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Purpose: To describe a digital workflow for the management of the emergence profile and the restoration's finishing line on vertically prepared teeth using a digital data set. Materials and Methods: Three scans (the prepared teeth the day of the preparation, the provisional restoration placed on the preparation after soft tissue maturation, and the provisional restoration outside of the oral cavity) were combined under a common data set to provide the necessary information to design the final restoration. Results: The digital technique presented can facilitate the implementation of the vertical preparation, because the desired finish line can be defined by the clinician and be transferred predictably to the dental lab. The current approach provides an alternative gingival management method, taking advantage of the displacement of soft tissue after vertical preparation. Conclusions: Positioning of the final finishing line on vertically prepared teeth, management of soft tissue, and fabrication of the final restoration can be facilitated with this approach, combining a digital data set that has been obtained during a distinct phase of the treatment. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of a single infrapositioned ankylosed tooth or implant-supported restoration on smile esthetics. Materials and Methods: A series of 48 digitally modified images that simulated varying degrees of infraposition (from 0.25 to 2.0 mm, with a step of 0.25 mm) were created for each maxillary anterior tooth by altering the full-portrait image of a smiling man, adjusted to show medium and high smile lines. For the model with the high smile line, a series of 24 digitally modified images were created that simulated the infraposition of a single anterior tooth with a restored incisal edge. Smile esthetics for each of the images were evaluated by 160 participants (80 dentists and 80 laypersons), and a visual analog scale (VAS) was implemented. Results: For the images with the high smile line, an infraposition of ≥ 0.25 mm in the central incisor region and ≥ 0.5 mm in the region of the lateral incisor or the canine had a negative effect on the perceived smile esthetics for both the dentists and the laypersons. Regarding the medium smile line, an infraposition of ≥ 0.5 mm in the central and lateral incisor region had a negative effect on the perceived smile esthetics for both groups of observers. In the canine area, an infraposition of ≥ 0.5 mm for the dentists and ≥ 0.75 mm for the laypersons also had a negative impact on the smile esthetics. Conclusions: Even a minor infraposition of a single maxillary anterior ankylosed tooth or implant-supported restoration can reduce the perceived attractiveness of the smile. Infraposition in the canine site can be better tolerated in a medium smile line compared to a high smile line. In patients with a high smile line, prosthetic intervention is needed to restore the incisal edge of an infrapositioned tooth without harmonizing the gingival contour; this can be beneficial for the lateral incisor but ineffective for the central incisor and unfavorable for the canine. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the dimensional discrepancy between the diagnostic wax-up and the resulting mockup. Material and Methods: A maxillary model with misaligned teeth was scanned, and an initial cast was 3D printed. A total of 60 identical casts were 3D printed from the initial one after scanning. Based on a digital additive veneer wax-up on the six anterior teeth, 10 more casts were 3D printed. The specimens were allocated to seven groups (n = 10) as follows--group 1: transparent silicone matrix with a flowable light-cured composite resin; group 2: same as group 1 but with the addition of a prefabricated transparent tray; group 3: silicone impression putty (65 Shore A) and light-body silicone impression material with a dual-cured bisacryl resin; group 4: same as group 3 but without the light-body silicone; group 5: silicone laboratory putty (92 Shore A) with a dual-cured bisacryl resin; group 6: silicone laboratory putty (92 Shore A) with PMMA; group 7: wax-up casts (control). Scans from the mock-ups were coregistered, segmented, and superimposed with the scans from the wax-up. The difference between the mock-up and the wax-up was quantified by morphologic operations. Results were analyzed by Kruskal-Wallis test and Dunn post hoc test (P < .05). Results: All mock-ups were larger than the wax-up. Significant differences were found for every labial surface third. The incisal third was the least accurate third while the middle third the most accurate. The most accurate were groups 2 and 5, and the largest discrepancy was observed in group 6. Conclusions: The analog mock-up differs dimensionally from the wax-up, regardless of the technique/materials used. [ABSTRACT FROM AUTHOR]

