Two-year clinical performance of two one-step self-etching adhesives in the restoration of cervical lesions.

The aim of the study was to evaluate the clinical performance of two different one-step self-etching adhesives (Hybrid Bond/Sun Medical, Xeno III/Dentsply) in adhesive cervical resin composite restorations. In accordance with a split-mouth study design, 50 patients (57.3+/-13.5) received at least one pair of restorations. In each of two comparable cervical cavities, either the adhesive systems Hybrid Bond or Xeno III was used with the resin composite Filtek Supreme (3M ESPE). After 6, 12 and 24 months, the restorations were scored according to the Ryge and California Dental Association criteria. After 2 years, the resulting scores (percent) of the Ryge evaluation for the groups Hybrid Bond/ Filtek Supreme and Xeno III/ Filtek Supreme were marginal integrity, Alpha (92/78), Bravo (8/2), Charlie (0/0) and Delta (0/10); anatomic form, Alpha (92/82), Bravo (8/8) and Charlie (0/10); secondary caries, Alpha (100/100) and Bravo (0/0); marginal discoloration, Alpha (80/84), Bravo (20/12), Charlie (0/0) and not available (0/4); color match, Oscar (39/47), Alpha (51/45), Bravo (10/4), Charlie (0/0) and not available (0/4); surface, Romeo (78/69), Sierra (22/22), Tango (0/0) and Victor (0/10); tooth vitality, Alpha (98/94), Bravo (2/6); and integrity of tooth, alpha 1 (96/96) and alpha 2 (4/4). After 2 years, all Hybrid Bond restorations were retained and showed clinically acceptable results, while five Xeno III restorations were lost in part or in toto. For marginal integrity, anatomic form and surface, significant differences (p<0.05) were found but did not prove statistically significant after Bonferroni adjustment.

The influence of restorative materials on marginal gingiva.

BACKGROUND: A great variety of dental materials are now available for use in restorative treatments. Much attention has been devoted to physical and chemical properties, but the biological effects of these materials have been less frequently studied. AIM: The aim of this study is to test the influence of resin based restorations, amalgams and gold alloys, as restorative materials in immediate contact with the gingival tissues. METHODS: In 103 patients (54 male and 49 female, 39 smokers and 64 non-smokers, mean age: 34 +/- 13 years) with 255 restored teeth (101 resin-based materials, 98 amalgams, and 56 gold inlays), the marginal gingiva was examined. The restorations selected had to be in place more than 6 months. The patients participating in the study had no systemic diseases and pregnant patients were excluded, as were those under long-term medication and those with severe periodontal disease. The filling materials were examined for surface roughness, secondary carious lesions and gaps. The marginal gingiva in contact with the restorative materials was tested by reference to Bleeding Index (BI), Gingiva Index (GI), probing depth and degree of tooth mobility. As controls 255 teeth without fillings, of the same type, in the opposite jaw were used. RESULTS: The 101 resin-based restorations had a mean age of 3.1 (+/- 2.0) years, the amalgam fillings were in place 6.6 (+/- 4.1) years and the gold inlays had an average age of 4.7 (+/- 4.6) years. Surface roughness was observed in 66.3% of the resin-based restorations, in 47.9% of the amalgams and in 10.7% of the gold inlays. Absence of bleeding after probing was observed for 25.7% of the resin-based restorations, for 55.1% of the amalgam fillings, and for 58.9% of the gold inlays. All classes of restored teeth showed significant differences from the controls without fillings. The mean probing depth for the resin-based fillings was 3.6 mm (control 2.4 mm), for teeth with amalgams 3mm (control: 2.4 mm) and for teeth with gold inlays 2.5 mm (control 2.1 mm). A significant difference between smokers and non-smokers was only found in the group of resin-based restorations. The Bleeding Index was significantly higher in the group of smokers (p = 0.0005) in comparison to the non-smokers, as was the Gingiva Index (p=0.0106). CONCLUSION: The marginal adaptation of the restored teeth examined showed materially specific differences. The handling of resin-based materials, in comparison to amalgam or gold remains very sensitive and consequently there is prevalent error of technique. The high prevalence of gingival irritation in association with resin based materials may be caused by non-indicated applications, failures of technique, or simply the chemical properties of the materials.

Clinical performance of a packable resin composite for posterior teeth after 3 years.

