Evaluation of the effect of different desensitizers on pulpal blood flow after full crown preparation using laser Doppler flowmetry: a randomized clinical trial.

This study aims to evaluate the effect of Teethmate, Bifluoride 12, and Copal Varnish on the treatment of dentin hypersensitivity and the pulpal blood flow using laser Doppler flowmetry (LDF) after full crown preparations. Eighteen patients with 42 teeth with dentine hypersensitivity after full crown preparations were randomly treated with Teethmate, Bifluoride 12, and Copal Varnish. Dentine hypersensitivity was measured using a visual analog scale (VAS) and Schiff air index (SAI). LDF was used to assess the pulpal blood flow and results were recorded in perfusion units (PU). All measurements were performed at baseline, 5 min, 7 days, and 1 month after the application of desensitizers. Data were statistically analyzed by Wilcoxon and two-way ANOVA tests (p < 0.05). There was no significant difference between the tested desensitizers regarding VAS and PU values. VAS values decreased significantly at 7 days and 1 month after the application of desensitizers compared to baseline in all groups. The decrease in PU values significantly differed only in the Copal Varnish group at 5 min and 7 days after the application of the desensitizer (p < 0.05). A statistically significant difference was found between different times regarding SAI scores in all groups (p < 0.05). Teethmate, Bifluoride 12, and Copal Varnish showed similar effectiveness on dentine hypersensitivity and pulpal blood flow. Long-term clinical trials with larger sample sizes and histological studies are needed to evaluate their impacts on pulpal status.

Effect of abutment types and resin cements on the esthetics of implant-supported restorations.

PURPOSE: The aim of the study was to evaluate the optical properties of new generation (3Y-TZP) monolithic zirconia (MZ) with different abutment types and resin cement shades. MATERIALS AND METHODS: A1/LT MZ specimens were prepared (10 × 12 × 1 mm, N = 30) and divided into 3 groups according to cement shades as transparent (Tr), yellow (Y) and opaque (O). Abutment specimens were obtained from 4 different materials including zirconia (Group Z), hybrid (Group H), titanium (Group T) and anodized yellow titanium (Group AT). MZ and abutment specimens were then cemented. L*, a*, and b* parameters were obtained from MZ, MZ + abutment, and MZ + abutment + cement. ΔE001* (between MZ and MZ + abutment), ΔE002* (between MZ and MZ + abutment + cement) and ΔE003* (between MZ + abutment and MZ + abutment + cement) values were calculated. Statistical analyses included 2-way ANOVA, Bonferroni, and Paired Sample t-Tests (P < .05). RESULTS: Abutment types and resin cements had significant effect on L*, a*, b*, ΔE001*, ΔE002*, and ΔE003* values (P < .001). Without cementation, whereas zirconia abutment resulted in the least discoloration (ΔE001* = 0.68), titanium abutment caused the most discoloration (ΔE001* = 4.99). The least ΔE002* = 0.68 value was seen using zirconia abutment after cementation with yellow shaded cement. Opaque shaded cement caused the most color change (ΔE003* = 5.24). Cement application increased the L* values in all groups. CONCLUSION: The least color change with/without cement was observed in crown configurations created with zirconia abutments. Zirconia and hybrid abutments produced significantly lower ΔE002* and ΔE003* values in combination with yellow shaded cement. The usage of opaque shaded cement in titanium/anodized titanium groups may enable the clinically unacceptable ΔE00* value to reach the acceptable level.

Influence of abutment material, cement thickness, and crown type on the final color of implant-supported restorations.

