Is It Necessary to Photoactivate the Adhesive System Inside Ceramic Laminate Veneers in a Luting Procedure?

PURPOSE

To investigate the need for photoactivation of the adhesive system inside ceramic laminates before the luting procedure and to evaluate the color stability, nanohardness, and elastic modulus of the adhesive interface activated with singlewave and polywave light-curing units.

MATERIALS AND METHODS

A total of 44 lithium disilicate ceramic veneers (7.0 mm × 8.0 mm × 0.6 mm) were fabricated, bonded to enamel, and sorted into four experimental groups (n = 11 each) according to the type of light-curing unit (Radii-Cal [singlewave] or Valo [polywave]) and mode of adhesive system activation (with or without previous photoactivation). Two luting agents were used: the Tetric N-Bond adhesive system and Variolink Veneer resin cement. A visible ultraviolet spectrophotometer was used to evaluate the color stability before and after UVB artificial accelerated aging for 252, 504, and 756 hours (n = 8 samples from each group). A nanohardness tester under a load of 1,000 μN was used to evaluate the nanohardness and elastic modulus (n = 3 samples from each group). Data regarding the color stability and the mechanical properties (nanohardness and elastic modulus) were subjected to analysis of variance and Tukey protected least significant difference test (α = .05).

RESULTS

Prior activation of the adhesive system, the distinct light-curing units, and different aging periods exerted no significant difference on the color stability or mechanical properties of the resin cement (P > .05), except for in the group activated with Radii-Cal after 756 hours, in which the nonprevious activation showed lower color alteration compared to the previous photoactivation (P = .0285). Without prior activation of the adhesive with Valo, the polywave unit promoted higher nanohardness and elastic modulus values in the adhesive system (P < .05).

CONCLUSION

In general, singlewave and polywave light-curing units promoted no difference in color stability or the mechanical properties of the adhesive interface. The prior curing of an adhesive system inside ceramic laminate is not necessary.

Direct or Indirect Restoration of Endodontically Treated Maxillary Central Incisors with Class III Defects? Composite vs Veneer or Crown Restoration

PURPOSE

The aim of this ex-vivo study was to evaluate the load capacity of direct or indirect endodontically restored maxillary central incisors with Class III defects, with or without glass-fiber posts.

MATERIALS AND METHODS

Seventy-two extracted human maxillary central incisors were endodontically treated and bi-proximal Class III cavities were prepared. Specimens were randomly allocated to six groups (n = 12): direct restoration with composite (C); direct restoration with composite and additional glass-fiber post (CP); ceramic veneer restoration (V), ceramic veneer restoration and additional glass-fiber post (VP), ceramic crown restoration (Cr), ceramic crown restoration and additional glass-fiber post (CrP). Specimens were exposed to thermomechanical loading (TML: 1.2 million cycles, 1 to 50 N; 6000 thermal cycles between 5°C and 55°C for 1 min each), and subsequently linearly loaded until failure (Fmax [N]) at an angle of 135 degrees 3 mm below the incisal edge on the palatal side. Statistical tests were performed using the Kruskall-Wallis and Mann-Whitney U-Test.

RESULTS

During dynamic loading by TML, one early failure occurred in group C, CP, and CrP. Subsequent linear loading resulted in mean fracture load values [N] of C = 483 ± 219, CP = 536 ± 281, V = 908 ± 293, VP = 775 ± 333, Cr = 549 ± 258, CrP = 593 ± 259. The Kruskal-Wallis test showed significant differences of load capacity between groups (p < 0.05). Mann-Whitney U-test revealed significantly lower maximum fracture load values of group C compared to group V (p = 0.014), after Bonferroni-Holm correction. Non-restorable root fracture was the most frequent type of failure.

CONCLUSION

Endodontically treated maxillary central incisors with Class III defects directly restored with composite are as loadable as indirect crown restorations. Compared to full-coverage restorations, less invasive veneers appear to be more beneficial. Additional placement of glass-fiber posts shows no positive effect.

Color stability of ceramic veneers as a function of resin cement curing mode and shade: 3-year follow-up

The influence of curing mode and shade of resin cements on the color stability of minimum-thickness ceramic veneers after a three-year storage time in distilled water was evaluated in this study. Ninety-six 0.5-mm-thick feldspathic ceramic veneers (Mark II) were luted onto resin composite substrates (Filtek Z350 XT, shade A2E) with two light-cured (NX3 Light-cure and AllCem Veneer) and dual-cured resin cements (NX3 dual-cure and AllCem) in various shades. The specimens were stored in distilled water at 37°C. Color measurements were performed with a spectrophotometer at the following times: 1h and 24h; 7, 30, and 180 days; and 1, 2, and 3 years. Data for color difference (ΔE_ab) light-cured and dual-cured resin cements were analyzed by two-way ANOVA with repeated measures and Tukey’s test (α = 0.05). For the light-cured cements, the ΔE_ab values were as follows: NX3-Yellow (2.37±1.35) = ACV-A1 (2.40±1.21) = ACV-Trans (2.52±1.46) = ACV-E-Bleach M (2.56±1.42) = NX3-White (2.69±1.49) = NX3-Clear (2.98±1.68). The lowest ΔE values were found for 1 h (0.61±0.36)^a, followed by 24 h (1.15±0.55)^b and 30 days (2.48±1.11)^c. One year, 180 days, and 2 and 3 years presented higher ΔE_ab values (3.34±0.94, 3.52±1.04, 3.52±0.95 and 3.55±1.14, respectively)^d. For the dual-cured cements, the ΔE_ab values varied as follows: NX3-Clear (2.32±1.24)^a = NX3-Yellow (2.37±1.32)^a = NX3-White (2.76±1.43)^a < AC-Trans (3.77±1.91)^b = AC-A3 (4.13±2.11)^b < AC-A1 (5.38±2.92)^c. Considering time, the lowest ΔE_ab values were found for 1 h (0.48±0.25)^a, followed by 24 h (2.13 ±0.83)^b, 30 days (3.54±1.31)^c, and 180 days (3,70±1.73)^c. The follow-up times of 1 (4.43±2.15)^d, 2 (5.02±1.74)^e, and 3 years (4.90±2.12)^e presented higher ΔE_ab values. This study demonstrated that light-cured resin cements were less susceptible to color change than dual-cured cements. After 2 years of follow-up, all cements presented ΔE_ab values above the acceptability threshold.

Direct Composite Resin Veneers in Nonvital Teeth: A Still Viable Alternative to Mask Dark Substrates

Direct composite resin veneers are a practical esthetic restorative treatment for reestablishing the shape and color of affected anterior teeth. The present clinical case reports aim to describe restorative treatment techniques for nonvital anterior teeth presenting color alteration. The direct composite resin layering technique has proven to be an efficient method for recovering the esthetics of darkened teeth. The direct vs indirect restorative treatments are debated as well. Clinical follow-ups of the presented case reports demonstrate that direct composite resin restorations are not affected by the darkened tooth substrate over time.

