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Aim: The aim of this study was to make a retrospective analysis on teeth with apicectomized roots, closed off by retrograde with amalgam and SuperSeal-Ogna® (cement oxide of zinc and eugenol modified by acidity ethoxy-benzoic acid), in order to achieve clinical evaluation and radiographic evidence of treated dental elements and surrounding tissue SuperSeal (Ogna®)., Methods: The study was conducted on 420 teeth, single and multi rooted, pertaining to 366 patients (189 women and 177 men) endodontically treated, in between 1998 and 2007. The teeth were treated with endodontic technique step-back and closed off with gutta-percha. Following the roots were apicectomyzed and then was prepared a retrograde cavity using retrotip steel mounted on the ultrasonic device. After carrying out the retrograde cavity all the samples were divided into two groups . The retrograde filling in Group A was made in Superseal, group B with amalgama. Both groups were divided in those teeths who was treated with use of optical microscope and in groups of teeths preformed without microscope., Results: Nevertheless amalgam against the SuperSeal offers almost the same quality of the seal and the same prognosis. However SuperSeal as a material of choice, proved excellent, for carrying out the retrograde fillings free of some side effects, such as dimensional instability, mercury poisoning and pigmentation of tissues (tattoos from amalgam)., Conclusion: In any case, whatever the type of material is, the operative microscope significantly affects the occurrence of failure. This demonstrates the importance of the microscope in order to obtain greater visibility and accuracy of the apex seal, more than minor sacrifice of healthy tissue.

Aim: The purpose of this study was to evaluate the interaction of a novel dentinal desensitizer Twin Pro with enamel-dentinal adhesive preparations or filling materials and dentine using scanning electron microscopy (SEM) technology., Methods: Black's I class cavities were drilled extracted molar teeth free of caries or fissures, and the cavities disinfected. The specimens were divided into 4 groups of 2 teeth each treated as follows: Group A: Twin Pro, fluid (Tetric-Flow Vivadent) and micro-hybrid (Tetric-Ceram Vivadent) composites placed on the etched (Liner Bond 2V Clearfil) cavities. Group B: Twin Pro, PQ1-Ultradent loaded Primer-Bonding plus fluid and micro-hybrid composites applied to the acid-etched (37% orthophosphoric acid) cavities. Group C: Twin Pro plus Silver amalgam alloy (Phasealloy- Sybram Kerr). Group D (control group): self-etching primer plus fluid and micro-hybrid composite. Specimens were investigated by SEM., Results: The results obtained in all groups show that the application of Twin Pro does not alter the adhesiveness of the restorative composite materials to the dental wall. In fact the desensitizer and the adhesive layers are indistinguishable at SEM observation, and well adherent to the dentinal surface of the cavities., Conclusion: The results of SEM investigations show that Twin Pro does not decrease the adhesion of restorative materials to the tooth surface, as it establishes an efficient interconnection with the different materials used, and it forms a uniform layer covering and occluding dentine tubules, and this might constitute an efficacious sealing of dentinal tubules which possibly contribute to decrease dentinal sensitivity to environmental nociceptive stimuli.

Background: It was considered appropriate to update of the significance and use of the different mercury exposure indicators., Objective: The aim of the this paper was to correctly select biological media and sampling time and to understand the toxic kinetics of mercury for assessment of accurate biological monitoring., Results: It was confirmed that mercury in blood (B-Hg) is a good indicator of recent exposure, while urinary mercury (U-Hg) indicates current exposure when mercury reaches the renal steady state. B-Hg values are greatly influenced by fish consumption, while the variables influencing U-Hg values are amalgam fillings, commercial gamma-globulin preparations, vaccines, topical remedies, environmental pollution and hobbies, occupational exposure and, partly, fish consumption. The speciation of mercury (Hg0, Hg++, methylmercury and ethylmercury) in biological media, should provide additional and important information in evaluating mercury toxicity., Conclusion: It was stressed that the appropriate choice of exposure indicators has to take account of the different variability factors and the characteristics of the toxic kinetics of mercury. The results of biological monitoring must be compared with references values, which are generally in the order of several micrograms/g creatinine, and limit values such as ACGIH BEI (U-Hg 35 micrograms/g creatinine and B-Hg 15 micrograms/l) or the DFG BAT (U-Hg 100 micrograms/l and B-Hg 25 micrograms/l).

Background: The aim of this research is to study the shear bond strength of 4 adhesive systems of the last generation: All-Bond 2 (AB2), Clearfil Liner Bond 2 (CL), Scotchbond MP plus (SBMP) and High Q Bond plus (HQB). According to the manufacturing company these products are suitable for amalgam adhesion to dentin., Methods: Forty extracted human third molars have been ground to expose a flat dentin surface. The teeth were randomly assigned to 4 groups, and every group was treated with one of the adhesive system according to the manufacturer's instructions. Samples were then secured in a split Teflon mould, having a 6 mm diameter opening and a spherical amalgam was triturated and condensed onto the treated dentin surfaces. The amalgam cylinders have been exposed to a tensile bond test using a Universal Testing Machine (Instron 4500). ANOVA test has been used to the statistic study among groups., Results: The study of the tensile mean range, showed that dentin shear bond strength values (MPa) for the adhesive systems tested were: 8.13 +/- 1.48 for AB2, 7.06 +/- 1.41 for SBMP, 4.2 +/- 1.06 for HQB, 3.04 +/- 0.68 for CL. The statistic test revealed significant differences among the 4 groups (p < 0.05)., Conclusions: The bond strength mean values of amalgam adhesives are lower than the ones for composite resins, nevertheless dentin-enamel adhesive systems specific for amalgam have to be taken into consideration particularly in case of conservative restorations that need chemical retention as a support, when the mechanical one is not enough.