(1) Background: Cementation of glass fiber posts to root canals has been associated with various failures, especially debonding. This narrative review aims to present the contemporary concepts concerning the adhesive cementation of glass fiber post and to discuss the optimal management of these factors. (2) Methods: Electronic search was performed in MEDLINE/Pub Med and Google Scholar using selected keywords examining the parameters post length, surface treatment of glass fiber posts, post space preparation and dentin pretreatment, resin cement selection, adhesive systems and hybrid layer formation, and clinical techniques. (3) Results: The search led to the selection of 44 articles. Epoxy resin-based endodontic sealers are recommended and the use of temporary cement in the root canal should be avoided. The minimum length of a glass fiber post adhesively cemented to a root canal is 5 mm. Irrigating the root canals with chlorhexidine, MTAD, or EDTA (alone or in combination with NaOCl) after post space preparation seems to enhance the bond strength. Silane application on the surface of the post seems to be beneficial. Concerning resin cements and adhesive systems, the results were rather inconclusive. Finally, resin cement should be applied inside the root canal with an elongation tip and photoactivation should be delayed. (4) Conclusions: Contemporary concepts of adhesive cementation of glass fiber posts can indeed improve the bond between glass fiber posts, resin cement, and root canal dentin, however, evidence coming from long-term randomized prospective clinical trials is needed in order to obtain safer conclusions. [ABSTRACT FROM AUTHOR]

Purpose: The objective of the present article was to evaluate the ımpact of dental midline angulation in asymmetrical faces. Materials and Methods: A full‐portrait image was used to create a set of digitally modified images with a different degree of facial asymmetry, towards the right and the left side of the face respectively. Half of the images were designed with an equivalent angulation of the dental midline in respect to the curve of the lower third of the face and half of them without. Through a web survey, 250 laypeople and 250 orthodontists were asked to assess the attractiveness of each image separately. Results: As the asymmetry of the face was increased, facial attractiveness was further decreased both for laypersons and orthodontists. For each one of the modified images, when the dental midline was following the curve that was formed from the inclination of the simulated asymmetry of the face, the smile attractiveness scores were significantly higher compared to a straight dental midline. Conclusion: Facial asymmetries derived from the inclination of the nose, the chin and the commissural line of the lips can significantly affect the smile attractiveness. An orientation of the dental midline towards the facial asymmetry in order to follow the facial curve, can be beneficial for the smile attractiveness compared to a perpendicular to the face dental midline. During the design of a smile, clinicians have to take into consideration deviations in facial midline, in order their restorations to be in harmony with the rest of the face. Clinical Significance: During the design of a smile, clinicians have to take into consideration deviations in the facial midline, in order their restorations to be in harmony with the rest of the face. [ABSTRACT FROM AUTHOR]

Aim: To describe a digital workflow utilizing 3D printing technology to guide esthetic crown lengthening and control tooth preparation. Clinical considerations: After the initial intraoral and face scans, an esthetic treatment plan was performed digitally based on the patient's personality and face type using artificial intelligence-based 3D smile design software. A 3D-printed tray relined with silicone over a 3D-printed model was used for the mock-up. A 3D-printed guide was implemented to assist esthetic crown lengthening by incorporating, simultaneously, information about the desired free gingival line and the alveolar bone level. Based on the initial planning, a set of reduction guides was 3D printed to check and correct the tooth preparation. Prior to the start of construction of the final monolithic restorations, their design was verified using 3D-printed prototypes. A stabilization splint was digitally designed and 3D printed to protect and maintain the final result. Conclusions: Technologic advances can improve the predictability of an interdisciplinary esthetic approach. Digital planning can be transferred to clinical reality using a digital workflow, utilizing a set of appropriate 3D-printed guides, which can help to control clinical procedures based on the initial planning. Clinical significance: By following the proposed step-by-step workflow, clinicians can achieve predictable results through an interdisciplinary approach, guiding both the periodontal plastic surgery and the restorative treatment after an individualized CAD/CAD procedure for 3D-printed guides. (Int J Esthet Dent 2023;18:330-344) [ABSTRACT FROM AUTHOR]

Objective: Define the color of anterior teeth of a selected population and correlate it (by using coverage error [CE] and the frequency of best match) with the final color of all possible enamel‐dentine combinations of three different resin composite systems. Materials and methods: Color of 636 vital unrestored anterior teeth (central incisors, lateral incisors and canines; n = 212) and disk specimens (12 mm diameter, varying thickness) corresponding to enamel‐dentin combinations of all available enamel (0.5 mm and 1.0 mm thickness) and dentin shades (3.0 mm thickness) of Essentia, Enamel Plus HRi and IPS Empress Direct composite systems was measured using a clinical dental spectrophotometer (Spectroshade Micro). CE and frequency of best match for all composite systems were calculated for the measured in‐vivo teeth color space. Results: Natural in‐vivo teeth exhibit higher lightness when compared to enamel‐dentin composite combinations, independently of the enamel thickness used. The best (lowest) CE was found for IPS Empress, while the highest values were found for Enamel Plus Hri independently of tooth type and enamel thickness (p < 0.001). The use of 0.5 mm instead of 1.0 mm enamel thickness within enamel‐dentin composite combinations resulted in a lower CE for in‐vivo tooth color (p < 0.001). Conclusions: The color space defined by all possible enamel‐dentin combinations of the studied resin composite systems does not fully match the color range of anterior teeth. All composite systems examined lack combinations with lightness values as high as the population's. IPS Empress Direct composite system represented better the in‐vivo teeth color. Clinical significance: The use of 0.5 mm enamel shade thickness is suggested when building layered restorations, as it provided better color coverage than using 1.0 mm thickness. [ABSTRACT FROM AUTHOR]

