Background: Periodontal diagnosis relies heavily on traditional two‐dimensional radiographic assessment. Despite efforts in improving reliability, current methods of detecting bone level changes over ...time or determining three‐dimensional architecture of osseous defects are inadequate. To address these issues, computed tomography (CT) has been explored because of its ability to produce accurate three‐dimensional imaging, but limitations such as radiation, machine size, and cost have made this approach impractical. Recently, cone beam computed tomography (CBCT) has turned this concept into potential reality because these lower‐cost small machines produce high‐quality data. Yet there is little research to establish periodontal bone measurement using CBCT as a valid method. Therefore, the aim of this study was to compare CBCT measurements of periodontal defects to traditional methods.
Methods: Artificial osseous defects were created on mandibles of dry skulls. CBCT scanning, periapical radiography (PA), and direct measurements using a periodontal probe were compared to an electronic caliper that was used as a standard reference.
Results: Linear measurements for all defects revealed no statistical differences between bone sounding, radiography, and CBCT. There was a significant difference when comparing isolated interproximal measurements using a probe versus the caliper (P <0.001) but no significant difference for CBCT or radiography. All bony defects were identifiable and measurable directly or with CBCT. In comparison, buccal and lingual defects could not be measured with radiographs.
Conclusions: Overall, all three modalities are useful for identifying interproximal periodontal defects. Compared to radiographs, the three‐dimensional capability of CBCT offers a significant advantage because all defects can be detected and quantified.
Placement of dental implants requires precise planning that accounts for anatomic limitations and restorative goals. Diagnosis can be made with the assistance of computerized tomographic (CT) ...scanning, but transfer of planning to the surgical field is limited. Recently, novel CAD/CAM techniques such as stereolithographic rapid prototyping have been developed to build surgical guides in an attempt to improve precision of implant placement. However, comparison of these advanced techniques to traditional surgical guides has not been performed. The goal of this study was to compare the accuracy of a conventional surgical guide to that of a stereolithographic surgical guide.
CT scanning of epoxy edentulous mandibles was performed using a cone beam CT scanner with high isotropic spatial resolution, while planning for 5 implants on each side of the jaw was performed using a commercially available software package. Five surgeons performed osteotomies on a jaw identical to the initial model; on the right side a conventional surgical guide (control side) was used, and on the left side a stereolithographic guide was used (test side). Each jaw was then CT scanned, and a registration method was applied to match it to the initial planning. Measurements included distances between planned implants and actual osteotomies.
The average distance between the planned implant and the actual osteotomy was 1.5 mm at the entrance and 2.1 mm at the apex when the control guide was used. The same measurements were significantly reduced to 0.9 mm and 1.0 mm when the test guide was used. Variations were also reduced with the test guide, within surgeons and between surgeons.
Surgical guidance for implant placement relieves the clinician from multiple perioperative decisions. Precise implant placement is under investigation using sophisticated guidance methods, including CAD/CAM templates.
Within the limits of this study, implant placement was improved by using a stereolithographic surgical guide.
The aviation industry uses crew resource management (CRM) to address the human aspect of error. Dentistry can incorporate these concepts to reduce dental error. The authors provide a checklist to ...help clinicians mitigate error.
Health care systems have begun to focus on medical error. During the past 30 years, the airline industry has developed mitigation strategies that are being adapted for medicine. CRM involves the use of information, equipment and people to increase safety by targeting early identification of errors.
To enhance safety, practitioners must implement forward-thinking strategies. Because human error is inevitable, threat and error management (TEM) techniques are needed to help identify and trap error before it develops into unexpected outcomes. Risk analysis increases situational awareness (SA) of potential dental error. Efficiency increases with early error detection.
The authors provide a dental checklist that is divided into "appointment review," "before procedure," "procedure," "before dismissal" and "after dismissal" to organize dental activities in a manner that enhances error detection.
The dental checklist is a tool to incorporate CRM and TEM techniques into the dental care environment to increase SA, safety and efficiency.
The mandibular first molar (M1) tooth of the dog is commonly involved in dental procedures. Tooth roots and the mandibular canal can vary in location, which has not been described on a large scale. ...The objective of this study was to describe the three-dimensional anatomic relationship of the mandibular M1 tooth roots and the mandibular canal in dogs. Cone-beam computed tomography (CBCT) was used to evaluate the anatomic relationship between the M1 tooth roots and the mandibular canal. CBCT images were collected from 101 canine cadaver heads from a variety of unknown breeds. All skulls used in this study were mesaticephalic, confirmed by facial index calculations. The position of the apex in relation to the mandibular canal and in relation to the buccal and lingual cortices was recorded and analyzed in relation to mandibular bone height: root length ratio. When evaluating the apex in a buccal-lingual relationship, the tooth roots were found to be located closer to the lingual cortex in 73.3% of M1 roots. Tooth root apical positions were found to be symmetric between the right and left side of the mouth in 93% of mesial roots and 95% of distal roots. Apical positions relative to the mandibular canal within the same tooth were found to be consistent in 52% of teeth. Teeth with roots dorsal to the mandibular canal were associated with the largest mandibular bone height: root length ratio. CBCT provides a more precise overview than dental radiographs of three-dimensional anatomy. The tooth root position can be estimated in a clinical setting based on the ratio of mandibular bone height to tooth root length obtained from intraoral radiographs. Understanding the relative location of important anatomic structures is key to avoiding complications associated with various dental procedures. This study has documented that assessing anatomic structures with 2D imaging alone is flawed, and the large majority of dogs have M1 roots closer to the lingual aspect than the buccal aspect of the mandible.
