Three-year clinical performance of cast gold vs ceramic partial crowns.

Cast gold partial crowns (CGPC) and partial ceramic crowns (PCC) are both accepted for restoring posterior teeth with extended lesions today. However, as esthetics in dentistry becomes increasingly important, CGPC are being progressively replaced by PCC. The aim of the present prospective split-mouth study was the comparison of the clinical performance of PCC and CGPC after 3 years of clinical service. Twenty-eight patients (11 men and 17 women) participated in the 3-year recall with a total of 56 restorations. In each patient, one CGPC (Degulor C) and one PCC (Vita Mark II ceramic/Cerec III) had been inserted at baseline. CGPC were placed using a zinc phosphate cement (Harvard); PCC were adhesively luted (Variolink II/Excite). All restorations were clinically assessed using modified US Public Health Service (USPHS) criteria at baseline, 1 year, 2 years, and 3 years after insertion. Twenty-eight CGPC and 14 PCC were placed in molars, and 14 PCC were placed in premolars. Early data were reported previously under the same study design. After 3 years, the evaluation according to USPHS criteria revealed no statistically significant differences between both types of restorations with the exception of marginal adaptation and marginal discoloration: A statistically significant difference within the PCC group (baseline/3 years) was determined for the criterion marginal adaptation. For the 3-year recall period, overall failure was 0% for CGPC and 6.9% for PCC. At 3 years, PCC meet American Dental Association Acceptance Guidelines criteria for tooth-colored restorative materials for posterior teeth.

Inserts--megafillers in composite restorations: a literature review.

Modern insert systems have been available on the dental market since the late 1980s. In general, two major systems can be distinguished: those with and those without preparation instruments in combination with matching standardized inserts. It is claimed that one of the advantages of insert systems is the better marginal adaptation of insert/composite restorations compared to mere composite restorations: the integration of inserts reduces the polymerization shrinkage stress and lowers the overall coefficient of thermal expansion. In vitro data indicate that adapting the insert size to the most precise fit produces a quality of marginal adaptation comparable to that of ceramic inlays. Inserts also facilitate the establishment of a proximal contact. With respect to wear, no significant differences are detected between composite and insert restorations. The bond between insert and composite is susceptible to contamination during operative procedures. Short-term clinical investigations confirm in vitro findings regarding improved marginal adaptation and increased wear resistance. Long-term controlled clinical studies are in progress, but data are not yet available. Based upon the present in vitro and in vivo data it can be concluded that the insert technology shows promising results, but further investigations regarding, for example, stability of the insert/composite bond, fracture resistance of the overall restoration, and wear behavior are necessary to predict the clinical success of this alternative restoration procedure.

Total bonding vs selective bonding: marginal adaptation of Class 2 composite restorations.

For improving the marginal integrity of composite restorations, a total bonding method has been advocated besides the conventional selective bonding method. Total bonding avoids the placement of a base. The entire internal cavity surface is available for the adhesive bond. Selective bonding involves the placement of a base covering the pulpal floor as well as the pulpoaxial wall. In this study, five dentin/enamel bonding system/composite combinations were used to restore 60 class 2 cavities with their cervical margins below the cementoenamel junction (CEJ); six teeth per material were restored according to the total bonding and the selective bonding methods. Before and after simultaneous thermo-cycling and mechanical loading (TCML) marginal adaptation was evaluated on replicas in the SEM. Microleakage was determined by dye penetration on the original samples after TCML. The data were statistically evaluated with the Mann-Whitney U-test and the Wilcoxon test. The error rates method was applied. In SEM analysis the error rates method indicated a significant difference between the two restoration methods in general. In the pairwise comparisons, no significant differences between the selective bonding and total bonding methods were found for Syntac/Tetric, Gluma 2000/Pekafill, and Gluma/Pekafill. With Scotchbond Multi-Purpose (SBMP) and All-Bond 2 (AB2), total bonding revealed significantly (P < or = 0.01) less gap formation before and after TCML than selective bonding. Accordingly, total bonding showed significantly less (P < or = 0.01) dye penetration with Scotch-bond Multi-Purpose and All-Bond 2 compared to selective bonding. In conclusion, the reduction of microleakage by application of the total bonding method depended upon the bonding system used. Total bonding could be an alternative procedure for the adhesive restoration of class 2 cavities when their gingival margins are apical to the cementoenamel junction, provided the proper system is used and pulp damage is prevented.

