Color Change of Laminate Veneer Restorations Applied to Bleached Teeth.

OBJECTIVE: The aim of this study was to examine the color stability of laminate veneer restorations restored with CAD/CAM material applied to bleached teeth. MATERIAL AND METHODS: In this study, 80 upper central teeth extracted because of periodontal, orthodontic or trauma problems were used. The teeth were embedded in acrylic blocks and divided into 8 groups (n=10). Groups A, B, C and D were bleached with vital bleaching agent before preparation, and teeth were prepared for laminate veneer restorations. Groups E, F, G and H were prepared without bleaching. Groups A and E were restored with A1 GC LiSi Initial HT blocks, Groups B and F were restored with A1 GC LiSi Initial LT blocks, Groups C and G were restored with A1 IPS Emax CAD HT blocks, Groups D and H were restored with A1 IPS Emax CAD LT blocks. All restorations were adhesively cemented and aged for 2 and 5 years with thermal cycle. Color measurements of the restorations at the beginning, after 2 and 5 years of aging were measured with a spectrophotometer. RESULTS: All bleached groups had more color changes than the unbleached groups. The least color change after 2 years of aging was observed in GC LiSi Initial LT (ΔE00=0.81) and IPS Emax CAD LT (ΔE00=0.81) materials which were used on unbleached teeth and the most color change was observed in GC Initial LiSi HT (ΔE00=0.93) and IPS Emax CAD HT material (ΔE00=0.92) which were used on bleached teeth. After 5 years of aging, the least color change was observed in IPS Emax CAD LT (ΔE00=0.83) and GC LiSi Initial LT material (ΔE00=0.84) which were used on unbleached and the highest color change was observed in GC Initial LiSi HT (ΔE00=0.96) and IPS Emax CAD HT material (ΔE00=0.94) which were used on bleached teeth. CONCLUSION: Bleaching and translucency affect the color stability. No difference was detected between the color changes of GC LiSi Initial and IPS Emax CAD materials. The increase in aging time increased the color changes of all materials. CLINICAL SIGNIFICANCE: Bleaching and laminate veneer restorations may be preferred in many patients. For this reason, the long-term color change of laminate veneer restorations applied to bleached teeth is clinically very important. This study aimed to evaluate the effect of tooth bleaching on the long-term color change of laminate veneer restorations produced with different translucent CAD/CAM materials.

Evaluation of clinical success and marginal adaptations of inlay and onlay restorations manufactured after conventional and digital impressions: a prospective randomized controlled clinical study.

AIM: The aim of the present study was to compare inlay and onlay restorations fabricated from conventional impressions and two different digital impression systems in terms of clinical features and marginal fit. MATERIALS AND METHODS: Participants were randomly assigned to three groups according to the type of impression system used. The impressions were taken with polyvinyl siloxane silicone material for the control group (CON). For the digital impressions, Trios Pod Scanner (3Shape) was used for the TRIOS group and Cerec AC Omnicam (Sirona) for the CEREC group. A total of 40 IPS e.max CAD and 20 IPS e.max Press (both Ivoclar Vivadent) inlay and onlay restorations were then placed in 24 participants. Clinical evaluations, Plaque Index, Gingival Index, and pocket probing depth measurements were taken at baseline, 6 months, and 12 months using FDI criteria. The continuous margin percentages were quantitatively examined by scanning electron microscopy at baseline and 12 months. RESULTS: All the restorations showed clinically acceptable measurements at baseline, 6 months, and 12 months. The continuous margin evaluations showed no statistically significant difference between the groups. CONCLUSIONS: Based on the 12-month follow-up results, inlay and onlay restorations fabricated with digital impressions were found to be a reliable alternative to conventional impressions.

In Vitro Evaluation of the Marginal and Internal Accuracy of Different Types of Dental Ceramic Restorations Fabricated Based on Digital and Conventional Impressions.

PURPOSE: To compare the marginal and internal gap values of different types of ceramic crowns fabricated based on digital and conventional impression methods. MATERIALS AND METHODS: Ten noncarious extracted human teeth were prepared, and 60 restorations were made using six different impression and fabrication methods. Silicone replicas were obtained for marginal and internal gap evaluation. Statistical analyses were performed using Mann-Whitney U and Kruskal-Wallis tests (P < .05). RESULTS: Statistically significant differences were found among various impression and fabrication methods. The smallest gap value was shown by the monolithic zirconia indirect digital scanning group (31.13 µm), and the largest for the lithium disilicate indirect digital scanning group (90.09 µm). CONCLUSION: The marginal and internal gap values of the restorations in the present study were 31.13 to 90.09 µm. The marginal and internal discrepancies of the tested materials were considered clinically acceptable.

