Computer-aided Rapid Prototyping Research Articles

Development of an Adaptive Centrifugal Working Tool for Mineral Fertilization Using Rapid Prototyping Technologies

Introduction. Improvement of the agro-industrial complex involves the creation of new and modernizations of existing working tools and machines. The important conditions for this are the application of modern technologies and ongoing cooperation with the actual manufacturing. The aim of the research is to develop an adaptive centrifugal working tool and improve the quality of mineral fertilization. Materials and Methods. The adaptive centrifugal working tool was developed and manufactured based on studying the state of the matter and requirements to machines for mineral fertilization. At all stages of the research, there were used computer-aided design and rapid prototyping methods based on additive technologies. Results. As a result of the use of the presented working tools, the machine operating width has increased by 10.0‒22.5%. Experimental working tools, in comparison with serial ones, allow decreasing uneven distribution of mineral fertilizers by 13.4% due to their redistribution from the central zone to the edges. Discussion and Conclusion. As a result of experimental studies, the efficiency of the developed adaptive centrifugal working tools has been proved. It allows increasing uniformity of mineral fertilizer distribution and the machine operating width. Modern design methods make it possible to considerably reduce time and costs.

Advanced Design and Fabrication of Islamic Tile Ceramic Wall Tiles With Indonesian Batik Patterns Using Artistic CAD/CAM and 3D Printing Technology

The ceramic tile wall is a decorative element used inside restaurants, museums, hotels, aristocratic residences, and places of worship. It plays a critical role in the development of a structure with strong personality and unique qualities by providing relief patterns specific to history or era. The demand for distinctive ornamental wall ceramics that can be mass produced with precision and accuracy has been a challenge for numerous ceramic enterprises in Indonesia, which have historically relied on the skills of artistic professionals in a handmaking process. The purpose of this research was therefore to develop and apply a ceramic tile design process that integrates computer design and fabrication methods with traditional ceramic production techniques. Using the ArtCAM 2015R2 software, photos of batik and Islamic themes were effectively converted into a 2.5D computer-aided design model. Additive manufacturing technology was then used in conjunction with Objet30 Pro 3D printer to precisely produce master molds with Islamic nuances such as puzzle and floral patterns, then conventional ceramic fabrication technology was employed to produce ceramic tiles using these molds. By combining computer-aided design and rapid prototyping technologies, a variety of exact and detailed Islamic decorative ceramic wall tiles were produced with dimensional accuracies within 2.00 mm. Furthermore, the proposed approach demonstrated a 90% reduction in design-to-production time from to 10–12 months to roughly 1–1.5 months.

Mid-term outcomes and periodontal prognostic factors of autotransplanted third molars: A retrospective cohort study.

Tooth autotransplantation is a valid method for replacing non-restorable teeth. This study aimed to assess mid-term survival and success of autotransplanted third molars and the clinical periodontal parameters and factors predicting successful periodontal attachment apparatus regeneration. In total, 36 patients who had undergone extraction and subsequent autotransplantation of 36 third molars using virtual planning and computer-aided rapid prototyping models by an oral surgeon and endodontist were eligible. Probing pocket depth (PPD), gingival recession (REC), clinical attachment level (CAL), pulpal and periapical healing, root resorption, and radiographic bone loss (RBL) were evaluated. Additionally, a questionnaire evaluated patient-reported outcomes. The mean age of the participants was 30.2 years with a mean follow-up duration of 29.42 ± 14.56 months. The overall survival and success rates were 97.2% and 91.7%, respectively. No statistically significant differences were found in success and survival rates between open and closed apex groups or between compromised and intact buccal bone groups. No signs of pulp necrosis were found in the open apex group. Progressive replacement resorption was detected in one closed apex case. The mean PPD was 2.7 ± 0.45mm for all transplanted teeth. REC was 0.13mm higher in transplanted teeth than in previous hopeless teeth. CAL changes were neither clinically relevant (-0.17 ± 0.66mm) nor statistically significant. The reported patient satisfaction was high. Autotransplantation of third molars is a predictable treatment method, with a 2.5-year cumulative tooth survival and success of 97.2% and 91.7%, respectively, which were not influenced by recipient site integrity or root development.

