Smile Design

Journal of Prosthodontics

Sadid‐Zadeh

Watanabe

et al. 2023

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PurposeThis study aimed to assess the fracture resistance of monolithic zirconia‐reinforced lithium silicate laminate veneers (LVs) fabricated on various incisal preparation designs.Materials and methodsSixty maxillary central incisors with various preparation designs were 3D‐printed, 15 each, including preparation for: (1) LV with feathered‐edge design; (2) LV with butt‐joint design; (3) LV with palatal chamfer; and (4) full‐coverage crown. Restorations were then designed and manufactured from zirconia‐reinforced lithium silicate (ZLS) following the contour of a pre‐operation scan. Restorations were bonded to the assigned preparation using resin cement and following the manufacturer's instructions. Specimens were then subjected to 10,000 thermocycles at 5 to 55°C with a dwell time of 30 s. The fracture strength of specimens was then assessed using a universal testing machine at a crosshead speed of 1.0 mm/min. One‐way ANOVA and Bonferroni correction multiple comparisons were used to assess the fracture strength differences between the test groups (α = 0.001). Descriptive fractographic analysis of specimens was carried out with scanning electron microscopy images.ResultsComplete coverage crown and LV with palatal chamfer design had the highest fracture resistance values (781.4 ± 151.4 and 618.2 ± 112.6 N, respectively). Single crown and LV with palatal chamfer had no significant difference in fracture strength (p > 05). LV with feathered‐edge and butt‐joint designs provided significantly (p < 05) lower fracture resistance than complete coverage crown and LV with palatal chamfer design.ConclusionThe fracture resistance of chairside milled ZLS veneers was significantly influenced by the incisal preparation designs tested. Within the limitation of this study, when excessive occlusal forces are expected, LV with palatal chamfer display is the most conservative method of fabricating an indirect restoration.

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Effect of incisal preparation design on the fracture strength of monolithic zirconia‐reinforced lithium silicate laminate veneers

Journal of Prosthodontics

Sadid‐Zadeh

Watanabe

et al. 2023

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“…Visual assessment of tooth translucency may sound like a simple procedure. However, this technique is subjective and has several external factors that can misguide the result, such as the ambient light, the distance between the shade guide and the tooth, and the operators’ experience and sex 19–23 . Spectrophotometers are digital devices that analyze optical properties such as tooth translucency and dental restorations 24 .…”

Section: Discussionmentioning

confidence: 99%

“…However, this technique is subjective and has several external factors that can misguide the result, such as the ambient light, the distance between the shade guide and the tooth, and the operators' experience and sex. [19][20][21][22][23] Spectrophotometers are digital devices that analyze optical properties such as tooth translucency and dental restorations. 24 The present study used a SpectroShade Micro II (SpectroShade USA) to map the surface translucency.…”

Section: Discussionmentioning

confidence: 99%

Effect of sintering on the translucency of CAD–CAM lithium disilicate restorations: A comparative in vitro study

Journal of Prosthodontics

Afrashtehfar

Hyer

et al. 2023

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PurposeThe available independent data on the translucency of novel pre and fully sintered chairside computer‐aided design and computer‐aided manufacturing (CAD–CAM) lithium disilicate are limited. This comparative in vitro study evaluated the translucency degree of pre and fully sintered chairside CAD–CAM lithium disilicate crowns after optional, required, and additional firing processes.Materials and methodsOne hundred and five maxillary left central incisor crowns manufactured by three different CAD–CAM lithium disilicate brands shade A1 were assigned into seven groups as follows (n = 15): (1) Straumann n!ce without sintering; (2) Straumann n!ce with one additional sintering process; (3) Straumann n!ce with two additional sintering processes; (4) Amber Mill with one sintering process; (5) Amber Mill with two sintering processes; (6) IPS e.max CAD with one sintering process; and (7) IPS e.max CAD with two sintering processes. The translucency of all crowns was evaluated with a color imaging spectrophotometer. All statistical analyses were performed using statistical software. A standard level of significance was set at α < 0.05.ResultsAll the milled crowns presented different degrees of translucency, and additional sintering processes altered it. IPS e.max CAD with two (4.33 ± 0.26) and one (4.01 ± 0.15) sintering processes displayed the highest translucency, whereas Straumann n!ce with no sintering process provided the lowest value (2.82 ± 0.16).ConclusionsThe translucency of chairside lithium disilicate single‐unit full‐coverage restorations manufactured with subtractive technology was significantly influenced by the brand and the number of sintering processes. The traditional presintered IPS e.max CAD and the fully crystallized glass–ceramic Straumann n!ce considerably increased the translucency after one additional firing process, whereas Amber Mill decreased its translucency.

“…Dental esthetic treatment is a rapidly growing field, with patients increasingly seeking procedures to enhance their smile’s appearance. Maxillary teeth size, shape, and spacing are essential in dental and facial esthetics [ 5 ]. Among these teeth, the maxillary central incisors are particularly important.…”

Section: Introductionmentioning

confidence: 99%

Minimally Invasive Laminate Veneer Therapy for Maxillary Central Incisors

Guzman-Perez¹,

Azpiazu‐Flores

et al. 2023

Medicina

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Minimally invasive dentistry is a considered process that requires the clinician to be prepared with the ideal sequence and the tools needed. This report describes a well-planned ultraconservative approach using only two ceramic laminate veneers for the maxillary central incisors to significantly improve the patient’s overall smile. A 30-year-old female presented with the chief complaints of having diastemas between the central and lateral incisors as well as incisal wear. Diagnostic wax-up and mock-up were performed, and the patient approved the minimally invasive treatment with veneers only for central incisors. A reduction guide aided the conservative tooth preparations, and hand-crafted feldspathic veneers were bonded under total isolation with a rubber dam. The two final conservative veneers significantly improved the smile and fulfilled the patient’s expectations. Following proper planning and sequencing, predictable outcomes were obtained and fulfilled the patient’s esthetic demands. Minimally invasive restorative dentistry with only two single veneers can impact the entire smile frame. Overtreatment in the esthetic zone is unnecessary to meet a patient’s esthetic expectations.