There is a wide range of materials suitable for posterior resin-composite restorations. The objective of this clinical study was to evaluate the clinical performance of a packable resin composite (Solitaire, Heraeus-Kulzer, Hanau, Germany) in stress-bearing posterior cavities according to the Ryge criteria every 6 months over a 3-year period. A total of 250 class I (28%) and II (72%) restorations were placed in 120 patients using adhesive-bonding techniques without the use of rubber dam. After 3 years, 165 restorations (66%) were still in place during the follow-up investigation. Twelve restorations (4.8% out of the baseline number) had to be replaced due to postoperative sensitivity over the 3-year evaluation period. After 3 years, 65.5% of the restorations were scored Alpha for Marginal Adaptation, 18.2% Bravo, 2.4% Charlie, and 13.9% Delta. For the Ryge criteria Anatomic Form 70.9% of the restorations were scored Alpha, 15.2% Bravo, and 13.9% Charlie. Secondary caries was documented in 3.5% of the restorations. A Bravo score for Marginal Discoloration was determined in 26.1% of the restorations; 2.1% were scored Charlie. After 3 years, only 79.0% (summation effect of negative scores) of the restorations were still performing at clinically acceptable levels. Therefore, the packable resin composite Solitaire failed the criteria of the American Dental Association for resin restoratives. Bulk fractures (14 molar and 9 premolar restorations = 9.2% of the baseline number) due to poor physical properties of the material were the main reason for clinical failure.

A comparative study of 2 fluoride-based mouthrinses.

OBJECTIVE: The purpose of this study was to compare the effectiveness of 2 mouthrinses (conventional Meridol and alcohol-free Meridol). METHOD AND MATERIALS: A controlled, single-blind clinical study of 3 weeks' duration was conducted on 80 adult subjects in good general health and without severe periodontitis (probing depths no deeper than 4 mm). The mouthrinses supplemented regular measures of oral hygiene for the reduction of plaque and gingivitis. In preliminary examinations to determine general conditions of oral health, especially the level of plaque, gingivitis, and periodontal findings, the approximal plaque index, sulcular bleeding index, and gingival index were established for each subject. Afterward the subjects were provided with a professional toothcleaning, as required. Each subject was randomly provided with 1 of the 2 mouthrinses, to be used 3 times daily in addition to routine oral health measures. The 3 indexes were reevaluated after 3 weeks; in addition, an optional stain index was employed. RESULTS: In both subject groups, a statistically significant reduction in plaque accumulation, as well as a reduction in inflammation and the tendency to bleeding, was observed. Reversible staining of the teeth and tongue was observed in fewer than one third of the subjects in both groups. CONCLUSION: Comparison of the 2 Meridol mouthrinses revealed no difference in effectiveness related to the alcohol content.

Stress reduction in resin-based composites cured with a two-step light-curing unit.

PURPOSE: To examine the stress reduction of different resin-based composites, cured with a two-step polymerization unit (Elipar Highlight) by means of a photoelastic investigation. MATERIALS AND METHODS: For each material (Pertac II, Tetric Ceram, Charisma F, Solitaire, Dyract, Dyract AP, Definite), a minimum of 10 resin samples, embedded in acrylic-glass plates, were polymerized using a standard polymerization process of 700 mW/cm for 40 s. Another 10 samples were polymerized with a light output of 150 mW/cm2 for 10 s and then with a light output of 700 mW/cm2 for 30 s. RESULTS: For Pertac II the reduction of polymerization stress in the two-step-mode was 15.5%, for Tetric Ceram 14.5%, for Solitaire 8.1%, for Dyract AP 6.5% and for Definite 4.7%. These differences in polymerization stress between the standard and two-step-polymerization mode were statistically significant (P < 0.01, Wilcoxon test). No statistically significant differences in polymerization stress could be found for Charisma F and Dyract.

The intra-oral camera, dental health communication and oral hygiene.

This study aimed to determine the effectiveness of oral-hygiene instruction in improving oral health in 100 patients following oral hygiene instruction, with and without use of an intra-oral camera. The two groups of 50 patients were similar in age and sex distributions, frequency of caries, plaque accumulation and gingival bleeding. Prospective improvements in oral hygiene and compliance were measured by means of plaque levels and gingival bleeding at baseline and four weeks later. While both groups showed a clear reduction in plaque accumulation, the test group benefited from the use of the intra-oral camera. A majority of patients (88 per cent) thought that the extra information provided by the camera was helpful and desirable. This study demonstrates that the intra-oral camera can effectively augment oral-hygiene instruction and help create improvements in patient compliance.

