Implant surgical guides are often fabricated using CBCT technology. In this study, an alternative technique is proposed. The aim of this in vitro study was to compare the accuracy of the guide sleeve ...corrections of a geometric approach to guided surgery to the accuracy of in vitro studies of stereolithographic guides.
Four arch forms were milled from acrylic blocks each with 12 root form sites. Root form inserts were made. Holes were milled in the inserts at arbitrary angles. Guide posts were placed in these sites. Guide sleeves were placed on the posts and connected with light-cured resin to form verification jigs. The goal was to correct the angles of the guide sleeves to a vertical position 90 degrees from the base of the arch forms. The initial angles from the vertical and horizontal positions of the center of each guide sleeve were determined radiographically and geometrically. Horizontal and angle corrections were made using two-piece guide posts. Guide sleeves placed over the corrected guide posts were connected with light-cured resin, forming new verification jigs. The accuracy of the angle correction and the coronal horizontal and apical horizontal deviations of the 3-mm guide sleeves were determined. The experimental sites were divided into two groups to determine if the size of the initial angles of the guide sleeves had any effect on the accuracy of the corrections.
The initial angles of the guide sleeves before corrections revealed the mean difference between the two methods of measurements in groups 1 and 2 as 0.36 degrees (P = .14) and 0.69 degrees (P = .07), respectively. A comparison of the angle error measurements from 90 degrees after corrections between the two groups in the mesiodistal and buccolingual planes was not significant. The coronal and apical horizontal deviations after corrections revealed a significant difference between the two groups at the coronal level (P = .005) but not at the apical level (P = .14). In comparison of the methods of the two measurements of the angle error from vertical after corrections, the mean difference was 1.23 degrees (P = .01) and 0.69 degrees (P = .02).
The in vitro accuracy of the guide sleeve corrections made with the geometric approach for implant guidance was compared to the results of the meta-analyses of in vitro studies of implant placement with stereolithographic guides. The mean errors were smaller and within the recommendations of the EAO Consensus Conference of 2012.
The systemic oral health connection: Biofilms Kurtzman, Gregori M; Horowitz, Robert A; Johnson, Richard ...
Medicine,
2022-Nov-18, 2022-11-18, 20221118, Volume:
101, Issue:
46
Journal Article
Peer reviewed
Open access
Frequently, periodontal health and it's associated oral biofilm has not been addressed in those patients who have systemic health issues, especially those who are not responding to medical treatment ...via their physician. Oral biofilm may be present in the periodontal sulcus in the absence of clinical disease of periodontal disease (bleeding on probing, gingival inflammation) and periodontal reaction is dependent on the patient's immune response to the associated bacterial and their byproducts. Increasing evidence has been emerging the past decade connecting oral biofilm with systemic conditions, either initiating them or complicating those medical conditions. The patient's health needs to be thought of as a whole-body system with connections that may originate in the oral cavity and have distant affects throughout the body. To maximize total health, a coordination in healthcare needs to be a symbiosis between the physician and dentist to eliminate the oral biofilm and aid in prevention of systemic disease or minimize those effects to improve the patient's overall health and quality of life. Various areas of systemic health have been associated with the bacteria and their byproducts in the oral biofilm. Those include cardiovascular disease, chronic kidney disease, diabetes, pulmonary disease, prostate cancer, colon cancer, pancreatic cancer, pre-term pregnancy, erectile dysfunction Alzheimer's disease and Rheumatoid arthritis. This article will discuss oral biofilm, its affects systemically and review the medical conditions associated with the oral systemic connection with an extensive review of the literature.
Peri-implantitis is an inflammatory process initiating in the soft tissue and then progressing to the hard tissue surrounding dental implants leading to loss of osseous support and potential loss of ...the implant if not identified early in the process. This process initiates in the soft tissue, which become inflamed spreading to the underlying bone leading to decreases in bone density with subsequent crestal resorption and thread exposure. In the absence of treatment of the peri-implantitis, the bone loss at the osseous implant interface progresses with inflammatory mediated decrease in the bone density that moves apically, eventually leading to mobility of the implant and its failure. Low-magnitude high-frequency vibration (LMHFV) has been shown to improve bone density, stimulate osteoblastic activity, and arrest progression of peri-implantitis with improvement of the bone or graft around the affected implant with or without surgery as part of the treatment. Two cases are presented using LMHFV to augment treatment.