Noninvasive interdisciplinary treatment of a dischromic partially worn dentition

According to the classic concepts of prosthodontics the treatment of a patient presenting severely worn and dischromic dentition would involve a complex and demolitive treatment including periodontal surgery, endodontic therapy, posts and cores, and crowns; nowadays these problems can be solved with noninvasive procedures that allow preservation of dental and periodontal tissues. This article describes the interdisciplinary team approach (orthodontist, dental technician, prosthodontist) for the treatment of a patient showing attrition of the mandibular incisors in a deep bite relationship, contraction of the posterior sextants of both arches, diastemas in the anterior region of the maxilla, and highly dischromic teeth. The gingival tissue levels and the tooth malposition were corrected by orthodontic therapy, the abraded and the healthy dischromic teeth were restored with 20 additional veneers (the molars were the only teeth not involved in the restorative phase); tooth structure, tooth vitality, and bone level were maintained. No provisional restorations were delivered and no anesthesia was necessary either for tooth preparation or final impression. A protocol is shown to treat in a conservative and comfortable manner the structural and esthetic problems in a patient presenting highly dischromic teeth, worn mandibular incisors, and diastemas on the maxillary sextant.

Merging Clear Aligner Therapy With Digital Smile Design to Maximize Esthetics and Minimize Tooth Reduction

Digital smile design (DSD) used in combination with an esthetic pre-evaluative temporary restoration is a reliable means of minimizing the removal of tooth structure when ceramic veneers are being placed. When patients present with poorly aligned teeth, the use of clear aligners may be considered to properly position the teeth based on the desired outcome. This article, which illustrates a method to systematically diagnose, plan, and stage treatment for a smile makeover, describes the merging of DSD with clear aligner therapy to enable clinicians to recognize digitally where to position the teeth using orthodontic movement. This approach allows the desired esthetic design to be attained while enabling minimal tooth reduction.

The decision-making process in interdisciplinary treatment: digital versus conventional approach. A case presentation

The digital technology can be a GPS in designing a multidisciplinary treatment that involves orthodontics and restorative dentistry. A proper hierarchy of decisions and responsibilities need to be defined. Form is everything but position and size. For this reason the orthodontist first needs to set up the proper occlusion deciding the position and the available size that will be necessary for the restorative dentist to obtain the proper form with a minimally invasive preparation. This case report illustrates with a step-by-step approach all the clinical issues of the treatment, from diagnosis to orthodontic guided position of Tads, materials of choice and laminate veneers realization passing through all the interactions between the dental team members explaining who does what and when and proposing a clear hierarchy of decision. A review of digital and classical possibilities for the realization of laminate veneers is proposed with its pros and cons.

Optimizing the composite resin stratification technique with prefabricated templates: a case report

Direct freehand veneers with composite resin (CR) require high clinician ability and a long chair time. Although CR restorations remain the most-used technique for meeting high esthetic demands, and new technologies mean that materials are nowadays more similar to tooth structure, layering techniques for natural results are still considered difficult to achieve. Through advances in adhesive dentistry, systems of prefabricated veneers using conventional techniques have been launched onto the market as an option for the clinician. This case report presents complete step-by-step descriptions of two techniques using prefabricated templates for directly built-up veneers. Both maxillary lateral incisors were simultaneously reconstructed with direct CR veneers with different layering techniques to achieve esthetic results in a shorter chair time. Simple stratification techniques using prefabricated templates may allow clinicians to optimize both time and clinical outcome while obtaining predictable results.

Current status of zirconia-based all-ceramic restorations fabricated by the digital veneering technique: a comprehensive review

OBJECTIVES

Delamination and chipping are major complications of veneering material on zirconia-based all-ceramic restorations. The digital veneering technique was introduced to overcome these complications as both zirconia frameworks and veneering ceramic are fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM). The aim of this review is to report all articles that evaluate zirconia-based all-ceramic restorations fabricated by the digital veneering technique. Three different digital veneering techniques were detected: the Lava DVS Digital Veneering System (3M ESPE), the Rapid Layer Technology (Vita Zahnfabrik), and the CAD-on technique (Ivoclar Vivadent). There are also some modifications of these techniques in the literature.

MATERIALS AND METHODS

For this review, a comprehensive literature search was conducted. Detected studies are reported according to fracture resistance, flexural strength, wear performance, shear bond strength, microtensile bond strength, mechanical performance of restorations on implant abutments, marginal fit, color reproducibility, and clinical success for all types of digital veneering techniques.

RESULTS AND CONCLUSIONS

Anatomical framework design and digital veneering using lithium disilicate and fusion porcelain might decrease the risk of chipping and delamination of veneering ceramic on zirconia-supported all-ceramic restorations. However, this result is mainly supported by in vitro studies. More clinical studies with a large sample size, longer follow-up period, and different fixed dental prosthesis designs are needed.

Effect of framework design and firing cycle on the success rate of bilayered zirconia crowns

OBJECTIVE

This study investigated the effect of framework design and modification of porcelain firing cycle on the occurrence of fractures of metal-ceramic and bilayered zirconia crowns after cyclic loading.

METHOD AND MATERIALS

Twenty-four zirconia crowns with two different apicocoronal incisal veneering porcelain lengths (ZS = 2.0 mm and ZL = 4.0 mm) were fabricated. Twenty-four metal-ceramic crowns with the same apicocoronal incisal veneering porcelain lengths (MS = 2.0 mm and ML = 4.0 mm) served as the control. All the specimens (n = 48) were thermally and mechanically cycle-loaded (49 N) for 1,200,000 cycles, and then evaluated for cracks and/or bulk fractures with an optical stereomicroscope (×10). In the second part of the study, the influence of firing cycle modification on the success rate of twenty-four bilayered zirconia crowns was also evaluated. Finally, two specimens from each group (n = 12) were sectioned and analyzed using a scanning electron microscope. Load-to-failure of the specimen that did not present bulk fracture was further assessed using a universal testing machine. Statistical analysis was performed with Fisher exact test and Kruskal-Wallis test.

RESULTS

A statistically significant lower occurrence of fractures (P < .05) was found after cyclic loading for bilayered zirconia versus metal-ceramic crowns. Modification of the firing cycle did not significantly influence the outcome after cyclic loading for zirconia bilayered crowns (P > .05).

CONCLUSION

Within the limitations of this study, porcelain-firing cycle with an extended cooling time did not appear to influence the occurrence of cracks and fractures of bilayered zirconia crowns.

Minimally invasive vertical preparation design for ceramic veneers: a multicenter retrospective follow-up clinical study of 265 lithium disilicate veneers

The esthetic treatment of the anterior teeth has always presented a challenge in clinical practice. With the improvement of dental materials, many restorative options such as resin composites, all-ceramic crowns, and ceramic veneers have become available. The current challenge in reconstructive dentistry is how to obtain excellent esthetic results while preserving the biological structures involved as much as possible. Thanks to the introduction of high-strength etchable dental ceramics, clinicians and technicians now have materials and procedures at their disposal that allow for the restoration of esthetics and function through a minimally invasive approach. New-generation, all-ceramic restorations and adhesive systems allow greater preservation of residual hard tooth structures, especially with regard to single elements.

PURPOSE

To evaluate the clinical performance of lithium disilicate (LiDiSi) veneers with a feather-edge finish line margin.

