Publications by authors named "Sergio A Gehrke"

Article Synopsis
  • This study used a rabbit model to test a new dental implant design (Collo group) with a concave cervical section against a standard implant design (Control group), focusing on implant stability and bone integration.
  • The implants were evaluated by measuring initial stability (ISQ) immediately after insertion and at later time points, along with analyzing bone-implant contact (BIC%) and tissue area fraction occupancy (TAFO%) through histological sections at 3 and 4 weeks post-implantation.
  • Results indicated that the Collo group demonstrated significantly greater stability and better integration with surrounding bone over time compared to the Control group, suggesting potential advantages of the new implant design.
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The present study evaluated the mechanical behavior of five designs of Morse taper (MT) connections with and without the application of loads. For this, the detorque of the fixing screw and the traction force required to disconnect the abutment from the implant were assessed. A total of 100 sets of implants/abutments (IAs) with MT-type connections were used, comprising five groups ( = 20/group): (1) Group Imp 11.

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The number of chronic kidney disease (CKD) patients requiring renal replacement therapy is increasing, often exhibiting oral manifestations including periodontal disease, gingival hyperplasia, altered saliva composition, and uremic stomatitis. Uremic stomatitis, xerostomia, and candidiasis are very frequent, particularly among patients undergoing dialysis or kidney transplant recipients. CKD patients also experience profound alterations in bone metabolism inherent in the homeostasis of calcium, phosphorus, vitamin D, parathyroid hormone, and fibroblast growth factor (FGF).

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Dental implants and bone augmentation are among dentistry's most prevalent surgical treatments; hence, many dental implant surfaces and bone grafts have been researched to improve bone response. Such new materials were radiologically, histologically, and histomorphometrically evaluated on animals before being used on humans. As a result, several studies used animals to evaluate novel implant technologies, biocompatibility, surgical techniques, and osseointegration strategies, as preclinical research on animal models is essential to evaluate bioactive principles (on cells, compounds, and implants) that can act through multiple mechanisms and to predict animal behavior, which is difficult to predict from in vitro studies alone.

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Background: The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived aesthetics is in high demand among patients. This factor, combined with the increase in the number of non-invasive facial aesthetic treatments, has led to the need to understand potential risk factors in the application of medical devices to the perioral skin in patients with fixed orthodontic appliances.

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Purpose: To examine the impact of two implant designs that promote different insertion torque values on implant stability and to histomorphometrically evaluate the bone healing after immediate implant placement in fresh sockets in a sheep model.

Materials And Methods: Twelve female sheep (mean weight: 35.0 ± 5.

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The present study compared three different implant and abutment sets of type Morse taper (MT) connection, with- and without-index, were analyzed regarding their mechanical behavior without and with cyclic load application simulating the masticatory function. Ninety implant and abutment (IA) sets were used in the present study, divided into three groups (n = 30 samples per group): Group A, Ideale solid straight abutment (one piece) without index; Group B, Ideale abutment with an angle of 30-degree (two pieces) without index; Group C, Ideale abutment with an angle of 30-degree (two pieces) with index. The abutment stability quotient (ASQ) values, detorque value and rotation angle were measured before and after the cycling load.

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Background: The goal of this in vitro study was to compare three different surfaces: two types of implant surfaces commercially available ([a] smooth/machined and [b] acid-treated surface) (c) anodized surface. Discs were manufactured with commercially pure titanium (CP) grade IV, which were subsequently analyzed by scanning microscopy and fibroblastic and osteoblastic cell cultures.

Methods: Ninety-nine discs (5 × 2 mm) were manufactured in titanium grade IV and received different surface treatments: (i) Mach group: machined; (ii) AA group: double acid etch; and (iii) AN group: anodizing treatment.

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To assess the literature comparing histologic levels of osseointegration for titanium vs zirconia dental implants. This systematic review was conducted following the PRISMA guidelines and was registered in PROSPERO (CRD42021236781). Electronic and manual searches were carried out through the PubMed/MEDLINE, PubMed Central, and Embase databases with a platform-specific search strategy combining controlled terms (MeSH and Emtree) and text words.

