Effect of scan powder and scanning technology on measured deviations of complete-arch implant supported frameworks digitized with industrial and intraoral scanners.

OBJECTIVES: To evaluate the suitability of intraoral scanners (IOSs) to analyze the fabrication trueness of titanium complete-arch implant-supported frameworks by comparing with an industrial-grade scanner and investigate how anti-reflective scan powder affects measured deviations. METHODS: Ten titanium complete-arch implant-supported frameworks were milled from a reference standard tessellation language (STL) file. An industrial-grade blue light scanner (ATOS Core 80 (AT)) and three IOSs (Primescan (PS), TRIOS T3 (T3), and TRIOS T4 (T4)) with (PS-P, T3-P, and T4-P) or without (PS, T3, and T4) anti-reflective scan powder application were used to generate test STL (TSTL) files of the frameworks. Reference STL and TSTLs were imported into a metrology-grade analysis software (Geomagic Control X) and whole surface root mean square (RMS) values were calculated. Another software (Medit Link v 2.4.4) was used to virtually isolate marginal surfaces of all STL files and marginal RMS values were calculated by using the same metrology-grade analysis software. A linear mixed effects model was used to compare the transformed deviations of the scans performed by using each IOS (with or without powder) with the deviations of those performed by using the reference AT scanner within each surface, where a Box-Cox type transformation was used for variance stability. Bonferroni corrected post-hoc tests were used to compare conditions within each IOS (α=0.05). RESULTS: All IOSs had significantly higher whole surface and marginal RMS values than AT, regardless of the condition (P≤.002). However, scan powder application did not affect the whole surface and marginal RMS values in scans of tested IOSs (P≥.054). CONCLUSION: Measured whole surface and marginal deviations in all IOS scans performed with or without the use of scan powder were higher than those in AT scans. The application of anti-reflective scan powder did not affect the deviations in scans of tested IOSs. CLINICAL SIGNIFICANCE: Even though deviations measured in the scans of tested scanners were significantly different than those in the reference scanner, the maximum raw mean difference was 37.33 µm and the maximum raw confidence interval value of estimated differences was 47.88 µm, which can be considered clinically small taking into account the size of the frameworks tested. Therefore, tested intraoral scanners may be feasible to scan prostheses similar to or smaller than tested frameworks for fabrication trueness analysis, which may facilitate potential clinical adjustments.

Comparison of intraoral and laboratory scanners to an industrial-grade scanner while analyzing the fabrication trueness of polymer and titanium complete-arch implant-supported frameworks.

OBJECTIVES: To compare the scans of different intraoral scanners (IOSs) and laboratory scanners (LBSs) to those of an industrial-grade optical scanner by measuring deviations of complete-arch implant-supported frameworks from their virtual design file. MATERIAL AND METHODS: Ten polyetheretherketone (PEEK) and 10 titanium (Ti) complete-arch implant-supported frameworks were milled from a master standard tessellation language (STL) file. An industrial-grade blue light scanner (AT), 2 LBSs (MT and E4), and 3 IOSs (PS, T3, and T4) were used to generate STL files of these frameworks. All STLs were imported into an analysis software (Geomagic Control X) and overall root mean square (RMS) values were calculated. Marginal surfaces of all STL files were then virtually isolated (Medit Link v 2.4.4) and marginal RMS values were calculated. Deviations in scans of tested scanners were compared with those in scans of AT by using a linear mixed effects model (α = 0.05). RESULTS: When the scans of PEEK frameworks were considered, PS and T3 had similar overall RMS to those of AT (p ≥ .076). However, E4 and T4 had higher and MT had lower overall RMS than AT (p ≤ .002) with a maximum estimated mean difference of 13.41 µm. When the scans of Ti frameworks were considered, AT had significantly lower overall RMS than tested scanners (p ≤ .010) with a maximum estimated mean difference of 31.35 µm. Scans of tested scanners led to significantly higher marginal RMS than scans of AT (p ≤ .006) with a maximum estimated mean difference of 53.90 µm for PEEK and 40.50 µm for Ti frameworks. CONCLUSION: Only the PEEK framework scans of PS and T3 led to similar overall deviations to those of AT. However, scans of all tested scanners resulted in higher marginal deviations than those of AT scans. CLINICAL SIGNIFICANCE: Scans performed by using PS and T3 may be alternatives to those of tested reference industrial scanner AT, for the overall fabrication trueness analysis of complete-arch implant-supported PEEK frameworks.

