Tissue sealing

The most common oral condition and dental emergency is dental caries, which is a destructive disease of the hard tissues of the teeth due to bacterial infection with Streptococcus mutans and other bacteria. It is characterized by destruction of enamel and dentine. Dental decay presents as opaque white areas of enamel with grey undertones and in more advanced cases, brownish discoloured cavitations. Dental caries is initially asymptomatic and pain does not occur until the decay impinges on the pulp, and an inflammation develops. Treatment of caries involves removal of the softened and infected hard tissues, sealing of exposed dentines and restoration of the lost tooth structure with porcelain, silver, amalgam, composite plastic, gold etc. 

Karasek, L. Hajslova, J. Rosmus, J. Huhnerfuss, H., Methylsulfonyl PCB and DDE metabolites and their enantioselective gas chromatographic separation in human adipose tissues, seal blubber and pelican muscle Chemosphere 2007, 67, S22-S27. 

Insulating substrate for vessel or tissue sealing instrument... 

Vascular access ports typically consist of a self-sealing siUcone septum within a rigid housing which is attached to a radiopaque catheter (see Radiopaques). The catheter must be fabricated from a low modulus elastomeric polymer capable of interfacing with both soft tissue and the cardiovascular environment. A low modulus polyurethane-based elastomer is preferred to ensure minimal trauma to the fragile vein. 

Biomedical. Heart-valve parts are fabricated from pyrolytic carbon, which is compatible with living tissue. Such parts are produced by high temperature pyrolysis of gases such as methane. Other potential biomedical apphcations are dental implants and other prostheses where a seal between the implant and the living biological surface is essential. Plasma and arc-wire sprayed coatings are used on prosthetic devices, eg, hip implants, to achieve better bone/tissue attachments (see Prosthetic and BiOLffiDiCALdevices). 

However, the reaction with water can be made to be extremely slow. Because the alkaline electrolyte is corrosive toward human tissue as well as toward the materials ia devices, it is more important to have a good seal toward preventing electrolyte leakage ia an alkaline battery than ia a carbon—2iac cell. The formation of a good seal is, however, iacompatible with the formation of a noncondensable gas like hydrogen. 

The most extensive experience with tissue adhesive drug delivery exists in the fibrin sealant literature. This is clearly an off-label use of this agent as it is only currently approved for hemostasis in cardiac and splenic trauma surgery and for colon sealing at the time of colostomy closure. 

FIGURE 2-8. Z-track injection (A) The tissue is tensed laterally at the injection site before the needle is inserted. This pulls the skin, subcutaneous tissue, and fat planes into a Zformation. (B) After the tissue has been displaced, the needle is thrust straight into the muscular tissue. (Q After injection, tissues are released while the needle is withdrawn. As each tissue plane slides by the other, the track is sealed. 

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