The computer-aided design and rapid prototyping fabrication of removable partial denture framework for occlusal rehabilitation: clinical report

The objective of this case report was to describe the clinical sequence for occlusal vertical dimension (OVD) recovering with the manufacture of removable partial dentures (RPD) produced by computer-aided design and rapid prototyping. The patient presented to the Dentistry Department of the Federal University of Rio Grande do Norte reporting dissatisfaction with the superior RPD. At clinical investigation, a fracture in the minor connector and support at the region of tooth 15 was observed, in addition to severe OVD loss. In this case, after obtaining correct OVD, four more sessions were necessary for RPD fabrication. In the first appointment, intraoral scanning was performed to generate STL files used for path of insertion determination in the CAD software. The need for a guide plane on tooth 15 was observed, thus a preparation guide was designed and 3Dprinted to aid axial tooth reduction. At the second visit, after mouth preparation, another intraoral scanning was performed to acquire virtual working models. The RPD framework was designed and 3D printed in a castable resin pattern and invested for cobalt-chromium alloy melting. In the third visit, clinical evaluation of the framework and teeth and artificial gingiva colors selection were performed. The articulated models were then 3D printed, enabling pre-fabricated teeth to be assembled and acrylized. On the fourth appointment, RPD was installed and the patient received routine instructions. In this sense, the use of CAD/CAM technologies presented as a valuable tool to enhance restoration of OVD by the manufacturing of RPD.

Retrospective Evaluation of Immediate Impacted Third Molars Autotransplantation After Extractions of Mandibular First and/or Second Molars With Chronic Periapical Lesions

To evaluate the success rate of simultaneous autotransplantation of the immature impacted third molars with the guidance of computer-aided rapid prototyping (CARP) to the place of mandibular first or secondmolars with extraction indication due to the untreatable radiographic periapical lesions. Twelve radiographically and clinically hopeless mandibular first or secondmolars with periapical lesions of 10 patients between the ages of 15 to 21 were included in this retrospective clinical study. Cone-beam computed tomography (CBCT) images were used to produce the CARP models of the donor impacted third molars. Following the extractions of the mandibular first or secondmolars with periapical lesions, sockets were curetted and prepared with proper burs until a suitable infraocclusal fit of the CARP models. The donor teeth were transplanted synchronously with their surgical extractions. Postoperatively patients were followed clinically and radiographically in the 3rd and 6th months and every 6th month thereafter for at least 18months. Clinically, the mobility, periodontal plaque, bleeding on probing, percussion sensitivity, periodontal pocket, vitality, and occlusion, and radiographically, the root resorption, ankylosis, presence of lamina dura, and healing of periapical lesion were assessed. By the end of 12th month, and thereafter, all transplanted teeth were in occlusion and functioning properly with no clinical or radiological signs of pathology. All of the autotransplantation cases involved in this clinical study were successful within a mean follow-up period of 20.4months with the least one of 18months. Immediate autotransplantation of the immature third molars to the place of mandibular first or secondmolars with extraction indication due to the periapical lesion can be a proper treatment option for adolescent patients.

Fully Guided Tooth Autotransplantation Using a Multidrilling Axis Surgical Stent: Proof of Concept

IntroductionDigital technology has been progressively introduced into tooth autotransplantation to enhance both treatment planning and surgery. The aim of this report was to describe a novel protocol for fully guided tooth autotransplantation. MethodsThis report includes 10 consecutive patients treated with a complete virtual planning and a multidrilling axis surgical guide in combination with the computer-aided rapid prototyping model. ResultsAll transplanted teeth fulfilled the criteria for success over a mean follow-up duration of 13.1 months. No signs of progressive root resorption or pain were found during follow-up. One case required minimal adjustment of the surgical stent to allow correct seating, whereas a second case could not be performed fully guided because of limited mouth opening. ConclusionsOur protocol for fully guided tooth autotransplantation is a viable option that involves minimal bone preparation in a short surgical time. Future research should focus on further investigation of the benefits of this novel protocol in a larger sample.

