/29 00:00 [accepted] PHST- 2021/04/14 06:00 [pubmed] PHST- 2021/06/30 06:00 [medline] PHST- 2021/04/13 05:44 [entrez] AID - S0109-5641(21)00114-7 [pii] AID - 10.1016/j.dental.2021.03.011 [doi] PST - ppublish SO - Dent Mater. 2021 Jul;37(7):1121-1133. doi: 10.1016/j.dental.2021.03.011. Epub 2021 Apr 10.