Predictable Restorative Work Flow for Computer-Aided Design/Computer-Aided Manufacture-Fabricated Ceramic Veneers Utilizing a Virtual Smile Design Principle

Facially driven guided crown lengthening using a complete digital workflow: A dental technique

A facially driven digital guided crown lengthening method using the virtual smile design approach supplemented with a static 3-dimensional face scan that demonstrates the digital data of extraoral soft tissue is presented. The technique enables the practitioner to virtually design the new smile and surgically plan the crown lengthening procedure.

Contemporary treatment techniques for excessive gingival display caused by altered passive eruption or lip hypermobility

OBJECTIVES

Excessive gingival display (EGD), also known as gummy smile, has various causes, including altered passive eruption (APE) and hypermobile upper lip (HUL). This state-of-the art narrative review explores current concepts regarding soft tissue EGD etiologies and the contemporary modalities available for APE or HUL treatment.

DATA, SOURCES, STUDY SELECTION

Literature search was conducted for a narrative review on the etiology, diagnosis, and treatment of EGD caused by APE and HUL. Searching for articles was carried out in PubMed and Google Scholar. Published articles, including case reports, case series, observational and interventional clinical trials, and critical appraisals of the literature (e.g., systematic reviews) on the etiology, diagnosis, and treatment of EGD caused by APE and HUL were retrieved and reviewed. Particular focus was placed on novel treatment modalities introduced in the last five years.

CONCLUSIONS

Recent research evidence indicates that APE and HUL are the two major soft tissue-based EGD etiologies. Aesthetic crown lengthening (ACL) and lip repositioning surgery (LRS) are the established surgical treatment modalities for APE and HUL, respectively. The last few years have seen the introduction of new techniques for APE and HUL management, an expansion of the available ACL and LRS technique variations, and additional evidence further supporting the effectiveness of these two procedures. Several of the recently introduced approaches offer unique, innovative, and potentially impactful concepts. However, for many of these newly described treatments the available evidence is limited to case reports and the exact indications remain to be adequately defined.

CLINICAL SIGNIFICANCE

Altered passive eruption and hypermobile upper lip are the common soft tissue causes of gummy smile and can be successfully managed through aesthetic crown lengthening and lip repositioning surgery, respectively. A wide range of newly introduced approaches promises to further facilitate gummy smile treatment and improve outcomes.

CAD-CAM natural restorations-Reproducing nature using a digital workflow

OBJECTIVES

Natural restorations combine digital workflow and shell technique to create CAD/CAM restorations with the form and texture of natural teeth. This case report describes an interdisciplinary digital workflow combined with CAD/CAM natural restorations to achieve the naturalness of an anterior rehabilitation.

CLINICAL CONSIDERATIONS

A 38-year-old patient attended to the office with esthetic issues. An interdisciplinary treatment plan was conducted, which included periodontal surgery to recreate the gingival contour, associated with bleaching and manufacturing CAD/CAM ceramic veneers to return an optimal teeth surface texture and shape.

CONCLUSIONS

The design and manufacturing of CAD/CAM natural restorations using a digital workflow allowed a predictable result and overcame the limitations of conventional shell technique.

CLINICAL SIGNIFICANCE

Conventional shell technique is used to create restorations with the form and texture of natural teeth. This article presents a combination of the conventional shell technique with a digital workflow, facilitating the design and manufacturing of CAD/CAM natural restorations.

Smile Design and Treatment Planning-Conventional versus Digital-A Pilot Study

INTRODUCTION

Several methods are currently available for providing a preview of the prosthodontic treatment, including computer simulations, 3D models, wax-ups, and mock-ups. The aim of this study is to compare the aesthetic aspects and assessment of conventional versus digital prefigurative methods.

METHODS

The study included 5 patients and 3 observers, for each of whom a wax-up was made in both the conventional and digital techniques. The analog method, which implied a mock-up molding with a silicone matrix of the wax-up, was compared to a digital workflow, which consisted of a mock-up milling from a digital design. The patient's clinical mock-ups were recorded with digital photographs and assessed for nine different criteria by three observers.

RESULTS

The analysis has shown a balanced assessment of the aesthetic criteria without any significant difference between the analog and digital prefigurative methods.

CONCLUSIONS

Between the two wax-ups (conventional and digital), there were some variations in smile and dental criteria; however, the obtained data were very similar. When it comes to the smile criteria, the general average grades of the mock-ups conducted using the conventional method are slightly higher than the ones using the digital technique.