Effect of analysis software program on measured deviations in complete arch, implant-supported framework scans.

STATEMENT OF PROBLEM: Implementation of fabrication trueness analysis by using a recently introduced nonmetrology-grade freeware program may help clinicians and dental laboratory technicians in their routine practice. However, knowledge of the performance of this freeware program when compared with the International Organization for Standardization recommended metrology-grade analysis software program is limited. PURPOSE: The purpose of this in vitro study was to evaluate the effect of an analysis software program on measured deviations in the complete arch, implant-supported framework scans. MATERIAL AND METHODS: A total of 20 complete arch, implant-supported frameworks were fabricated from a master standard tessellation language (STL) file from either polyetheretherketone (PEEK) or titanium (Ti) (n=10). All frameworks were then digitized by using different scanners to generate test STLs. All STL files were imported into a nonmetrology-grade freeware program (Medit Link) and a metrology-grade software program (Geomagic Control X) to measure the overall and marginal deviations of frameworks from the master STL file by using the root mean square (RMS) method. Data were analyzed by using the two 1-sided paired t test procedure, in which 50 µm was considered as the minimal clinically meaningful difference (α=.05). RESULTS: When overall RMS values were considered, the nonmetrology-grade freeware program was not inferior to the metrology-grade software program (P<.05). When marginal RMS values were considered, the nonmetrology-grade freeware program was inferior to the metrology-grade software program only when PEEK frameworks were scanned with an E4 laboratory scanner (P>.05). CONCLUSIONS: The use of the tested nonmetrology-grade freeware program resulted in overall deviation measurements similar to those when a metrology-grade software program was used. The freeware program was inferior when marginal deviations were analyzed on E4 scans of a PEEK framework, which was the only scanner-material pair that led to a significant difference, among the 15 pairs tested.

Effect of cross-polarization filters on the trueness of colors obtained with a single-lens reflex camera, macro lens, and a ring flash.

OBJECTIVE: To investigate the effect of cross-polarization filters on the colors of shade tabs obtained with a digital single-lens reflex (DSLR) camera, macrolens, and a ring flash. MATERIALS AND METHODS: Digital images of four shade tables (1M1, 3L2.5, 3R2.5, and 5M3) from the VITA Toothguide 3D-Master shade guide were taken using a DSLR camera, 100 mm macrolens, and ring flash with two different cross-polarizing filters (Polar_eyes and Filtropolar), and without (Nonpolarizer; n = 7). The CIE L*a*b* color coordinates of digital images were calculated and remeasured with a spectroradiometer (SR). The color differences (ΔE00 ) between the SR and digital images were calculated and analyzed with the two-way analysis of variance (ANOVA) and Tukey HSD test (α = 0.05). RESULTS: ΔE00 values of all test groups were higher than the clinically acceptable threshold (∆E00 > 1.80). While the ∆E00 values of Filtropolar (6.19 ± 0.44) and Polar_eyes (7.82 ± 0.23) groups were significantly higher than the Nonpolarizer (4.69 ± 0.32) for the 1M1 shade tab, ∆E00 value of Polar_eyes (6.23 ± 0.34) was significantly lower than Nonpolarizer (10.71 ± 0.48) group for 5M3 shade tab (p < 0.05). CONCLUSION: The color-matching results of tested digital photography techniques with and without cross-polarization were unacceptable, compared to a spectroradiometer. While digital photography with Polar_eyes cross-polarizing filter has closer results to the reference device for the low-in-value shade table (5M3), for the high-in-value shade table (1M1), improved results were obtained without a cross-polarizing filter. CLINICAL SIGNIFICANCE: The cross-polarization filters are increasingly used in dentistry for tooth color communication with digital photography techniques. However, the digital photography techniques with-without cross-polarization filterers should be improved to obtain clinically acceptable color-matching results.

Comparing the shear bond strength of veneering materials to the PAEKs after surface treatments.