MATERIALS AND METHODS

A total of 265 LiDiSi veneers were cemented with resin cement after fluoridric acid and silane surface treatment and observed by different clinicians. These veneers were placed in 53 (32 female, 21 male) patients between October 2009 and April 2015, with a mean observation period of 54.4 months. Of these, 211 veneers were placed in the maxilla (77 central incisors, 65 lateral incisors, 49 canines, 12 first bicuspids, 5 second bicuspids, 2 first molars, 1 second molar), and 54 in the mandible (16 central incisors, 14 lateral incisors, 13 canines, 6 first bicuspids, 1 second bicuspid, 2 first molars, 2 second molars). The clinical evaluation used the modified California Dental Association (CDA) and Ryge criteria after recalling all patients between January and March 2017. The clinical parameters evaluated were color matching, quality of the ceramic surface, the presence of marginal discoloration, and marginal integrity. The data were analyzed through descriptive statistical analysis.

RESULTS

The clinical survival of the 265 veneers over the follow-up period was 99.63%. One restoration showed adhesive failure due to a traumatic event after 3 years of clinical service. The color matching parameter was classified as Alfa in 93.9% (248/265) and Bravo in 6.4% (17/265) of the restorations, with no Charlie or Delta ratings recorded. The ceramic surface was rated as Alfa in 97.7% (259/265) and Bravo in 2.2% (6/265), marginal discoloration as Alfa in 97.3% (257/265) and Bravo in 3% (8/265), and marginal integrity as Alfa in 96.9% (256/265) and Bravo in 3.4% (9/265) of the restorations.

CONCLUSION

In this retrospective analysis, LiDiSi veneers with a vertical finish line showed good clinical performance in terms of color matching, ceramic surface, marginal discoloration, and marginal integrity. Despite the present results, further clinical studies are needed in order to investigate the long-term performance of this type of restoration.

Tooth preparation for ceramic veneers: when less is more

Historically, preparations for ceramic veneers have varied from extremely aggressive to a minimal reduction or a lack of preparation. Today, we are moving toward minimally invasive dentistry with the philosophy that less is more. Less tooth reduction means more adhesion and clinical longevity. What must be considered when performing minimally invasive preparations is that in a significant number of cases the dental element will receive a veneer that will modify its final contour. This is quite common in cases of conoid teeth, diastemas or loss of dental structure by abrasion, erosion or attrition. The aim of this article is to present a step-by-step protocol to achieve conservative preparations for ceramic veneers, called the mock-up driven technique. This technique takes into account the final contour desired for the veneer, and results in considerably less invasive dental preparations.

Effects of Lithium and Phosphorus on the Efficacy of a Liner for Increasing the Shear Bond Strength Between Lithium Disilicate and Zirconia

PURPOSE

To evaluate the effect of the chemical formulation of liners on the shear bond strength (SBS) between lithium disilicate veneering ceramic and zirconia core.

MATERIALS AND METHODS

Four experimental groups (n = 12) were designed according to liner composition: negative control group (lithium and phosphorus removed from the conventional liner), Li group (lithium added to the negative control group), P group (phosphorus added to the negative control group), and Li+P group as the positive control (conventional liner). After applying the liner, lithium disilicate was pressed on zirconia. Specimens were stored in distilled water (37°C, 24 h) before testing the SBS. To test the SBS, shear force was applied perpendicular to the lithium disilicate-zirconia interface. The differences in the SBS between the veneer lithium disilicate and zirconia substructure were evaluated with one-way ANOVA (significance level of 0.05).

RESULTS

The presence or absence of lithium and phosphorus influenced the efficacy of the liner. The negative control and P groups showed mainly cohesive failures, and the Li group mainly showed mixed failures. Both adhesive and mixed failures were observed in the Li+P group. The groups including lithium showed significantly higher SBS than the negative control or Li+P group (p < 0.05). The group including phosphorus, which showed higher crystallinity, showed significantly lower SBS than the negative control and Li+P groups (p < 0.05).

CONCLUSIONS

The differences in the composition of the liner can affect the wettability and reactivity, and as a result, the SBS was different.

Evaluation of Adhesion Between Carbon Fiber Frameworks and Esthetic Veneering Materials

PURPOSE

To assess bond strength and failure patterns of carbon fiber-reinforced composite (CFRC) and veneering materials.

MATERIALS AND METHODS

A total of 20 samples were prepared: 10 veneered with polymethylmethacrylate (group A) and 10 with composite resin (group B). Shear bond strength (SBS) was measured, and failed samples were microscopically observed.

RESULTS

The mean ± standard deviation (SD) SBS of specimens in group A was slightly higher (7.39 ± 0.24 MPa) than specimens in group B (5.68 ± 0.29 MPa). Microscopic observation showed an adhesive fracture pattern at the CFRC-adhesive interface in both groups.

CONCLUSION

Adhesion between CFRC and veneering material is reliable and predictable, although a specific protocol needs to be developed to improve adhesion.

Randomized Controlled Clinical Trial of All-Ceramic Single-Tooth Implant Reconstructions Using Modified Zirconia Abutments: Results at 5 Years After Loading

The objective of this trial study was to assess whether submucosal veneering of internally connected zirconia abutments influences clinical, radiographic, and technical outcomes of single-tooth implant-borne reconstructions at 5 years after loading. A total of 20 patients with 20 single-tooth implants in the anterior or premolar area of the maxilla or mandible were included. The implants were randomly restored with fixed single-tooth reconstructions using either pink-veneered customized zirconia abutments (test group = 10) or nonveneered customized zirconia abutments (control group = 10). All reconstructions were adhesively cemented with all-ceramic crowns. Follow-up examinations were performed at baseline (7 to 10 days after crown insertion) and at 1, 3, and 5 years after loading, at which points the following were assessed: periodontal parameters such as probing depth (PD), bleeding on probing (BOP), and marginal bone levels, as well as technical outcomes using the modified United States Public Health Service (USPHS) criteria. Statistical comparisons were based on the Wilcoxon-Mann-Whitney test. Sixteen patients attended the 5-year follow-up. At 5 years, the implant survival rate was 100% and the prosthetic survival rate was 94.1% (one abutment fracture in the test group). Veneering of the submucosal part of zirconia abutments resulted in significantly higher mean PD values: 3.6 ± 0.4 mm (test group) and 3.0 ± 0.5 mm (control group), P = .042. Marginal bone levels at 5 years and changes up to 5 years were not significantly different between groups (P > .05). One crown exhibited an abutment fracture and two crowns a minor chipping (17.6% overall technical complication rate). Limited by a small sample size, veneering of the submucosal part of internally connected zirconia abutments led to outcomes that were less favorable biologically (PD, BOP, and KM), but similar to nonveneered abutments radiographically and technically.

The Use of Different Photoinitiator Systems in Photopolymerizing Resin Cements Through Ceramic Veneers

OBJECTIVE

To evaluate the effect of different photoinitiator systems on photopolymerizing resin cements through ceramic veneers with different thickness on microshear bond strength (μSBS), flexural strength (FS), and ultimate tensile strength (UTS) and verify the light attenuation through these ceramic veneers.

