The effects of a common stainless steel orthodontic bracket on the diagnostic quality of cranial and cervical 3T-MR images: a prospective, case-control study

Abstract OBJECTIVES: To evaluate the effect of orthodontic stainless steel brackets and two different types of archwires (stainless steel and nickel-titanium) on the diagnostic quality of 3T-MR images. METHODS: This prospective, case-control study was conducted following STROBE guidelines. The imaging protocol consisted of the axial Fluid Attenuated Inversion Recovery (FLAIR) and axial oblique double echo proton density (PD) and weighted/turbo spin echo (TSE) T2-weighted sequences for brain, paranasal sinuses and cervical region evaluation; sagittal TSE T2w, sagittal TSE T1w and axial T2* Gradient echo sequences (GRE) sequences for the cervical vertebrae; axial and coronal TSE T2w images for the head and neck structures; and sagittal, axial and coronal PD and TSE T2-weighted sequences for the temporo-mandibular joint. Two experts in neuroradiology evaluated the images. The statistical analysis was performed at the level of anatomical districts. The following statistical methods were used: descriptive statistics, Cohen's kappa coefficient (k), Kruskal-Wallis test, pairwise comparisons using the Dunn-Bonferroni approach. Significance was set at p≤0.05. RESULTS: 80 patients were included, providing 80 MRI. The presence of stainless steel brackets with or without archwires negatively influenced the MR images of the cervical region, paranasal sinuses, head and neck region and cervical vertebrae but did not influence the MR images of brain and temporomandibular joint regions. CONCLUSIONS: Patients with a stainless steel multi-bracket orthodontic appliance should remove it before cervical vertebrae, cervical region, paranasal sinuses and head and neck MRI scans. The brain and temporomandibular joint regions MRI should not require the removal of such appliances

Performance of mesenchymal cell-scaffold constructs in human oral reconstructive surgery: a systematic review

Background: Different sources of cultured cells combined with different scaffolds (allogenic, xenogeneic, alloplastic or composite materials) have been tested extensively in vitro and in preclinical animal studies, but there have been only a few clinical trials involving humans. Aim: This study reviewed all of the English language literature published between January 1990 and December 2015 to assess the histological performance of different mesenchymal cell-scaffold constructs used for bone regeneration in human oral reconstructive procedures. Methods: An electronic search of the MEDLINE and Cochrane Central Register of Controlled Trials databases complemented by manual searching was conducted to identify studies involving histological evaluation of mesenchymal cell-scaffold constructs in human oral surgical procedures. The methodological quality of randomized controlled clinical trials and controlled clinical trials was assessed using the Cochrane Collaboration tool for assessing the risk of bias. Heterogeneity was assessed using Review Manager software. Considering the heterogeneity, the data collected were reported by descriptive methods and a meta-analysis was applied only to the articles that reported the same outcome measures. The articles were classified and described based on the material scaffolds used. Results: The search identified 1030 titles and 287 abstracts. Full-text analysis was performed for 32 articles, revealing 14 studies that fulfilled the inclusion criteria. Three randomized controlled clinical trials were identified as potentially eligible for inclusion in a meta-analysis. The studies were grouped according to the scaffold materials used: bone allograft (three studies), polyglycolic-polylactic scaffold (four studies), collagen sponge (two studies), and bovine bone matrix (five studies). The stem cells used in these studies had been sourced from the iliac crest, periosteum, dental pulp and intraoral sites. Conclusions: The very small amount of available data makes it impossible to draw any firm conclusions regarding the increase in bone formation in human oral reconstructive procedures when using graft materials engineered with autogenous stem cells

Comparative histological and histomorphometric results of six biomaterials used in two-stage maxillary sinus augmentation model after 6-month healing