Fusion is a developmental disturbance of dental hard tissues resulting from the union of two adjacent tooth germs. This report discusses the multi-disciplinary management of a maxillary central incisor fused with a supernumerary tooth with apical periodontitis and a fractured crown. Non-surgical root canal treatment using a mineral trioxide aggregate (MTA) plug as an apical seal was performed on the fused teeth followed by aesthetic restoration with glass fibre posts and composite resin. The patient remained asymptomatic and the periapical pathosis completely healed 1 year later. The aim of this article is to describe the diagnostic process and the significance of it is the final outcome and the clinical problems faced during the management of this case. Its early and accurate diagnosis is pivotal for successful root canal treatment. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the influence of lightness difference of a single anterior maxillary tooth on difference smile attractiveness. Methods: A frontal view full‐portrait image of a smiling male Caucasian, was digitally modified altering a single tooth, creating a series of images with varying lightness (ΔL) for the maxillary central, lateral and canine. A total of 160 participants (80 dentists, 80 laypersons) were asked to fill out a Visual Analog Scale questionnaire for every image recording smile attractiveness. Results: For central incisors ΔL≥1 negatively affected attractiveness. There was a higher tolerance for lightness mismatch when one lateral incisor is lighter and the same applies when the canine was darker. Difference in lightness affected smile attractiveness both for dentists and laypersons. No difference between males and females was observed for the dentists. For laypersons, females perceived smiles with lightness difference as significantly less attractive compared to males. Dentist's age did not affect smile attractiveness perception. Younger laypersons perceived darker color, as less attractive. Conclusions: Changes in lightness of a single anterior tooth significantly affected smile attractiveness in a different way for the central vs lateral vs canine. For the dentists, age and gender did not significantly affect smile perception, in contrast to laypeople. Clinical significance: Lightness differences of a single anterior tooth affects smile attractiveness. [ABSTRACT FROM AUTHOR]

Objective: To investigate the color difference using both ΔE*ab and CIEDE2000 formulas of all combinations of all enamel and dentin shades of three different composite systems with three different shade guides, to compare the coverage error (CE) of the shade guides for each composite and to investigate whether coverage error is affected by enamel shade layer thickness (0.5 vs 1 mm). Materials and Methods: Disk specimens from all enamel and dentin shades of Essentia, Enamel Plus HRi, and IPS Empress Direct composites were fabricated. Color measurements were performed for all enamel‐dentin combinations and for two thicknesses per enamel shade: 0.5 and 1 mm. Color was measured for three shade guides: Vitapan Classical, 3DMaster, and Ivoclar. Minimum color difference between layered composites and shade tabs, closest shade tab match and CE of all shade guides were calculated for all composite shade combinations. Results: In most cases, the closest match was a mismatch. CE of 3DMaster was significantly lower for IPS Empress Direct and Enamel Plus HRi at 0.5 mm enamel thickness. Shade guides exhibited higher lightness values compared to composites and composites lower chroma values compared to shade guides. Conclusions: Shade guides do not match well to the layered composites. 3DMaster performed better than the other two shade guides, in most cases. [ABSTRACT FROM AUTHOR]

