|Year : 2022 | Volume
| Issue : 1 | Page : 77-80
Achieving esthetics with computer-aided design-computer-aided manufacture ceramic veneers
Maninder Hundal, Vaibhav Jain
Indian Naval Dental Centre, Danteshwari, INHS Ashwini, Mumbai, Maharashtra, India
|Date of Submission||19-Nov-2020|
|Date of Decision||30-Apr-2021|
|Date of Acceptance||22-Jul-2021|
|Date of Web Publication||05-Apr-2022|
Executive Officer and Classified Specialist Prosthodontia, Indian Naval Dental Centre, Colaba, Mumbai
Source of Support: None, Conflict of Interest: None
Continuous evolution of materials, laboratory techniques, and clinical procedures has made the ceramic laminate veneers a reliable modern technique. Veneers are mainly fabricated from conventional low fusing feldspathic porcelain. Two popular methods for fabrication of porcelain veneers are the platinum foil technique and the refractory die technique. However, these are time-consuming and technique sensitive. In contrast, the computer-aided design/computer-aided manufacture (CAD/CAM) restorations can be made in one visit, and the new equipment and softwares have shown to result in improved marginal fit. This scientific paper focuses on two case reports with different clinical indications restored successfully with two different types of CAD-CAM veneer materials.
Keywords: Computer-aided design/computer-aided manufacture materials, ceramic veneers, clinical cases, techniques, technology
|How to cite this article:|
Hundal M, Jain V. Achieving esthetics with computer-aided design-computer-aided manufacture ceramic veneers. J Dent Def Sect. 2022;16:77-80
| Introduction|| |
Ever since their introduction nearly three decades ago, etched laminates and veneers have attained great clinical success with their primary advantage being a minimally invasive treatment modality used to correct tooth form, position, and color. In addition, bonded ceramic restorations are associated with less secondary caries and gingival inflammation. Compared to the time-consuming conventional platinum foil or refractory die technique, the computer-aided design/computer-aided manufacture (CAD/CAM) restorations allow for digital impression taking, digital designing as part of the treatment planning thus decreasing wastage of material, conserving precious man hours, and allowing a preview of the final appearance to the patient. Two types of ceramic materials recommended for the fabrication of veneers using CAD/CAM technology are the feldspathic ceramics and lithium disilicate reinforced ceramics which are industrially manufactured in a reproducible manner resulting in high-quality materials. This case report includes two cases rehabilitated by using the two different types of CAD-CAM materials along with separate clinical techniques for preparation of teeth thereby meeting the requirements of the individual case.
| Case Reports|| |
Case report 1: Masking discoloration due to fluorosis
A 26-year-old serving sailor reported at the outpatient department (OPD) of INDC Danteshwari with the chief complaint of discolored upper anterior teeth since childhood, fractured teeth number 14, 15, 37 with old chipped and dislodged ceramometal crowns for teeth 15, 37. Intraoral examination revealed generalized fluorosis of enamel [Figure 1]a, [Figure 1]b, [Figure 1]c. A diagnosis of moderate dental fluorosis (Deans' index code-4) was established. Various treatment options from all-ceramic crowns in direct and direct composite veneers to conventional as well as CAD-CAM ceramic veneers were discussed with the patient, and finally, it was decided to give him the feldspathic ceramic; TriluxeTM veneers [VITA Zahnfabrik, Germany; as seen in [Figure 5]a having incisal overlap for teeth 11, 12, 13, 21, 22, 23, 24. Intraoperative radiograph of fiber post with composite core build up followed by CAD-CAM all-ceramic (In-ceram zirconia by Vita, Germany) crowns for teeth 15 and14; and porcelain-fused-to-metal crown for tooth 37 were chosen. Intraoperative radiograph showing fiber post and composite core for tooth 15 and composite core build up for tooth 14 after completion of randomized controlled trial can be seen in [Figure 1]d. Diagnostic impressions along with diagnostic wax up were carried out. The teeth were cosmetically contoured taking care that the preparation was driven to restore the original instead of existing volume of the tooth. Preparation was done using the Shofu all-ceramic preparation kit. It was initiated from the labial surface using the depth cutting burs from mesioproximal line angle to distoproximal line angle. Three-depth cuts in each cervical, middle, and incisal third of the teeth were given and then merged maintaining dual convergence of labial reduction to preserve anatomical form. Supragingival chamfer finish line was established. The incisal edges of the teeth were prepared to provide the bulk for the porcelain terminating at the linguoincisal line angle. The recommended thicknesses are approximately <0.3–0.5 mm in the cervical area, 0.7 mm in the middle and incisal thirds, and a minimum of 1.5 mm for incisal. Gingival retraction was done using the nonimpregnated ultrapak 000 knitted gingival retraction cord, and impression was made using polyvinyl siloxane elastomeric impression material (3M ESPE, Germany). The cast was poured and the porcelain laminate veneers were fabricated. The finished laminates were tried in using colorless silicone and finally bonded after treatment of both veneer and the tooth surface using the composite resin bonding kit, Calibra marketed by Dentsply. The occlusion was refined with microthin articulating film of 0.0008 (Arti-fol, Bausch Germany). The final polishing of the laminate was done using the Shofu ceramic polishing kit. Postoperative view of case can be seen in [Figure 2]a and [Figure 2]b, [Figure 3]a and [Figure 3]b. Instructions for maintenance were given followed by periodic recall.
