129 research outputs found
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
Prevention and early diagnosis of oral carcinoma in construction workers in Italy: a pilot project
Objectives: A research project on occupational exposure in relation to oral carcinoma was periodic compulsory check-ups, oral
examinations were performed to detect pathologies and the prevalence of potentially neoplastic oral conditions and a selfassessment
questionnaire was administered to all of the subjects. The questionnaire was structured to collect information regarding
demographic and clinical characteristics, risk habits (tobacco and alcohol consumption) and oral health habits, and to allow an
assessment of knowledge about oral cancer, related risk factors and early signs. Results: The study cohort included people with
different ethnicities, and there were significant differences in clinical characteristics between Italians and other Europeans. The
subjects showed a good knowledge about oral cancer and related risk factors (with correct answers provided to >50% of the
questions) but insufficient knowledge about the early signs of oral carcinoma (correct-answer rates of 16–42%). There were high
rates of habits that are potentially harmful to oral health, such as smoking (43.8%) and alcohol consumption (57%). The daily habit
of brushing teeth was present in 92.6% of the subjects, but they had a low propensity to undergo regular dental examinations. The
percentage of subjects with pathologies of the oral cavity was 18.6%. Conclusions: Despite the smallness of the sample, this pilot
project could facilitate the acquisition of valid and cost-effective data for the primary prevention of oral cancer through information
and educational campaigns on the related risk factors
Histomorphometric evaluation of bone regeneration induced by biodegradable scaffolds as carriers for dental pulp stem cells in a rat model of calvarial "critical size" defect
Objective: The aim of this study was to test specific stem cells that could enhance bone formation in combination
with specific scaffolds.
Methods: Dental Pulp Stem Cells (DPSCs) were seeded with Granular Deproteinized Bovine Bone (GDPB) or Beta-Tricalcium Phosphate (ß-TCP) in a rat model of calvarial "critical size" defect. DPSCs were isolated from permanent human teeth, obtained and characterized using specific stem cells markers (Nanog and Oct-4) by real time-PCR and immunofluorescence. Cells were differentiated for 10-15 days towards the osteoblastic phenotype with 100μM L-ascorbic acid, added every day in culture medium and 20 vol. percentage of FBS in α-MEM medium. Osteogenic commitment was evaluated with real time-PCR by measuring the expression of specific markers (osteonectin and runx2). When a sufficient cell number was obtained, DPSCs were trypsinized, washed in culture medium and seeded onto the GDPB and ß-TCP scaffold sat a density of 0.5-1×106 cells/scaffold. Two bilateral critical-size circular defects (5 mm diameter; 1 mm thickness) were created from the parietal bone of the 8 athymic T-cell deficient nude rats. One cranial defect for each rat was filled with the scaffold alone and the other defect with the scaffold seeded with stem cells. After 12 weeks post-surgery animals were euthanized and histomorphometric analysis was performed. Differences between groups were analyzed by one-way analysis of variance (ANOVA) followed by Fisher's Protected Least Significant Difference (PLSD) post-hoc test. A p-value <0.05 was considered statistically significant.
Results: GDPB group presented higher percentage of lamellar bone than that of GDPB/DPSC, Ăź-TCP alone had lower levels as compared to Ăź-TCP/DPSC. The addition of stem cells significantly increased woven bone formation in both scaffold-based implants, although still higher in GDPB based implants.
Conclusion: Our findings indicate that GDPB and Ăź-TCP used as scaffold to induce bone regeneration may benefit from adding DPSC to tissue-engineered constructs
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
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
Survival and complication rates of tooth-implant versus freestanding implant supporting fixed partial prosthesis: a systematic review and meta-analysis
Purpose: This systematic review was performed to compare tooth, implant and prosthesis failures and biological and technical complications in toothimplant vs freestanding implant supported fixed partial prostheses, in order to evaluate the effectiveness and predictability in combining teeth and implants in the same fixed partial prosthesis.