[The bactericidal activity of mouthwashes containing 0.10%, 0.12% and 0.20% chlorhexidine digluconate]. / Activité bactericide de bains de bouche contenant 0,10%, 0,12% et 0,20% de digluconate de chlorhexidine.

Antiseptic activity of five mouthrinses containing 0.10%, 0.12% and 0.20% chlorhexidine, as well as aqueous chlorhexidine solutions at the same concentrations were determined under usual conditions (advocated dilutions by the manufacturers and short contact time) and according to French Pharmacopoeia recommendations. The three aqueous solutions and two mouthrinses containing 0.12% chlorhexidine were not antiseptic according to the fixed criteria. Bactericidal activities of the different dilutions of products were tested with an appropriate micromethod against nine-bacterial species involved in periodontal disease. Efficacity of mouthrinses were variable and were not agreed with the aqueous chlorhexidine-corresponding solutions: the mouthrinse containing 0.10% chlorhexidine reached 0.20% aqueous solution efficacy, and the mouthrinses containing 0.12% chlorhexidine were generally less active than the 0.12% aqueous chlorhexidine solution. Therefore, antibacterial activity of this type of product cannot be anticipated with the sole concentration factor, excipients playing essential part in the chlorhexidine activity.

Clinical evaluation of different adhesive systems for restoring teeth with erosion lesions.

This investigation evaluated the performance of a resin-modified glass ionomer, a compomer, and a bonding system/composite combination for the restoration of cervical erosion lesions without cavity preparation. Forty-eight lesions (11 patients) were restored with a bonding agent/composite combination [Prime & Bond 2.1/PrismaTPH (P & B/TPH); DeTrey/Dentsply], a compomer (Dyract; DeTrey/Dentsply), or a light-curing glass ionomer (Fuji II LC; Fuji). The materials were randomly assigned to the patients in triplets. No cavity preparation was performed. The procedures strictly followed the manufacturers' instructions. The restorations were evaluated clinically, using modified USPHS criteria, and by quantitative scanning electron microscope (SEM) analysis, at baseline and 12 months. The clinical data were statistically evaluated with the Pearson chi-square test, the SEM data (criterion gap formation) were analyzed with the Mann-Whitney U-test and error rates method. Clinically, two restorations could not be evaluated. One Dyract restoration failed. With respect to marginal discoloration, recurrent caries and contour, no significant differences could be found between the materials. The surface texture of P & B/TPH and Dyract was significantly better than that of Fuji II LC at baseline and 12 months. Compared to P & B/TPH and Fuji II LC, Dyract revealed a significant decrease in marginal integrity between baseline and 12 months. In SEM analysis, gap formation was determined as follows: baseline, enamel interface: 4% Dyract= 4% Fuji >2% P & B/TPH and dentin interface: 11% Dyract >9% P & B/TPH >2% Fuji; 12 months, enamel interface: 15% Dyract >4% Fuji >3% P & B/TPH and dentin interface: 11% P & B/TPH >6% Fuji >5% Dyract. The error rates method revealed no significant differences, in general, between the three materials with regard to gap formation. In conclusion, the restorations of erosion lesions with different classes of adhesive materials were well retained after 12 months. None of the materials studied revealed superiority over the other materials. All materials revealed shortcomings with respect to either surface texture, marginal integrity or color stability clinically and for all materials gap formation was recorded in the SEM evaluation.