METHODS AND MATERIALS

Four photopolymerizing experimental resin cements were produced with the same resin matrix and associated with four different photoinitiator systems: camphorquinone (CQ), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), Ivocerin, and TPO + Ivocerin. Eighty disc-shaped ceramic veneers (IPS Empress Esthetic, Ivoclar Vivadent) were fabricated (10-mm diameter) in two different thicknesses: 0.7 and 1.5 mm. A previously characterized multiwave LED (Bluephase G2, Ivoclar Vivadent) was standardized for 40 seconds of photoactivation. Light transmittance through each ceramic veneer thickness (n=5) was measured using a spectrometer (USB 2000, Ocean Optics). The μSBS of each resin cement (n=15) to the ceramic veneer was evaluated using 0.5-mm cylinders with 0.7-mm diameters photoactivated through the different ceramic veneer thicknesses. Samples for FS and UTS tests were made either with or without ceramics veneers (0.7 and 1.5 mm) fixed to the light-curing tip. Data were submitted to two-way analysis of variance and the Tukey test (α=0.05).

RESULTS

The multiwave LED emitted higher irradiance into the blue wavelength spectra than into the violet wavelength spectra (p=0.0001). Light transmittance through the ceramic veneers was reduced in a systematic manner based on thickness regardless of the wavelength spectra emitted from the multiwave LED (p=0.00037). The μSBS was reduced in a systematic manner based on thickness regardless of the photoinitiator system (p<0.05). However, resin cements with CQ and Ivocerin showed higher bond strength values in comparison to the resin cement with TPO regardless of the ceramic veneer thickness (p<0.05). The FS and UTS means decreased (p<0.05) with the interposition of 0.7- and 1.5-mm ceramic veneers for all resin cements. The resin cement containing only TPO showed the lowest FS and UTS means (p<0.05) for all ceramic veneers.

CONCLUSIONS

The thickness of the ceramic veneers reduced the irradiance of the multiwave LED in all wavelength spectra. Ivocerin alone or associated with TPO showed to be an effective alternative photoinitiator to substitute for CQ. The resin cement containing only TPO had lower bond strength values in comparison to resin cements with CQ, Ivocerin, and Ivocerin + TPO.

An In Vitro Comparative Evaluation of Shear Bond Strengths of Veneering Porcelain and Different Core Materials

AIM

The aim of the present study was to evaluate and compare the bond strengths of different core structures to veneering porcelain.

MATERIALS AND METHODS

Sixty specimens were divided into 4 groups of 15 each. Specimen fabrication was done according to the International Organization for Standardization (ISO) specifications 9693:1999. Group 1 comprised core structure made of cast alloy, group 2 from sintered metal, group 3 from milled zirconia and group 4 milled zirconia without liner at the interface. The shear bond strengths were recorded and the values obtained were statistically examined.

RESULTS

Highest values were recorded in group 3 and there were significant differences between groups 1 and 3 while groups 3 and 4 were not statistically different. This led us to imply that zirconia as a core structure provided maximum strengths and laser sintered metal came second. The results also pointed out that the role of the zirconia liner is not that crucial to attaining adequate strength.

CONCLUSION

The present study concluded that zirconia and laser sintered metal are excellent core materials and feasible alternatives to cast alloy. We also concluded from our study that a zirconia liner did not affect the bond strength significantly and is not absolutely essential.

CLINICAL SIGNIFICANCE

This study helps us to understand the role of materials used as core structures in enhancing the shear bond strength to veneer porcelains and also clarifies the role of a zirconia liner in the process.

Prefabricated Laser Sintered Composite Veneers and Occlusal Vertical Dimensions: Case Reports

AIM

To highlight the concept of prefabricated veneers and occlusal vertical dimension (OVD) and series of case report using edelweiss prefabricated veneer system.

BACKGROUND

Edelweiss prefabricated veneer system presents a concept of biofunctional esthetics using laser sintered composite resins. The system's biofunctionality and versatile area of application combined with its time and cost saving procedure make the Edelweiss veneer and occlusion system a sound investment for the future.

CASE DESCRIPTION

A series of case reports treated using prefabricated laser sintered composite veneer system has been presented.

CONCLUSION

Prefabricated veneer is a milestone in operative dentistry, as it contributes tremendously to direct composite application, helping a larger number of our patients to receive esthetic restorations that are more conservative and affordable.

CLINICAL SIGNIFICANCE

The prefabricated composite veneering technique provides a minimally invasive, chair-side technique for esthetic and full mouth rehabilitation.

[Treatment of fractured maxillary anterior teeth in the young patient with Cerec composite partial veneers. A case report]

Children with attention-deficit hyperactivity disorder ADD/ ADHD are often difficult to be treated. If the anterior teeth have to be treated in case of trauma, the patient and the therapist quickly come to their limits. In the present case, with the help of the Cerec and composite partial veneers, an attempt was made to divide the treatment into two relatively short treatment periods for the patient. The two phases were interrupted by a longer construction and grinding phase. The composite partial veneers showed acceptable aesthetics. The patient and the parents experienced the three-phase Cerec treatment as very pleasant and less stressful than other treatments, and were highly satisfied with the restorations. A long-term prognosis cannot be made at the present time, the clinical studies are missing.

A Powdering Technique for Veneering Zirconia and Its Effect on the Flexural Strength of Ceramic Bilayers

The aim of this study was to assess the powdering technique and its effects on the flexural strength of bilayered zirconia. Bars made of zirconia partially stabilized by yttrium (Y-TZP) received porcelain by the following techniques (n = 10 per group): (1) L: VM9 application; (2) P: powdering technique + VM9 application; (3) C: Y-TZP coloring before sintering + Y-TZP sintering + VM9 application; or (4) CP: Y-TZP coloring before sintering + Y-TZP sintering + powdering technique + VM9 application. The powdering technique consisted of the application of VM9 margin powder followed by sintering. The samples were subjected to a 4-point flexural strength test and contact angle. Data were analyzed by one-way ANOVA and Tukey test (α = 5%). Surface treatments did not affect the flexural strength of bilayered specimens (P = .1264), but contact angle was affected by surface treatments (P < .0001), wherein the association of coloring and powdering (CP) reached higher values of wettability. Powdering did not affect the flexural strength of bilayered specimens, but did increase the Y-TZP wettability.

Ultrathin Monolithic Zirconia Veneers: Reality or Future? Report of a Clinical Case and One-year Follow-up

Yttria-stabilized polycrystalline zirconia ceramics have greatly advanced over the past few years. High-translucent zirconia is a newly introduced ceramic that affords high strength and esthetics and that has significantly increased the clinical indications of monolithic zirconia restorations. Thus, the purpose of this case report was to evaluate the performance of ultrathin monolithic zirconia veneers adhesively luted to enamel surfaces after minimally invasive preparations; in addition, we aimed at presenting a clinical protocol for zirconia surface treatment in order to promote bonding effectiveness to resin cement. This type of restoration presented very acceptable esthetic results and decreased the risk of fracturing the veneer during try-in and clinical use. The results were still satisfactory after one-year follow-up. However, randomized, prospective, controlled clinical trials are required to determine the long-term clinical durability of this treatment.

Ultra-thin occlusal veneers bonded to enamel and made of ceramic or hybrid materials exhibit load-bearing capacities not different from conventional restorations

OBJECTIVES

The objective of this study was to test whether or not the load-bearing capacity of occlusal veneers bonded to enamel and made of ceramic or hybrid materials does differ from those of porcelain-fused-to-metal or lithium disilicate glass ceramic crowns.