Fracture resistance of endodontically treated canines restored with different sizes of fiber post and all-ceramic crowns.

PURPOSE: The aim of this study was to determine the fracture resistance and the mode of fracture of endodontically treated teeth restored with different fiber posts and all-ceramic crowns. MATERIALS AND METHODS: Two glass fiber reinforced post systems in two different sizes and polyethylene fiber ribbon in two different thicknesses (n=10) were used. The specimens, restored with all-ceramic crowns, were subjected to a compressive load (in N) delivered at a 130-degree angle to the long axis until a fracture could be noted. The results were analyzed statistically with a One-Way ANOVA test (P<.05). RESULTS: Statistically significant differences were observed between the mean fracture resistance values of Postec, Snowlight, and Kerr Connect thin specimens (P<.0095). The Postec results (395.70 N) were found to be significantly higher than the others. No statistical difference was observed among the thick specimens (P<.2657). The mean fracture resistance values of the Snowlight thick samples were found to be higher than those of the Snowlight thin samples. The specimens were always fractured around the cemento-enamel junction at the palatinal side. No post fracture was observed for the thin Snowlight and Kerr Connect specimens or for the thick Postec and Kerr Connect specimens. Among the common failure types of the specimens, the worst was observed to be the root fracture failure. The highest post dislodgement failure result (80%) was obtained from the thin Kerr Connect specimen. CONCLUSION: In terms of optimizing fracture resistance, the fiber post size selection should be done according to the forces applied to the restored teeth.

Clinical gap changes after porcelain firing cycles of zirconia fixed dentures.

PURPOSE: The aim of this study was to measure the changes on the marginal and internal adaptation of zirconia based anterior fixed partial dentures after the porcelain firing process. MATERIALS AND METHODS: A total of 34 anterior fixed partial dentures using LAVA CAD/CAM system (3M ESPE, Germany) were applied. Two silicone replicas were obtained: one is obtained before porcelain firing process (initial) and the other is obtained after porcelain firing process (final), followed by the examination under a binocular stereomicroscope. Kruskal Wallis and Wilcoxon Signed Ranks tests were used for the statistical analysis (P<.05). RESULTS: No statistically significant difference was found between initial and final marginal gap values (P>.05). At the internal gap measurements, final marginal area values (59.54 µm) were significantly lower than the initial marginal area values (68.68 µm)(P<.05). The highest and the lowest internal gap values were observed at the incisal/occlusal area and at the marginal area, respectively. In addition, lower internal gap values were obtained for canines than for central incisors, lateral incisors and premolars at the incisal area (P<.05). CONCLUSION: The firing cycles did not affect the marginal gap of Lava CAD/CAM system, but it is controversial for the internal gap.

Bond strength and stability of 3 luting systems on a zirconia-dentin complex.

This study compared the bond strength and stability of 3 different luting systems to a zirconia ceramic crown. Sixty cylinders of zirconia ceramic were cemented to flat dentin surfaces of extracted human teeth, using 3 different luting agents (n = 20): a glass ionomer (GI) cement, a resin-modified glass-ionomer (RMGI) cement, and a resin cement containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP). The specimens from each cement group were then divided into 2 subgroups (n = 10). Three subgroups (1 from each cement) were selected to test shear bond strength (SBS) immediately before an aging process of thermocycling and water storage, the remaining 3 subgroups were tested for SBS after the aging process. The aging process affected the bond strength of the MDP and RMGI cements. The MDP cement demonstrated superior bond strength compared to the GI and RMGI cements; the GI cement consistently had the lowest bond strength. The RMGI cement had higher cohesive failures at cement (70%), while the GI and the MDP cements had higher percentages of adhesive failure at the ceramic-cement interface (70% and 100%, respectively). The MDP cement promoted better adhesion between dentin and the zirconia ceramic.

Factors affecting the distribution and prevalence of oral mucosal lesions in complete denture wearers.