Mutagenicity of the root canal sealer AHPlus in the Ames test.

The mutagenic activity of the root canal sealing cement, AHPlus, was tested in a bacterial gene mutation assay (Ames test). The material was mixed according to the manufacturer's instruction and tested immediately after mixing and after a setting time of 24 h at 37 degrees C in a humidified chamber. The set material was powdered and both the freshly mixed and the powdered material were eluted in dimethyl sulfoxide (DMSO) and physiological saline (0.1 g/2 ml) for 24 h at 37 degrees C. Aliquots of serially diluted eluates were then used in the standard plate incorporation assay. The Salmonella typhimurium tester strains TA98 and TA100 were employed to detect the induction of frameshift mutations and base pair substitutions both in the presence and in the absence of a metabolically active microsomal fraction from rat liver (S9 fraction). No mutagenic and no toxic effects were found with physiological saline eluates of the freshly mixed material and of mixed material which was set for 24 h. However, DMSO eluates of the freshly mixed AHPlus were mutagenic in tester strain TA100 in a dose-related manner in the absence of S9. A four- to fivefold increase of the mutation frequencies was induced by 2.5 mg AHPlus per plate compared with the number of spontaneous mutants. The mutagenic effect was completely abolished in the presence of a metabolically active S9 fraction. Also, no mutagenic effects were observed with DMSO eluates of AHPlus set for 24 h. However, the set material was more toxic towards bacteria than the freshly mixed sealer. This difference was indicated by a tenfold lower amount of material necessary to cause complete absence of the background lawn in both S. typhimurium tester strains. Therefore, we conclude that at least two different compounds of AHPlus are biologically active in DMSO eluates to cause mutagenic and toxic effects in S. typhimurium TA100 and TA98.

Retrospective clinical investigation and survival analysis on ceramic inlays and partial ceramic crowns: results up to 7 years.

This study retrospectively evaluated the clinical performance of 287 all-ceramic restorations placed during routine patient care in the University setting in the past 7 years. All patients (n = 106) with ceramic inlays or partial ceramic crowns (PCC), placed during 1988-1994 (n = 327) by five experienced dentists were asked to take part in a clinical investigation, and 92 patients with 287 restorations (232 inlays, 55 PCC) agreed to do so. The following ceramics were used: 44 (15.3%) Dicor (Dentsply), 126 (43.9%) IPS-Empress (Ivoclar), 82 (28.7%) Mirage II, 33 (11.5%) Cerec-Vita-Mark 1 (Vita), and 2 (0.7%) Duceram LFC (Ducera) restorations. The restorations were placed using the following luting composites: 73 (25.4%) Dual Cure Luting Cement (Optec), 81 (28.3%) Variolink high viscosity (Ivoclar), 32 (11.1%) Microfill Pontic C (Kulzer), 51 (17.8%) Dual Zement (Ivoclar), 40 (13.9%) Dicor Light Activated Cement (Dentsply), and 10 (3.5%) Vita Cerec Duo Cement (Vita). Restorations were evaluated according to the modified USPHS criteria. Kaplan-Meier analysis was used to calculate the probability of survival. Of the 287 restorations 270 (94.2%) were still in function without any need of intervention. Fourteen restorations (4.8%) had failed before starting the clinical investigation, and in three a fracture was found during the investigation. These 17 failed restorations consisted of 14 PCC and 3 ceramic inlays. The results of the clinical investigation revealed 59.2% Alpha-ratings for marginal adaptation. Only one restored tooth showed recurrent caries. The probability of survival (95% confidence interval) for 7 years was 98% (97.99-98.01%) for ceramic inlays and 56% (46-66%) for PCC. Our findings show that ceramic inlays can be regarded as an acceptable alternative to cast gold restorations within the methodological limitations of the present study. For PCC further experience with more recent ceramics is warranted.

SEM analysis of marginal expansion and gap formation in Class II composite restorations.