BACKGROUND: This study aimed to evaluate the impact of various surface treatments on the shear bond strength (SBS) of polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) polymers to indirect laboratory composite (ILC) and lithium disilicate ceramic (LDC) veneering materials. METHODS: Polymer specimens (7 × 7x2 mm) were sectioned from PEEK and PEKK discs (N = 294) and randomly allocated to 7 groups (n = 20); untreated (Cnt), plasma (Pls), 98% sulfuric acid (Sa), sandblasting with 110 µm Al2O3 (Sb), tribochemical silica coating with 110 µm silica modified Al2O3 (Tbc), Sb + Sa, Tbc + Sa. Scanning electron microscopy assessments were performed on one sample of each treatment group, and veneering materials were applied to the remaining specimens (n = 10). The specimens were subjected to the SBS test after being soaked in distilled water (24 h, 37 °C). Three-way ANOVA, independent sample t-test, and Tukey HSD test were performed for statistical analyses (α = .05). RESULTS: The surface treatment, polymer, veneering material types, and their interactions were significant on SBS results according to the 3-way ANOVA (p < 0.001). The SBS values of ILC veneered groups were significantly higher than LDC groups, regardless of surface treatment and polymer type (p < 0.05). The highest SBS values were obtained for Sa-applied ILC veneered PEEK (21.55 ± 1.45 MPa) and PEKK (17.04 ± 1.99 MPa) polymer groups (p < 0.05). CONCLUSION: The effect of surface treatment and veneering materials may be significant on the SBS values of PAEKs. Therefore, the application parameters of surface treatments should be more specified for the applied veneering material and polymer type.

Influences of Toothbrushing and Different Toothpastes on the Surface Roughness and Color Stability of Interim Prosthodontic Materials.

The surface properties and color stability of interim crown materials may vary depending on the toothbrushing procedure. This study aimed to investigate the effects of toothbrushing and different toothpastes on the surface roughness (Ra) and color stability of different interim crown materials. Disc-shaped specimens were prepared from four interim crown materials (Tab 2000 (ChPM), Imident (LaPM), Protemp 4 (ChDM), and Telio-CAD (CadPM)). Specimens were divided into four subgroups for the control group (Cnt) and for simulated toothbrushing with distilled water (Dw) or with two different toothpastes (whitening toothpaste (WTp), activated charcoal toothpaste (ACTp)). The specimens' Ra values were measured before and after 10,000 cycles of toothbrushing. The color parameters were measured and the color differences (ΔE00) were calculated. Data were statistically analyzed by two-way analysis of variance (ANOVA) and Tukey's HSD tests. A significant increase in the Ra values was observed after toothbrushing, except for the LaPM_Dw, ChDM_Dw, and all the CadPM specimens (p < 0.05). Toothbrushing with toothpastes increased the ΔE00 values of all ChPM and ChDM interim materials (p < 0.05). Before and after all toothbrushing procedures, the CadPM specimens had smoother and ChPM specimens had rougher surfaces than the other interim materials. The two tested toothpastes had similar effects on the Ra of all interim materials. Non-perceivable color changes were seen only with the CadPM_Dw group.

Influence of chairside surface treatments on the shear bond strength of PEKK polymer to veneering resin materials: An in vitro study.