MATERIAL AND METHODS

In 80 human molars occlusal enamel was removed without extending into the dentin in order to mimic substance defects caused by attrition. The restorations were digitally designed at a standardized thickness of either 0.5 mm or 1.0 mm. For each thickness, 4 test groups were formed each including a different restorative material: "0.5-ZIR": 0.5 mm thick zirconia (Vita YZ HT); "1.0-ZIR": 1.0 mm thick zirconia (Vita YZ HT); "0.5-LDC": 0.5 mm thick lithium disilicate ceramic (IPS e.max Press); "1.0-LDC": 1.0 mm thick lithium disilicate ceramic (IPS e.max Press); "0.5-HYC": 0.5 mm thick PICN (Vita Enamic); "1.0-HYC": 1.0 mm thick PICN (Vita Enamic); "0.5-COC": 0.5 mm thick tooth shaded resin composite (Lava Ultimate) and "1.0-COC": 1.0 mm thick tooth shaded resin composite (Lava ultimate). Each group consists of 10 specimens. Two additional groups of 10 specimens each were used as controls and exhibited conventional crown preparations. In one group the crowns were made of lithium-disilicate ceramic ("CLD": IPS e.max CAD) and the other group consisted of porcelain-fused to metal crowns ("PFM"). All restorations were cemented onto the prepared teeth following the manufacturer's instruction of the corresponding luting cement. Subsequently, they were thermo-mechanically aged and then loaded until fracture. Load-bearing capacities (F_max) between the groups were compared applying the Kruskal-Wallis test (p < 0.05) and pairwise group comparisons using the Dunn's method.

RESULTS

Median values (and quartiles) for the load-bearing capacity amounted to (F_max) 2'407 (1'670; 2'490) N for the CLD group and to 2'033 (1'869; 2'445) N for the PFM group. For the 0.5 mm thick restorations F_max reached the highest median value in group 0.5-HYC 2'390 (1'355; 2'490) N, followed by 0.5-COC 2'200 (1'217; 2'492) N and 0.5-LDC 1'692 (1'324; 2'355) N. No results were obtained for group 0.5-ZIR due to the impracticability to fabricate ultra-thin specimens. The distribution of the values for the 1.0 mm thick restorations was 2'489 (2'426; 2'491) N for 1.0-COC, 2'299 (2'156; 2'490) N for 1.0-ZIR, 2'124 (1'245; 2'491) N for 1.0-HYC, and 1'537 (1'245; 1'783) N for 1.0-LDC. The differences of the medians between the test and the control groups did not reach statistical significance for the 0.5 mm thick specimens (KW: p = 0.6952 and p = 0.6986). Within the groups exhibiting 1.0 mm thickness, however, significant different medians were found: 1.0-LDC < 1.0-ZIR and 1.0-LDC < 1.0-COC (KW: p < 0.0209).

CONCLUSIONS

Regarding their maximum load-bearing capacity, minimally invasive occlusal veneers made of ceramic and hybrid materials can be applied to correct occlusal tooth wear and thus replace conventional crown restorations.

Minimally Invasive Complete Mouth Reconstruction using Full-Contour Ceramic Veneers: A Clinical Report

This case report illustrates a full-mouth rehabilitation for a patient that presented with severe non-carious tooth surface loss. The patient was restored following a minimally invasive tooth preparation, with 28 full-contour veneers. The patient was evaluated at baseline and at 2, 9, and 13 months following cementation to assess the integrity of the restorations, the proximal and occlusal contacts, pulp vitality, and tooth mobility. After 13 months, no postoperative sensitivity was reported. In addition, no secondary caries, loss of tooth vitality, or chipping or fractures of the veneers were detected. The clinical outcome of using a minimally invasive adhesive technique was an esthetic, mechanical, and biological success.

The Effect of Try-In Paste and Resin Cement Shade on Colour Properties of Dental Veneers

OBJECTIVES

The purpose of this study was to investigate how different shades of try-in pastes, uncured and cured resin cements affect the overall colour of porcelain veneer restorations.

METHODS

A total of 90 porcelain veneers of shade Vita 1M1 VM7 and 0.6 mm thick were applied to bovine teeth using 3 shades of resin cement and their try-in paste produced by 3 manufacturers.

RESULTS

Colour differences produced between the try-in pastes and the corresponding shades of cured resin cements ranged from (ΔE* 1.18-3.1). The colour differences between uncured and cured resins of the same shade ranged from (ΔE* 0.78 - 1.41).

CONCLUSIONS

Different shades of try-in pastes and resin cements produced colour changes which are clinically useful in changing the colour of veneer restorations and therefore assist in colour matching to adjacent teeth. Clinically significant differences were noticed between try-in pastes and the cured resin of the same shade, however, there were relatively small changes measured between un-cured and cured resins. The colour match obtained by the try-in paste has to be treated with caution and further evaluation of the restoration made with the resin in place before curing is recommended.

Influence of ageing on glass and resin bonding of dental glass-ceramic veneer adhesion to zirconia: A fracture mechanics analysis and interpretation

Adhesion plays a major role in the bonding of dental materials. In this study the adhesion of two glass-ceramic systems (IPS e.max and VITABLOCS) to a zirconia sintered substrate using a glass (for IPS e.max) and resin (VITABLOCS) before and after exposure to ageing for 14 days in distilled water at 37 °C are compared using two interfacial fracture mechanics tests, the 3 point bend Schwickerath (Kosyfaki and Swain, 2014; Schneider and Swain, 2015) and 4 point bend (Charalambides et al., 1989) approaches. Both tests result in stable crack extension from which the strain energy release rate (G, N/m or J/m²) can be determined. In the case of the 3 PB test the Work of Fracture was also determined. In addition, the Schwickerath test enables determination of the critical stress for the onset of cracking to occur, which forms the basis of the ISO (ISO9693-2:2016) adhesion test for porcelain ceramic adhesion to zirconia. For the aged samples there was a significant reduction in the resin-bonded strengths (Schwickerath) and strain energy release rate (both 3 and 4 PB tests), which was not evident for the glass bonded specimens. Critical examination of the force-displacement curves showed that ageing of the resin resulted in a major change in the form of the curves, which may be interpreted in terms of a reduction in the critical stress to initiate cracking and also in the development of an R-curve. The extent of the reduction in strain energy release rate following ageing was greater for the Schwickerath test than the Charalambides test. The results are discussed in terms of; the basic mechanics of these two tests, the deterioration of the resin bonding following moisture exposure and the different dimensions of the specimens. These in-vitro results raise concerns regarding resin bonding to zirconia.

STATEMENT OF SIGNIFICANCE

The present study uses a novel approach to investigate the role of ageing or environmental degradation on the adhesive bonding of two dental ceramics to zirconia. This continues to be a major clinical problem but current approaches, till now, have relied upon a myriad of strength based tests to quantify the extent of environmental degradation with time. In this paper we use two fracture mechanics approaches, based upon simple 3 and 4 point bend testing procedures that enable stable debonding crack extension to occur. The paper provides a more critical approach to evaluate the role of environmental degradation of adhesion for dental materials.