PURPOSE: To evaluate the influence of abutment material, cement thickness, and crown type on the esthetics of implant supported restorations. MATERIAL AND METHODS: Sixty specimens were prepared to represent 6 abutment groups; Group PA = Pink-anodized Ti, Group GA = Gold-anodized Ti, Group T = Non-anodized Ti, Group H = Hybrid (Ti + zirconia), Group P = PEEK (Ti + PEEK), and Group C = Composite resin, (control). Crown specimens (n = 120) were 2 obtained from Vita Enamic (VE) and Vita Suprinity (VS). Two cement thicknesses (0.1 and 0.2 mm) were used. The color values of crown configurations were measured and ΔE00* values were calculated. Statistical analyses were included Shapiro Wilk, 3-way ANOVA and Tukey HSD tests (P ≤ 0.05). RESULTS: Abutment (P < 0.001) and crown materials (P = 0.001) had a significant effect on ΔE00* values, while cement thickness did not. Groups PA and H resulted in significantly lower mean ΔE00* values than other abutments, whereas Group T revealed the highest. Unlike VS, cement thicknesses created a significant difference on the ΔE00* values for VE (P ≤ 0.05). CONCLUSIONS: Pink-anodized Ti or hybrid abutments for VE and pink- or gold-anodized Ti for VS seem to be better options, in terms of color change. Cement thickness of 0.1 mm resulted in higher ΔE00* value than 0.2 mm for VE (P ≤£ 0.05). Int J Prosthodont. 10.11607/ijp.8564.

Evaluation of the effects of different composite materials and surface roughening techniques in bonding attachments of clear aligner on monolithic zirconia.

OBJECTIVE: The aim of this study is to evaluate the bond strengths of two different composite types used in the production of clear aligner attachments on monolithic zirconia with three different surface roughening processes. MATERIALS AND METHODS: Packable composite Filtek Z250 was used in one group (PC-G) and flowable composite Filtek Supreme Ultra Flowable was used in the other group (FC-G). PC-G and FC-G groups were also divided into three subgroups as diamond bur+silane (Group 1), 50 µm aluminium oxide (Al2 O3 ) sandblasting+silane (Group 2) and 110 µm Al2 O3 sandblasting+silane (Group 3). Scanning electron microscopy (SEM) analysis was performed. Clear aligner attachments were bonded to the monolithic zirconia specimens. Shear bond strength (SBS) values were measured. Statistical analysis was performed using two-way ANOVA and post-hoc Tukey's tests (P < .05). RESULTS: The highest SBS value was found in PC-G sandblasted with 110 µm Al2 O3 (P ≤ .001). The etching method with 110 µm sandblasting showed high SBS values in both composite types. The lowest SBS value gave FC-G in diamond bur roughening (P ≤ .001). CONCLUSIONS: For the bonding of clear aligner attachments on monolithic zirconia, roughening with 110 µm particle size sandblasting and the choice of packable composite could be recommended in terms of retention.

Effect of sintering and aging processes on the mechanical and optical properties of translucent zirconia.

STATEMENT OF PROBLEM: Sintering holding times and aging conditions may affect the optical, mechanical, and structural properties of polychromatic multitranslucent zirconia. However, a consensus on the ideal sintering condition for this material is lacking. PURPOSE: The purpose of this in vitro study was to investigate the effect of different sintering holding and autoclave aging times on the flexural strength (FS), grain size, and translucency parameter (TP00) of a translucent zirconia. MATERIAL AND METHODS: Sixty bar-shaped and 60 rectangular-shaped specimens were prepared from computer-aided design and computer-aided manufacturing (CAD-CAM) zirconia blocks and split into 2 groups to be sintered at 1550 °C for different holding times (regular: 2 hours, prolonged: 5 hours). The specimens were then divided into 3 subgroups and subjected to aging processes (control, aging for 60 minutes, aging for 120 minutes). FS values were obtained by using a 3-point bend test and Weibull analysis was conducted. Grain size evaluations were performed by using scanning electron microscope (SEM) observations. TP00 was measured with a spectrophotometer. Statistical evaluation included the Kolmogorov-Smirnov, 2-way ANOVA, and Tukey HSD tests (α=.05). RESULTS: The sintering procedure, aging, and their interaction significantly influenced the TP00 (P<.05). FS values and grain sizes were affected by aging only (P<.001). Both aging times resulted in reduced FS and increased grain sizes. Prolonged sintering in combination with 120 minutes of aging negatively affect the TP00 scores (P<.05). CONCLUSIONS: FS values were similar under regular and prolonged sintering. Prolonged sintering led to a decrease in translucency after 120 minutes of aging. Steam autoclave aging can affect the optical and mechanical properties of translucent zirconia.