STATEMENT OF PROBLEM: High-performance thermoplastics have been adopted as an alternative restorative material to metal or ceramics. However, a straightforward surface modification process to provide a durable bond strength between the polymer and the veneering material is lacking. PURPOSE: The purpose of this in vitro study was to evaluate the shear bond strength (SBS) of different veneering resin materials to polyetherketoneketone (PEKK) after different surface treatments. MATERIAL AND METHODS: Rectangular (7×7×2 mm) PEKK specimens (N=120) were randomly allocated to the following 6 groups (n=20): untreated (Cnt); nonthermal plasma (NTP) treated; tribochemical silica airborne-particle abrasion with 30-µm silica-modified Al2O3 (Tbc); abraded with a coarse-grit diamond rotary instrument (Ab); tribochemical silica airborne-particle abrasion + plasma treated (Tbc_NTP); abraded + plasma treated (Ab_NTP). After a bonding agent (PEKK Bond) was applied to the specimens, each group was divided into 2 subgroups according to the applied veneering resin materials: polymethylmethacrylate (PMMA) and nanohybrid composite resin (NHC, n=10). The specimens were stored in water for 24 hours at 37 °C and subjected to the SBS test by using a universal testing machine, and failure modes were evaluated using a stereomicroscope. Two-way analysis of variance (ANOVA) was performed followed by the Tukey honestly significant difference (HSD) test to statistically analyze the data (α=.05). RESULTS: The 2-way ANOVA showed that surface treatment methods, veneering material, and their interactions were significantly different on the SBS values (P<.001). The highest SBS values were determined for the Tbc and Tbc_NTP treatment groups not only for PMMA (10.71 to 11.63 MPa) but also for NHC (19.80 to 20.60 MPa) veneering resin materials (P<.05). CONCLUSIONS: The bonding capacity of PEKK to the PMMA and NHC veneering resin materials can be significantly improved by using tribochemical silica airborne-particle abrasion alone or with nonthermal plasma surface treatment techniques. Furthermore, using NHC veneering resin material is recommended over PMMA.

Effects of denture cleaning solutions on the retention of Hader bar clips.

STATEMENT OF PROBLEM: The clinical performance of implant-retained overdentures (IODs) with plastic bar clips made of different materials in the same design and dimensions may vary according to the patient's daily home care procedures. However, information about the effects of denture cleaning solutions on the retention of Hader bar clips is lacking. PURPOSE: The purpose of this in vitro study was to evaluate the retention of Hader bar clips made of different polymers after being soaked in denture cleaning solutions. MATERIAL AND METHODS: Ninety Hader bar clips made of polyamide (PA, n=30), polytetrafluoroethylene (PTFE, n=30), and polyetherketoneketone (PEKK, n=30) materials were tested. Two multiunit abutments were screwed onto the implant analogs and embedded into an acrylic resin block in a standardized position. The digital scanning of the abutments was acquired, and the bar patrix of each material system milled from a cobalt-chromium (Co-Cr) alloy disk by using computer-aided design and computer-aided manufacturing (CAD-CAM). After the milled bar patrices were screwed onto abutments and the metal housings of the bar clips were embedded into acrylic resin blocks, they were connected passively at the same angulation to a universal testing machine. The initial retention values of all Hader bar clips were measured, and each material system was divided into 3 subgroups (n=10) before soaking in the cleaning solutions: distilled water (DW), 5% sodium hypochlorite (NaOCl), or sodium bicarbonate-sodium perborate (SBSP). Each material was soaked for the equivalent of 3 months of clinical use. The final retention values of each Hader bar clip were measured. The data were statistically analyzed by using a 2-way analysis of variance (ANOVA), the Tukey honestly significant difference (HSD) test, and the paired sample t test (α=.05). RESULTS: The 2-way ANOVA showed that the denture cleaning solution, the clip material, and their interactions led to significantly different retention values (P<.001). A decrease was observed for the retention values of all test groups after soaking in the cleaning solutions (P<.05). No retention was observed for the PTFE clips after soaking in the 5% NaOCI solution. CONCLUSIONS: The denture cleaning solutions negatively affected the retention of Hader bar clips, regardless of the type of solution and clip material. The 5% NaOCI solution not only decreased the retention of PTFE clips but also completely degraded it. It is recommended that 5% NaOCI solution be avoided for the daily care of IODs with PTFE clips.

Effects of adhesive systems at different temperatures on the shear bond strength of orthodontic brackets.

Background. The temperature might affect the physical and mechanical properties of adhesive materials by reducing the polymerization rate. The present study aimed to evaluate the effect of temperature on the shear bond strength of metallic orthodontic brackets using various adhesive resin systems. Methods. Extracted human premolar teeth were randomly assigned to 8 groups (n=10) for bonding with the two available orthodontics adhesive systems (Transbond XT and NeoBond) at different temperatures: refrigeration temperature (4°C), room temperature (20°C), human body temperature (36°C) and high temperature (55°C). The shear bond strength (SBS) test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. The adhesive remnant index (ARI) was assigned to the fractured orthodontic brackets. Data were analyzed with one-way ANOVA, post hoc Tukey tests and independent t-test. Results. Transbond XT exhibited higher SBS values compared to Neobond at all the tested temperatures; however, a statistically significant difference was not observed (P>0.05). The SBS results were minimum at 4°C and maximum at 36°C in both the adhesive groups (P<0.05). Conclusion. Pre-heating orthodontic adhesives up to the body temperature prior to bonding the brackets in orthodontic treatment increased the bond strength of orthodontic brackets.