Analysis of Marginal Adaptation of Porcelain Laminate Veneers Produced by Computer-Aided Design/Computer-Assisted Manufacturing Technology: A Preliminary In Vitro Study

PURPOSE

To analyze the marginal adaptation of computer-aided design/computer-assisted manufactured (CAD/CAM) porcelain laminate veneers.

MATERIALS AND METHODS

A total of 25 three-dimensional (3D) machine-milled laminate veneers were divided into five groups of five each according to fabrication material (E-max; Empress; Lava Ultimate; Suprinity; and Vita Mark II) and cemented in 25 prepared acrylic central incisors. Digital microscopy images (×7.5 magnification) were analyzed for gaps in the mesial/distal surfaces of the prepared tooth and in the cervical, medial, and incisal thirds.

RESULTS AND CONCLUSION

All CAD/CAM laminate veneers except for Empress and Suprinity in the middle and incisal thirds showed good results (ie, gaps < 120 μm in the cervical, middle, and incisal thirds).

Color Differences Between Pink Veneering Ceramics and the Human Gingiva

The aim of this study was to examine 10 different shades of pink ceramic to determine which one best matches the mean color of human gingiva. Bar-shaped zirconia samples were fabricated and veneered with 1 of 10 pink zirconia veneering ceramics. The color of the gingiva at the central maxillary incisors of 20 healthy volunteers was compared to the pink veneering ceramics using a spectrophotometer (Spectroshade, MHT). The obtained color parameters L*, a*, and b* (CIELAB) of the gingiva and the ceramics were used to calculate the color difference (ΔE). Mean ΔE values were descriptively analyzed and compared to the threshold value for visibility of color differences of gingiva (ΔE = 3.1). The lowest pink ceramic ΔE value obtained (closest to the mean ΔE of all the volunteers' gingiva) was 6.2. All the tested ceramics exhibited a color difference above the threshold value for visibility.

Veneer or Interproximal Enamel Reduction?

BACKGROUND

Clinicians often ask, "Veneer or no to veneer?" Clinicians usually think of porcelain veneers for cases in which patients are dissatisfied with their teeth shape. Interproximal reduction can change teeth's shape and appearance within the enamel to improve gingival contour, eliminate black gingival triangles, and correct the Curve of Spee.

AIM

Our aim is to present to clinicians the option of reshaping and interproximal reduction (IPR) as a valid alternative to porcelain veneers.

CASE REPORT

A male patient with round bulbous-shaped anterior maxillary teeth sought a better masculine smile. Interproximal reduction with thin bur size was performed to reshape the anterior teeth in order to achieve a proportional teeth width to height and give a more rectangular rather than square shape. Finally, the orthodontist closed the multiple diastemas using round wires in order to reduce anterior teeth proclination. The patient received bleaching treatment and minor composite fillings.

CONCLUSION

Not every cosmetic case should be treated with veneers and crowns. Conservative minimal intervention, such as IPR was more than sufficient in treating such cases. It is the right of the patients to be informed and educated about all possible treatment options.

CLINICAL SIGNIFICANCE

Minor reshaping and IPR preserving teeth structures can be helpful in achieving esthetic results and patients' confidence.

Oral Rehabilitation of Young Adult with Amelogenesis Imperfecta

BACKGROUND

Amelogenesis imperfecta is a heterogeneous group of hereditary disorders that affect the enamel formation of the primary and permanent dentitions while the remaining tooth structure is normal. Appropriate patient care is necessary to prevent adverse effects on dental oral health, dental disfigurement, and psychological well-being.

AIM

This clinical report presents a 27-year-old Chinese male with amelogenesis imperfecta (AI) and his restorative management.

CASE REPORT

This clinical report presents a 27-year-old Chinese male with AI and his restorative management. Extraoral examination showed a skeletal class III profile and increased lower facial proportion. Intraorally, all the permanent dentition was hypoplastic with noticeable tooth surface loss and a yellow-brown appearance. This was complicated with a mild maloc-clusion and food packing on his posterior teeth. The patient wanted to improve his appearance and masticatory efficiency. Orthodontic treatment was performed to treat the mild malocclu-sion and create physiological interproximal spacing to minimize tooth preparation and facilitate oral hygiene.

CONCLUSION

This report demonstrates how a multidisciplinary approach for the management of AI can achieve a predictable, functional, and esthetic outcome. Orthodontic treatment facilitated a conservative prosthodontic treatment outcome by selectively increasing interproximal space, minimizing tooth preparation, correcting posterior bilateral cross-bite, as well as an anterior reverse overjet and derotation of the canines.

CLINICAL SIGNIFICANCE

This case report demonstrates the effective restoration of AI using a multidisciplinary approach to overcome crowding using a relatively conservative approach.

Prospective Evaluation of Posterior Fixed Zirconia Dental Prostheses: 10-Year Clinical Results

PURPOSE

To investigate the clinical survival and success rates of conventionally luted three- and four-unit fixed dental prostheses (FDPs) with zirconia frameworks (Cercon Smart Ceramics, DeguDent) after a mean observation period of 119 ± 36 months.

MATERIALS AND METHODS

A total of 75 patients were treated in the Department of Prosthodontics at the University of Goettingen, Germany, and a total of 99 posterior FDPs were inserted and luted with zinc phosphate cement. Time-dependent survival and success rates were calculated using Kaplan-Meier curves, and their relationships with the type of veneer (ceramic), location (maxilla vs mandible), and span length (three-unit vs four-unit) were analyzed with a Cox regression model (P < .05).

RESULTS

Of the 99 inserted FDPs, 24 were lost to follow-up, 51 remained functional and passed the 10-year examination (overall survival rate: 75.0%; 95% confidence interval [CI]: 0.64, 0.85), and 13 were absolute failures caused by technical events (technical survival rate: 84%; 95% CI: 0.64, 0.85). In 50 FDPs, relative failure required a clinical intervention to maintain function (overall success rate: 40%; 95% CI: 0.29, 0.52). For 35 of these FDPs, the relative failure was caused by technical events (technical success rate: 61%; 95% CI: 0.49, 0.73). None of the evaluated factors showed an association with overall or technical survival or success.

CONCLUSION

Zirconia-based posterior FDPs produced with a first-generation computer-assisted manufacturing (CAM) system revealed high rates of absolute and relative failure, mainly due to technical events, after a mean observational period of 10 years. Further clinical studies with updated computer-assisted design (CAD)/CAM systems are needed to determine the long-term performance of zirconia-based FDPs.

Long-Term Esthetic and Functional Success Following an Initial Treatment Complication

This case describes the successful long-term outcome of a patient's treatment after a restorative failure occurred soon after delivery. The esthetic and restorative treatment has been successful for nearly a decade due largely to a careful, objective evaluation of all possible causes of the restorative failure. The treatment plan for the patient, who was assessed as high risk biomechanically and functionally, was carried out in the following phases: (1) an implant placement that required an osteotome sinus lift; (2) placement of feldspathic bonded veneers for the maxillary anterior teeth to minimize removal of tooth structure; (3) numerous core-supported restorations, with fixed partial dentures placed for teeth Nos. 19 through 21 and 28 through 30; and (4) the use of a Kois deprogrammer™ to determine condylar position/centric relation reference. Finally, the maxillary teeth were lengthened to create a pleasing smile and the vertical dimension increased and restored in centric relation.

