ABSTRACT
OBJECTIVE: The objective of this study was to investigate if cryopreservation of teeth for long-term storage leads to cracks in enamel and dentin. STUDY DESIGN: Three teeth, which were extracted for orthodontic reasons, were cryopreserved in liquid nitrogen (temperature -196°C) and thawed according to standard protocols after 4 months. Micro computed tomography using synchrotron radiation was performed to detect cracks in the tooth hard tissues. RESULTS: Cracks were found in the enamel of all teeth, which are associated with forceps application during extraction. Cracks with a width larger than 0.8 µm were not identified in dentin and cementum. CONCLUSION: Although cryopreservation of teeth according to the standard protocol does not generate cracks more than 0.8 µm wide, the use of forceps can result in prominent cracks.
Subject(s)
Cryopreservation , Dental Enamel/injuries , Dentin/injuries , Tooth Extraction/adverse effects , Tooth Fractures/pathology , Dental Enamel/pathology , Dentin/pathology , Humans , Specimen Handling , Tooth Extraction/instrumentation , Tooth Fractures/etiology , X-Ray MicrotomographyABSTRACT
After tooth loss dental implants or fixed prosthetic restorations are not indicated in children and adolescents due to incomplete maxillary and mandibular development. Cryopreservation is a method for long-term storage of healthy teeth which were removed for orthodontic reasons or due to traumatic origin. These preserved teeth can be used as autogenous replants or transplants after tooth loss. During transport to and from the freezing facilities prior to freezing the teeth are stored in a cell culture medium. The tooth is transferred into a freezing tube containing cell culture medium and cryoprotectant DMSO. Teeth autotransplanted after cryopreservation show vitality of the PDL cells. Usually no enamel and/or dentinal cracks can be observed. After tooth loss transplantation of cryopreserved teeth could be an effective and biological therapy for tooth replacement.
Subject(s)
Cryopreservation , Tooth/transplantation , Cryopreservation/methods , Humans , Tissue Banks , Tooth Extraction , Transplantation, AutologousABSTRACT
BACKGROUND: Approximately 25% of Staphylococcus aureus carriers have exclusive throat carriage. We aimed to identify the populations at risk for exclusive throat carriage to improve sensitivity to detect carriers. METHODS: Four groups underwent nasal and throat screening for S. aureus. Three groups of individuals in the community (n = 2632) with different estimated levels of exposure to the health care system (HCS) were screened, including 1500 healthy blood donors, 498 patients from a school of dental medicine, and 634 health care workers (HCWs) at a trade fair. The fourth group comprised in-hospital patients and HCWs (n = 832) and was considered the group with the highest estimated exposure to the HCS. As a primary outcome, we analyzed risk factors for exclusive throat carriage in exclusive throat carriers vs all nasal carriers. RESULTS: Of 3464 individuals screened, 428 (12.4%) had exclusive throat carriage, and 1260 (36.4%) had carriage in the nares only or in the nares and the throat. The most important independent risk factor for exclusive throat carriage was age 30 years or younger (odds ratio, 1.66; P < .001). Exposure to the HCS was a significant protective factor for exclusive throat carriage (odds ratio, 0.67; P = .001). Healthy blood donors were almost twice as likely to have exclusive throat carriage than in-hospital patients and HCWs (30.2% vs 18.4% of all carriers, P < .001). CONCLUSIONS: Absence of exposure to the HCS and younger age predicted exclusive throat carriers, a population at high risk for community-onset methicillin-resistant S. aureus. Screening for S. aureus should include swabs from the anterior nares and from the throat to improve the likelihood of detecting carriers.
Subject(s)
Carrier State/microbiology , Pharynx/microbiology , Staphylococcus aureus/isolation & purification , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Methicillin Resistance , Middle Aged , Risk FactorsABSTRACT
We assessed the frequency of carriers of methicillin-resistant Staphylococcus aureus (MRSA) among 500 dental patients of a university clinic. From each participant, two specimens were taken from the anterior nares and the pharynx and analysed by culture. The participants completed a questionnaire on possible risk factors of MRSA infection. Two hundred ten individuals carried S. aureus, 90 in the nares only, 51 in the throat only and 69 in nares and throat. Isolates of 208 patients were methicillin-sensitive; two isolates were methicillin-resistant, both carried in the throat exclusively. In conclusion, the frequency of nasal and/or throat carriers of MRSA among dental patients was low and suggests few opportunities of exposure in the dental clinic assessed.