Effect of ultrasonic and Nd: Yag laser activation on irrigants on the push-out bond strength of fiber post to the root canal.

OBJECTIVE: This in vitro study aimed to compare the efficacy of irrigants using various irrigation activation methods to the push-out bond strengths of fiber post to root canal luted with self-adhesive resin cement (SARC). METHODOLOGY: Forty-eight decoronated human canines were used. The specimens were divided into four groups corresponding with the post-space irrigation process and were treated as follows: distilled water (DW) (Control) group received 15 mL of DW; sodium hypochlorite (NaOCl)+ethylenediaminetetraacetic acid (EDTA) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW; passive ultrasonic irrigation (PUI) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW, and each irrigant was agitated with an ultrasonic file; and laser activated irrigation (LAI) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW, and each irrigant was irradiated with Nd: YAG laser. Fiber posts were luted with SARC, and a push-out test was performed. Data was analyzed using one-way analysis of variance and Tukey HSD test. RESULTS: The bond strength values for the groups obtained were as follows: Control (10.04 MPa), NaOCl+EDTA (11.07 MPa), PUI (11.85 MPa), and LAI (11.63 MPa). No statistically significant differences were found among all experimental groups (p>0.05). The coronal (12.66 MPa) and middle (11.63 MPa) root regions indicated a significantly higher bond strength compared with the apical (9.16 MPa) region (p<0.05). CONCLUSIONS: Irrigant activation methods did not increase the bond strength of fiber post to canal.

The effect of layer thickness on the porcelain bond strength of laser-sintered metal frameworks.

STATEMENT OF PROBLEM: Laser sintering has become a common manufacturing technique in the fabrication of metal-ceramic restorations. The layer thickness of the sintering process may affect the surface morphology and hence the porcelain bond strength. However, limited information is available on the effect of layer thickness on porcelain bond strength. PURPOSE: The purpose of this in vitro study was to evaluate the porcelain bond strength of direct metal laser-melted (DMLM) cobalt-chromium (Co-Cr) metal frameworks sintered with 25-µm and 50-µm layer thicknesses. MATERIAL AND METHODS: Thirty metal frameworks (n=10) were fabricated by using the lost-wax technique (group C [control]), DMLM with a 25-µm layer thickness (group L25), and DMLM with a 50-µm layer thickness (group L50) according to the International Organization for Standardization (ISO) 9693-1. The surface roughness of 1 metal specimen from each group was analyzed by atomic force microscopy. After porcelain firing, a 3-point bend test was applied to each metal-ceramic specimen as in ISO 9693-1. In addition, 1 metal framework from each group was prepared and examined by scanning electron microscopy to evaluate surface morphology. Data were analyzed statistically by using 1-way analysis of variance and the Tukey honestly significant difference tests (α=.05). RESULTS: Group C and group L25 showed significantly higher (P<.001) mean porcelain bond strength values than group L50, and no significant bond strength difference was found between groups C and L25. All groups generally exhibited an adhesive type of failure. CONCLUSIONS: The results indicate that layer thickness may affect the porcelain bond strength of DMLM metal frameworks.

Spectrophotometric analysis of discoloration and internal bleaching after use of different antibiotic pastes.