Abstract Apicoectomy is a surgical procedure requiring precise planning and access to locate apices and avoid vital anatomic structures. Traditional methods limit treatment because they rely on ...two-dimensional radiography and corrective actions during surgery. Surgical guidance, which uses computed tomography and computer-aided design and computer-aided manufacturing processing, has been utilized in dentistry, but not in endodontics. Therefore, the aim of this study was to introduce periapical surgical guidance using computed tomography and computer-aided design and computer-aided manufacturing surgical guides and to compare apical access accuracy using guidance versus a conventional method. Results showed that distance from the apex was 0.79 mm (±0.33 SD) using guidance and 2.27 mm (±1.46 SD) using freehand drilling. An error greater than 3 mm occurred over 22% of the time freehand, yet never occurred with guidance. This in vitro study suggests that greater accuracy and consistency can be achieved during endodontic surgery with surgical guidance. Advantages also include presurgical visualization in three dimensions.
Purpose: Growth factors such as platelet‐derived growth factor (PDGF) exert potent effects on wound healing including the regeneration of periodontia. Pyridinoline cross‐linked carboxyterminal ...telopeptide of type I collagen (ICTP) is a well‐known biomarker of bone turnover, and as such is a potential indicator of osseous metabolic activity. The objective of this study was to evaluate the release of the ICTP into the periodontal wound fluid (WF) following periodontal reconstructive surgery using local delivery of highly purified recombinant human PDGF (rhPDGF)‐BB.
Methods: Forty‐seven human subjects at five treatment centres possessing chronic severe periodontal disease were monitored longitudinally for 24 weeks following PDGF regenerative surgical treatment. Severe periodontal osseous defects were divided into one of three groups and treated at the time of surgery with either: β‐tricalcium phosphate (TCP) osteoconductive scaffold alone (active control), β‐TCP+0.3 mg/ml of rhPDGF‐BB, or β‐TCP+1.0 mg/ml of rhPDGF‐BB. WF was harvested and analysed for local ICTP levels by radioimmunoassay. Statistical analysis was performed using analysis of variance and an area under the curve analysis (AUC).
Results: The 0.3 and 1.0 mg/ml PDGF‐BB treatment groups demonstrated increases in the amount of ICTP released locally for up to 6 weeks. There were statistically significant differences at the week 6 time point between β‐TCP carrier alone group versus 0.3 mg/ml PDGF‐BB group (p<0.05) and between β‐TCP alone versus the 1.0 mg/ml PDGF‐BB‐treated lesions (p<0.03). The AUC analysis revealed no statistical differences amongst groups.
Conclusion: This study corroborates the release of ICTP as a measure of active bone turnover following local delivery of PDGF‐BB to periodontal osseous defects. The amount of ICTP released from the WF revealed an early increase for all treatment groups. Data from this study suggests that when PDGF‐BB is delivered to promote periodontal tissue engineering of tooth‐supporting osseous defects, there is a direct effect on ICTP released from the wound.
To maximize the outcome of implant placement, the use of advanced radiographic procedures such as computerized tomography, along with fabrication of surgical guides, has been advocated to inform ...surgeons of ideal implant location. More recently, simulation computer software has been introduced to view radiographic images and test potential implant locations. Yet, surgical guides are processed based on ideal tooth position, with little consideration for underlying anatomical limitations, which creates a disconnection between diagnostic planning and surgical restrictions. In response to this "missing link," computer-assisted design and computer-assisted manufacturing, as well as real-time surgical navigation were recently developed to obtain fully integrated surgical and prosthetic planning. Today, there are several technologies available, but, to our knowledge, a systematic assessment of surgical guidance has not yet been performed. Therefore, the aims of this review are to introduce advanced radiographic and software modalities, and present a detailed assessment of computer-assisted design and computer-assisted manufacturing methods and surgical navigation.
Objectives: Implant osseointegration is dependent upon various factors, such as bone quality and type of implant surface. It is also subject to adaptation in response to changes in bone metabolism or ...transmission of masticatory forces. Understanding of long‐term physiologic adjustment is critical to prevention of potential loss of osseointegration, especially because excessive occlusal forces lead to failure. To address this issue, wide‐diameter implants were introduced in part with the hope that greater total implant surface would offer mechanical resistance. Yet, there is little evidence that variation in diameter translates into a different bone response in the implant vicinity. Therefore, this study aimed at comparing the impact of implant diameter on surrounding bone.
Material and methods: Twenty standard (3.75 mm) and 20 wide (5 mm) implants were placed using an animal model. Histomorphometry was performed to establish initial bone density (IBD), bone to implant contact (BIC) and adjacent bone density (ABD).
Results: BIC was 71% and 73%, whereas ABD was 65% and 52%, for standard and wide implants, respectively. These differences were not statistically different (P>0.05). Correlation with IBD was then investigated. BIC was not correlated with IBD. ABD was not correlated to IBD for standard implants (r2=0.126), but it was correlated with wide implants (r2=0.82). In addition, a 1 : 1 ratio between IBD and ABD was found for wide implants. It can be concluded, within the limits of this study, that ABD may be influenced by implant diameter, perhaps due to differences in force dissipation.
In recent years, dental implant rehabilitation has faced demands from prosthetic and esthetic arenas that call for increasingly ideal outcomes, which require precise surgical planning and placement. ...Anatomic limitations and bone quantity and quality can now be evaluated using more sophisticated radiographic techniques, although transferring this information to the surgical phase has been at best a difficult task. Recently, computer-aided design and manufacturing have made it possible to use data from computerized tomography to not only plan implant rehabilitation, but also to transfer this information to the surgery. One of these techniques uses stereolithography, a laser-driven polymerization process that fabricates an anatomic model and surgical templates. This novel approach is illustrated with two advanced cases, demonstrating that the technique not only allows for the precise translation of the treatment plan directly to the surgical field, but also offers many significant benefits over traditional procedures.
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