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This paper investigates the hypothesis that mercury from silver dental fillings (amalgam) may be related to multiple sclerosis (MS). It compares blood findings between MS subjects who had their amalgams removed to MS subjects with amalgams. MS subjects with amalgams were found to have significantly lower levels of red blood cells, hemoglobin and hematocrit compared to MS subjects with amalgam removal. Thyroxine levels were also significantly lower in the MS amalgam group and they had significantly lower levels of total T Lymphocytes and T-8 (CD8) suppressor cells. The MS amalgam group had significantly higher blood urea nitrogen and lower serum IgG. Hair mercury was significantly higher in the MS subjects compared to the non-MS control group. A health questionnaire found that MS subjects with amalgams had significantly more (33.7%) exacerbations during the past 12 months compared to the MS volunteers with amalgam removal. The paper also examines epidemiological correlations between dental caries and MS; as well as how mercury could be causing the pathological and physiological changes found in multiple sclerosis.

Some brief remarks, partly based on Dutch legislation, are made on the dentists' attitude towards the use of dental amalgam. The patient is entitled to ask for dental restorative materials other than amalgam. On the other hand, the dentist is entitled to refuse to apply materials that are, according to the prevailing professional standards, inappropriate in a given situation.

As the value of amalgam restorations is increasingly being questioned in modern dentistry, the clinical potential of amalgam restorations in general has been evaluated in this literature review. The major factors limiting the longevity of amalgam restorations are operator- and patient-related. Both factors will likewise influence the longevity of any new restorative concepts. Nevertheless, amalgam restorations remain the standard against which alternative materials are evaluated. Amalgam restorations are slowly loosing ground to the use of tooth-colored materials, which are gaining in popularity. However, amalgam can not currently be withdrawn from the list of possible restorative materials used for patients in Switzerland.

The 4-year evaluation of a randomized controlled clinical trial to the functioning of Extensive Amalgam Restorations (EAR) is reported. In this trial 300 EAR were made by three operators on molar teeth. Five different auxiliary retention methods were used to retain these restorations. In the evaluation a differentiation in 'absolute' and 'relative' failures was made. After 4 years seven absolute failures (EAR dislodged or removed) were encountered (2%). When relative failures (endodontic treatment or restoration at margin) are also taken into account the number of failures increased to 31 (10%). Due to the low number of failures, no significant influences from experimental variables (c.q. retention method or operator) could be detected. It may be concluded that the results of this interim analysis of the clinical functioning of EAR are promising. It is thought that careful evaluation of cusp strength and reducing weak cusps diminishes clinical failure and as a result, it is not necessary to protect an EAR with a cast restoration in the first 4 years of its clinical life.

The aim of this study was to compare the clinical durability of four dental amalgams. In each of eighty-two patients one class 2 cavity was restored with Dispersalloy (Johnson and Johnson) which served as the control and all the other class 2 cavities were randomly restored with one of the following amalgams: Amalgaphase, Amalga 43 (Amalgam Alloys-South Africa) or Permite C (Southern Dental Industries). Matrix bands were placed and Kalzinol bases and Polyvar varnishes applied in all cavities. The amalgams were mixed according to the manufacturers' instructions, the cavities overpacked with amalgam, condensed by hand, carved and then burnished with a ball burnisher. Twenty-four hours later all restorations were polished and colour photographs taken. The restorations were evaluated using the Ryge and Snyder (1973) evaluation system, as well as comparison of the colour photographs. The Fisher's Exact Test was used for the statistical analysis. The two South African manufactured amalgams compared well with the two imported amalgams. However, at the end of the third year the score for the marginal integrity of Amalgaphase, one of the local products, was significantly different (p < 0.083) and inferior to that of the control, Dispersalloy. Evidence is produced to suggest that over a three year period Amalgaphase performed better than Dispersalloy, Amalga 43 and Permite C.

Perforations created in the pulpal floors of 30 extracted molars were repaired with amalgam, Cavit, and light cured glass ionomer cement. After the pulp chambers and access openings were filled with composite resin, the teeth were then immersed in 2% Erythrocin B solution for 1 week. After longitudinal sectioning of the teeth, dye penetration was measured. The results indicated significant differences between the three materials. Light cured glass ionomer exhibited the least dye penetration followed by Cavit and amalgam.

The aim of this study was to determine the clinical durability of two locally manufactured amalgams. In each of eighty-two patients one class II cavity was restored with Dispersalloy (Johnson and Johnson) which served as the control and all the other class II cavities were randomly restored with one of the following amalgams: Amalgaphase, Amalga 43 (Amalgam Alloys-South Africa) or Permite C (Southern Dental Industries). Matrix bands were placed. Kalzinol bases and Polyvar varnish were applied in all cavities. All amalgams were mixed according to the manufacturers' instructions. The cavities were overpacked with amalgam, and the amalgam condensed by hand, carved and then burnished with a ball burnisher. Twenty-four hours later all restorations were polished with a Shofu polishing system and colour photographs were taken. The restorations were evaluated using the Ryge and Snyder (1973) evaluation system, as well as comparison of the colour photos. The Fisher's Exact Test was used for the statistical analysis. During the second year there were no significant (p < 0.05) differences between the four brands of amalgam restorations except as regards the gloss category. The two South African manufactured amalgams compared well with the two imported amalgams. During the second year the marginal integrity and surface texture of Amalgaphase compared well with that of Permite C. Dispersalloy and Permite C showed more deterioration in anatomic form than the two South African amalgams. Amalgaphase was the only amalgam to show no bulk fracture within a period of two years. Amalgaphase performed better in the gloss category than the other three amalgams during the second year evaluation. According to the weighted product calculation Amalgaphase was the best amalgam followed by Dispersalloy, Amalga 43 and Permite C.

The author presents the results of physicochemical trials and preliminary clinical assessment of modified copper amalgam, carried out to master the optimal method for its preparation. The optimal conditions for the preparation of a filling from modified copper amalgam consist in mixing 0.42 +/- 0.02 g of the alloy powder and 0.3 g of mercury within 25-35 sec. Clinical trials have demonstrated the advantages of this modification vs. the filling manufactured in this country previously, this recommending it for practical pedodontics.

One-hundred twenty experimental furcation perforations were created in the mandibular and maxillary premolars and molars of six rhesus monkeys. Tricalcium phosphate, hydroxylapatite, amalgam, and Life were used to repair the furcation perforations. The animals were sacrificed at the intervals of 2, 4, and 6 months after the experiment. Histological evaluation revealed lack of complete healing of furcation perforations repaired with any materials. Epithelium was present in the furcation perforations in both experimental and positive control groups. No hard tissue formation was observed in this study. Inflammation in the furcation area may be due to inadequate sealing ability of the repair materials.

The disadvantage of conventional amalgams lies in the fact that they form the so-called gamma-2 phase, which corrodes very easily. The gamma-2 phase can be reduced or suppressed by either adding powder with globules of a eutectic silver-copper alloy in portions of 9-33% to a common filing powder (dispersion type alloy) or by producing the powder from a homogeneous alloy of silver, copper and tin (one-component alloy). NG-2 amalgams show noticeably better physical properties than conventional amalgams. Nevertheless, they, too, corrode.