Three generations of zirconia: From veneered to monolithic. Part I

This article presents the historical development of the different generations of zirconia and their range of indications, from veneered to monolithic zirconia restorations. Because of the large extent of this topic, it is divided into two parts. In Part I, the mechanical and optical properties of the three generations of zirconia materials are discussed critically and theoretically. A short summary is given of the current scientific literature, investigating the third generation of zirconia comparatively regarding the properties discussed.

Effect of Different Computer-aided Design/Computer-aided Manufacturing (CAD/CAM) Materials and Thicknesses on the Fracture Resistance of Occlusal Veneers

The aim was to evaluate, in vitro, the influence of different computer-aided design/computer-aided manufacturing (CAD/CAM) materials (IPS e.max CAD, Vita Enamic, and Lava Ultimate) and thicknesses (0.6 mm and 1.5 mm) on the fracture resistance of occlusal veneers. Sixty human third molars were prepared to simulate advanced erosion of the occlusal surface, and the teeth were randomly divided into six experimental groups (n=10) according to the material and thickness used to build the veneers. Ten sound teeth formed the control group. The veneers were adhesively luted and submitted to mechanical cyclic loading (1 million cycles at 200-N load). The fracture resistance test was performed in a universal testing machine. The failures were classified as "reparable" and "irreparable." According to two-way analysis of variance and the Tukey test, the interaction (material × thickness) was significant ( p=0.013). The highest fracture resistance was obtained for IPS e.max CAD at a 1.5-mm thickness (4995 N) and was significantly higher compared to the other experimental groups ( p<0.05). The lowest fracture resistance was obtained for Vita Enamic at 0.6 mm (2973 N), although this resistance was not significantly different from those for IPS e.max CAD at 0.6 mm (3067 N), Lava Ultimate at 0.6 mm (3384 N), Vita Enamic at 1.5 mm (3540 N), and Lava Ultimate at 1.5 mm (3584 N) ( p>0.05). The experimental groups did not differ significantly from the sound teeth (3991 N) ( p>0.05). The failures were predominantly repairable. The occlusal veneers of IPS e.max CAD, Vita Enamic, and Lava Ultimate, with thicknesses of 0.6 mm and 1.5 mm, obtained fracture resistances similar to those associated with sound teeth.

Arab Societal Awareness of Dental Veneers

AIM

The aim of this study is to assess the Arab society's knowledge, awareness, and attitudes toward dental veneers.

MATERIALS AND METHODS

A cross-sectional study was performed by collecting data through an online questionnaire created using the Survey Monkey website and distributed among Middle Eastern societies through social media to ascertain participants' knowledge and awareness regarding dental veneers. The sample included Arab laypeople who were over 18 years old, to represent the awareness of the majority regarding dental veneers.

RESULTS

The sample of this study included 1,332 subjects from different Middle Eastern nationalities, mainly Saudis, Kuwaitis, and Emiratis (15.6% of males and 84.4% of females). The results of this study showed that the total knowledge of dental veneers is 50.12%. The respondents with the highest level of knowledge acquired their information mainly from newspapers and magazines, followed by the Internet, then dentists, then social media, and, finally, friends and relatives. Cost was the only factor limiting 38.4% of subjects from receiving veneers, and 56% of the subjects would receive veneers if they were free of cost. In total, 72.6% of the respondents believed that veneers are currently overused.

CONCLUSION

The knowledge and awareness of dental veneers were below a satisfactory level. Participants who relied on social media as a source of information had lower knowledge levels.

CLINICAL SIGNIFICANCE

This study emphasized the need for continual societal education regarding dental veneers.

[Wear intensity and surface roughness of microhybrid composite and ceramic occlusal veneers on premolars after the thermocycling and cyclic mechanical loading tests]

OBJECTIVE

To evaluate the wear intensity and surface roughness of occlusal veneers on premolars made of microhybrid composite resin or two kinds of ceramics in vitro after the thermocycling and cyclic mechanical loading tests.

METHODS

In the study,24 fresh extracted human premolars without root canal treatment were prepared (cusps reduction of 1.5 mm in thickness to simulate middle to severe tooth wear, the inclinations of cusps were 20°). The prepared teeth were restored with occlusal veneers made of three different materials: microhybrid composite, heat-pressed lithium disilicate ceramic and computer-aided design/computer-aided manufacturing (CAD/CAM) lithium disilicate ceramic in the thickness of 1.5 mm. The occlusal veneers were cemented with resin cement. The specimens were fatigued using the thermocycling and cyclic mechanical loading tests after being stored in water for 72 h. The wear of specimens was measured using gypsum replicas and 3D laser scanner before and after the thermocycling and cyclic mechanical loading tests and the mean lost distance (mm) was used to indicate the level of wear. The surfaces of occlusal contact area were observed and the surface roughness was recorded using 3D laser scanning confocal microscope before and after the fatigue test. Differences between the groups were compared using ONE-way ANOVA(P<0.05).

RESULTS

All the specimens successfully survived after the thermocycling and cyclic mechanical loading tests. The mean wear of microhybrid composite group, heat-pressed lithium disilicate ceramic group, and CAD/CAM lithium disilicate ceramic group was (-0.13±0.03) mm, (-0.05±0.01) mm and (-0.05±0.01) mm, the wear of microhybrid composite was significantly higher than the two ceramic groups(P<0.001).The mean surface roughness(Ra)before the fatigue test was(1.24±0.20) μm, (0.75±0.09) μm, (0.73±0.14) μm and it became (1.81±0.24) μm, (1.53±0.26) μm and (1.77±0.23) μm after the test . Before the fatigue test, the surface roughness of microhybrid composite was significantly higher than the two ceramic groups(P<0.001) and after the test, the surface roughness of heat-pressed lithium disilicate ceramic was significantly lower than microhybrid composite(P=0.005) and CAD/CAM lithium disilicate ceramic (P=0.010).

CONCLUSION

From the view of wear speed, microhybrid composite was significantly higher than the two kinds of ceramics, but it was similar to enamel when the opposing tooth was natural. The surface roughness before the themocycling and cyclic mechanical loading test of microhybrid composite was significantly higher than that of the two ceramic groups. After the test, the surface roughness of heat-pressed ceramic was significantly lower than that of the other two groups. From the view of surface roughness, heat-pressed ceramic has more advantage.

Conservative Approach for Treatment of Maxillary Lateral Incisor Agenesis With the Deciduous Tooth Retained: 18-Month Follow-Up

This case describes a female patient with agenesis of the maxillary right lateral incisor, with her permanent canine in its position and the deciduous canine retained. Additionally, she presented with a maxillary left peg lateral incisor. To solve her functional and esthetic complaints, a multidisciplinary approach involving perio-restorative procedures was proposed. Periodontal surgeries were performed to align the gingival contour, and the restorative approach utilized ceramic veneers. At the 18-month clinical and radiographic follow-up, the treatment outcome was stable, with maintenance of the clinical results achieved and without any sign of deciduous tooth resorption.