OBJECTIVES: Morphological changes in terms of marginal expansion have been observed at the dentin-composite interface of resin composite restorations with the scanning electron microscope (SEM), which could not be described with the criteria conventionally used for quantitative marginal analysis. The purpose of the present study was to elucidate the influence of marginal expansion upon marginal integrity and clarify the cause of these morphological changes. METHODS: A total of 22 extracted human molars were restored with Class II resin composite restorations, with and without the use of a dentin bonding agent. The cervical restoration margin was located below the cemento-enamel-junction (CEJ). The marginal adaptation at the dentin- and enamel-composite interfaces was evaluated and measured on replicas using quantitative SEM analysis after different storage periods. The chemical composition of the marginal expansion was determined qualitatively by EDX (Energy Dispersive X-Ray) analysis using original tooth samples. The results obtained from quantitative SEM analysis were statistically analyzed by applying the Mann-Whitney U-test and the error rates method. RESULTS: Significantly less marginal expansion occurred at the enamel interface than at the dentin-composite interface (p < or = 0.01). Within the dentin, less marginal expansion was observed with the use of a dentin bonding agent than without a dentin bonding agent (p < or = 0.05). At 1 y, a significant (p < or = 0.05) decrease in marginal expansion was observed in both groups. EDX analysis revealed that the chemical composition of the marginal expansion is comparable to the resin composite, since peaks for silicon, barium and ytterbium could be found at these sites. SIGNIFICANCE: In Class II resin composite restorations below the CEJ, partial disruption of the adhesive bond may occur initially when curing the restoration. Water sorption causes gap reduction by hygroscopic expansion, seen in the SEM as a volume increase. Thus, the observed morphological changes can be regarded as an early sign of insufficient adhesion between composite and dentin at sites where disruption of the bond occurred initially, whether or not a dentin bonding agent was used.

Clinical evaluation of heat-pressed glass-ceramic inlays in vivo: 2-year results.

In the present study, the 2-year clinical and scanning electron microscope (SEM) results for heat-pressed ceramic inlays are reported. In a selected patient population, 51 cavities were restored with all-ceramic inlays. All margins were located within the enamel. The inlays were luted to the cavities with a high-viscosity, dual-cure luting composite. After 2 days, 1 year, and 2 years, the restorations were evaluated clinically, using the modified USPHS criteria. Quantitative margin analysis was performed in the SEM on the replicas fabricated at the recall times. The data were tested for significant differences, using the chi-square test for the clinical evaluation and the Mann-Whitney U-test for the margin analysis. After 2 years, the clinical evaluation of the margin adaptation revealed Bravo ratings for 14 restorations (27.5%); 37 restorations (72.5%) were rated Alfa. Compared to the baseline data, this difference was statistically significant (p < or = 0.5). SEM analysis revealed that the ceramic-composite interface exhibited significantly (p < or = 0.01) more gap formation than the enamel-composite interface at all times of evaluation. Wear of the luting composite could be determined along 50% of the restoration interface during the first year, 53% during the second year. The inlay restorations controlled in this study perform well after a period of 2 years.

Resin-modified glass ionomers for luting posterior ceramic restorations.