OBJECTIVE: To determine the frequency of the oral lesions related to gender, age, the length of time of denture usage, education level and economic status. METHODS: The 153 patients with old complete dentures (CD) were asked to participate in the investigation. The subjects (76 male and 77 female) were 37-85 years of age with a mean age of 61.8 ± 9.8 years. Education, economic status and age factors were estimated in subgroups. The data obtained were evaluated by one-way anova, Mann-Whitney U-test, Kruskal-Wallis test, Student's t-test and chi-squared test. The level of statistical significance was set at p<0.05. RESULTS: The patients who had denture stomatitis and traumatic ulcers were statistically significantly older than the ones who did not have these lesions (p<0.05). Based on the length of denture usage, patients who had a flabby ridge, fibrous inflammatory hyperplasia, traumatic ulcers (p<0.01) and denture stomatitis (p<0.05) were using their dentures statistically significantly longer than the ones who had healthy tissues. CONCLUSIONS: The CD wearers should be advised to visit their dentist regularly to prevent oral mucosal lesions due to the changing supporting tissues during the length of denture usage and to improve their quality of life.

Factors triggering the oral mucosal lesions by complete dentures.

Oral mucosal lesions may represent acute or chronic reactions to factors related with dentures. The aim of this study was to determine the frequency of the oral lesions related to gender, age, the length of time of denture usage, the balance of denture and cleaning methods and frequency. The 106 patients who have old complete dentures came to the Dental Faculty of Marmara University, Istanbul (Turkey) to have new complete dentures were asked to participate in the investigation. The subjects (51 men and 55 women) were 37-80 years of age with a mean age of 60.28+/-10.52 years. All main factors were estimated in subgroups: cleaning methods and frequency were divided into 3 subgroups respectively as toothbrush and toothpaste/soap, denture cleansing tablets and sodium carbonate, and 3 times a day, everyday, every 3 day and once a week. The data obtained was evaluated by One-way ANOVA, Mann-Whitney U-test, Kruskal-Wallis-test, Student t-test and chi(2)-test. The level of statistical significance was set at p<0.05. The patients displayed statistically significant differences in the topics of the length of time of denture usage and the balance of denture in terms of retention. The complete denture wearers should be educated in the importance of periodic examination due to the changing of supporting tissues for detection early mucosal lesions to maintain their oral and dentures hygiene in optimum level.

Satisfaction of the complete denture wearers related to various factors.

All dentists who have worked with complete denture wearers know that patient satisfaction is not based only on the technical quality of the dentures. The aim of this study was at assessing the effect of gender, the number of the dentures used before, the length of time of denture usage, education and age on the satisfaction of the complete denture wearers. The students of the Dental Faculty of Marmara University (Turkey) made new dentures for 342 patients who were asked to participate in the investigation. The subjects (137 men and 205 women) were 39-89 years of age with a mean of 61.62 years. The attitude toward dentures in general was measured by means of 11 items of a questionnaire. The 10 main questions of the questionnaire were answered by the participants, and quantified on a 7-point scale, while the 11th issue (general satisfaction) was evaluated on a scale of 1-10. All main factors were also estimated in subgroups. For example, the education was analyzed in 4 subgroups, the time of denture usage was divided into two subgroups (below and above 3 years) and the number of dentures used before was also taken as up to 3 or more than 3 dentures. The age of the subjects was taken in 3 subgroups: 40-55, 56-65 and >65 years. One-way ANOVA, Tukey and Student t-tests were used to evaluate the answers to the questionnaire. Our patients displayed statistically significant differences only in the topics of their ability of cleaning their dentures, due to education and number of previously used dentures.

Replacement of a maxillary central incisor using a polyethylene fiber-reinforced composite resin fixed partial denture: a clinical report.

Fiber-reinforced composite resin (FRC) restorations generally consist of a composite resin veneer supported by a fiber-reinforced composite resin substructure and prepared chairside to be used when the patient needs a short-term solution. It is an esthetic, conservative treatment alternative and allows for future options. This article describes the use of a polyethylene fiber-reinforced composite resin fixed partial denture (PFRCFPD) with a ceramic pontic for the replacement of a missing central incisor due to trauma.

Multidisciplinary approach in the treatment of subgingivally fractured anterior teeth.

With the advances in adhesive technology, dentists have gained great popularity with their esthetics treatment options. The enamel and partially dentin adhesive systems have proved their potential effect. This study presents the multidisciplinary approach in the treatment of subgingivally fractured anterior teeth. Empress II crowns were cemented entirely on the prepared root portion of a left maxillary lateral incisor and canine after orthodontic eruption. The clinical results after 2 years were successful.

Prospective clinical trial of polyethylene fiber ribbon-reinforced, resin composite post-core buildup restorations.