Full Digital Workflow in the Esthetic Dental Restoration

This case report presented a fully digital workflow in esthetic dental restoration. A 51-year-old female patient was referred to BDMS Wellness Clinic due to a fracture of the maxillary left central incisor. An immediate dental implant was planned to restore tooth 21 with esthetic crown lengthening of upper front teeth and new zirconia crowns for teeth 11, 12, 13, 21, 22, and 23. Digital impression was made using a digital scanner (PRIMESCAN®, Dentsply Sirona, Bensheim, Germany); surgical guide (Cerec Guide 3, Dentsply Sirona, Bensheim, Germany) was designed by using a designing software (Galileos Software, Dentsply Sirona, Bensheim, Germany) and was milled by using a milling machine (MCXL milling machine, Dentsply Sirona, Bensheim, Germany) to create a precise surgical guide. 3D smile design was done by using the Digital Smile Design (DSD) program, the crown lengthening guide was designed according to DSD designed by using a designing software (Inlab 19 Software, Dentsply Sirona, Bensheim, Germany), and the guide was fabricated by a 3D printer (FormLabs Form 2, Formlab, MA, USA). Provisional crowns (splinted) for teeth 11, 12, 13, 21, 22, and 23 were milled by using polymer (VIPI BLOCK TRILUX®, VIPI Industria, Pirassununga, SP, Brazil) using a milling machine (MCX5, Dentsply Sirona, Bensheim, Germany). The zirconia crowns were designed by using software (Inlab19 Software, Dentsply Sirona, Bensheim, Germany) and milled using the same milling machine. At the implant position, Ti-base is cemented by using an abutment (Multilink Hybrid Abutment, Ivoclar Vivadent, Schaan, Lichtenstein, Germany) with zirconia coping (Cercon base white shade, Dentsply Sirona, Bensheim, Germany) utilized as the abutment. The zirconia crowns (Cercon Xt, Dentsply Sirona, Bensheim, Germany) were sintered and characterized and then cemented. The patient was satisfied with the esthetic outcome of the treatment.

Three Dimensional Digitally Designed Surgical Guides in Esthetic Crown Lengthening: A Clinical Case Report with 12 Months Follow Up

Introduction

The digital workflow has improved the quality of dental care. The integration of computer-aided design/computer-aided-manufacturing (CAD/CAM), cone-beam-computer-tomography (CBCT) and three-dimensional (3D) printing offers significant advantages for treatment planning and allows the dentist to visualize the treatment outcomes before they are initiated. Digital dental technology has become reliable and affordable with many applications for surgical and restorative solutions.

Case Description

The aim of the presented case is to demonstrate the advantages of 3D digitally-designed surgical guides in periodontal surgery. The patient needed esthetic crown lengthening to correct the altered passive eruption. Digital impressions, digital smile design (DSD) and CBCT were used for treatment planning and fabricating of 3D printed surgical guides using a 3D printer. These surgical guides were then used clinically. The clinical outcomes of 12 months follow up were precise and the surgeries were straight-forward, with relatively short procedure time. This is consistent with published literature comparing digitally generated guides to free-hand procedures.

Conclusion

The digitally generated 3D printed guides are reliable tools to perform surgeries precisely. Digital planning software is an efficient communication tool with referring dentists.

Automated integration of facial and intra-oral images of anterior teeth

BACKGROUND AND OBJECTIVE

Digital smile design is the technique that dentists use to analyze, design, and visualize therapeutic results on a computing workstation prior to actual treatment. Despite it being a crucial step in digital smile design, the process of labeling and integrating the information in facial and intra-oral images is laborious. Therefore, this study aims to develop an automated photo integrating system to facilitate this process.

METHODS

The teeth in intra-oral images were distinguished by their curvature and finely segmented using an active contour model. The facial keypoints were detected by a sophisticated facial landmark detector algorithm; these keypoints were then overlaid on the corresponding intra-oral image by extracting the contour of the teeth in the facial and intra-oral photographs. With this system, the tooth width-to-height ratios, smile line, and facial midline were automatically marked in the intra-oral image. The accuracy of the proposed segmentation algorithm was evaluated by applying it to 50 images with 274 maxillary anterior teeth.