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: The primary objective of the present retrospective clinical study was to evaluate and compare the clinical performance presented by castable abutments developed for the MT system versus intermediate machined abutments, specifically regarding prosthetic or implant fractures/loss; the secondary objective was to verify the looseness of the abutments and the behavior of the peri-implant soft tissues. : This clinical retrospective study was conducted on patients rehabilitated between 2019 and 2020. Inclusion criteria were patients in good general health, with an implants-supporting single crown; with solid machined abutments (control group) or castable UCLA abutments; with a connection portion (base) machined in cobalt-chrome (test group) over Morse taper DuoCone implants in the posterior mandible area; and at least two years in function.

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: The objective of this study was to evaluate the load transmitted to the peri-implant bone by seven different restorative materials in single-unit rehabilitations with morse taper implants using a strain gauge. : In a polyurethane block that simulated type III bone, a morse taper platform implant was installed (3.5 × 11 mm) in the center and 1 mm below the test base surface, and four strain gauges were installed around the implant, simulating the mesial, distal, buccal and lingual positions.

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The goal of this in vitro study was to evaluate and propose a new strategy for osseodensification technique using a drill counterclockwise to densification of bone of low density. Synthetic bone blocks of two different low densities (type III and IV) were used for the tests. The conventional drilling group (CD group) used Turbo-drill in a clockwise direction, and the osseodensification group (OD group) applied Turbo-drill in a counterclockwise direction.

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The goal of this systematic review was to verify the marginal bone loss (MBL) and other clinical parameters comparing external hexagon (EH) and Morse taper (MT) implants when they were evaluated within the same study. The focused question was, "For patients (P) treated with external connection (I) or Morse taper (C) dental implants, were there differences in the marginal bone crest maintenance after at least three months in occlusal function (O)"? As for the inclusion criteria that were considered, they included clinical studies in English that compared the MBL in implants with EH and MT, with follow-up of at least three months, that were published between 2011 and 2022; as for the exclusion criteria, they included publications investigating only one type of connection that analyzed other variables and did not report results for the MBL, reports based on questionnaires, interviews, and case reports/series, systematic reviews, or studies involving patients with a significant health problem (ASA Physical Status 3 and above). The PubMed/MEDLINE, Embase, and Web of Science databases were screened, and all of the data obtained were registered in a spreadsheet (Excel).

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Objectives: Micromotion between a dental implant and abutment can adversely affect clinical performance and compromise successful osseointegration by creating a bacterial harbor, enabling screw loosening, and imparting disruptive lateral forces on the cortical bone. Thus, the aim of the present study was to measure the abutment stability evolution using resonance frequency analysis (RFA) in vivo at four different times (baseline, 3, 4, and 12 months), and compare these data obtained with the RFA measured after mechanical cycling (in vitro) corresponding to the proposed times in numbers of cycles.

Methods: To evaluate the abutment stability, RFA was performed in 70 sets of implant/abutment (IA) with a total of 54 patients (31 women, 23 men).

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Background: the prevalence of peri-implant diseases is constantly growing, particularly with the increasing use of dental implants. As such, achieving healthy peri-implant tissues has become a key challenge in implant dentistry since it considers the optimal success paradigm. This narrative review aims to highlight the current concepts regarding the disease and summarize the available evidence on treatment approaches clarifying their indications for usage following the World Workshop on the Classification of Periodontal and Peri-implant Diseases (2017).

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The goal of this retrospective clinical study was to evaluate the behavior of Morse-taper indexed abutments by analyzing the marginal bone level (MBL) after at least 12 months of function. Patients rehabilitated with single ceramic crowns between May 2015 and December 2020 received single Morse-taper connection implants (DuoCone implant) with two-piece straight abutment baseT used for at least 12 months, presenting periapical radiograph immediately after crown installation were enrolled. The position of the rehabilitated tooth and arch (maxilla or mandible), crown installation period, implant dimensions, abutment transmucosal height, installation site (immediate implant placement or healed area), associated with bone regeneration, immediate provisionalization, and complications after installation of the final crown were analyzed.