The aim of this prospective clinical trial was to determine the outcome of polyethylene fiber ribbon-reinforced, resin composite post-and-core restorations used as endodontic buildups to support all-ceramic crowns. A total of 42 teeth (31 anterior, 11 posterior) with a mean follow-up time of 35.85 months (range, 10 to 73 months) were treated with 3-mm-wide polyethylene fiber ribbon-reinforced resin composite as post-and-core material. The posts and cores were assessed by clinical and radiographic examination. During the evaluation period, only 1 dentin-cement failure was observed as a post dislodgement after 11 months of clinical service. Performance of polyethylene fiber ribbon post and resin composite core foundation restorations provided clinically satisfactory support for all-ceramic crowns.

Effect of five staining solutions on the colour stability of two acrylics and three composite resins based provisional restorations.

The effect of coffee, tea, coca-cola, orange-juice and red wine on the colour stability of acrylic and composite based provisional materials were evaluated. Two acrylic resins and three composite resins were studied. 48 standardized specimens for each provisional material were prepared. Each group was divided into 6 subgroups. Specimens from each group were immersed in staining solutions at room temperature for 30 days. Red wine and tea caused the most significant colour changes and orange juice showed the least significant colour changes. deltaE of all of the provisional restorations materials was changed after the immersion in all of the staining solutions during the experimental process.

Replacement of two mandibular central incisors using a zirconium resin-bonded fixed partial denture: a clinical report.

Maxillary and mandibular anterior tooth loss may cause esthetic and functional problems. Successful treatment for these situations may necessitate a minimally invasive technique to preserve sound remaining abutment tooth structure. This article describes the use of zirconium resin-bonded fixed partial denture as a conservative treatment option for the replacement of 2 mandibular central incisors.

Effect of three bleaching agents on the surface properties of three different esthetic restorative materials.

STATEMENT OF PROBLEM: Information related to the effect of night-guard vital bleaching procedure on the surface properties of esthetic dental restorative materials is incomplete. PURPOSE: The aim of this study was to examine the effects of 3 proprietary carbamide peroxide bleaching agents on the surface properties of 3 dental esthetic restorative materials. MATERIAL AND METHODS: Three bleaching products (Nite White, Opalescence, and Rembrandt Lighten Gel) and 3 restorative materials (Duceram, Fuji II LC, and Silux Plus) were studied. A stainless steel mold and a 6-mm-thick polytetrafluoroethylene plate with a 1-cm-diameter hole were used to prepare 30 standardized specimens for each of the 3 restorative materials tested. Each group was divided into 3 subgroups (n=10). Two specimens from each subgroup were selected to form a control group. Three different carbamide peroxide bleaching agents were applied to each restorative material group for 8 hours per day for 30 days, respectively. Initial roughness measurements (Ra measured in microm) were made by use of a profilometer, at repeated intervals of 24 hours, 48 hours, 1, 2, 3, and 4 weeks (30 days). Surface topography of the specimens was assessed by scanning electron microscopy, and results were compared with the control group graphically. Surface structure and alterations of atomic weight percentages of element were made by use of energy-dispersive x-ray microanalysis. One-way analysis of variance was used to evaluate the surface roughness measurements. Significant results were evaluated with Fisher and Duncan's multiple range test (P<.005) RESULT: Surface roughness values for all restorative materials increased during the bleaching procedure. The only significant increase was found with the effect of Rembrandt bleaching gel on modified glass ionomer cement (mean Ra was 0.48 microm initially, 0.5 microm at 24 hours, 0.75 microm at 2 weeks, and 0.83 microm at 30 days). Surface roughness values increased significantly during the first 2 weeks (P<.005) for all bleaching groups of each restorative material, and no significant changes were seen in the following periods. SEM micrographs of the feldspathic porcelain specimens for each bleaching agent appeared to be similar to the control group. All of the modified glass ionomer specimens revealed serious cracking areas, whereas microfilled composite specimens showed increased surface porosity and cracks in certain areas when compared with control specimens. Surface spectral analyses results indicated a decrease in the SiO(2) content in the feldspathic porcelain and the microfilled composite groups for all bleaching agents. Modified glass ionomer specimens bleached with Nite White and Rembrandt showed an increase in mass percentage of SiO(2), whereas Opalescence specimens showed a decrease. However, there were no significant differences between the groups. CONCLUSION: Within the limitations of this study, no significant difference was found between bleaching agents. Most changes occurred in the first 2 weeks; the products tested were relatively stable in the following test periods. No significant change in the surface roughness of feldspathic porcelain was observed. On the other hand, the microfilled composite tested showed slight changes in the surface roughness. Significant changes were found for the modified glass ionomer cement (P>.005).