This investigation studied the metal ceramic interface for two representative high-palladium alloys each of the Pd-Cu-Ga and Pd-Ga systems, using scanning electron microscopy and x-ray energy dispersive spectroscopy. The Pd-Cu-Ga alloys produced complex subsurface oxidation regions with thicknesses ranging from 15 to 20 μm for one alloy and 5 to 10 μm for the other alloy. Ga, In, and Sn accumulated at the interfaces, and Ga-rich deposits were found in the subsurface scale. One Pd-Ga alloy presented a surface oxidation region which dissolved in the ceramic, producing "islands" rich in Pd and Ga with a width that ranged from ito 2 μm. These islands were separated from the alloy by a band rich in Ga and Si which was 1 to 2.5 μm thick. While the other Pd-Ga alloy presented similar interfacial microstructures, the "islands" formed for this alloy were relatively sparse. The Pd-Cu-Ga alloys had a more favorable interface for metal ceramic bonding, which agrees with previous characterization of bond failures between these alloys and dental porcelain. [ABSTRACT FROM AUTHOR]

A quantitative measure of implant stability would be beneficial to decision-making regarding the status of the bone anchorage around an implant. The Periotest device has been reported to provide such a measure, but the in vivo data are incomplete and inconclusive in support of this claim. The purpose of this study was to determine in an in vivo model the relationship between Periotest values (PTV), three different implant biomaterials, and torque to failure. A total of 79 screw-shape implants made of commercially pure titanium, titanium alloy, and HA coated alloy were evaluated in the posterior maxillary and mandibular quadrants of six female baboons following healing for 3 to 4 months. At uncovering, the implants were tested with the Periotest device and torqued to failure using an electronic torque driver. Analysis of the PTV-biomaterial relationship revealed no significant difference among the implants based on the biomaterial (P = .7453). Analysis of PTV-torque revealed a significant relationship (P = .0117), however, the association between PTV and torque was not strong and does not explain 92% of the variation between the parameters (Pearson correlation .2823, R² = .08). [ABSTRACT FROM AUTHOR]

Torque failure for endosseous implants has been used as a biomechanical measure of anchorage, though the significance of such data is not known. A practical understanding of the resistance to torque failure of implant-tissue interfaces at stage 2 surgery would help in assigning torque levels for implant abutment-screw fastening. The purpose of this study was to measure torque failure levels of commercially pure (CP) titanium, Ti-6Al-4V, hydroxyapatite-coated (HA-coated) screw-shaped implants placed into the maxillae and mandibles of baboons. Implants identical in size were placed into the edentulous posterior maxillae and mandibles of six female baboons (n = 37 each group) using a standardized surgical protocol. Reverse-torque data were collected at postinsertion time intervals ranging from 3 to 4 months using a counterclockwise torque driver and the data were analyzed (repeated measures ANOVA) for torque differences related to time, biomaterial, and jaw. The HA-coated implants exhibited significantly greater torque-removal values compared to both metallic implants (HA: 186.0 Ncm [50.1]; Ti-6Al-4V: 78.6 Ncm [18.1]; CP Ti 74.0 Ncm [24.4]). Analysis of torque interactions with jaw showed no significant difference; however, the mandible was found to be greater than the maxilla in torque resistance for all groups tested. Understanding the risks in inferring animal data to human application, the clinical implications of these data suggest that the recommended torque level of 35 Ncm for abutment fastening may provide a margin of safety for most implants of similar design and material as used in this study. The range of data suggests that 1 in 20 metallic implants may fall below this torque-fastening level. [ABSTRACT FROM AUTHOR]

Purpose: The influence of the curing mode (dual vs light) and of the photopolymerization through ceramic or resin composite on the degree of remaining carbon bonds was investigated via infrared spectroscopic analysis for 1 resin cement (Calibra, Caulk/Dentsply). Materials and Methods: The 0.5-mm cement layer was photopolymerized for 40 s through the 2-mm-thick ceramic Empress 2 (Ivoclar) and Vitadur Alpha (Vident) and the laboratory-processed resin composite Sinfony (3M/ESPE). Results: The dual-cured system polymerized better than the light mode. Photopolymerization of the resin cement through the translucent materials reduced its curing efficiency in both curing modes. The resin composite induced a more negative effect than the 2 ceramics tested. Conclusion:The curing mode and photopolymerization of dual-cured resin cements through esthetic restorative materials affects the degree of remaining double carbon bonds. [ABSTRACT FROM AUTHOR]