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Background: The aim of this systematic review and case reports was to evaluate osseointegration and implant survival rate in patients with chronic kidney disease.

Methods: The paper screening process was conducted on electronic databases in order to identify clinical studies concerning the study topic. The literature data were evaluated for eligibility and studies were included for the qualitative synthesis.

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Objectives: The present study compared two implants with different macrogeometries placed in healed alveolar sites, evaluating the insertion torque (ITV) and implant stability quotient (ISQ) values at three different periods. Methods: Seventy patients with a total of 100 dental implants were allocated into two groups (n = 50 per group): DuoCone implants (DC group) that included 28 implants in the maxilla and 22 in the mandible, and Maestro implants (MAE group) that included 26 in the maxilla and 24 in the mandible. The ITV was measured during the implant placement, and the ISQ values were measured immediately at implant placement (baseline) and after 30 and 45 days.

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The lingual frenulum is a submucosal component significantly involved in the mobility of the tongue. In the case of short lingual frenulum, different surgical approaches have been proposed. Atmospheric plasma is a thermal technique of vaporization or sublimation of the superficial tissues, without going deep, and the resulting fine carbonized layer avoids bleeding.

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Objective: The aim of the present in vitro study was to evaluate the resistance on quasi-static forces and in the fatigue mechanical cycling of a new implant design compared to two other conventional implant designs.

Materials And Methods: Eighty-eight implants with their respective abutments were tested and distributed into four groups (n = 22 per group): Morse taper connection implant (MT group), conventional external hexagon implant (EH con group), new Collo implant of external hexagon with the smooth portion out of the bone insertion (EH out group), and new Collo implant of external hexagon with the implant platform inserted to the bone level (EH bl group). All the sets were subjected to quasi-static loading in a universal testing machine, and we measured the maximum resistance force supported by each sample.

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A large number of materials with different compositions and shapes have been proposed and studied for the purpose of bone tissue regeneration. Collagen-based materials have shown promising results for this application, with improved physicochemical properties. The aim of the present in vivo animal study was to evaluate and compare two commercially available collagen-based biomaterials for bone regeneration, with these being implanted in circumferential bone defects created in the calvarium of rabbits.

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The aim of the present in vivo study was to analyze and compare the effects on the crestal bone healing of two different implant macrogeometries installed in fresh socket areas and in normal bone areas with different insertion torque values. Two implant macrogeometries were used in the present study, DuoCone implant (DC) and Maestro implant (MAE), forming four groups: group DCws, in which the implants were installed in healing bone (without a socket); group DCfs, in which the implants were installed in post-extraction areas (fresh sockets); group MAEws, in which the implants were installed in healing bone (without a socket); group MAEfs, in which the implants were installed in post-extraction areas (fresh sockets). After 30 and 90 days of implantations in the bilateral mandibles of 10 sheep, eighty implants were evaluated through digital X-ray images and histologic slices.

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Background: Various ceramic materials have been used for esthetic rehabilitation with implants, but the issues regarding the dissipation of masticatory loads are not well understood.

Objectives: This in vitro quasi-static study aimed to evaluate with the photoelasticity test the dissipation of stress around dental implants with regard to different rehabilitation materials.

Material And Methods: A photoelastic model was elaborated in resin, where a conical Morse-tapered implant was inserted.

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Dental implants are not routinely used for rehabilitation in veterinary dentistry. For some veterinarians, further studies are necessary to be considered for clinical use in animals. The objective of the present study was to evaluate static fatigue of dental implants and to correlate that with the bite strength of dogs described in the literature.

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This study aims to evaluate the effects of implant macrogeometry on the early period of the osseointegration process, comparing four different implant models through biomechanical and histological analysis after implantation in rabbit tibiae. Twenty New Zealand rabbits were used, evaluated at two different times (21 and 28 days) after installation of the implant. Eighty implants with different macrogeometries were used, forming four groups (n = 20 per group): cylindrical implants Ø4.

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