Autotransplantation of third molars with completely formed roots to replace compromised molars with the computer-aided rapid prototyping.

To describe a method to fabricate donor tooth replica to assist surgeons in preparation of recipient socket during tooth autotransplantation. A total of 28 compromised molars in 27 patients were transplanted with third molars using computer-aided rapid prototyping (CARP) technique. Surgery time and extra-alveolar time were documented. Postoperatively, the distance between cervix of transplanted tooth and the alveolar wall was measured. The degree of postoperative pain experienced was assessed with visual analog scale at day 1, 3, and 7. From 28 clinical cases, the average extra-alveolar time and surgery time were 2.5 minutes (±1.3) and 44 minutes (±6.8), respectively. Postoperatively, the average distance between cervix of transplanted tooth and the alveolar wall was 0.87 mm (±0.15) at the mesial-cervix, 0.95 mm (±0.17) at the distal-cervix, 0.88 mm (±0.18) at the buccal-cervix, and 0.95 mm (±0.13) at the lingual-cervix. The value of visual analog scale score significantly decreased from day 1 to day 3. CARP is a reliable technique for fabrication of tooth like surgical replicas in conventional autotransplantation. CARP technique minimized extra-oral time, reduced iatrogenic damage, and consequently increased the survival rate of tooth autotransplantation.

The masks of Lorenzo Tenchini: their anatomy and surgical/bioengineering clues.

An academic, anatomist, and Lombrosian psychiatrist active at the University of Parma in Italy at the end of the 19th century, Lorenzo Tenchini produced ceroplastic-like masks that are unique in the anatomical Western context. These were prepared from 1885 to 1893 with the aim of 'cataloguing' the behaviour of prison inmates and psychiatric patients based on their facial surface anatomy. Due to the lack of any reference to the procedure used to prepare the masks, studies were undertaken by our group using X-ray scans, infrared spectroscopy, bioptic sampling, and microscopy analysis of the mask constituents. Results showed that the masks were stratified structures including plaster, cotton gauze/human epidermis, and wax, leading to a fabrication procedure reminiscent of 'additive layer manufacturing'. Differences in the depths of these layers were observed in relation to the facial contours, suggesting an attempt to reproduce, at least partially, the three-dimensional features of the facial soft tissues. We conclude the Tenchini masks are the first historical antecedent of the experimental method for face reconstruction used in the early 2000s to test the feasibility of transferring a complete strip of face and scalp from a deceased donor to a living recipient, in preparation for a complete face transplant. In addition, the layering procedure adopted conceptually mimics that developed only in the late 20th century for computer-aided rapid prototyping, and recently applied to bioengineering with biomaterials for a number of human structures including parts of the skull and face. Finally, the masks are a relevant example of mixed ceroplastic-cutaneous preparations in the history of anatomical research for clinical purposes.

Virtual Simulation of Autotransplantation Using 3-dimensional Printing Prototyping Model and Computer-assisted Design Program

This case report describes an innovative virtual simulation method using a computer-aided rapid prototyping (CARP) model and a computer-aided design (CAD) program for autotransplantation of an immature third molar.A compromised left mandibular second molar (#18) was extracted and replaced by autotransplantation using an immature left mandibular third molar (#17). In order to minimize the surgical time and injury to the donor tooth, a virtual 3-dimensional (3D) rehearsal surgery was planned. Cone-beam computed tomographic images were taken to fabricate the 3D printing CARP model of the donor tooth and tentative extraction socket. Subsequently, both CARP models were scanned with an intraoral scanner (CEREC Omnicam; Dentsply Sirona, Bensheim, Germany) followed by superimposition and virtual simulation of osteotomy preparation of the recipient alveolus using the CAD analysis program. During the surgery, the extraction socket was precisely prepared according to the predetermined location and dimensions via virtual simulation rehearsal surgery using CAD analysis. The donor tooth was atraumatically transplanted into the prepared socket. The follow-up examination revealed that the root developed with a normal periodontal ligament and lamina dura.Virtual simulation using a 3D printing CARP model and a CAD program could be clinically useful in autotransplantation of an immature third molar by ensuring an atraumatic and predictable surgery.