Shear bond strengths of aged and non-aged CAD/CAM materials after different surface treatments.

PURPOSE: To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. MATERIALS AND METHODS: Cerasmart (CE), Vita Enamic (VE), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 × 12 × 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P≤.05). RESULTS: The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. CONCLUSION: Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.

Evaluating Ceramic Repair Materials in Terms of Bond Strength and Color Stability.

PURPOSE: To evaluate the shear bond strength (SBS) and color stability (ΔE) of four ceramic veneers (VITA VM 9; VITA VM 13; VITA VMK 95; and IPS e.max Ceram) following repair with three different self-adhesive composite resins (Fusio Liquid Dentin; Constic; and Vertise Flow) and BISCO Intraoral Repair Kit + Filtek Supreme (BC + FS). MATERIALS AND METHODS: A total of 96 specimens were prepared per ceramic material, and each ceramic group was divided into subgroups according to testing method (32 specimens for color stability analysis and 64 specimens for SBS testing). ΔE and SBS (SBS1 = non-aged, SBS2 = thermally aged) values of the repaired specimens were calculated. One specimen from each of the thermally aged groups was investigated under scanning electron microscopy (SEM). Two-way ANOVA was used to analyze the mean ΔE, SBS1, and SBS2 values. The differences between SBS1 and SBS2 values were analyzed using independent-samples t test. RESULTS: The lowest ΔE values were calculated for Constic (P ≤ .05). The SBS2 values among all groups were lower than the SBS1 values (P ≤ .05). The lowest SBS2 values were observed for Vertise Flow (2.3 ± 1.47 MPa) (P ≤ .05) and were below the acceptable limit of 5 MPa. CONCLUSION: All of the investigated repair materials in combination with the ceramic veneers exhibited ΔE values that were higher than the clinically acceptable limits. Thermal aging negatively affected the SBS values in all groups (P ≤ .05). All tested self-adhesive composite resins, with the exception of Vertise Flow, could be used instead of a repair kit with flowable composite resin, especially in noncooperative patients, for the purpose of repairing chipping fractures for VITA VM 9, VITA VM 13, and VITA VMK 95 (P > .05).

Effect of shade and sintering temperature on the translucency parameter of a novel multi-layered monolithic zirconia in different thicknesses.

OBJECTIVE: The objective of the present research was to evaluate the effect of sintering temperatures (1350°C, 1450°C, and 1600°C) of a novel multi-layered esthetic zirconia material (Katana 12Z/STML) on the grain sizes and on the translucency parameters (TP00 ) for 2 different shades (A2-A3) and 2 different thicknesses (1-1.5 mm). MATERIAL AND METHODS: A total of 120 non-sintered specimens were randomly divided into three subgroups according to sintering temperatures. The TP00 and grain sizes of the sintered specimens were calculated. Statistical analyses were performed using 3-way ANOVA, 1-way ANOVA, and Tukey's post hoc tests. RESULTS: TP00 increased 1.2 to 1.5 times as the specimen thickness decreased from 1.5 to 1 mm (P ≤ .05). The lowest TP00 values were recorded for sintering at 1350°C for the investigated thicknesses and shades (P ≤ .05). The interaction of sintering temperature and shade was significant (P ≤ .05). Grain sizes were ordered according to sintering temperature as 1350°C < 1450°C < 1600°C (P ≤ .05). CONCLUSIONS: TP00 values decreased with the increase in the thickness of the monolithic zirconia. The sintering temperatures and their interaction with shade significantly affected TP00 values. The grain size increased with increasing sintering temperature. CLINICAL SIGNIFICANCE: The translucency of a novel multi-layered monolithic zirconia increased with higher sintering temperatures and lower thickness. The grain size increased with the increase in the sintering temperature. The sintering temperature of 1600°C led to a significant change in translucency for shade A3.

Effect of UV aging on translucency of currently used esthetic CAD-CAM materials.

