The Use of Dermal Substitutes for Donor Site Closure After Radial Forearm Free Flap Harvesting.

OBJECTIVE: The aim of our study was to analyze the aesthetic and functional outcome in the radial forearm free flap donor site using a simple split thickness skin grafting (STSG) closure compared with the use of dermal scaffold supporting the STSG closure. METHODS: The study analyzed 18 patients, divided in 2 groups based on the donor site closure modality. In STSG group, a simple STSG was used to cover the defect. In the DS + STSG group, the defect was covered by the use of dermal substitute (MatriDerm) supporting the STSG. Groups were compared on the following outcome variable: scar status; hand function; circumferences at most proximal and most distal point of the graft. All patients were followed up 1, 6, and 12 months post-operative. RESULTS: Nine patients from STSG group showed a difference in circumference between the operated and contralateral limbs respectively of 2.9 mm proximal and 1.2 mm distal; in the 9 patients of DS + STGS group the difference was respectively of 1.2 mm proximal and 1.3 mm distal. Welch unequal variances t-test demonstrated statistical significance of the values with P < 0.004 (P < 0.5). The average VSS was 1.82 ±â€Š0.2 for STSG group and 1.75 ±â€Š0.2 for DS + STGS group. The DASH score was 21.8% in STSG group and 19.4% in DS + STGS group. CONCLUSION: Our study shows that patients treated with Matriderm + STSG obtained a better result both in esthetic and functional outcomes.

Loading stress distribution in posterior teeth restored by different core materials under fixed zirconia partial denture: A 3D-FEA study.

PURPOSE: To evaluate the effect of different substrate stiffness [sound dentin (SD), resin composite core (RC) or metal core (MC)] on the stress distribution of a zirconia posterior three-unit fixed partial denture (FPD). METHODS: The abutment teeth (first molar and first premolar) were modeled, containing 1.5 mm of axial reduction, and converging axial walls. A static structural analysis was performed using a finite element method and the maximum principal stress criterion to analyze the fixed partial denture (FPD) and the cement layers of both abutment teeth. The materials were considered isotropic, linear, elastic, homogeneous and with bonded contacts. An axial load (300 N) was applied to the occlusal surface of the second premolar. RESULTS: The region of the prosthetic connectors showed the highest tensile stress magnitude in the FPD structure depending on the substrate stiffness with different core materials. The highest stress peak was observed with the use of MC (116.4 MPa) compared to RC and SD. For the cement layer, RC showed the highest values in the molar abutment (14.7 MPa) and the highest values for the premolar abutment (14.4 MPa) compared to SD (14.1 and 13.4 MPa) and MC (13.8 and 13.3 MPa). Both metal core and resin composite core produced adequate stress concentration in the zirconia fixed partial denture during the load incidence. However, more flexible substrates, such as composite cores, can increase the tensile stress magnitude on the cement. CLINICAL SIGNIFICANCE: The present study shows that the choice of the cast core and metallic post by the resin composite core and fiberglass post did not improve the biomechanical behavior of the FPD. This choice must be performed based on clinical criteria (other) than mechanical.

Comparison of Bulk Polymeric Resin Composite and Hybrid Glass Ionomer Cement in Adhesive Class I Dental Restorations: A 3D Finite Element Analysis.

This study aimed to investigate the mechanical behavior of resin composites and hybrid glass ionomer cement in class I adhesive dental restorations under loading and shrinkage conditions. Three CAD models of a mandibular first molar with class I cavities were created and restored with different techniques: a bi-layer of Equia Forte HT with Filtek One Bulk Fill Restorative composite (model A), a single layer of adhesive and Filtek One Bulk Fill Restorative (model B), and a single layer of Equia forte HT (model C). Each model was exported to computer-aided engineering software, and 3D finite element models were created. Models A and B exhibited a similar pattern of stress distribution along the enamel-restoration interface, with stress peaks of 12.5 MPa and 14 MPa observed in the enamel tissue. The sound tooth, B, and C models showed a similar trend along the interface between dentine and restoration. A stress peak of about 0.5 MPa was detected in the enamel of both the sound tooth and B models. Model C showed a reduced stress peak of about 1.2 MPa. A significant stress reduction in 4 mm deep class I cavities in lower molars was observed in models where non-shrinking dental filling materials, like the hybrid glass ionomer cement used in model C, were applied. Stress reduction was also achieved in model A, which employed a bi-layer technique with a shrinking polymeric filling material (bulk resin composite). Model C's performance closely resembled that of a sound tooth.