To evaluate the performances of six different bone substitute materials used as graft in maxillary sinus augmentation by means of histological and histomorphometric analysis of bone biopsies retrieved from human subjects after a 6-month healing period. Materials and Methods. Six consecutive patients (3 males, 3 females, aged 50-72 years), healthy, nonsmokers, and with good oral hygiene, presenting edentulous posterior maxilla with a residual bone crest measuring ≤ 4 mm in vertical height and 3 to 5 mm in horizontal thickness at radiographic examination, were selected to receive sinus augmentation and delayed implant placement. Under randomized conditions, sinus augmentation procedures were carried out using mineralized solvent-dehydrated bone allograft (MCBA), freeze-dried mineralized bone allograft (FDBA), anorganic bovine bone (ABB), equine-derived bone (EB), synthetic micro-macroporous biphasic calcium-phosphate block consisting of 70% beta-tricalcium phosphate and 30% hydroxyapatite (HA-β-TCP 30/70), or bioapatite-collagen (BC). After 6 months, bone core biopsies were retrieved and 13 implants were placed. Bone samples were processed for histological and histomorphometric analysis. CT scans were taken before and after surgery. After 4 months of healing, patients were restored with a provisional fixed acrylic resin prosthesis, as well as after further 2-4 months with a definitive cemented zirconia or porcelain-fused-to-metal crowns. Results. There were no postoperative complications or implant failures. The histological examination showed that all biomaterials were in close contact with newly formed bone, surrounding the graft granules with a bridge-like network. No signs of acute inflammation were observed. The histomorphometry revealed 20.1% newly formed bone for MCBA, 32.1% for FDBA, 16.1% for ABB, 22.8% for EB, 20.3% for HA-β-TCP 30/70, and 21.4% for BC. Conclusions. Within the limitations of the present investigation, all the six tested biomaterials showed good biocompatibility and osteoconductive properties when used in sinus augmentation procedures, although the FDBA seemed to have a better histomorphometric result in terms of newly formed bone and residual graft material. This trial is registered with ClinicalTrials.gov Identifier (Registration Number): NCT03496688

Surgical management of extrafollicular variant of adenomatoid odontogenic tumor in the maxillary posterior region

Background. Adenomatoid odontogenic tumor (AOT) is a relatively uncommon benign neoplasm of odontogenic epithelial origin, accounting for less than 5% of odontogenic tumors. Case Report. The reported case describes morphological characteristics, clinical course, radiographic and histopathological features, and surgical therapy of an extrafollicular variant of AOT in the maxillary posterior region. An asymptomatic swelling on the left side in the posterior region of the maxilla, gradually increased since approximately 12 months, developed in a 16-year-old Caucasian female patient. Radiographic images revealed a well-defined, unilocular radiolucency, with some small foci of radiopacity inside, and root resorption of the first and second molars. On the base of the histological examination of the specimen retrieved by incisional biopsy, the diagnosis of AOT was made, and the conservative surgical enucleation of the lesion was performed. Discussion. The present case was reported in agreement with an extensive review, in which it was recommended to discontinue reporting classic follicular cases because their clinicopathological profile was well-known, but to continue reporting well-documented cases of the extrafollicular variant, with indication of the exact position. Conclusion. The present case was reported in order to expand the knowledge about the clinical behavior and surgical treatment of the extrafollicular variant of AOT

Trueness and precision of 3D-printed versus milled monolithic zirconia crowns: An in vitro study.

Abstract Purpose To compare the trueness and precision of 3D-printed versus milled monolithic zirconia crowns (MZCs). Methods A model of a maxilla with a prepared premolar was scanned with an industrial scanner (ATOSQ®, Gom) and an MZC was designed in computer-assisted-design (CAD) software (DentalCad®, Exocad). From that standard tessellation language (STL) file, 10 MZCs (test) were 3D-printed with a Lithography-based Ceramic Manufacturing (LCM) printer (CerafabS65®, Lithoz) and 10 MZCs (control) were milled using a 5-axis machine (DWX-52D®, DGShape). All MZCs were sintered and scanned with the aforementioned scanner. The surface data of each sample (overall crown, marginal area, occlusal surface) were superimposed to the original CAD file (ControlX®, Geomagic) to evaluate trueness: (90-10)/2, absolute average (ABS AVG) and root mean square (RMS) values were obtained for test and control groups (MathLab®, Mathworks) and used for analysis. Finally, the clinical precision (marginal adaptation, interproximal contacts) of test and control MZCs was investigated on a split-cast model printed (Solflex350®, Voco) from the CAD project, and compared. Results The milled MZCs had a significantly higher trueness than the 3D-printed ones, overall [(90-10)/2 printed 37.8 µm vs milled 21.2 µm; ABS AVG printed 27.2 µm vs milled 15.1 µm; RMS printed 33.2 µm vs milled 20.5 µm; p = 0.000005], at the margins [(90-10)/2 printed 25.6 µm vs milled 12.4 µm; ABS AVG printed 17.8 µm vs milled 9.4 µm; RMS printed 22.8 µm vs milled 15.6 µm; p= 0.000011] and at the occlusal level [(90-10)/2 printed 50.4 µm vs milled 21.9 µm; ABS AVG printed 29.6 µm vs milled 14.7 µm; RMS printed 38.9 µm vs milled 22.5 µm; p = 0.000005]. However, with regard to precision, both test and control groups scored highly, with no significant difference either in the quality of interproximal contact points (p = 0.355) or marginal closure (p = 0.355). Conclusions Milled MZCs had a statistically higher trueness than 3D-printed ones; all crowns, however, showed high precision, compatible with the clinical use. Clinical significance Although milled MZCs remain more accurate than 3D-printed ones, the LCM technique seems able to guarantee the production of clinically precise zirconia crowns