The influence of oral bacteria on the surfaces of resin-based dental restorative materials--an in vitro study.

Three tooth-coloured, resin-based restorative materials (Charisma, Dyract, and Pertac) were exposed to typical oral bacteria (S. mutans, S. oralis and A. naeslundii) over a period of up to 35 days. The three strains of bacteria all colonised the resin-based materials within a few hours and formed thick bacterial films. Determination of the bacterial glucose consumption and lactate production during the incubation period showed no difference from the controls which contained no resin samples. Following the experimental exposure, the materials were examined by scanning electron microscopy (SEM) for possible surface damage and roughness was measured in a perthometer. Little damage to the resin-based composite material surfaces (Charisma, Pertac) could be observed, whereas the polyacid-modified composite material (Dyract) showed greater damage. There was a significant difference in the resin surface roughness after exposure to S. mutans and to A. naeslundii. The study clearly showed that the bacteria used strongly adhered to the resin-based restorative materials. As a consequence of bacterial colonisation and/or poor oral hygiene, damage to the restorative materials might develop. This suggests the need for dentists to evaluate personal oral hygiene, along with general indications and economic factors, in selecting materials for restorations, since the known anti-bacterial properties of amalgam are considerable.

The effectiveness and side effects of 0.1% and 0.2% chlorhexidine mouthrinses: a clinical study.

OBJECTIVE: The study compared two commercial chlorhexidine mouthrinses (Chlorhexamed 0.1% and Corsodyl 0.2%) for their effects on dental plaque and gingival inflammation, their side effects (eg, tooth staining and mucosal irritation), and patient acceptance. METHOD AND MATERIALS: One hundred thirty healthy volunteers were randomly distributed into two groups of 65 each. Each volunteer had gingivitis or chronic marginal periodontitis and used the rinse two times a day for 4 weeks. The sulcular bleeding index, approximal plaque index, gingival index, and a discoloration index were taken at baseline and once a week thereafter. The patients were questioned about taste disturbances, mucosal irritation, and their perception of the taste of the mouthrinse. RESULTS: In both groups, after 4 weeks, the mean sulcular bleeding index, approximal plaque index, and gingival index scores had decreased significantly. The discoloration index had increased significantly in both groups. There were no statistically significant differences between the two mouthrinses in any of these measurements. There were no significant differences in side effects reported by the two groups. CONCLUSION: The increase in concentration of chlorhexidine provided no clinical advantages or disadvantages.

Retentive strengths of cast gold crowns using glass ionomer, compomer, or resin cement.

PURPOSE: The retention forces of a newly developed compomer cement (Dyract Cem), a glass ionomer cement (Ketac Cem Aplicap), and a resin cement (F21) were examined. MATERIAL AND METHODS: Cemented cast gold crowns were removed along the path of insertion with a Zwick universal testing device. The impact of both a cured and a noncured additional bonding layer that were applied to the inner surface of the crowns was examined across the Dyract Cem group. RESULTS: The mean adhesive strength was measured at 2.36 +/- 0.69 N/mm2 in the Ketac Cem group, at 0.60 +/- 0.28 N/mm2 in the F21 group, and at 1.85 +/- 0.94 N/mm2 in the Dyract Cem group, respectively. The application of an additional bonding layer to the inner surface of the crowns did not significantly improve the retentive strength of Dyract Cem; the respective mean strengths were observed at 1.46 +/-0.33 N/mm2 for the uncured and at 1.70 +/- 0.76 N/mm2 for the cured bonding layers. CONCLUSIONS: Dyract Cem and Ketac Cem showed significantly higher retentive strengths than F21 (p < 0.001, Wilcoxon test, 5% level). No significant difference was found in bond strength between Ketac Cem and Dyract Cem.

Clinical plaque removing efficacy of a new power toothbrush.