The elective management of maxillofacial trauma: improving surgical outcomes using computer-aided design and rapid prototyping for patient-specific solutions

The elective management of maxillofacial trauma: improving surgical outcomes using computer-aided design and rapid prototyping for patient-specific solutions

RETRACTED

At the request of the editorMayank Shah 'Auricular prosthesis fabrication using computer-aided design and rapid prototyping technologies' Prosthetics and Orthotics International, published online before print on October 8, 2013 as doi:10.1177/0309364613504779has been retracted. This is because it contains unattributed overlap withK. Subburaj, C. Nair, S. Rajesh, S. M. Meshram, B. Ravi 'Rapid development of auricular prosthesis using CAD and rapid prototyping technologies' International Journal of Oral & Maxillofacial Surgery 2007; 36: 938-943 doi:10.1016/j.ijom.2007.07.013.

Minimizing the extra-oral time in autogeneous tooth transplantation: use of computer-aided rapid prototyping (CARP) as a duplicate model tooth

ObjectivesThe maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique.Materials and MethodsBriefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth.ResultsThe average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model.ConclusionsThese data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation.

Autotransplantation with Simultaneous Sinus Floor Elevation

Introduction Autotransplantation of the third molar is a viable option for replacing missing molars and has some benefits. This case report showed successful autotransplantation with simultaneous sinus floor elevation and implant installation. Methods The patient suffered a loss of maxillary molars and had a pneumatized maxillary sinus under the area in need of restorative treatment. Instead of implant installation in the molar area, we performed autotransplantation of the mandibular third molar with simultaneous sinus floor elevation with the aid of computer-aided rapid prototyping model. Results Healing was uneventful. There were no subsequent long-term symptoms or discomfort in the transplanted area. Clinical examinations revealed no mobility of the transplanted tooth, and there was no radiographic evidence of root resorption or ankylosis at a follow-up visit 4 years after transplantation. Conclusions Autotransplantation with simultaneous sinus floor elevation is a potential treatment alternative to implant installation in selected cases.

A Focus On Use

This article analyses the need and benefit of the working of industrial designers and product engineers together. According to engineers and others at the forefront of product development, to do the job right requires a collaboration involving design engineers, industrial designers, manufacturing engineers, and several other players, like marketing people, all of whom have important knowledge that needs to influence a design. Companies such as Trek Bicycle Corp. and Empire Level Manufacturing Corp. have developed practices that foster innovative, human-centered product development. Experts agree that computer-aided design (CAD) and rapid prototyping applications are the two most helpful systems, even though the two types of designers may use the tools in somewhat several ways. According to Rainer Gawlick, vice president of marketing at SolidWorks in Concord, Massachusetts, current CAD systems can help bridge the design-to-engineering-to-manufacturing gap.

Three-dimensional visualization of a mandibular first molar with three distal roots using computer-aided rapid prototyping

Nonsurgical endodontic therapy of a right mandibular first molar with 3 distal roots was successfully performed with the aid of magnification. 3D data (DICOM format) of the tooth were obtained from a CT HighSpeed Advantage and a Denta Scan program produced by GE Medical Systems. The CT protocol used for this procedure involved a slit thickness of 1 mm. The 3D digital data obtained were fed into a visualization program (V-works; Cybermed Co) and then exported to the rapid prototyping machine for fabrication of the actual-sized tooth model. The material for the model-making process was starch. The 3D digital visualization and the computer-aided rapid prototyping (CARP) model clearly showed 3 separate distal roots (distobuccal, distolingual, and middle distal). The CARP technique seems to be a useful imaging technology to document unusual root anatomy in clinical dentistry.