Knowledge and attitude towards retrograde peri-implantitis among Italian implantologists: a cross-sectional survey

Abstract Background: Retrograde peri-implantitis (RPI) is a pathological entity with an unclear etiology (e.g., overheating during implant insertion, residual infection of the tooth replaced by the implant or the endodontic lesion of neighboring teeth) and an extremely low prevalence and has been scarcely investigated. Therefore, the aim of this cross-sectional survey was to evaluate the knowledge and attitude of Italian implantologists regarding RPI. Methods: An anonymous questionnaire was sent via email to implantologists randomly selected, including a section about demographic information and questions related to RPI origin, radiographic representation, symptoms and treatment options. All questions were multiple answer and close-ended. Binomial logistic regression was performed to investigate the relationship between correct answers and the following independent variables: age, years of experience and number of dental implants placed per year. Results: In total, 475 implantologists completed the questionnaire, with a response rate of 46.3%. Based on the results of the study, incorrect answers were associated with less experienced participants (<80 implants/year) for all questions evaluated, with the exception of treatment strategies. Furthermore, 26.7% of the survey takers did not recognize radiographic representation of RPI and 35.5% picked "implant removal" when asked about treatment modality. Conclusions: The majority of participants were able to recognize symptoms and indicated the probable causes of RPI; however, around 30% of them showed very limited knowledge of available management strategies

Xeno-Hybrid composite scaffold manufactured with CAD/CAM technology for horizontal bone-augmentation in edentulous atrophic maxilla: a short communication

Abstract: The present short communication described a new procedure for the reconstruction of the horizontal severely resorbed edentulous maxilla with custom-made deproteinized bovine bone block, fabricated using three-dimensional imaging of the patient and computer-aided design/computer-aided manufacturing (CAD/CAM) technology. The protocol consisted of three phases. In the diagnosis and treatment planning, cone-beam computed tomographic scans of the patient were saved in DICOM (digital imaging and communication in medicine) format, anatomic and prosthetic data were imported into a dedicated diagnostic and medical imaging software, the prosthetic-driven position of the implants, and the graft blocks perfectly adapted to the residual bone structure were virtually planned. In the manufacturing of customized graft blocks, the CAD-CAM technology and the bovine-derived xenohybrid composite bone (SmartBone® on Demand - IBI SA - Industrie Biomediche Insubri SA Switzerland) were used to fabricate the grafts in the exact shape of the 3D planning virtual model. In the surgical and prosthetic procedure, the maxillary ridge augmentation with custom-made blocks and implant-supported full-arch screw-retained rehabilitation were performed. The described protocol offered some advantages when compared to conventional augmentation techniques. The use of deproteinized bovine bone did not require additional surgery for bone harvesting, avoided the risk of donor site morbidity, and provided unlimited biomaterial availability. The customization of the graft blocks reduced the surgical invasiveness, shorting operating times because the manual shaping of the blocks and its adaptation at recipient sites are not necessary and less dependent on the clinician’s skill and experience

Navigated Antral Bone Expansion (NABE): a prospective study on 35 patients with 4 months of follow-up post implant loading