OBJECTIVES: Until recently, esthetic inlay restorations in posterior teeth have been limited to cavities surrounded by enamel. Dentin adhesive systems in combination with luting composites and light-cured resin-modified glass ionomer cements offer a possibility for bonding ceramic inlays to cavities when the cervical margin is in dentin. This study was designed to compare in vitro marginal integrity of ceramic inlays bonded to dentin to restorations placed in cavities with margins located entirely in the enamel. METHODS: In the present in vitro study, the sealing abilities of a dentin bonding agent/luting composite combination (Syntac/Dual Cement, Vivadent) and resin-modified glass ionomers (Photac Fil, Photac Bond, ESPE; Dyract, De Trey Dentsply; Fuji II LC, GC Dental Industrial Corp.; and Vitremer, 3M Dental Products) used as luting agents in cavities extending beyond the cemento-enamel junction, were compared to the sealing abilities of a conventional luting composite (Vita Cerec Duo Cement, Vita) in cavities within sound enamel. SEM analysis and dye penetration were performed to evaluate marginal integrity at the cervical cavity margins. RESULTS: The dentin bonding agent/luting composite combination (Syntac/Dual Cement) rendered a marginal seal within the dentin similar to the quality obtained with the conventional luting procedures within sound enamel. When three out of the five resin-modified glass ionomers were used as luting agents (Dyract, Fuji II LC and Vitremer), the results were comparable to those reported for the dentin bonding agents and the conventional method. SIGNIFICANCE: Light-cured resin-modified glass ionomer cements may be considered as an alternative to dentin bonding agents when the cavity margins of ceramic inlay restorations are within the dentin. However, further studies, e.g., wear resistance, must be performed.

Effect of dimension of luting space and luting composite on marginal adaptation of a class II ceramic inlay.

This study evaluated the in vitro marginal quality at the interproximal cervical margin of class II Cerec restorations. Marginal quality was evaluated separately by (1) SEM analysis before and after simultaneous thermocycling and mechanical loading for the integrity of the restoration surface and (2) dye penetration after thermocycling and mechanical loading to evaluate the strength of the bond within the depth of the cavity. The results reveal that marginal integrity is influenced by the width of the luting space and the luting composite. With a luting space of 100 microns, marginal quality with as little as 3% to 14% loss of adhesion can be obtained. Luting spaces greater than 100 microns can partially be compensated by the luting composite. For Cerec inlays, highly filled luting composites with a high viscosity are recommended.

[Marginal fit of ceramic and composite inlays in vitro]. / Randspaltverhalten von Keramik- und Kompositinlays in vitro.

Direct and indirect composite and ceramic inlays exhibit a space between inlay and tooth, which is filled with a luting composite resin. The aim of the present study was to evaluate the influence of the width of this space upon the quality of the marginal seal of the inlay system. The marginal quality of class II-inlays with small (0.2 mm) and large (0.4 mm) spaces was examined using quantitative SEM analysis and dye penetration. Regular class-II composite fillings served as controls. After thermal and mechanical loading the composite inlays with the wider composite layer showed more marginal gaps than both groups of ceramic inlays. The ceramic inlays did not show a significant deterioration of the margins. The least amount of dye penetration was observed in ceramic inlays with a wider composite layer at the interproximal cavity wall. Composite fillings showed more dye penetration than inlays.

[HIV seropositivity and pregnancy. Apropos of 48 cases (how should they be managed at the present time?)]. / Séropositivité HIV et grossesse. A propos de 48 observations (quelle conduite à tenir pratique adopter aujourd'hui?)

We describe the gynaecological and obstetrical management of 48 HIV seropositive, pregnant women and review the literature. We did not find that pregnancy aggravated the development of the condition from the asymptomatic anti-HIV related complex (ARC) and AIDS. It seemed that fetal malformations, especially of the face, occurred most frequently in babies born to HIV seropositive mothers. Materno-fetal transmission of HIV was found in the uterus in 50% of our cases. In conclusion, we recommend safe contraception to prevent pregnancies in anti HIV seropositive women. If that fails, induced first trimester abortion is medically indicated and should be carried out if possible, as should strict medical control post-partum of both mother and child if the pregnancy is carried to term.

[Transmission of HIV (Human Immunodeficiency Virus) from mother to child. Apropos of 16 cases]. / Transmission du HIV (Human Immunodeficiency Virus) de la mère à l'enfant. A propos de 16 cas.

From a personal series of 16 cases, the authors report in this article the various arguments in favor of a vertical or neonatal transmission of HIV. The risk of contamination when the mother is sero-HIV positive seems to be 50 to 60 p. cent, for most teams.