Evaluation of the prognosis and causes of failure in 182 cases of autogenous tooth transplantation

Autotransplantation is a viable option for treating missing teeth when a donor tooth is available. The aim of this study was to evaluate the prognosis in addition to the causes of failure in 182 autotransplanted teeth. A total of 182 cases of autotransplantation were analyzed. All the transplants were performed according to a computer-aided rapid prototyping technique with an average extraoral time of 7.58 minutes. These cases were followed for 2 to 60 months after surgery. The prognosis was divided into 4 groups, complete healing, incomplete healing, uncertain healing, and failure. The initial stability, root resorption, and ankylosis were also analyzed. Most transplanted teeth showed complete healing between postoperative 2 months and 8 months. The transplanted teeth with a good initial stability showed better initial healing than those with a poor initial stability. The average extraoral time was 7.58 min (range: immediately after extraction up to 25 min). There was no relationship (P > .05) between the extraoral time and either root resorption (4 cases, 2.4%) or ankylosis (18 cases, 10.7%) within this experimental time period. Nine cases (4.5%) failed. This study showed a 4.5% failure rate during the short to intermediate observation period. Autotransplantation is a very useful method for replacing missing teeth, provided that the extraoral time and other factors are well controlled.

Clinical Application of Stereolithographic Surgical Guides for Implant Placement: Preliminary Results

The success of implant-supported restorations requires detailed treatment planning, which includes the construction of a surgical guide. Recently, computer-aided rapid prototyping has been developed to construct surgical guides in an attempt to improve the precision of implant placement. The aim of the present study was to evaluate the match between the positions and axes of the planned and placed implants when a stereolithographic surgical guide is employed. Six surgical guides used in four patients (three women, one man; age from 23 to 65 years old) were included in the study and 21 implants were placed. A radiographic template was fabricated and computer-assisted tomography (CT) was performed. The virtual implants were placed in the resulting 3-dimensional image. Using a stereolithographic machine, liquid polymer was injected and laser-cured according to the CT image data with the planned implants, generating three surgical guides, with increasing tube diameters corresponding to each twist drill diameter (2.2, 3.2, and 4.0 mm), for each surgical area. During the implant operation, the surgical guide was placed on the jawbone and/or the teeth. After surgery, a new CT scan was taken. Software was used to fuse the images of planned and placed implants, and the locations and axes were compared. On average, the match between the planned and the placed implant axes was within 7.25 degrees +/- 2.67 degrees ; the differences in distance between the planned and placed positions at the implant shoulder were 1.45 +/- 1.42 mm, and 2.99 +/- 1.77 mm at the implant apex. In all patients, a greater distance was found between the planned and placed positions at the implant apex than at the implant head. Clinical data suggest that computer-aided rapid prototyping of surgical guides may be useful in implant placement. However, the technique requires improvement to provide better stability of the guide during the surgery, in cases of unilateral bone-supported and non-tooth-supported guides. Further clinical studies, using greater number of patients, are necessary to evaluate the real impact of the stereolithographic surgical guide on implant therapy.

Computer-aided paleontology: a new look for dinosaurs

Over the past 150 years, our perception of how dinosaurs looked has changed on the basis of museum displays and artists' renditions. Reproductions of lumbering dinosaurs at London's Crystal Palace during the mid 1800s look little like the creatures in the 40-year-old murals at Yale University's Peabody Museum of Natural History, or the computer-animated images of agile animals depicted in the Jurassic Park movies and recent television documentaries. Now, researchers are combining techniques from computer-aided design, rapid prototyping, and biomechanics to develop more accurate theories of dinosaurs' posture and movements. This information will affect paleontologists' concepts of how the animals lived and what they ate. Perhaps the most notable example of this synergy of paleontology and computing-related fields has been the restoration of the Smithsonian Institution's trademark dinosaur -a triceratops mounted some 90 years ago - as part of a refurbishing of the dinosaur hall in the Smithsonian's National Museum of Natural History in Washington, DC.

In via recta celeriter (in the right way quickly)

Provides a short history of the biggest collaborative research project on rapid prototyping in Europe – Computer‐Aided Rapid Prototyping (CARP) – which is concerned with the concept of design and manufacture “right first time”. Introduces the organizations involved with the project, and discusses some of the results, including the manufacture of functional components from rapid prototype models. Discusses some of the issues relating to data transfer and the limitations of CAD. Finishes with a view of how the technology is evolving and how and where it might be applied in the near future.