Amalgam is still the material most often used to restore posterior teeth, since it is easy to use, it has a low cost and a long clinical life. However, its use requires the solutions of several problems: lack of adhesion to tooth structure, marginal leakage, postoperative sensitivity and susceptibility to corrosion. In order to combine the advantages of dentinal adhesives with the excellent mechanical properties and good long clinical behaviour of amalgam, their use under amalgam restorations has been proposed. Adhesives improve marginal sealing and guarantee an additional retention to restorations, due to the formation of a layer linked with micromechanical bonds both to the tooth and the amalgam; they create a barrier that occludes dentinal tubules access, protecting the pulp. In this article the results of several in vitro studies performed to assess amalgam restorations properties are summarized. Present knowledge, based on an accurate literature review, allows to consider bonded amalgam restorations as a real progress in conservative dentistry: if long-term longitudinal studies, that are presently carried out, confirm the good short-term results, bonded restorations will represent the solution of choice for amalgam application.

Background: One of the components of Ag amalgam is mercury which, owing to its organic derivatives, can pass into the organs and biological fluids. One particularly interesting but worrying aspect of this transition is the possibility that mercury may pass through the placental barrier and reach the fetus. The aim of this study was to evaluate the concentration of total mercury in human amniotic fluid and compare it with the number and occlusal extension of fillings using Ag amalgam., Methods: A group of 56 pregnant women were selected due to undergo amniocentesis. A dental check-up was carried out in each patient to identify the number and extension of amalgam fillings. Mercury levels in the amniotic liquid were assayed using a spectrophotometer with atomic absorption and a FIAS-amalgam technique., Results: Mercury concentrations in the samples examined ranged from a minimum of 0.00 ng/ml to a maximum of 2.55 ng/ml, mean 0.44 +/- 0.53 ng/ml. The correlations between the variables examined were evaluated by calculating the coefficient of linear regression. No direct relationship was found with mercury levels. The data obtained were used to construct a model of logistic regression showing scant statistical significance (p = 0.05) between the number of fillings and mercury levels, whereas the occlusal extension of dental repairs was significantly correlated with metal concentrations (p < 0.05)., Conclusions: The authors recommend that silver amalgam should be used with considerable caution during pregnancy.

The purpose of this study was to evaluate whether etching, bonding and filling with composite a cavity increase tooth resistance to fracture, considering that in posterior teeth stressed cusps are likely to bend. MOD conservative cavities (isthmus width/intercuspal distance = 0.25) were made in 10 extracted upper premolars, filled with P30 (3M) and tested by using a MTS machine. A metal bar (5 mm in diameter and 10 mm in length) was employed to load the cusps and their fracture resistance was recorded. The control group consisted of 16 extracted upper premolars: MOD cavities were made in only 9 teeth, then filled with amalgam. As a result, MOD cavities treated with Scotchbond, filled with P30 and tested by a MTS machine don't seem to be more resistant to a static load than cavities filled with amalgam.

A survey, in order to ascertain the reasons for placement and replacement of amalgam and composite restorations was made with the consent of the Italian Academy of Conservative Dentistry. 62 dentists answered the questionnaire, analysing their daily restorative work for two weeks: a total of 2,960 restorations were scored. The results show a prevalence of the primary caries over the replacements, and a prevalence of the secondary caries over the remaining reasons for replacement. Both data possibly mean the need for a more preventive approach to dental caries in Italy, even if the results fit fairly well into the values of the international research.

After a review about the gingival surface damages by amalgam alloy overhang, the Authors report a series of cases, which have been resolved either with a new amalgam or reducing the overhang.

The Authors used two different materials: amalgam and composite, for the restoration of the same dental element. This type of reconstruction, defined as "mixed-restoration" is analysed both theoretically, demonstrating the principles which allowed its realization, and from a practical view-point, through the presentation of three clinical cases which clarify the technique used.

The Authors study conservative preparation designs for Class II amalgam restorations, with and without an occlusal dovetail. They propose the use of a high-copper filing admix allow in Clas II preparation with occlusal dovetail and the use of high-copper spherical alloy in box only restorations.

Teeth with small interproximal lesions can be treated with reduced cavities for amalgam. This kind of reconstruction produces a good retention while removing less healthy dental tissue and safeguarding the aesthetic appearance with the advantages of amalgam, which is better compared with composite resins, especially for proximal contact and marginal adaptation.

Microleakage of class V restorations in posterior teeth was studied, using different types of materials and cavity varnish. Significantly less microleakage was recorded by applying some layers of cavity varnish and using spherical alloy.

The authors explain a clinical study for the achievement of restorative amalgams linked together to some fluid resin. Many researches have revealed a clear improvement of the immediate marginal closing when are employed dentin-enamel adhesives as liner in the amalgam fillings.