A multidisciplinary clinical study of patients suffering from illness associated with release of mercury from dental restorations. Medical and odontological aspects.

OBJECTIVE: To describe medical and odontological aspects of patients who believed their illness was caused by mercury in dental fillings. DESIGN: Comparison of self-reported and assessed medical and odontological variables. SETTING: The School of Dentistry, Karolinska Institute. SUBJECTS: Sixty-seven patients, referred for suspected side-effects of mercury in dental fillings, and 64 matched controls. MAIN OUTCOME MEASURES: Incidence of medical and odontological diagnoses, own perception of health, and incidence of self-reported symptoms. RESULTS: Three quarters of the patients were women. The mean age was 49 years. Thirty-seven patients (55%) and 47 controls (73%) (NS) showed no sign of somatic disease. Half of the patients felt ill or very ill at the time of the examination. Patients reported twice as many symptoms as the controls during a 3-month period. Patients reported a higher prevalence of very low resting saliva secretion rate, and a higher number of decayed tooth surfaces and of instances of temporomandibular joint dysfunction. CONCLUSION: Patients' feelings of ill-health were more likely related to psychiatric than somatic diagnoses. This study underlines the importance of making an overall diagnosis, including both mental and somatic disorders, especially in unclear cases and in self-diagnosed illnesses.

A multidisciplinary clinical study of patients suffering from illness associated with mercury release from dental restorations: psychiatric aspects.

The aim of this study was to map the psychological/psychiatric, odontological and medical aspects of patients with symptoms allegedly related to the side-effects of mercury in dental fillings. A total of 67 consecutive patients and 64 controls matched for age, sex and residential area were included in the study. The most striking result was the high prevalence of psychiatric disorders in the patients (89%) compared to the controls (6%), predominantly somatoform disorders. The personality traits differentiating the patients according to the Karolinska Scales of Personality (KSP) were somatic anxiety, muscular tension, psychasthenia and low socialization. More patients than controls showed alexithymic traits. The prevalence of diagnosed somatic diseases was higher, but not sufficiently so to explain the large difference in perceived health. The multiple symptoms and signs of distress displayed by the patients could not be explained either by the odontological data or by the medical examination. Our data indicate that the patients show sociodemographic and clinical patterns similar to those of somatizing patients. The medicalization of the suffering of these patients and the neglect of psychiatric problems prevent the use of appropriate psychotherapeutic approaches.

Pulpal reaction to a dental adhesive in deep human cavities.

In the last years several dental adhesives have been developed. They are supposed to chemically adhere to dentin and a liner to protect the pulp is not used. The aim of this study was to compare the short-term pulpal reaction, in an intra-toothpair study, between a dental adhesive, Scotchbond 2, and a lining system, Tubulitec, in combination with P-50 in surface-sealed cavities. Deep buccal cavities in 16 human pairs of premolars, 32 teeth, were restored in vivo with a light cured composite resin, P-50. To minimize bacterial contamination all cavities were treated with a cleanser, Tubulicid, and the cavities were surface-sealed with temporary cement, Coltosol. One tooth in each pair, the test, was treated with Scotchprep Dentin Primer and Scotchbond 2 Light Cure Dental Adhesive. In the other tooth in the pair, the control, Tubulitec Primer and Liner were used. The teeth were extracted after 6-14 days. The sections were evaluated for degree of inflammation and the presence of bacteria. Irrespective of treatment of dentin the majority of teeth, 23, including one pulpal exposure, revealed no inflammation or a few inflammatory cells. In four test teeth, including one pulpal exposure, and two controls, growth of bacteria was found on the cavity walls and slight or moderate inflammation was seen in the corresponding pulps. In one test and two control teeth slight inflammation was seen but no bacteria could be detected. In the absence of bacteria Scotchbond 2 did not seem to irritate the pulp.(ABSTRACT TRUNCATED AT 250 WORDS)

A study in vitro of threaded titanium pins used for retrograde obturation of root canals.

The microleakage of four retrograde filling materials was compared in vitro. Fifty-three single rooted teeth were instrumentated and root filled with resin chloroform and gutta-percha. The gutta-percha cones were left extruding from the access opening. All teeth were apicected and retrograde fillings placed. The materials used were a non gamma 2 amalgam (Amalcap), a glass ionomer cement (ChemFil II), threaded titanium pins cemented with a glass ionomer cement (ChemFil II) and identical titanium pins cemented with a silicone material (Adheseal). After removal of the gutta-percha with tweezers, a radioactive isotope solution was placed in the teeth. Extraradicular samples were taken at 3, 7, 28, 77 and 104 days. All retrograde fillings showed some microleakage. The group with titanium pins cemented with silicone showed the least leakage: significantly less than the teeth with glass ionomer cement (P < 0.01) and with amalgam (P < 0.01). No significant differences were found between other groups.

