PURPOSE: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. METHODS: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. RESULTS: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. CONCLUSIONS: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.
Artifacts ; Bone-Implant Interface ; New Zealand ; Tibia ; X-Ray Microtomography

Purpose: This study aimed to find a correlation between the occlusal plane and two reference planes that are frequently used in semi-adjustable articulators. Materials and Methods: Sixty-two males and fifty females with normal articulation were recruited and the lateral cephalograms of these patients were taken. The angles between the Frankfort horizontal (FH) and the occlusal planes, the angles between the gnathologic and the occlusal planes, and the angles between the FH and gnathologic planes were measured on the lateral cephalograms.Result: The mean angles between the FH and the occlusal planes was 8.29°±3.62°, with 8.88°±3.09° and 7.63°±4.10°for male and female patients, respectively. The mean angles between the gnathologic and the occlusal planes was 2.77°±3.62°, and the angle between the FH and the gnathologic planes was 5.52°±3.62°. No significant differences were found in the measured angles between the male and female patients (P>0.05). Conclusion Different guidance angles may be applied to articulators for prosthodontic restoration, depending on the reference planes that the articulators use.

Computer aided design and manufacturing and implant surgery using a guide template improve restoration-driven implant treatment procedures. This case utilized those digital technologies to make definitive prostheses for a patient. According to the work flow of digital dentistry, cone beam computed tomography established the treatment plan, which was followed to make the guide template for implant placement. The template guided the implants to be installed as planned. The customized abutments and surveyed fixed restorations were digitally designed and made. The metal framework of the removable partial denture was cast from resin pattern using an additive manufacturing technique, and the artificial resin teeth were replaced with the zirconia onlays for occlusal stability. These full mouth rehabilitation procedures provided functionally and aesthetically satisfactory results for the patient.
Computer-Aided Design ; Cone-Beam Computed Tomography ; Dentistry ; Denture, Partial, Removable ; Humans ; Inlays ; Mouth Rehabilitation* ; Mouth* ; Prostheses and Implants ; Tooth ; Workflow

Smile design has transitioned from traditional analog methods to modern digital techniques. This case report presents a smile design technique using a digital workflow facilitated by an application on smart devices as a reference. This approach enables real-time chairside modifications, incorporating the patient’s preferences. Furthermore, it improves communication among the patient, clinician, and dental technician, providing an efficient solution for prosthetic rehabilitation.

Smile design has transitioned from traditional analog methods to modern digital techniques. This case report presents a smile design technique using a digital workflow facilitated by an application on smart devices as a reference. This approach enables real-time chairside modifications, incorporating the patient’s preferences. Furthermore, it improves communication among the patient, clinician, and dental technician, providing an efficient solution for prosthetic rehabilitation.

Smile design has transitioned from traditional analog methods to modern digital techniques. This case report presents a smile design technique using a digital workflow facilitated by an application on smart devices as a reference. This approach enables real-time chairside modifications, incorporating the patient’s preferences. Furthermore, it improves communication among the patient, clinician, and dental technician, providing an efficient solution for prosthetic rehabilitation.

Smile design has transitioned from traditional analog methods to modern digital techniques. This case report presents a smile design technique using a digital workflow facilitated by an application on smart devices as a reference. This approach enables real-time chairside modifications, incorporating the patient’s preferences. Furthermore, it improves communication among the patient, clinician, and dental technician, providing an efficient solution for prosthetic rehabilitation.

PURPOSE: Contact and distance osteogenesis occur around all endosseous dental implants. However, the mechanisms underlying these processes have not been fully elucidated. We hypothesized that these processes occur independently of each other. To test this, we used titanium (Ti) tubes to physically separate contact and distance osteogenesis, thus allowing contact osteogenesis to be measured in the absence of possible triggers from distance osteogenesis. METHODS: Sandblasted and acid-etched (SLA) and modified SLA (modSLA) implants were used. Both types had been sandblasted with large grit and then etched with acid. The modSLA implants then underwent additional treatment to increase hydrophilicity. The implants were implanted into rabbit tibiae, and half were implanted within Ti tubes. The bone-to-implant contact (BIC) ratio was calculated for each implant. Immunohistochemical analyses of bone morphogenetic protein (BMP)-2 expression and new bone formation (Masson trichrome stain) were performed. RESULTS: The implants outside of Ti tubes were associated with good bone formation along the implant surface. Implantation within a Ti tube significantly reduced the BIC ratio (P<0.001). Compared with the modSLA implants, the SLA implants were associated with significantly higher BIC ratios, regardless of the presence or absence of Ti tubes (P=0.043). In the absence of Ti tubes, the bone adjacent to the implant had areas of new bone formation that expressed BMP-2 at high levels. CONCLUSIONS: This study disproved the null hypothesis and suggested that contact osteogenesis is initiated by signals from the old bone that undergoes distance osteogenesis after drilling. This signal may be BMP-2.
Bone and Bones ; Bone Morphogenetic Proteins ; Bone-Implant Interface ; Dental Implants ; Hydrophobic and Hydrophilic Interactions ; Osteogenesis* ; Tibia* ; Titanium

This report describes two cases of complete arch implant-supported restorations. The first patient had seven dental implants in each arch with monolithic zirconia frameworks. At four weeks' follow-up, the one-piece maxillary framework was fractured, which was re-designed and re-fabricated using laser-sintered cobalt-chrome alloy. The second patient had four implants in the mandible only. A mandibular monolithic zirconia framework and a maxillary conventional complete denture were fabricated and delivered. At five years' follow-up, the patient reported no significant discomfort. Careful consideration and monitoring of the status of antagonistic arches and stress distribution on zirconia frameworks were suggested for complete arch implant-supported fixed restorations
Alloys ; Dental Arch ; Dental Implants ; Dental Prosthesis, Implant-Supported ; Dental Stress Analysis ; Denture, Complete ; Follow-Up Studies ; Humans ; Mandible ; Mouth, Edentulous

With the development of digital dentistry, it is being applied in various ways of dental treatment. This case report presents the definitive prosthesis designed in advance with a re-established vertical dimension and the digital technology, which determined the amount of tooth preparation, in order to preserve as much tooth structure as possible in a patient with pathological wear of the posterior teeth and loss of vertical dimension. For accurate tooth preparation, the guides of the occlusal and axial surfaces were digitally and additively manufactured. Then, aesthetics and anterior guidance were established at the provisional stage. The information of the provisional restoration was delivered to the definitive stage by double scanning. The digital technology, including the virtual planning and the guided tooth removal, produced the definitive restorations satisfactory to both the patient and clinician.