The Effect of Conservative vs. Radical Treatment of Ameloblastoma on Recurrence Rate and Quality of Life: An Umbrella Review.

Ameloblastoma is a rare, benign, but locally aggressive odontogenic tumor that originates from the epithelial cells involved in tooth development. The surgical approach to treating an ameloblastoma depends on the type, size, location, and extent of the tumor, as well as the patient's age and overall health. This umbrella review's aim is to summarize the findings from systematic reviews (SRs) and meta-analyses on the effect of radical or conservative treatment of ameloblastoma on the recurrence rate and quality of life, to evaluate the methodological quality of the included SRs and discuss the clinical management. Three electronic databases (PubMed, Scopus, The Cochrane Library) were checked. The primary outcome was the recurrence rate after surgical treatment, while the secondary outcomes were the post-operative complications, quality of life, esthetic, and functional impairment. The methodological quality of the included SRs was assessed using the updated version of "A Measurement Tool to Assess Systematic Review" (AMSTAR-2). Eighteen SRs were included. The quality of the included reviews ranged from critically low (three studies) to high (eight studies). Four studies were included in meta-analysis, and they revealed that the recurrence rate is about three-times more likely in the conservative treatment group compared to the radical treatment group, and this result is statistically significant. Despite the high recurrence rate, the latter was more appropriate in the case of smaller lesions and younger patients, due to better post-operative quality of life and reduced functional and esthetic impairments. Based on the results of this overview, conservative treatment may be recommended as the first-line approach for intraosseous ameloblastoma not involving soft tissue. However, given the expectation of a higher recurrence rate, it is advisable to reduce the interval between follow-up visits. However, further prospective studies are needed to establish the best treatment choice and follow-up period.

Effect of crown stiffness and prosthetic screw absence on the stress distribution in implant-supported restoration: A 3D finite element analysis.

This in-silico investigation evaluated the mechanical impact of Morse tape implant-abutment interface and retention system (with and without screw) and restorative materials (composite block and monolithic zirconia) by means of a three-dimensional finite element analysis (3D-FEA). Four 3D models were designed for the lower first molar. A dental implant (4.5 × 10 mm B&B Dental Implant Company) was digitized (micro CT) and exported to computer-aided design (CAD) software. Non-uniform rational B-spline surfaces were reconstructed, generating a 3D volumetric model. Four different models were generated with the same Morse-type connection, but with a different locking system (with and without active screw) and a different crown material made of composite block and zirconia. The D2 bone type, which contains cortical and trabecular tissues, was designed using data from the database. The implants were juxtaposed inside the model after Boolean subtraction. Implant placement depth was simulated for the implant model precisely at crestal bone level. Each acquired model was then imported into the finite element analysis (FEA) software as STEP files. The Von Mises equivalent strains were calculated for the peri-implant bone and the Von Mises stress for the prosthetic structures. The highest strain values in bone tissue occurred in the peri-implant bone interface and were comparable in the four implant models (8.2918e-004-8.6622e-004 mm/mm). The stress peak in the zirconia crown (64.4 MPa) was higher than in the composite crown (52.2 MPa) regardless of the presence of the prosthetic screw. The abutment showed the lowest stress peaks (99.71-92.28 MPa) when the screw was present (126.63-114.25 MPa). Based on this linear analysis, it is suggested that the absence of prosthetic screw increases the stress inside the abutment and implant, without effect on the crown and around the bone tissue. Stiffer crowns concentrate more stress on its structure, reducing the amount of stress on the abutment.

Odontogenic keratocystic can be misdiagnosed for a lateral periodontal cyst when the clinical and radiographical findings are similar.