Study selection: A comprehensive and systematic literature research was conducted, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, to identify human trials, with a minimum sample size of 10 patients, comparing tooth-implant to freestanding implant supported fixed partial prostheses. Four groups of meta-analyses were performed based on the patients treated with toothimplant vs freestanding implant-supported fixed partial prostheses: abutment failures, biological and mechanical complications, prosthesis failures, and prosthetic (technical) complications.
Results: The search yielded 749 records, after removal of duplicates. Based on the title assessment, the abstracts reading and the full-texts evaluation, 8 articles, published between 1999 and 2013, fulfilled the inclusion criteria and were included in the meta-analysis. The studies included were: 4 controlled clinical trials, 2 prospective and 2 retrospective cohort studies. The meta-analysis revealed no significant difference between tooth-implant and implant-implant supported fixed in the number of abutment (implant or tooth) failures, biological complications, prosthesis lost, and prosthetic complications.
Conclusions: Within the limitations of the present systematic review, although the freestanding implant supported fixed partial prosthesis remains the first choice, joining teeth and implants to support fixed prosthesis in partially edentulous patients becomes a valid alternative with an acceptable success rate
Clinical Study Histological and Histomorphometric Human Results of HA-Beta-TCP 30/70 Compared to Three Different Biomaterials in Maxillary Sinus Augmentation at 6 Months: A Preliminary Report
Objective. The aim of this investigation was to examine the bone regenerative potential of newly biphasic calcium phosphate ceramics (HA--TCP 30/70), by assessing histological and histomorphometric results of human specimens retrieved from sinuses augmented with HA--TCP 30/70, and comparing them to anorganic bovine bone (ABB), mineralized solvent-dehydrated bone allograft (MSDBA), and equine bone (EB), after a healing period of 6 months. Materials and Methods. Four consecutive patients with edentulous atrophic posterior maxilla were included in this report. A two-stage procedure was carried out for sinus augmentation with HA--TCP 30/70, ABB, MSDBA, and EB. After 6 months, specimens were retrieved at the time of implant placement and processed for histological and histomorphometric analyses. Results. At histological examination, all biomaterials were in close contact with the newly formed bone and showed the same pattern of bone formation; the grafted granules were surrounded by a bridge-like network of newly formed bone. A limited number of ABB particles were partially covered by connective tissue. The histomorphometric analysis revealed 30.2% newly formed bone for Ha--TCP 30/70, 20.1% for ABB, 16.4% for MSDBA, and 21.9% for EB. Conclusions. Within the limitations of the present investigation, these results support the successful use of HA--TCP 30/70 for sinus augmentation
The Smallest Scale of Hierarchy Survey (SSH). II. Extended star formation and bar-like features in the dwarf galaxy NGC 3741: recent merger or ongoing gas accretion?
Using Large Binocular Telescope deep imaging data from the Smallest Scale of
Hierarchy Survey (SSH) and archival Hubble Space Telescope data, we reveal the
presence of two elongated stellar features contiguous to a bar-like stellar
structure in the inner regions of the dwarf irregular galaxy NGC 3741. These
structures are dominated by stars younger than a few hundred Myr and
collectively are about twice as extended as the old stellar component. These
properties are very unusual for dwarf galaxies in the nearby Universe and
difficult to explain by hydro-dynamical simulations. From the analysis of
archival 21-cm observations, we find that the young stellar "bar" coincides
with an HI high-density region proposed by previous studies to be a purely
gaseous bar; we furthermore confirm radial motions of a few km/s, compatible
with an inflow/outflow, and derive a steeply-rising rotation curve and high HI
surface density at the center, indicating a very concentrated mass
distribution. We propose that the peculiar properties of the stellar and
gaseous components of NGC 3741 may be explained by a recent merger or ongoing
gas accretion from the intergalactic medium, which caused gas inflows towards
the galaxy center and triggered star formation a few hundred Myr ago. This
event may explain the young and extended stellar features, the bar-like
structure, the very extended HI disc and the central HI spiral arms. The high
central HI density and the steeply rising rotation curve suggest that NGC 3741
may be the progenitor or the descendant of a starburst dwarf
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