Synergistic interactions between corrosion and wear at titanium-based dental implant connections: A scoping review.

Two-piece implant systems are mainly used in oral implantology involving an osseointegrated implant connected to an abutment, which supports prosthetic structures. It is well documented that the presence of microgaps, biofilms and oral fluids at the implant-abutment connection can cause mechanical and biological complications. The aim of this review paper was to report the degradation at the implant-abutment connection by wear and corrosion processes taking place in the oral cavity. Most of the retrieved studies evaluated the wear and corrosion (tribocorrosion) of titanium-based materials used for implants and abutments in artificial saliva. Electrochemical and wear tests together with microscopic techniques were applied to validate the tribocorrosion behavior of the surfaces. A few studies inspected the wear on the inner surfaces of the implant connection as a result of fatigue or removal of abutments. The studies reported increased microgaps after fatigue tests. In addition, data suggest that micromovements occurring at the contacting surfaces can increase the wear of the inner surfaces of the connection. Biofilms and/or glycoproteins act as lubricants, although they can also amplify the corrosion of the surfaces. Consequently, loosening of the implant-abutment connection can take place during mastication. In addition, wear and corrosion debris such as ions and micro- and nanoparticles released into the surrounding tissues can stimulate peri-implant inflammation that can lead to pathologic bone resorption.

Atypical odontalgia: an up-to-date view.

Atypical odontalgia (AO) is a little known chronic pain condition. It usually presents as pain in a site where a tooth was endodontically treated or extracted, in the absence of clinical or radiographic evidence of tooth pathology. It is a rare clinical challenge for most clinicians, which leads to the patients being referred to several specialists and sometimes undergoing unnecessary surgical procedures. The pain mechanisms involved in AO are far from clear, and numerous potential mechanisms have been suggested. Currently, the most accredited hypothesis is that AO is a neuropathic pain condition caused by deafferentation. The differential diagnosis of AO remains difficult, because it shares symptoms with many others pathologies affecting this area. Patients have difficulties accepting the AO diagnosis and treatment. As a result, they frequently change physicians, and may potentially also receive several invasive treatments, usually resulting in an aggravation of the pain. Although some patients do get complete pain relief following treatment, for most patients the goal should be to achieve adequate pain management. Currently, most management is based on expert opinion and case reports. More research and high quality randomized controlled trials are needed in order to develop evidence-based treatments, currently based on expert opinion or carried over from other neuropathic pain conditions in the orofacial region.

Chlorhexidine (CHX) in dentistry: state of the art.

Chlorhexidine (CHX) is one of the most commonly prescribed antiseptic agents in the dental field. It has a long-lasting antibacterial activity with a broad-spectrum of action and it has been shown to reduce plaque, gingival inflammation and bleeding. Its use is considered a powerful adjuvant to mechanical oral hygiene (brushing and flossing), especially in those cases in which it cannot be performed correctly. Available as mouthwash, gel, aerosol, spray and disks, CHX is considered a safe compound, with minimal and transitory local and systemic side effects. Data support its periodic use as an adjuvant to normal brushing and flossing in subjects unable to maintain proper oral hygiene due to physical and/or mental impairment, or lack of motivation, or decreased salivary rate. CHX is also a useful alternative to mechanical oral hygiene procedures in those cases in which they are contraindicated, e.g. after a surgical procedure, or as a preoperative rinse before procedures in which use of a dental dam is not possible. The aim of this article is to offer a complete review of literature regarding the characteristics, the applications and the problems associated with the use of chlorhexidine in the dental field.