|Figure 1: (a) Preoperative frontal view showing fluorosed teeth. (b) Preoperative occlusal view showing fractured Teeth 14, 15. (c) Preoperative occlusal view showing fractured tooth 37. (d) Intraoperative IOPA showing fiber post and composite core for tooth 15 and composite core build up for tooth 14 after completion of randomized controlled trial|
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|Figure 2: (a) Postoperative frontal view showing coronal preparation for all-ceramic laminates for teeth; 11, 12, 13, 21, 22. (b) Postoperative occlusal view showing incisal overlap preparation for all-ceramic laminates, 23, 24|
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|Figure 3: (a) Postoperative frontal view with all. (b) Patient with improved smile ceramic laminates in situ|
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|Figure 4: (a) Preoperative intraoral view showing midline diastema. (b) Teeth preparation for laminate veneer. (c) Postoperative intraoral view|
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|Figure 5: (a) VITABLOCS TriLuxe forte (feldspathic porcelain). (b) Vitablocs Suprinity@ Pc (zirconia reinforced lithium disilicate). (c) CAD-CAM fabrication of laminate veneer. (d) Shofu porcelain veneer polishing kit. (e) Shofu all-ceramic preparation Kit|
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Case report 2: Closure of midline diastema
A 22-year-old female patient reported to the OPD of INDC Danteshwari with the chief complaint of spacing in upper central incisor teeth compromising her looks as well as speech [Figure 4]a. Orthodontic treatment for closure was ruled out due to both constraints of time and unavailability for multiple visits. CAD veneers which would suit her requirements of esthetics, elimination of hissing in phonation, time restraints, and longevity of the prosthetic restoration were key factors in choosing VITA SUPRINITY, ZLS [Figure 5]b (VITA Zahnfabrik, German) of medium opacity for restoration. The diastema was 1.4 mm. Maxillary central incisors were prepared following the same principles as mentioned in case report 1 except that the preparation was terminated at the incisal edge without the overlap [Figure 4]b. The final restorations with a mesial overlap of 0.70 mm each were prepared and cemented using the above-mentioned technique [Figure 4]c.
| Discussion|| |
Earlier simplified techniques for tooth preparation included the use of depth cutters guided by the existing tooth surface; however, that approach did not take into consideration alterations of the tooth owing to aging, wear, or loss of enamel and thus led to greater risks for dentin exposures. More recent and sophisticated methods have integrated an additive diagnostic procedure (wax-up or mock-up) to compensate for these alterations. This approach allows for more enamel preservation and as a consequence more predictable bonding, biomechanics, and esthetics. The CAD-CAM material used for first patient was feldspathic ceramic; TriluxeTM veneers [VITA Zahnfabrik, Germany; as seen in [Figure 5]a] and for second patient was VITA SUPRINITY, ZLS [Figure 5]b (VITA Zahnfabrik, German) depending on properties and requirement of esthetics by the patient. Apart from the regular crown preparation burs, there are dedicated kits for tooth reduction for veneers that simplify the preparation offering limited number of instruments, e.g. the Shofu all-ceramic kit [Figure 5]c and [Figure 5]d used by us, the Touati Brasseler kit, etc.
Three basic types of preparation have been described for the incisal, namely the window or intra-enamel preparation, the overlapped incisal edge preparation, and the feathered incisal preparation. The overlapped incisal preparation allows the dental technician more control on the esthetic characteristics of the incisal part of the porcelain veneer. In addition, this preparation is stated to make the restoration more resistant to incisal fractures.,
Ceramic veneers processed through available CAD/CAM systems; whether feldspathic or lithium disilicate with reinforcements, e.g. of zirconia though now available in different translucencies are basically monolithic restorations, which means that the final shape of the restoration will be obtained in a single ceramic material and that usually lacks the most common effects of the incisal edge of the anterior dentition such as opalescence, counter-opalescence, different kind of characterizations such as white spots, and well-defined mamelons. The final desired shade can be achieved by three methods for characterization of the incisal third using nanofluorapatite ceramics: (a) cut-back technique; (b) staining technique; and (c) layering technique.
| Conclusion|| |
CAD-CAM all-ceramic veneers are one of the most esthetically pleasing prosthodontic restorations. Their chief disadvantage is their susceptibility to fracture, although this can be lessened by the use of the resin-bonded technique and higher strength ceramics as brought out in the above case report.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]