Lateral periodontal cyst (LPC) and odontogenic keratocystic (OK) are two osteolytic lesions of the jaw with different local invasiveness and percentage of recurrence. The aim of this study was to highlight the attention on the differential diagnosis of these lesions that sometimes can have unexpected location and can lead doubts on diagnosis, therapy, and follow-up. A 34-year-old man presented to our department with a complaint of soft pain in the vestibular aspect of left mandibular second premolar and left mandibular first molar. Vital teeth in the left mandible, no mucosal swelling, and no drainage were observed. The CBCT showed a well circumscribed hypodensity area, extending between 3.5 and the apex of mesial root of 3.6. No displacement and no resorption of the roots were notified. Upon clinical and radiographical examination, a provisional diagnosis of LPC was made and enucleation of the lesion and histological examination were planned. Histologically, a cystic wall partially lined by a keratinizing squamous epithelium was observed. Surrounding and within the lesion, there was a chronic inflammatory infiltrate also of granulomatous type and with cholesterol clefts. Based on these findings, the diagnosis of odontogenic keratocystic was done. Radiolucent lesions in the premolar and canine region are frequently clinically and radiographically misdiagnosed. The identification of keratocyst in a location preoperatively favoring a lateral periodontal cyst should be suspected and biopsy must be considered in all cases to establish the nature of the lesion, the best surgical treatment, and the follow-up appointments.

Use of piezosurgery device in management of surgical dental implant complication: a case report.

An implant displacement into the maxillary sinus could be a complication of implant surgery in the upper jaw. In such cases, implant removal is needed to avoid the occurrence of sinus pathologies. Piezosurgery techniques could assure safer management of such complications because of clear surgical visibility and a selective ability to cut. The aim of this report is to present a case of an implant-related oral surgery complication that was resolved by means of a piezosurgery technique.

The role of cortical zone level and prosthetic platform angle in dental implant mechanical response: A 3D finite element analysis.

OBJECTIVE: The aim of this study was to evaluate the influence of three different dental implant neck geometries, under a combined compressive/shear load using finite element analysis (FEA). The implant neck was positioned in D2 quality bone at the crestal level or 2 mm below. METHODS: One dental implant (4.2 × 9 mm) was digitized by reverse engineering techniques using micro CT and imported into Computer Aided Design (CAD) software. Non-uniform rational B-spline surfaces were reconstructed, generating a 3D volumetric model similar to the digitized implant. Three different models were generated with different implant neck configurations, namely 0°, 10° and 20°. D2 quality bone, composed of cortical and trabecular structure, was modeled using data from CT scans. The implants were included in the bone model using a Boolean operation. Two different fixture insertion depths were simulated for each implant: 2 mm below the crestal bone and exactly at the level of the crestal bone. The obtained models were imported to FEA software in STEP format. Von Mises equivalent strains were analyzed for the peri-implant D2 bone type, considering the magnitude and volume of the affected surrounding cortical and trabecular bone. The highest strain values in both cortical and trabecular tissue at the peri-implant bone interface were extracted and compared. RESULTS: All implant models were able to distribute the load at the bone-implant contact (BIC) with a similar strain pattern between the models. At the cervical region, however, differences were observed: the models with 10° and 20° implant neck configurations (Model B and C), showed a lower strain magnitude when compared to the straight neck (Model A). These values were significantly lower when the implants were situated at crestal bone levels. In the apical area, no differences in strain values were observed. SIGNIFICANCE: The implant neck configuration influenced the strain distribution and magnitude in the cortical bone and cancellous bone tissues. To reduce the strain values and improve the load dissipation in the bone tissue, implants with 10° and 20 neck configuration should be preferred instead of straight implant platforms.

Profilometric and standard error of the mean analysis of rough implant surfaces treated with different instrumentations.

PURPOSE: This study evaluated, in vitro, the effects of different instrumentations used in the treatment of peri-implantitis on implant surfaces coated with hydroxyapatite or titanium plasma spray (TPS). MATERIALS AND METHODS: There were 14 cylindrical rough implants used, including 7 hydroxyapatite and 7 TPS coated. Split in 2 parts for a total of 24 experimental surfaces, implants were treated with a stainless-steel curette, plastic curette, ultrasonic scaler tip, and air-powder-water spray. There was 1 hydroxyapatite and 1 TPS implant used as controls. Profilometry and scanning electron microscopy were used to examine instrumented surfaces for variations in surface topography. RESULTS: All experimental procedures determined changes on tested rough implant surfaces. Such alterations were related to the implant coating material, and the procedure consisting in coating removal and/or leveling of surface roughness. CONCLUSION: Although a plastic curette and air-powder-water spray induced less implant surface alterations, these instrumentations left deposits on the surface that may affect, in vivo, the tissue healing process.