Frozen section telepathology interpretation experience has been largely limited to practices with locations significantly distant from one another with sporadic need for frozen section diagnosis. In ...2010, we established a real-time nonrobotic telepathology system in a very active cancer center for daily frozen section service. Herein, we evaluate its accuracy compared to direct microscopic interpretation performed in the main hospital by the same faculty and its cost-efficiency over a 1-year period. From 643 (1,416 parts) cases requiring intraoperative consultation, 333 cases (690 parts) were examined by telepathology and 310 cases (726 parts) by direct microscopy. Corresponding discrepancy rates were 2.6% (18 cases: 6 0.9% sampling and 12 1.7% diagnostic errors) and 3.2% (23 cases: 8 1.1% sampling and 15 2.1% diagnostic errors), P = .63. The sensitivity and specificity of intraoperative frozen diagnosis were 0.92 and 0.99, respectively, in telepathology and 0.90 and 0.99, respectively, in direct microscopy. There was no correlation of error incidence with postgraduate year level of residents involved in the telepathology service. Cost analysis indicated that the time saved by telepathology was $19,691.00 over 1 year of the study period, whereas the capital cost for establishing the system was $8,924.00. Thus, real-time nonrobotic telepathology is a reliable and easy-to-use tool for frozen section evaluation in busy clinical settings, especially when frozen section service involves more than one hospital, and it is cost-efficient when travel is a component of the service.
•Analysis of frozen sections performed by real-time nonrobotic telepathology and direct microscopy.•A unique setting of resident/faculty cooperation team.•Cost analysis of using a relatively inexpensive telepathology system.
The formation of block copolymer nanoparticles is commonly obtained by switching solvent quality from good solvent for both blocks to a selective solvent for one block. The effect of the selective ...solvent on particle dimension, shape and inner structure has been analyzed in detail, instead less attention has been focused on the role of the common solvent. Poly(ethylene oxide)-block-poly(lactic acid) (PEO-b-PLA) is widely used for the preparation of nanometric drug delivery systems and the control of the particle morphology has relevant effects on bioactivity. In this work we investigate the effect of using different common solvents (acetone, dioxane, tetrahydrofuran, dimethylformamide) on the self-assembly behavior of narrowly dispersed PEO-b-PLA copolymers, synthesized by metal free ring-opening polymerization, with large variation of molecular weight of the hydrophobic block (from 65 to 1300 lactic units). Dynamic light scattering (DLS) and cryo-electron microscopy (cryo-EM) analyses of PEO-b-PLA nanoparticles reveal that their size and shape are strongly dependent on the hydrogen bonding ability of the common solvent used in the self-assembly process. As consequence of these variations, also the cytoxicity of the nanoparticles is affected.
Display omitted
•A library of PEO-b-PLA copolymers has been synthesized by DBU catalyzed ROP.•The self-assembly of PEO-b-PLA copolymers has been realized in a variety of common solvents.•The hydrogen bonding ability of the solvent has a relevant effect on the self-assembly.
When natural teeth fail, frequently there is a loss of hard and soft tissue. This may complicate subsequent dental implant placement by creating insufficient bone to house the implant. This also ...occurs when the tooth has been missing for an extended period, especially in the premaxilla, where the bone is less dense and often lacks sufficient volume of facial bone. Site reconstruction to accommodate implant placement often requires both hard and soft tissue augmentation. The modified interpositional vascularized augmentation neogenesis (mIVAN) technique achieves the desired treatment goals in both delayed and immediate placement scenarios. The technique will be discussed as well as the long-term follow-up on 20 cases.