OBJECTIVES: To investigate teeth's antibiotic-induced color differences after bleaching using two different techniques. MATERIALS AND METHODS: One hundred twenty extracted maxillar human incisors were examined. The specimens were randomly divided into six groups, each receiving one of six antibiotic paste fillings: (1) triple antibiotic paste (TAP) with minocycline, (2) double antibiotic paste (DAP), (3) TAP with amoxicillin, (4) TAP with cefaclor, (5) TAP with doxycycline, and (6) no filling (control group). Spectrophotometric measurements were obtained at baseline and then during the first, second, and third weeks after paste placement. The specimens discolored by antibiotics pastes were randomly divided into two subgroups: (1) internal bleaching with hydrogen peroxide (H2O2) and (2) internal bleaching with H2O2 plus Nd-YAG laser irradiation. The ∆E value was calculated and analyzed using a two-way analysis of variance and post-hoc Tukey's test (α = 0.05). RESULTS: The ∆E for all groups showed color differences exceeding the perceptibility threshold (∆E Ëƒ 3.7) at all time points except in the control and DAP groups. Minocycline-induced TAP showed the most severe coronal discoloration (32.42). When the ∆E was examined, thermo/photo bleaching (22.01 ± 8.23) caused more bleaching than walking bleaching (19.73 ± 5.73) at every time point (P = 0.19). No group returned to the original color after bleaching (P < 0.05). CONCLUSIONS: Except for DAP, all antibiotic pastes caused discoloration. Internal bleaching with Nd-YAG laser can be useful for bleaching/removing this discoloration. CLINICAL RELEVANCE: For clinically successful final appearances, understanding the effects of bleaching procedures on antibiotic paste discoloration is important.

Evaluation of the preventive efficacy of three dentin tubule occlusion methods against discoloration caused by triple-antibiotic paste.

The aim of this in vitro study was to evaluate the preventive efficacy of three dentin tubule occlusion methods against discoloration caused by triple-antibiotic paste (TAP). Sixty extracted human incisors were sectioned, and the access was opened. The specimens were randomly allocated to the following four groups (n = 15): bonding application (BD), teethmate desensitizer (TM), Nd:YAG laser application (LS), and no surface treatment (control, C). Specimens were discolored with TAP over a period of 3 weeks. The color was measured by spectrophotometry at two time-points: initially and after 3 weeks of TAP placement. Color differences (∆E) were calculated and analyzed. Discoloration was visually noticed in all teeth after 3 weeks. The differences between the control group and the three dentin tubule occlusion methods were statistically significant (p < 0.05); however, there were no statistically significant differences among the BD, TM, and LS groups (p > 0.05).

Effect of ultrasonic and Nd: Yag laser activation on irrigants on the push-out bond strength of fiber post to the root canal

Abstract Objective: This in vitro study aimed to compare the efficacy of irrigants using various irrigation activation methods to the push-out bond strengths of fiber post to root canal luted with self-adhesive resin cement (SARC). Methodology: Forty-eight decoronated human canines were used. The specimens were divided into four groups corresponding with the post-space irrigation process and were treated as follows: distilled water (DW) (Control) group received 15 mL of DW; sodium hypochlorite (NaOCl)+ethylenediaminetetraacetic acid (EDTA) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW; passive ultrasonic irrigation (PUI) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW, and each irrigant was agitated with an ultrasonic file; and laser activated irrigation (LAI) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW, and each irrigant was irradiated with Nd: YAG laser. Fiber posts were luted with SARC, and a push-out test was performed. Data was analyzed using one-way analysis of variance and Tukey HSD test. Results: The bond strength values for the groups obtained were as follows: Control (10.04 MPa), NaOCl+EDTA (11.07 MPa), PUI (11.85 MPa), and LAI (11.63 MPa). No statistically significant differences were found among all experimental groups (p>0.05). The coronal (12.66 MPa) and middle (11.63 MPa) root regions indicated a significantly higher bond strength compared with the apical (9.16 MPa) region (p<0.05). Conclusions: Irrigant activation methods did not increase the bond strength of fiber post to canal.

Effects of different etching methods and bonding procedures on shear bond strength of orthodontic metal brackets applied to different CAD/CAM ceramic materials.