Quantitative radioactive analysis of microleakage of four different retrograde fillings.

Sealing properties of four different retrograde filling materials were investigated in vitro. Radioactive isotopes were applied in the root canal, and leakage into an extraradicular fluid was measured at regular intervals. The method permitted repeated observation of the specimens over prolonged periods of time. Forty single-rooted human teeth were biomechanically instrumented and obturated using calcium-hydroxide paste. Following obturation, an apicectomy was performed and retrograde cavities were filled with four different materials: group 1, non gamma 2 amalgam (Amalcap); group 2, glass ionomer cement (Ketac Silver); group 3, calcium-hydroxide-based root canal sealer (Sealapex); group 4, composite resin (Palfique Light-S). After removal of the calcium hydroxide, the teeth were immersed in a fluid. An isotope solution was then placed in the root canals. Samples were taken from the fluid at 0, 3, 7, 28, 56, 105, 210, 285 and 376 days to determine the radioactivity. It was found that Sealapex and Palfique Light-S showed significantly less leakage than amalgam and glass ionomer cement, which had the highest apical leakage.

Pulpal response to restoration of deep cavities with high-copper amalgam.

The effect on the pulp of a high-copper amalgam was studied in buccal cavities in 16 pairs of human premolars, 32 teeth, restored with ANA 2000. To minimize the risk of bacterial contamination, the cavities were treated with a cleanser, Tubulicid, and the outer portion of the filling was replaced by zinc oxide-eugenol cement (ZOE), i.e. surface-sealing. In one cavity in each pair, the control, a thin lining was used. The teeth were extracted after 5-13 days, sectioned, stained with hematoxylin-eosin or Brown and Brenn and evaluated for the degree of pulpal inflammation and presence of bacteria. The results showed that regardless of whether lining was used or not, no inflammation or only a very few inflammatory cells were found in the 21 teeth in which the thickness of the remaining dentin varied from 0.15 mm to 0.5 mm, except for one pair showing slight to moderate inflammation. However, in this pair bacterial growth were found on the cavity walls. No other teeth showed bacterial growth. In the remaining eleven teeth the thickness of the remaining dentin was less than 0.08 mm, including five pulpal exposures. Slight to severe inflammation occurred in eight of these teeth. ANA 2000 per se did not seem to irritate the pulp except in very deep cavities or on direct exposures. The reason for this reaction is not known, but it might be attributable to the zinc content of the amalgam.

Materials techniques for lining composite resin restorations: a critical approach.

Composite resin restoration of posterior teeth necessitates a reassessment of cavity insulation and dentine conditioning. The primary function of cavity insulation under composite resin restorations is to prevent the formation of a bacterial, fluid-filled gap nearest the cavity walls. Gap formation can contribute not only to sensitivity to cold but also to pulpal complications and secondary caries. Unfortunately, none of the currently available systems for cavity insulation fulfil this basic requirement. The evidence suggests, however, that the most effective insulator is a very thin liner which does not pool in retention grooves and which can cover the entire cervical wall as well as the remaining cavity walls, except for etched enamel. Such a liner should not bond to composite resin and thus be detached from the dentine during polymerization contraction of the composite. Nor should it be leached away by the oral fluids. In order to preserve the liner, the air-filled contraction gap which forms between liner and composite should be impregnated with resin immediately after the major setting contraction of the composite. In this context the use of retention grooves in Class II and Class V cavities is recommended, to minimize the effect of thermal and occlusal stress. Combined with etched enamel walls, well-placed retention grooves can reduce the risk of gap formation and creep due to mechanical stress and the deformation potential of the tooth structure and the filling. The smear layer can disappear entirely and be replaced by fluid and bacteria. It should therefore be removed, but the smear plugs blocking the apertures of the dentinal tubules should be left undisturbed and reinforced by impregnation with fluoride.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of bonding agent types and incremental techniques on minimizing contraction gaps around resin composites.

In this in vitro study, large rectangular cavities were prepared on the proximal surfaces of human premolars with cervical margins placed beyond the cemento-enamel junction. Before the insertion of resin composite, the cavity walls were treated with Bowen's system, Scotchbond, or Gluma combined with different bonding agents. Various incremental techniques were tested. The contraction gap was determined by use of the resin impregnation technique: After polymerization shrinkage, a low-viscosity resin with a fluorescent additive was applied to the cervical and occlusal margins to penetrate the contraction gap. After being ground, the width of fluorescent resin could be measured with a microscope. All combinations of materials and techniques produced contraction gaps at the cervical wall. The range for mean width of the impregnated gap at the cervical wall was from 5 to 13 microns. The lowest mean value was obtained for Gluma in combination with Clearfil Bonding Agent. Placement of the composite in two increments significantly reduced the gap width. No reduction was achieved when a three-step insertion technique was used.