RESULTS

The proposed algorithm recognized 96.0% (263/274) of teeth in our selected image set. The results were then compared to those obtained by applying manual segmentation to the remaining 263 recognized teeth. With a 95% confidence interval, a Jaccard index of 0.928 ± 0.081, average distance of 0.128 ± 0.109 mm, and Hausdorff distance between the results and ground truth of 0.461 ± 0.495 mm were achieved.

CONCLUSIONS

The results of this study show that the proposed automated system can eliminate the need for dentists to employ a laborious image integration process. It also has the potential for broad applicability in the field of dentistry.

Digital Smile Design-An innovative tool in aesthetic dentistry

A fundamental objective of an aesthetic treatment is the patient's satisfaction and that the outcome of the treatment should meet the patient's expectation of enhancing his/her facial aesthetics and smile. A patient constantly doubting the end result of the treatment, which is an irreversible procedure, can be motivated and educated through Digital Smile Designing (DSD) technique. DSD is a technical tool which is used to design and modify the smile of patients digitally and help them to visualize it beforehand by creating and presenting a digital mockup of their new smile design before the treatment physically starts. It helps in visual communication and involvement of the patients in their own smile design process, thus ensuring predictable treatment outcome and increasing case acceptance. This article reviews the aspects of digital smile designing in aesthetic dental practice pertaining to its use, advantages, limitations and future prospects.

Milled versus moulded mock-ups based on the superimposition of 3D meshes from digital oral impressions: a comparative in vitro study in the aesthetic area

Background

Aesthetic porcelain veneers proved to be a long-term reliable prosthetic solution, ensuring minimal invasiveness. The use of veneers requires an adhesive cementation technique, so maintaining as much enamel as possible is to ensure lasting success. A diagnostic mock-up is a key tool that allows a preview of the outcome of the aesthetic restoration: it is obtainable both in an analog and digital way. With the recent developments in impression technology and the ever so fast growing use of CAD-CAM technologies it is useful to understand the pros and cons of either one of these techniques (analog and digital) in order to identify the easier and more convenient workflow in aesthetic dentistry.

Methods

After taking pictures and impressions of the dental arcs of a patient in need of aesthetic rehabilitation, 52 resin models were produced and a digital drawing of the smile was outlined. Both an analog and a digital wax-up were obtained from two of the 52 models: the latter was obtained using digital impressions and a dedicated software. The analog wax-up was then used to produce 25 matrices that have later been used to mould 25 resin mock-ups using a traditional moulding protocol (Control Group - CG). The digital wax-up was used to mill 25 PMMA mock-ups. Each mock-up, both milled and moulded (total 50), was then laid on the other 50 resin models as a digital impression of it was taken. The STL. files of the milled mock-ups were compared with the 3D CAD wax-up made using a specific software. The STL. files of the analog printed mock-ups were compared with the traditional wax-up design. A statistical analysis was carried out to evaluate the difference between the groups.

Results

The statistical analysis showed a significant difference (P > 0.01) between the mean value of the distance between the points of the overlapping STL. meshes in GC (0.0468 mm) and in TG (Test Group - TG) (0,0109 mm).

Conclusions

The study showed a difference in accuracy between traditional moulded and milled mock-ups compared to their original wax-up. The data analysis reports that the digital method allows for greater accuracy. Within the limitations of this study, a fully digital workflow is to considered more reliable when it come to creating an esthetic mockup: the digital procedure has been shown to be more accurate than the one made manually which is much more operator dependent and it brings an increase to the chance of error, and that could ultimately affect the final result.

Four-dimensional digital prediction of the esthetic outcome and digital implementation for rehabilitation in the esthetic zone

A technique for 4-dimensional (4D) digital prediction of the outcome of esthetic dentistry for a virtual patient is presented. Static 3D images (which incorporate predicted precise dentition and facial soft tissue in different smiling positions) can be converted into dynamic 3D images by using 3D intraoral imaging, 3D face imaging, and various computer software programs. This strategy can improve the visual perception and quality of esthetic prediction. In addition, the predicted esthetic outcome can be implemented by replicating the contour and shape of digital wax patterns in the definitive ceramic restorations.

Digital smile design and mock-up technique for esthetic treatment planning with porcelain laminate veneers

The use of digital tools offers a new perspective to daily clinical activities. The digital information serves as a starting point for a wax-up and intraoral mock-up, which is widely reported in literature as an objective and efficient communication tool among dentist, patient, and technician. This case report of a maxillary anterior rehabilitation demonstrates esthetic planning with the digital smile design (DSD) system and a direct mock-up technique. After preoperative photographs were obtained, digital planning was created using DSD. However, due to differences in virtual simulation, a direct mock-up with composite resin was performed. Porcelain laminate veneers using feldspathic ceramics were used to restore the anterior teeth. Many times, the DSD simulation is not enough for the patient to understand and observe the changes that will be performed on the anterior teeth. This combination of techniques can offer predictability to results as well increasing the patient expectation satisfaction.