OBJECTIVE: To investigate the shear bond strength (SBS) of orthodontic metal brackets applied to different types of ceramic surfaces treated with different etching procedures and bonding agents. MATERIALS AND METHODS: Monolithic CAD/CAM ceramic specimens (N = 120; n = 40 each group) of feldspathic ceramic Vita Mark II, resin nanoceramic Lava Ultimate, and hybrid ceramic Vita Enamic were fabricated (14 × 12 × 3 mm). Ceramic specimens were separated into four subgroups (n = 10) according to type of surface treatment and bonding onto the ceramic surface. Within each group, four subgroups were prepared by phosphoric acid, hydrofluoric acid, Transbond XT primer, and Clearfill Ceramic primer. Mandibular central incisor metal brackets were bonded with light-cure composite. The SBS data were analyzed using three-way analysis of variance (ANOVA) and Tukey HSD tests. RESULTS: The highest SBS was found in the Vita Enamic group, which is a hybrid ceramic, etched with hydrofluoric acid and applied Transbond XT Adhesive primer (7.28 ± 2.49 MPa). The lowest SBS was found in the Lava Ultimate group, which is a resin nano-ceramic etched with hydrofluoric acid and applied Clearfill ceramic primer (2.20 ± 1.21 MPa). CONCLUSIONS: CAD/CAM material types and bonding procedures affected bond strength ( P < .05), but the etching procedure did not ( P > .05). The use of Transbond XT as a primer bonding agent resulted in higher SBS.

Spectrophotometric Evaluation of Crown Fragment a Year After Reattachment Using Fiber-Reinforced Post: A Case Report.

BACKGROUND: Crown fracture is the most common type of fracture and frequently affects the anterior teeth. Crown fractures have been treated in several ways depending on the location and kind of fracture. This case emphasizes reattachment of fractured fragments using fiber-reinforced post. Also this case report underlines the related aesthetic concerns of reattaching of the fractured fragment. CASE REPORT: Intraorally, examination revealed a complicated crown-root fracture of the left maxillary central (#21) and lateral incisor (#22). Moreover, the incisal one-third of the right maxillary central incisor (#11) was fractured. Baseline color of the tooth was recorded with a spectrophotometer to compare final color of tooth treated with fiber post. The root canal of 21 and 22 was filled with a sealer and gutta-percha. Then, the fiber-reinforced post was placed into the canals, and fractured segments were bonded with self-adhesive resin cement. Direct composite resin restoration was applied to 11. A year later, a second color measurement was recorded, and color differences (ΔE) were calculated. RESULT: In 12 months' follow-up, 11, 21 and 22 were asymptomatic with satisfying aesthetics, maxillar right incisor was vital. When crown discoloration was examined, there was clinically perceptible but acceptable discoloration without periapical pathology. CONCLUSION: Fiber reinforced post empowers not only the protection and reinforcement of tooth structure but also provides esthetic restoration.

Comparative assessments, meta-analysis, and recommended guidelines for reporting studies on histomorphometric bone-implant contact in humans.

PURPOSE: To evaluate factors that have an influence on histomorphometric bone-to-implant contact (BIC) of dental implants in humans. MATERIALS AND METHODS: Using inclusion/exclusion criteria, eligible studies were searched in five databases and handsearched in 11 journals. A total of 351 articles were assigned to full text analysis. The extracted data were assigned to comparative statistical assessments and meta-analysis. RESULTS: A total of 55 articles were included in the analysis. The mean BIC found in comparative assessments and meta-analysis of implants in the mandible (70.97 and 69.744 ± 3.304, respectively) was higher than those in the maxilla (53.24 and 56.692 ± 3.598; P = .000 and P = .008, respectively). The mean BIC in the anterior mandible (79.42) and maxilla (74.19) were higher than the posterior mandible (69.14) and maxilla (36.68) (P < .05). Differences were detected in BIC of commercially available implants and experimental micro-implants (P < .05). Comparative assessments and meta-analysis showed that conventionally loaded implants (75.70 and 75.786 ± 4.889, respectively) had higher BIC than unloaded (54.07 and 53.24 ± 4.971, respectively) and immediately loaded implants (58.53 and 68.831 ± 4.972; P = .000 and P = .004, respectively). CONCLUSIONS: Based upon a meta-analysis of the literature the following conclusions can be made: The BIC in the mandible is higher than the maxilla. The BIC is higher in the anterior than the posterior regions. The implant design coupled with the anatomical region affects the amount of BIC. Placement of experimental micro-implants with different surfaces in the posterior region always result in low and almost comparable BIC. The loading state and healing period seems to have an influence on BIC. Specific reporting guidelines are required to improve reporting of studies on human BIC.