Frequently, sinus augmentation is required when replacing failing or missing molars in the maxilla due to loss of alveolar bone related to periodontal disease, pneumatization of the sinus or a ...combination of the two factors. Various materials have been advocated and utilized; these fall into the categories of allograft, xenograft and synthetic materials. This article shall discuss a study of 10 cases with a 2-year follow-up utilizing a novel synthetic graft material used for sinus augmentation either simultaneously with implant placement or in preparation for sinus augmentation and implant placement in the posterior maxilla. The results of the 10 cases in the study found consistent results over the 2-year study period with maintenance of the alveolar height at the maxillary sinus. A lack of complications or failures in the study group demonstrates the technique has useful applications in increasing ridge height to permit implant placement inferior to the sinus floor.
A significant percentage of lesions of endodontic origin require surgical management due to the possible diagnosis of odontogenic cysts and tumors in the maxilla and mandible. Ossifying fibroma is a ...benign fibro-osseous lesion that typically presents as a painless, slow-growing, and expansile lesion that appears as a well-demarcated lesion with a variable degree of internal calcification on radiography. Treatment results in a large osseous defect, utilization of a graft to fill the void accelerates healing and prevents complications that may result from failure to fill by the host response.
Following endodontic surgery placement of osseous graft material via Guided Tissue Regeneration to fill the defect aids to accelerate fill of the defect on a healthy 26-year-old female patient. A case discussing the one-step treatment of an ossifying fibroma of the anterior part of the mandible following endodontic microsurgery with associated retrograde fill of the apex, then site grating with biphasic calcium sulfate (Bond Apatite
) used in regeneration of the osseous defect related to the lesion and resulting surgery.
Histologically, the ossifying fibroma is dominated by connective tissue containing cell rich areas with a few fragments of fibrosis. Moreover, in the connective tissue numerous small fragments of spongy and compact bone with areas of partial necrosis present and a significant number of inflammatory cells are observed. Surgical removal of the cyst with thorough curettage of the osseous walls and grafting of the defect provides predictable healing and the desired clinical results sought. Utilization of the biphasic calcium sulfate graft material allows the elimination of the need to overlay the area with a membrane before the flap due to its hard set and the prevention of soft tissue ingrowth into the graft material during the healing phase. Additionally, the hard set of the material allows tenting of the area to maintain the desired volume and ridge contour. Conversion of the graft material depending on the volume placed to host bone occurs over a 3-6 month period.
The case report presented, as well as the authors experience mimics the literature on biphasic calcium sulfate in its use as an osseous graft material and is an effective method for the repair of osseous defects that result from the removal of tumors and cysts of the maxilla and mandible. Treatment of an ossifying fibroma is an ideal application of the use of this biphasic calcium sulfate material allowing tenting of the surgical site over the defect created after cyst removal without the need for resorbable collagen membranes. This simplifies its use and decreases material costs that may hamper patient acceptance of treatment without a decrease in expected clinical results.
Severe bone loss in the anterior maxilla poses challenges to implant placement, especially when treating the entire arch. Utilization of zygomatic implants may not allow positioning of the implant ...platform anterior enough to properly support the full arch prosthesis, leaving an anterior cantilever in some clinical cases.
Placement of implants into the trans-nasal bone between the pneumatized maxillary sinus and nasal fossa allows utilization of an extralong implant in this residual bone to augment zygomatic implants placed distal to this for better support of a full arch prosthesis.
A typical case is presented with insufficient alveolar height for traditional implant placement in the anterior maxilla following extraction of the dentition related to bone loss resulting from periodontal disease. Review of the anatomy and technique for placement of implants into the Z-point area for trans-nasal implants.
This article discusses the utilization of trans-nasal implants into the Z-point and the technique for placement in this residual bone with a case example.
The Z-point implant aids in the elimination of the anterior cantilever that may be present due to the most anterior the platform for the zygomatic implant can be placed. Trans-nasal implants should be considered as part of the treatment plan in severely resorbed maxillary arches to allow better implant to spread and load management during functioning.
PDF