Fully digital workflow, integrating dental scan, smile design and CAD-CAM: case report

Background

This report is a presentation of a clinical case that follows a full digital workflow.

Case presentation

A 47-year old man presented with pain in the TMJ (temporomandibular joint) and whose aesthetic concern was having a chipped maxillary central incisor veneer. The concern was solved following a fully digital workflow: it was applied the digital smile design protocol, as well as CAD-CAM monolithic lithium disilicate ceramic veneers and crowns (following a minimal invasive preparation approach). The aim of this rehabilitation was to solve a loss of vertical dimension, subsequent aesthetics and temporomandibular joint disorders.

Conclusion

Thanks to the evolution of technology in dentistry, it is possible to do a full digital case and solve problems such as loss of vertical dimension successfully. Nevertheless, more clinical studies are needed to obtain consistent results about the digital work flow compared to the conventional technique in loss of vertical dimension cases.

The Effect of Hydrofluoric Acid Concentration and Heat on the Bonding to Lithium Disilicate Glass Ceramic

The aim of this study was to evaluate the effects of hydrofluoric acid (HF) concentration and previous heat treatment (PHT) on the surface morphology and micro-shear bond strength (mSBS) of a lithium disilicate glass ceramic (EMX) to resin cement. One hundred four EMX specimens were randomly assigned to two groups (n=52) according to the HF concentration: 5% and 10%. A new random distribution was made according to the PHTs (n=13): control (no PHT); previously heated HF (70 °C); previously heated EMX surface (85 °C); the combination of heated HF + heated EMX surface. The etching time was set at 20 s. All EMX blocks were silanated and received a thin layer of an unfilled resin. Five resin cement cylinders were made on each EMX surface using Tygon tubes as matrices, and then stored for 24 h at 37 °C. One random etched EMX sample from each group was analyzed using field-emission scanning electron microscopy (FE-SEM). The data were subjected to two-way ANOVA and multiple comparisons were performed using the Tukey post hoc test (a=0.05). For the control groups, 5% HF showed statistically lower mSBS values when compared to 10% HF (p<0.05). PHT increased the mSBS values for 5% HF, yielding statistically similar results to non-PHT 10% HF (p<0.05). FE-SEM images showed increased glassy matrix removal when PHT was applied to HF 5%, but not to the same degree as for 10% HF. PHT has the potential to improve the bond strength of 5% HF concentration on lithium disilicate glass ceramic.

Predictable Outcomes with Porcelain Laminate Veneers: A Clinical Report

This clinical report describes how to achieve predictable outcomes for anterior teeth esthetic restorations with porcelain laminate veneers by associating the digital planning and design of the restoration with interim restorations. The previous digital smile design of the restoration eliminates the communication barrier with the patient and assists the clinician throughout patient treatment. Interim restorations (diagnostic mock-ups) further enhance communication with the patient and prevent unnecessary tooth reduction for conservative tooth preparation. Adequate communication between patient and clinician contributes to successful definitive restorations and patient satisfaction with the final esthetic outcome.

Digital Smile Design for Computer-assisted Esthetic Rehabilitation: Two-year Follow-up

OBJECTIVE

The esthetics of the smile are related to the color, shape, texture, dental alignment, gingival contour, and the relationship of these with the face.

PURPOSE

To present a two-year follow-up for an esthetic rehabilitation clinical case in which the method of digital smile design (DSD) was used to assist and improve diagnosis, communication, and predictability of treatment through an esthetic analysis of the assembly: face, smile, periodontal tissue, and teeth.

CLINICAL PROCEDURE

The smile's esthetics were improved through gingival recontouring, dental home bleaching, and a restorative procedure with thin porcelain laminate veneers using lithium disilicate glass-ceramic (e.max Ceram, Ivoclar-Vivadent) laminates on teeth 4 through 13.

DISCUSSION

The proposed technique had an acceptable clinical performance at the end of a two-year follow-up.

SIGNIFICANCE

DSD can be used to increase professional/patient communication and to provide greater predictability for the smile's esthetic rehabilitation.