A new method for sealing composite resin contraction gaps in lined cavities.

Composite resin restorations are often applied in cavities where cervical margins are left unetched, resulting in poorer adaptation in this area. Recent experiments have indicated the possibility of impregnating with resin the gap caused by polymerization contraction. Cavities were prepared in vitro and in vivo. A thin liner was applied inside and outside the cavity. Except for the cervical wall, enamel margins were bevelled and acid-etched, and the cavities restored with Concise Enamel Bond and Composite. In another series, cavities with unetched enamel were restored. Since the liner was placed outside the cavity margins, excess material could be removed without blockage of the air-filled gap. Enamel Bond with a fluorescent additive was applied to various margins. Ground sections were prepared, and the penetration of this resin into the gap was examined with a microscope. In most teeth, the resin penetrated from 0.5 to 2 mm from the cervical margins. Similar penetration was seen from unetched margins, except for the occlusal one. No penetration was seen at acid-etched margins. By impregnating gaps with low-viscous resin after the filling has cured, one can obtain an improved seal at unetched margins.

The initial gap around large composite restorations in vitro: the effect of etching enamel walls.

Composite resin restorations in cavities are generally associated with the development of a contraction gap during the first minutes after insertion. Enamel-Bond-Concise composite restoration were placed on both approximal sides of extracted pre-molars. The cervical walls of all cavities extended beyond the enamel-cement junction. The enamel walls of one of the cavities in each tooth were acid-etched. The contraction gap was kept air-filled and open at the margin through the use of a special technique. Enamel Bond resin with a fluorescent additive was applied to occlusal and cervical margins of the restorations. The fluorescent resin was "passively" drawn into the gap. In unetched cavities, resin penetrated both cervical and occlusal gaps and some areas of the gap at the axial wall. In cavities with etched enamel, the penetration occurred only at the cervical wall. The distance of penetration from the cervical margin varied from 1 to 6.5 mm, and the width of the contraction gap filled with the fluorescent resin varied from 3.5 to 16 micron. Comparison of the width of the gap at the cervical wall in etched and unetched cavities suggested larger gaps for etched cavities. The method used offers a new technique for the measurement of the contraction gaps around composite resin restorations.

Protective effect of polystyrene liners for composite resin restorations.

The main purpose of lining cavities before insertion of composite resin restorations is to prevent bacterial contamination at the cavity walls. A thin film of polystyrene liner dissolved in ethyl acetate applied to all surfaces by compressed air provided good protection against bacteria on cavity walls under composite resin restorations. An antibacterial primer in an alcohol solution applied prior to the liner may improve this protection. This procedure had no detectable injurious effect on the pulp.

Pulpal reaction and microorganisms under Clearfil Composite Resin in deep cavities with acid etched dentin.

Experimental buccal cavities were prepared on 31 pairs of contralateral human premolars. Both cavities were acid etched with 40% phosphoric acid for 15 seconds. The layer of etched enamel was removed from one of the cavities (test) in order to create conditions for microbial invasion to the presumed gap between the resin and dentin. Both cavities were filled with Clearfil Composite Resin after the application of Clearfil Bonding Agent. In the control cavity, the outer portion of the filling was removed and replaced with IRM cement in order to prevent microbial invasion. The teeth were extracted after 1 to 11 weeks. The presence of bacteria and pulpal reactions were studied using routine histological techniques. In several cases the inner resin surface analogous to the cavity floor was studied in the SEM. Bacterial growth was present on the dentinal walls as well as in some of the dentinal tubules in 24 of the 31 test cavities. The underlying pulpal areas showed signs of inflammation. Bacterial growth and pulpal inflammation were absent in 17 control cavities in spite of pulpal lesion or near lesion in 5 of the cavities. In 9 control cavities bacteria and pulpal inflammation were present. This suggests bacterial contamination and/or microbial invasion in spite of the IRM filling. The results show that Clearfil Bonding Agent in combination with Clearfil Composite Resin do not bind sufficiently to etched dentin in cavities to prevent the generation of a gap between the filling and dentinal wall. As a result infection can be established. The results also support the authors' earlier findings that neither acid etching of dentin for 15 seconds nor the chemical properties of resin materials have any especially injurious effect on the pulp, even in deep cavities.