PURPOSE: To evaluate the effect of adding a pulsating bristle action to the established oscillating/rotating action of the Braun Oral-B Ultra Plaque Remover (D9) on plaque removal. MATERIALS AND METHODS: Plaque removal was evaluated using the modified Quigley-Hein Plaque Index in a double blind randomized, crossover study involving 32 healthy volunteers without any dental training. After 2 weeks use of the D9 during which time subjects received training in its use, subjects abstained from oral hygiene for 48 hours. They were then assessed for plaque after which they brushed their teeth using an experimental toothbrush randomly set to either the D9 oscillating/rotating action or to the new 3D action with an additional pulsating movement of the brush head in the direction of the long axis of the bristles. After brushing, plaque was again evaluated. Following a further 2 weeks of normal home use of the D9, subjects returned and the procedure was repeated using the brush set in the second mode. RESULTS: Both toothbrush actions were found to be effective at removing plaque from all sites and surfaces in the mouth. The 3D action was consistently more effective than that of the D9, the difference being statistically significant for the whole mouth, the upper jaw, the lingual surfaces and for all interproximal sites, in particular in the upper jaw.

A robot system for evaluating plaque removal efficiency of toothbrushes in vitro.

A robot system simulating three-dimensional brushing motions as a function of time has been developed. In association with a typodont and either artificial plaque or chromogenic stain, the robot system can be used to assess the plaque removal efficiency or the cleaning effectiveness of toothbrushes. In particular, the influence of different brush head designs of powered toothbrushes was examined. The study compared the plaque removal efficiency of a cup-shaped brush head (Braun Oral-B EB 5) and a modified brush head (Braun Oral-B EB 9) that incorporates longer filaments on the outer ring, designed for additional interdental penetration. A specially designed artificial plaque was applied to the plastic teeth of typodonts. Artificial teeth were cleaned by the robot system for a 2-minute period with a wet brush head without a dentifrice. The remaining plaque was assessed visually by two independent examiners, with a modification of the global Plaque Index. In comparison to the EB 5, the new brush head significantly reduced artificial plaque overall. In vitro data demonstrated the ability of the robot system to reveal reproducible significant differences of the cleaning effectiveness of powered toothbrushes.

The development of the Braun Oral-B Ultra Plaque Remover: an in vitro robot study.

PURPOSE: To assess the efficacy of a new brush head design and brushing action using a novel robot system which simulates normal clinical toothbrush use. The system allows developments in toothbrush design to be assessed prior to embarking on expensive and time consuming clinical trials. MATERIALS AND METHODS: Using this system, the efficacy of a new brush head design combined with a modified brushing speed, was compared with the clinically established Braun Oral-B Plaque Remover (D7 handle and EB5 brush head). RESULTS: A combination of a new brush head (EB9) with longer tufts of bristles designed to improve interdental penetration, and an increased frequency of bristle movement (63Hz, 3,800 strokes per minute - D9 handle) was associated with significantly greater removal of artificial plaque. Visual observation of typodonts suggested that this increased efficacy is related to greater removal of plaque from interdental surfaces and occlusal fissures. These results suggest that the D9/EB9 prototype electric toothbrush is suitable for further investigation and clinical evaluation.

Effects of hydrogen peroxide-containing bleaching agents on the morphology of human enamel.

The effects of four bleaching agents (Opalescence, HiLite, 30% hydrogen peroxide, and 30% hydrogen peroxide mixed with sodium perborate) and 37% phosphoric acid on the external surface of human enamel were examined with the scanning electron microscope. The materials were applied to the enamel surfaces of 60 specimens obtained from 10 teeth. Each test agent was applied to one specimen from each tooth. One specimen of each tooth was left untreated. Comparison to the untreated control surfaces revealed that enamel exposed to the bleaching agents underwent slight morphologic surface alterations. The enamel surfaces treated with phosphoric acid, in contrast, showed severe morphologic alterations.

Rise in pulp temperature during finishing and polishing of resin composite restorations: an in vitro study.

The aim of this study was to establish the effects of the working speed, the use of coolant, and the pressure applied on the temperature of the pulp when resin composite restorations are finished and polished. One hundred eighty teeth with resin composite restorations are finished and polished. One hundred eighty teeth with resin composite restorations were randomly distributed into groups to be finished and polished with violet, blue, or yellow flexible disks. Each group was randomly subdivided into six subgroups of 10 each. Four subgroups were finished and polished, without water cooling, under constant pressure at speeds of 10,000, 8,000, 6,000 or 4,000 rpm. The other two subgroups were finished and polished at 10,000 rpm, one without water cooling while work was carried out intermittently and the the other with water cooling while work was carried out constantly. Results implied that a maximal speed of 4,000 rpm should be applied when polishing is carried out continuously without water coolant. When water cooling is used, flexible disks can safely be used at a speed of 10,000 rpm and with continuous pressure.