The insertion of dental implants in the atrophic posterior maxilla can be a challenge. One option is to modify the residual native bone in preparation for proper, prosthetically-driven implant placement. The procedure presented in this study is called Navigated Antral Bone Expansion (N.A.B.E). This procedure employs the use of a navigation system to plan and guide the initial pilot drilling, bone expansion, final site preparation, and implant insertion. The aim of this study was to compare the distance between the alveolar ridge and the sinus floor measured before and after the surgery performed using the N.A.B.E.Methods: Thirty-seven partially edentulous patients who were candidates for implant supported restoration in the posterior maxilla, with a bone height ranging from 4 to 7 mm were enrolled. The N.A.B.E procedure was used to increase the bone height. Paired-samples t-test evaluated the distance between the alveolar ridge and the sinus floor measured before and after surgery. The occurrence of post-surgical complications, and the angular deviation between the planned osteotomy and the actual placed implant trajectories were evaluated. Results: Out of the 37 consecutive patients enrolled in the study, 35 were considered in the data analyses. Patients' bone height after surgery compared to the bone height before surgery showed a statistically significant increase (p < .0005) of 3.96 mm (95% CI, 3.62 mm to 4.30 mm). No post-operative complications were observed in the 35 patients. The mean angular deviation between the planned osteotomy trajectory and the placed implant trajectory ranged between 12.700 to 34.900 (mean 25.170 ± 5.100). Conclusions: This study provides evidence that N.A.B.E. technique is able to provide a significant bone increase, and could be considered an alternative method to the management of the atrophic posterior maxilla with a minimally invasive approach

Effects of an amino acid buffered hypochlorite solution as an adjunctive to air-powder abrasion in open-flap surface decontamination of implants failed for peri-implantitis: an ex vivo randomized clinical trial

Objectives: To evaluate ex vivo the efficacy of an amino acid buffered hypochlorite solution supplemented to surface debridement with air-powder abrasion in removing bacterial biofilm following open-flap decontamination of implants failed due to peri-implantitis. Materials and methods: This study was an ex vivo, single-blind, randomized, intra-subject investigation. Study population consisted of 20 subjects with at least three implants failed for peri-implantitis (in function for > 12 months and progressive bone loss exceeding 50%) to be explanted. For each patient, implants were randomly assigned to surface decontamination with sodium bicarbonate air-powder abrasion (test-group 1) or sodium bicarbonate air-powder abrasion supplemented by amino acid buffered hypochlorite solution (test-group 2) or untreated control group. Following open-flap surgery, untreated implants (control group) were explanted. Afterwards, test implants were decontaminated according to allocation and explanted. Microbiological analysis was expressed in colony-forming units (CFU/ml). Results: A statistically significant difference in the concentrations of CFU/ml was found between implants of test-group 1 (63,018.18 ± 228,599.36) (p = 0.007) and implants of test-group 2 (260.00 ± 375.80) (p < 0.001) compared to untreated implants (control group) (86,846.15 ± 266,689.44). The concentration of CFU/ml on implant surfaces was lower in test-group 2 than in test-group 1, with a statistically significant difference (p < 0.001). Conclusion: The additional application of amino acid buffered hypochlorite solution seemed to improve the effectiveness of implant surface decontamination with air-powder abrasion following open-flap surgery. Clinical relevance: Lacking evidence on the most effective method for biofilm removal from contaminated implant surfaces, the present experimental study provides further information for clinicians and researchers

Comparison of the effects of air-powder abrasion, chemical decontamination, or their combination in open-flap surface decontamination of implants failed for peri-implantitis: an ex vivo study

Objectives To compare, using an ex vivo model, the biofilm removal of three surface decontamination methods following surgical exposure of implants failed for severe peri-implantitis. Materials and methods The study design was a single-blind, randomized, controlled, ex vivo investigation with intra-subject control. Study participants were 20 consecutive patients with at least 4 hopeless implants, in function for >12 months and with progressive bone loss exceeding 50%, which had to be explanted. Implants of each patient were randomly assigned to the untreated control group or one of the three decontamination procedures: mechanical debridement with air-powder abrasion, chemical decontamination with hydrogen peroxide and chlorhexidine gluconate, or combined mechanical-chemical decontamination. Following surgical exposure, implants selected as control were retrieved, and afterwards, test implants were decontaminated according to allocation and carefully explanted with a removal kit. Microbiological analysis was expressed in colony-forming-units (CFU/ml). Results A statistically significant difference (p < 0.001) in the concentrations of CFU/ml was found between implants treated with mechanical debridement (531.58 ± 372.07) or combined mechanical-chemical decontamination (954.05 ± 2219.31) and implants untreated (37,800.00 ± 46,837.05) or treated with chemical decontamination alone (29,650.00 ± 42,596.20). No statistically significant difference (p = 1.000) was found between mechanical debridement used alone or supplemented with chemical decontamination. Microbiological analyses identified 21 microbial species, without significant differences between control and treatment groups. Conclusions Bacterial biofilm removal from infected implant surfaces was significantly superior for mechanical debridement than chemical decontamination. Clinical relevance The present is the only ex vivo study based on decontamination methods for removing actual and mature biofilm from infected implant surfaces in patients with peri-implantitis