Objective: To assess the esthetic effectiveness of four illusion techniques applied to a composite resin veneer for diastema closure between maxillary central incisors. Materials and methods: An acrylic model with six natural maxillary anterior teeth was fabricated with a 2-mm diastema between the central incisors. Resin veneers were constructed on the left central incisor and the following cases were derived: V0: no veneer; V1: veneer without optical illusion features; V2: veneer with centralized interproximal ridges; V3: veneer with curved incisal edges; V4: veneer with gray pigment mesially/distally; V5: veneer with gray pigment on the developmental lobes. Digital printed photos of the models (13.2 × 17.8 cm, and 6.1 × 8 cm), with low, medium, and high smile lines and without a smile line (processed by Adobe Photoshop CS6) were shown to three groups of people (faculty members, senior undergraduate students, and patients; n = 25/group) for them to assess the overall size and width of the two central incisors. The results were analyzed by Pearson's and chi-square goodness of fit tests. Results: There was no significant influence in the estimation of the two central incisors as being the same size, according to the technique used (P = 0.869) and group of evaluators (P = 0.209). The estimated probability of assessing the tested incisor as wider was indicatively lower in V2 compared to V1 (adjusted odds ratio = 0.59; P = 0.088). The height of the smile line affected the evaluation of the veneers only in the large-sized photos. Conclusions: No interference is the best esthetic decision concerning a 2-mm diastema closure when restoring only one central incisor with a laminate veneer. The next best option is to deliver a veneer with centralized interproximal ridges. [ABSTRACT FROM AUTHOR]

Purpose: To assess the repeatability and accuracy of three dental color-matching devices under standardized and freehand measurement conditions. Materials and methods: Two shade guides (Vita Classical A1-D4, Vita; and Vita Toothguide 3D-Master, Vita), and three color-matching devices (Easyshade, Vita; SpectroShade, MHT Optic Research; and ShadeVision, X-Rite) were used. Five shade tabs were selected from the Vita Classical A1-D4 (A2, A3.5, B1, C4, D3), and five from the Vita Toothguide 3D-Master (1M1, 2R1.5, 3M2, 4L2.5, 5M3) shade guides. Each shade tab was recorded 15 continuous, repeated times with each device under two different measurement conditions (standardized, and freehand). Both qualitative (color shade) and quantitative (L, a, and b) color characteristics were recorded. The color difference (▵ E) of each recorded value with the known values of the shade tab was calculated. The repeatability of each device was evaluated by the coefficient of variance. The accuracy of each device was determined by comparing the recorded values with the known values of the reference shade tab (one sample t test; á = 0.05). The agreement between the recorded shade and the reference shade tab was calculated. The influence of the parameters (devices and conditions) on the parameter ▵ E was investigated (two-way ANOVA). Comparison of the devices was performed with Bonferroni pairwise post-hoc analysis. Results: Under standardized conditions, repeatability of all three devices was very good, except for ShadeVision with Vita Classical A1-D4. Accuracy ranged from good to fair, depending on the device and the shade guide. Under freehand conditions, repeatability and accuracy for Easyshade and ShadeVision were negatively influenced, but not for SpectroShade, regardless of the shade guide. Conclusion: Based on the total of the color parameters assessed per device, SpectroShade was the most reliable of the three color-matching devices studied. [ABSTRACT FROM AUTHOR]

Objectives: To compare color and translucency changes after light curing and finishing in various shades of five contemporary resin composites. Methods: Light and dark (A1 & A4 or equivalents), enamel (e) and dentin (d), shades were selected from the resin composites Enamel Plus HRi (Micerium), Miris 2 (Coltene), IPS Empress Direct (Ivoclar), Filtek Supreme (3M ESPE) and TPH Spectum (Densply). Ten disc-shaped samples (depth = 10 mm, thickness = 1 mm) per material and shade were fabricated. Three colorimetric readings, over white and black background, according to the CIELab system were taken before and after light polymerization and after finishing with wet carbide papers. Color (▵ E) and translucency (▵ TP) differences were calculated. Results were analyzed by ANOVA, post-hoc Scheffe's test and linear regression analysis. Results: Polymerization provided a wide range of color change, ranging from 1.36 (Hri/UD1) to 8.07 (Miris/WB). Translucency increased in all groups, except Miris/NT. Translucency change varied from -0.4 (Miris/NT) to 8.88 (Hri/UE3). After finishing, ▵ E ranged from 0.58 (Hri/ UD4) to 3.41 (Miris/NT). ▵ E was significantly positively correlated with ▵ L, ▵ b after curing and with ▵ L, ▵ a, ▵ TP after finishing. Conclusions: Polymerization caused remarkable color and translucency changes, which were product and shade dependent. Thirteen out of 18 of the tested resin composites exhibited clinically perceptible (▵ E>2.6) color change after light curing and 2 out of 18 after finishing. Clinical significance: Shade matching with non-polymerized resin composite may be erroneous. [ABSTRACT FROM AUTHOR]