OBJECTIVES: To evaluate the relative translucency parameter (RTP) values of computer-aided design (CAD)-computer-aided manufacturing (CAM) materials after UV aging. MATERIALS AND METHODS: 70 specimens (n = 10) of Bruxzir Anterior (BA); E.max Cad (EC); Lava Ultimate (LU); Cerasmart (CE); Vita Enamic (VE); Vita Suprinity (VS); Vita Mark II (VM) were prepared (1 mm ± 0.01 mm). Color measurements were performed using a spectrofotometer (VITA Easyshade). RTP values of the specimens before (RTP1 ) and after UV aging (RTP2 ) were evaluated. Statistical analyses were done with repeated measurements of two-way-ANOVA with Bonferroni test (P < 0.05). RESULTS: Evaluating RTP1 and RTP2 values; significant differences were found (P < 0.05). There were no significant difference between the RTP1 values of CE and VS (P = 0.779); EC and VM (P = 0.952); VM and LU (P = 0.995); EP and LU (P = 0.653). Evaluating RTP2 values; VE and BA were found significantly different from the others (P < 0.05). For all evaluated groups TP values decreased after UV aging (P < 0.05). The most RTP reduction was observed for LU; while VM and EC were less affected. CONCLUSION: Glass ceramic VE showed the highest RTP and zirconia-based BA was the most opaque restorative CAD-CAM material. UV aging caused the CAD-CAM materials get more opaque. CLINICAL SIGNIFICANCE: In cases where translucency is needed chosing VE would give better esthetic results; while zirconia-based BA should be used if more opaque restoration is needed. Clinicians should be aware of that restorations get more opaque after usage.

Color relationships of natural anterior teeth: An In vivo study.

OBJECTIVES: To investigate the color relationships between the anterior teeth in vivo. MATERIALS AND METHODS: A total of 640 volunteers (age: 18-22) participated in the study. The color measurements of left maxillary and mandibular central, lateral, and canine were performed using a colorimeter. Color differences were calculated according to the CIE L*a*b* (ΔE*) and CIEDE2000 (ΔE00*) system. The National Bureau of Standards (NBS) ratings were also evaluated. Statistical analyses were performed using two-way ANOVA and Fisher's exact test (P < 0.05). RESULTS: Significant differences were found between the L*, a*, b*, and ΔE* values (P < 0.05), except for mandibular central and lateral. ΔE* values were found between 1.5 ΔE* (mandibular central-mandibular lateral) and 8.1 ΔE* (maxillary central-maxillary canine). While the highest L* (80.5) and the least b* (15.1) values were obtained for mandibular central, the mean L* (73.6) and the mean b* values (21.3) were obtained for the maxillary canine. a* value was found to be highest for the mandibular lateral (1.1) and the least for the maxillary central (-0.2) teeth. NBS values were between 1.3 and 7.4 units, and only mandibular central and mandibular lateral teeth exhibited "almost the same" color values, while the other teeth exhibited "slightly different," "very different," or "remarkably different" color values. CONCLUSION: Anterior maxillary and mandibular teeth exhibited "different" color values. Only mandibular incisors and mandibular laterals showed "almost the same" color. Canines were more dark/red/yellow for both mandible and maxilla. Centrals were more bright/green/yellow for maxilla and bright/green/blue for mandibular. Clinicians should select the color one by one for each tooth and be aware of their color relations for optimal esthetics.

Optical behaviors of esthetic CAD-CAM restorations after different surface finishing and polishing procedures and UV aging: An in vitro study.

