Galvanic corrosion and cytotoxic effects of amalgam and gallium alloys coupled to titanium

The aim of this study was to examine and compare the galvanic corrosion of a conventional, a dispersed high-copper, and a palladium-enriched spherical high-copper amalgam and a gallium alloy coupled to titanium in saline and cell culture solutions, and to evaluate the effects of the couples on cultured cells. The potentials and charge transfers between amalgams and titanium were measured by electrochemical corrosion methods. Cytotoxicity of the couples, as indicated by the uptake of neutral red vital stain, was determined in 24-h direct contact human gingival libroblast cell cultures. Results of this study indicated that before connecting the high-copper amalgams to titanium, the amalgams exhibited more positive potentials which resulted in initial negative charge transfers, i.e. corrosion of titanium. However, this initial corrosion appeared to cause titanium to passivate, and a shift in galvanic currents to positive charge transfers, i.e. corrosion of the amalgam samples. Lower galvanic currents were measured for the amalgam-titanium couples as compared to the gallium alloy-titanium couple. Coupling the conventional or the palladium-enriched high-copper amalgams to titanium did not significantly affect the uptake of neutral red as compared to cells not exposed to any test alloy. However, significant cytotoxic effects were observed when the dispersed-type high-copper amalgam and the gallium alloy were coupled to titanium. Even though the corrosion currents measured for these couples were less than gold alloys coupled to amalgam, these results suggest there is the potential for released galvanic corrosion products to become cytotoxic. These data warrant further investigations into the effects of coupling amalgam and gallium alloys to titanium in the oral environment.     

Relation of Gothic arch apex to dentist-assisted centric relation

This method of fabrication of an immediate nasal prosthesis has distinct advantages which recommend its use. These are (1) the use of an RTV silicone rubber impression as the refractory cast cuts fabrication time to minutes rather than hours, as compared with other methods of fabricating a nasal prosthesis; (2) the RTV silicone is permanent and stable and provides an exact reproduction of the part to be excised; (3) the initial RTV silicone impression may be used during fabrication of the definitive prosthesis as the mold for production of a wax sculpting model; (4) PVC prostheses offer a unique advantage of being soft enough for trimming with scissors at the time of surgery and are flexible and tissue-compatible; and (5) psychological trauma is minimized and the patient is better prepared for a definitive prosthetic restoration.     

Facial pain as first manifestation of lung cancer: a case of lung cancer-related cluster headache and a review of the literature

Facial pain can, on rare occasions, be the presenting symptom of lung cancer. This report describes a patient with non-metastatic lung cancer, which was associated with attacks of debilitating facial pain, presenting as cluster headache. Moreover, 32 reported cases of lung cancer-related facial pain (including the present one) are reviewed, and their clinical features are summarized. The facial pain is almost always unilateral, and is most commonly localized to the ear, the jaws, and the temporal region. The pain is frequently described as severe and aching, and may be continuous or intermittent. Aggravation and expansion of the pain, digital clubbing, increased erythrocyte sedimentation rate, and hypertrophic osteopathy, may contribute to the diagnosis. Referred pain, due to invasion or compression of the vagus nerve, as well as paraneoplastic syndrome secondary to the production of circulating humoral factors by the malignant tumor cells, is implicated in the pathophysiology of facial pain associated with non-metastatic lung cancer. Radiotherapy and tumor resection with vagotomy are very effective in aborting the facial pain. Thus, lung cancer should be included in the differential diagnosis of facial pain that is atypical and/or refractory to treatment.     

Injection pain and postinjection pain of the palatal-anterior superior alveolar injection, administered with the Wand Plus system, comparing 2% lidocaine with 1:100,000 epinephrine to 3% mepivacaine

PURPOSE: The purpose of this prospective, randomized, double-blind study was to compare injection pain and postinjection pain of 2% lidocaine with 1:100,000 epinephrine and 3% mepivacaine using the computer-assisted Wand Plus injection system to administer the palatal-anterior superior alveolar (P-ASA) injection. Additionally study was done to determine if the use of topical anesthetic decreased the pain of needle insertion with the P-ASA injection. STUDY DESIGN: Using a crossover design, 40 subjects randomly received, in a double-blind manner, P-ASA injections of 1.4 mL of 2% lidocaine with 1:100,000 epinephrine and 1.4 mL of 3% mepivacaine, at 2 separate appointments. The P-ASA injection was administered, utilizing the Wand Plus system, 6 to 10 mm into the incisive canal located lingual to the central incisors. The pain of needle insertion, needle placement, solution deposition and postinjection pain were recorded on a Heft-Parker visual analog scale for the 2 P-ASA injections. Eighty injections were randomly administered in the study, 40 using topical anesthetic gel and 40 using a placebo gel. RESULTS: For needle insertion, 30% of the subjects reported moderate/severe pain with the lidocaine solution and 43% reported moderate/severe pain with the mepivacaine solution. There was no significant difference (P > .05) between the topical and placebo groups. For needle placement into the incisive canal, 54% of the subjects reported moderate/severe pain with the lidocaine solution and 58% reported moderate/severe pain with the mepivacaine solution. For anesthetic solution deposition, 8% of the subjects reported moderate pain with the lidocaine solution and 12% reported moderate pain with the mepivacaine solution. There were no significant differences (P > .05) between the lidocaine and mepivacaine solutions. Regarding postinjection pain, when anesthesia wore off on the day of the injection, 20% of the subjects reported moderate/severe pain with the lidocaine solution and 14% reported moderate/severe pain with the mepivacaine solution. Pain ratings decreased over the next 3 days. There were no significant differences (P > .05) between the lidocaine and mepivacaine solutions. Postinjection, 12% and 18% of the subjects experienced temporary numbness/paresthesia of the incisive papilla with the lidocaine and mepivacaine solutions, respectively. Twenty percent and 28% of the subjects had incisive papilla swelling or soreness with the lidocaine and mepivacaine solutions, respectively. There were no significant differences (P > .05) between the lidocaine and mepivacaine solutions. CONCLUSIONS: The P-ASA injection of 1.4 mL of 2% lidocaine with 1:100,000 epinephrine or 3% mepivacaine, administered with the Wand Plus, has the potential to be a painful injection. The use of topical anesthetic did not significantly reduce pain of needle insertion when compared to a placebo. The incidence of postinjection pain, temporary numbness/paresthesia, and incisive papilla swelling or soreness would indicate that some pain and problems occur with the P-ASA technique, regardless of whether 2% lidocaine with 1:100,000 epinephrine or 3% mepivacaine is used.     

Intralesional chemotherapy for head and neck carcinoma: a review of the literature

In the last decade chemotherapy has gained widespread acceptance in the treatment of oral and pharyngeal cancer. Current standard treatment for advanced lesions consists of concomitant radiation and chemotherapy. This approach has provided marginal improvement of prognosis for Stage III-IV disease. Recent studies have explored the idea that locally delivered cytotoxic drugs could further improve prognosis in this patient population. We review this literature with the objective of popularizing these data and suggesting future directions for treatment and clinical research for head and neck cancer.     

Junger Patient mit ungewöhnlicher Raumforderung am Unterlid

Die Ophthalmologie - Eine Raumforderung der Lider im jungen Erwachsenenalter ist oft ein Zeichen einer Entzündung, eines Traumas oder einer benignen Neoplasie. Ziel dieser Kasuistik ist es,...