Anterior restorations: The performance of ceramic veneers

Adhesive bonding techniques in combination with tooth-colored restorative materials are one of the greatest achievements of restorative dentistry. Adhesively bonded veneers made from various silicate ceramic materials have contributed significantly to this. Ceramic veneers had long been considered to be only esthetic implements. However, their range of indications has been steadily increasing, making ceramic veneers a highly viable alternative to classic, far more invasive forms of restorative treatment. Today these veneers are used to restore the biomechanics of the dentition, to establish adequate function, to mask highly discolored endodontically treated teeth, and for many other purposes. The present article explains the principles of modern veneer technology based on clinical examples, with special emphasis on collaboration with the dental laboratory and communication within the dental team. This includes analyzing the case, defining the treatment goal, determining the right shade, selecting the most suitable ceramic material, finding the best preparation design, and choosing the most appropriate adhesive concept. The article will also explore the long-term prognosis of ceramic veneers as reported by a number of scientific studies.

Review of treatment methods of patients with uncomplicated teeth fractures

OBJECTIVE

Introduction: Taking into consideration the high prevalence of dental trauma, the issue dental trauma management in the frontal dentition is relevant, considering the principles of biological, economical feasibility and clinical features of each case. The aim: The purpose of this review article is to draw dentists' attention to the high prevalence of uncomplicated fractures of teeth (without pulp chamber exposure) and to highlight the most effective methods for their managment.

PATIENTS AND METHODS

Materials and methods: We have processed about 50 scientific sources devoted to the treatment of traumatic lesions of teeth. Among them are articles, scientific researches, clinical cases, laboratory researches.

CONCLUSION

Conclusions: The most appropriate method for teeth restoration in a case of uncomplicated fracture is to preserve the fragment of the tooth with its further reattachment applying an adhesion protocol with the preliminary preparation of hard tissues of teeth. To achieve the best aesthetic results and increase the endurance of restoration it is expedient to cover the repartitioned fragment of a tooth with ceramic veneers.

Effects of ceramic layer thickness, cement color, and abutment tooth color on color reproduction of feldspathic veneers

AIM

To optimize the esthetics of ceramic restorations, it is important to determine accurately the effects of various parameters on the final color of the restoration. However, there is a lack of information on what determines the color of translucent feldspathic veneers formed using ceramics such as Vita Mark II. The aim of this study was to evaluate the effects of the ceramic layer thickness, cement color, and abutment tooth color on the color of the feldspathic ceramic veneer restoration.

MATERIAL AND METHODS

A total of 30 all-ceramic monolithic veneers (Vita Mark II) were fabricated using a CAD/CAM system. The crowns were divided into three groups of differing ceramic thickness (0.4-, 0.7-, and 1.0-mm thick). Each type of crown was seated on six different-colored abutment teeth (1M1 [reference], 1M2, 2M2, 3M2, 4M2, and 5M2) using seven different try-in paste colors. The color of the resulting restoration was evaluated using spectrophotometry with a spot-measurement device (Vita Easyshade Advance 4.0). Color data are expressed in CIE L*a*b* system coordinates, and color differences ΔE relative to the reference tooth were calculated and analyzed using one-way analysis of variance (ANOVA) with the Bonferroni post hoc test at α = 0.05.

RESULTS

The color difference ΔE of the feldspathic all-ceramic veneer system was significantly affected by the thickness of the ceramic layer, the cement color, and the abutment tooth color (P < 0.05). The smallest values of ΔE compared with the reference color were found when try-in pastes shade -3 was used. As the thickness of the ceramic layer increased, a significant decrease in ΔE was found. As the color of the abutment tooth varied from light to dark, a significant increase was found in ΔE.

CONCLUSION

The thickness of the ceramic layer, the cement color, and the abutment tooth color significantly affected the color of the resulting CAD/CAM feldspathic ceramic veneer restoration.

Tooth movement with elastic separators before ceramic veneer treatment: Rearranging asymmetric diastemas by managing the horizontal distance

The treatment of diastemas should be conservative to preserve tooth structure, and porcelain veneers provide an esthetic solution with minimal tooth preparation. However, asymmetric diastemas can be difficult to treat and may require redistribution of spaces. Additionally, extensive proximal restorations may negatively impact periodontal health. Minor tooth movement with elastic separators can be used to redistribute the interdental spaces and provide space for the interdental papilla. The aim of this paper was to present a clinical treatment involving the movement of peg-shaped maxillary lateral incisors with elastic separators to rearrange the spaces of asymmetric diastemas, thereby managing the horizontal distance during rehabilitation of the smile with minimally invasive ceramic veneers.

No-Preparation Veneers: A Minimally Invasive Approach for a Naturally Esthetic Smile

Typically, dentists spend many years training to learn how to prepare teeth for restorations. Whether the restoration comprises a filling, veneer, crown, inlay, onlay, or bridge, teeth often require preparation to allow adequate space to accommodate the thickness of the restorative material. However, dentists may face a dilemma if a patient inquires about receiving an enhanced smile without tooth preparation. In such cases, the dentist needs to determine the optimal course of action for the patient. This also raises the issue of removing enamel, which is perhaps the most prized commodity in the dentition. This article discusses the question of whether to prepare or not to prepare a tooth for restoration and presents a case demonstrating the meticulous use of eight no-preparation porcelain veneers.

Career Focus: Film Falsies

Dental technician Gary Archer makes removable prosthodontic devices for hollywood movies. he shares some of the tricks of the trade with PDJ managing editor Amy Brewerton.

[Effects of ultra thin porcelain veneers in repair of anterior teeth gaps]

PURPOSE

To evaluate the clinical effect of ultra thin porcelain veneers in the repair of the anterior teeth gaps.

METHODS

The anterior teeth gaps in 42 patients were repaired from 2013 to 2014 with ultra thin porcelain veneers ,the clinical results of 145 porcelain veneers were evaluated at 6,12,24 and 36 months after repair.

RESULTS

Thirty six months after repair, 145 ultra thin porcelain veneers were successful retained, 99.3% veneers were found to be intact.Small wane existed in one veneer at the incisal areas. 98.6% teeth had acceptable marginal adaptation .Few teeth had little hyperesthesia of dentin early after repair, but disappeared after 12 months. Patients were satisfied with the colour and shape of veneers.

CONCLUSIONS

Ultra thin porcelain veneer is an satisfactory method to quickly repair anterior teeth gap.

Dental Ceramics for Restoration and Metal Veneering

A survey of the development of dental ceramics is presented to provide a better understanding of the rationale behind the development and clinical indications of each class of ceramic material. Knowledge of the composition, microstructure, and properties of a material is critical for selecting the right material for specific applications. The key to successful ceramic restorations rests on material selection, manufacturing technique, and restoration design, including the balancing of several factors such as residual stresses, tooth contact conditions, tooth size and shape, elastic modulus of the adhesives and tooth structure, and surface state.

Noninvasive approach to esthetic rehabilitation of conoid anterior teeth

Several factors, including anomalies of shape, color, or size, or positioning of the teeth, may interfere with smile esthetics. A 26-year-old woman was dissatisfied with the esthetics of her maxillary lateral incisors, which had defective composite resin restorations with alterations of color and shape. The aim of this article is to present a step-by-step description of the technique used to fabricate esthetic restorations for the conoid maxillary lateral incisors with a minimum of dental preparation. The successful outcome demonstrates the importance of correct planning for successful restorations.