STATEMENT OF PROBLEM: Esthetic computer-aided design and computer-aided manufacturing (CAD-CAM) materials have various chemical compositions and can be prepared by using different finishing and polishing procedures. Their optical properties may change over time, depending on these factors. However, information about their stain resistance is still scarce. PURPOSE: The purpose of this in vitro study was to evaluate the optical properties of esthetic CAD-CAM materials after different finishing and polishing procedures and ultraviolet (UV) aging. MATERIAL AND METHODS: Lava Ultimate, Cerasmart, Vita Enamic, Vita Suprinity, and Vita Mark II materials were used. A total of 150 specimens (14×12×1 mm) were prepared (n=10). A spectrophotometer was used to measure color parameters after different finishing and polishing procedures (control, manual polishing, glazing) and ultraviolet (UV) aging. Lightness (L*), green-red (a*), blue-yellow (b*), chroma (Ch), and hue (h) parameters were recorded, and change in lightness (ΔE*) values were calculated. Statistical analyses were performed with 2-way ANOVA, the Fisher least significant difference test, and the paired samples t test (α=.05). RESULTS: Significant interactions were noted between the aging conditions, material type, and finishing and polishing procedures for all evaluated parameters (P<.001). Vita Suprinity and Vita Mark II glazing groups resulted in significantly higher L1* values (P<.05) after the first color measurements. The b1* and C1 values of Vita Suprinity were higher than for other materials (P<.05). The highest ΔE* value was observed in the Lava Ultimate-glazing group (ΔE*=22.7) and the lowest in the Vita Mark II-control group (ΔE*=0.86). CONCLUSIONS: The optical properties of CAD-CAM materials can be affected by the material type and the applied surface finishing and polishing procedure. Manual polishing seems to be a better choice for Lava Ultimate and Cerasmart and glazing for Vita Enamic. For ceramic materials, manual polishing or glazing can be recommended in terms of color stability.

The Effect of Desensitizing Toothpastes and Coffee Staining on the Optical Properties of Natural Teeth and Microhybrid Resin Composites: An In-Vitro Study.

OBJECTIVE: To evaluate the effect of different desensitizing toothpastes and coffee staining on the discoloration rate of natural human tooth and composite materials. MATERIALS AND METHODS: A total of 56 human teeth and 56 composite specimens were used. After initial color measurements were taken, specimens and teeth were exposed to simulated toothbrushing with six desensitizing toothpastes containing different active ingredients: stannous fluoride, strontium acetate, potassium citrate and hydroxyapatite, cetylpyridinium chloride, arginine, and novamin. Specimens were then exposed to coffee staining. Throughout the staining procedure, the storing solution was refreshed every day and the specimens were brushed with the tested toothpastes. Color measurements and changes were recorded at each stage and analyzed with one-way ANOVA, Dunnett tests, and paired sample t-test (p<0.05). RESULTS: The largest color change was obtained with the stannous fluoride toothpaste after coffee staining for natural teeth (2.6 ΔE 00 ⁎) and composite specimens (3.1 ΔE 00 ⁎). Coffee staining resulted in significant changes for ΔE 00 ⁎ values of all groups, except for natural teeth brushed with a novamin-based (p= 0.06) toothpaste. For composite specimens, only the stannous fluoride and cetylpyridinium chloride-based toothpastes resulted in significant color changes relative to the control group. ΔL⁎ and Δb⁎ values were also increased after staining for all groups (p<0.05). CONCLUSIONS: Desensitizing toothpastes alone did not cause perceptible color changes; however, in combination with coffee staining, it tended to increased discoloration for both composites and natural teeth.

Storing Tooth Segments for Optimal Esthetics.

OBJECTIVE: A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. STUDY DESIGN: Sixty central incisor crowns were divided into 6 groups (n = 10); Group 1 was kept dry; Groups 2, 3, 4, 5, and 6 were placed in an isotonic solution, water, milk, saliva, and casein-phosphopeptide-amorphous-calcium-phosphate (CPP-ACP), respectively, for 30 min, 12 h, 1 day, 1 week, and 3 weeks. Color values were measured using a colorimeter. Data were analyzed with Kruskal-Wallis tests, Mann-Whitney U-tests, and Friedman Wilcoxon tests with Bonferroni stepwise corrections (p < 0.05). RESULTS: ΔE* values varied from 0.3 to 15.3 over the 3 week period. Group 1 demonstrated the greatest color changes over all durations; Group 6 exhibited the least. L*, a*, b*, and ΔE* values varied between time periods in all groups; the differences were significant (p < 0.01), except for L* and ΔE* values in Group 2 and a* values in Group 6 (p > 0.01). Comparing ΔE* values, Group 6 was significantly different from the other groups for all durations (p < 0.01), except Group 4. CONCLUSIONS: A CPP-ACP complex solution seems a good choice for tooth fragment storage. Milk and saliva solutions may cause perceptible color changes if tooth fragments are stored for 3 weeks before use.