Publications by authors named "Rafael Pla"

6 Publications

  • Page 1 of 1

Immunohistochemical characteristics of lateral bone augmentation using different biomaterials around chronic peri-implant dehiscence defects: An experimental in vivo study.

Clin Oral Implants Res 2021 Feb 25. Epub 2021 Feb 25.

Department of Periodontology, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain.

Aim: To investigate the immunohistochemical characteristics of a highly porous synthetic bone substitute and a cross-linked collagen membrane for guided bone regeneration.

Methods: Three experimental groups were randomly allocated at chronic peri-implant dehiscence defect in 8 beagle dogs: (i) biphasic calcium phosphate covered by a cross-linked collagen membrane (test group), (ii) deproteinized bovine bone mineral covered by a natural collagen membrane (positive control) and (iii) no treatment (negative control). After 8 and 16 weeks of submerged healing, dissected tissue blocks were processed for immunohistochemical analysis. Seven antibodies were used to detect the remaining osteogenic and angiogenic potential, and quantitative immunohistochemical analysis was done by software.

Results: The antigen reactivity of alkaline phosphatase was significantly higher in the test group compared to the positive and negative controls, and it maintained till 16 weeks. The intensity of osteocalcin was significantly higher in the positive control at 8 weeks than the other groups, but significantly decreased at 16 weeks and no difference was found between the groups. A significant large number of TRAP-positive cells were observed in the test group mainly around the remaining particles at 16 weeks. The angiogenic potential was comparable between the groups showing no difference in the expression of transglutaminase II and vascular endothelial growth factor.

Conclusion: Guided bone regeneration combining a highly porous biphasic calcium phosphate synthetic biomaterial with a crosslinked collagen membrane, resulted in extended osteogenic potential when compared to the combination of deproteinized bovine bone mineral and a native collagen membrane.
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February 2021

Hard and soft tissue changes after guided bone regeneration using two different barrier membranes: an experimental in vivo investigation.

Clin Oral Investig 2021 Apr 26;25(4):2213-2227. Epub 2020 Aug 26.

Postgraduate Periodontology Clinic, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain.

Objective: To assess the contour and volumetric changes of hard and soft tissues after guided bone regeneration (GBR) using two types of barrier membranes together with a xenogeneic bone substitute in dehiscence-type defects around dental implants.

Material And Methods: In 8 Beagle dogs, after tooth extraction, two-wall chronified bone defects were developed. Then, implants were placed with a buccal dehiscence defect that was treated with GBR using randomly: (i) deproteinized bovine bone mineral (DBBM) covered by a synthetic polylactic membrane (test group), (ii) DBBM plus a porcine natural collagen membrane (positive control) and (iii) defect only covered by the synthetic membrane (negative control group). Outcomes were evaluated at 4 and 12 weeks. Micro-CT was used to evaluate the hard tissue volumetric changes and STL files from digitized cast models were used to measure the soft tissues contour linear changes.

Results: Test and positive control groups were superior in terms of volume gain and contour changes when compared with the negative control. Soft tissue changes showed at 4 weeks statistically significant superiority for test and positive control groups compared with negative control. After 12 weeks, the results were superior for test and positive control groups but not statistically significant, although, with a lesser magnitude, the negative control group exhibited gains in both, soft and hard tissues.

Conclusions: Both types of membranes (collagen and synthetic) attained similar outcomes, in terms of hard tissue volume gain and soft tissue contours when used in combination with DBBM CLINICAL RELEVANCE: Synthetic membranes were a valid alternative to the "gold standard" natural collagen membrane for treating dehiscence-type defects around dental implants when used with a xenogeneic bone substitute scaffold.
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April 2021

Manual versus sonic powered toothbrushing in patients with intellectual disability: a cluster-randomized clinical trial.

J Clin Periodontol 2016 08 20;43(8):684-93. Epub 2016 May 20.

ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, Faculty of Odontology, University Complutense, Madrid, Spain.

Objectives: To compare the use of sonic powered or manual toothbrush in patients with intellectual disability (ID) in terms of plaque (PlI) and gingival (GI) indices and adverse effects.

Material And Methods: Subjects with ID were recruited for this cluster-randomized, single blinded (examiner), 6-month clinical trial, comparing powered versus manual toothbrushing. Outcome variables included PlI and GI, evaluated at baseline and 3 months after supervised toothbrushing and after 3 additional months of unsupervised used. Clinical outcome variables were analysed by repeated measures ANCOVA considering time and group as factors and respective baseline values as covariates (generalized linear model).

Results: Sixty-four patients (34 male, mean age 34.5) in six clusters were included in the study. No statistically significant effect of toothbrushing group was observed for PlI or GI. A significant effect of time was identified (p < 0.001) with mean reductions ranging 0.44-0.45 for PlI and 0.30-0.36 for GI from baseline to 3-6 months. No relevant adverse effect or technical problems were observed.

Conclusion: The tested sonic powered toothbrush was as effective and safe as the manual toothbrush. The use of powered or manual toothbrushes, together with fluoride toothpaste, may improve plaque and gingivitis levels, in patients with mild to limit ID.
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August 2016

A multicentre placebo-controlled randomised clinical trial of antibiotic prophylaxis for placement of single dental implants.

Eur J Oral Implantol 2009 ;2(4):283-92

Instituto Eduardo Anitua, Vitoria, Spain.

Purpose: To compare the efficacy and safety of 2 g amoxicillin orally with identical placebo tablets 1 hour before implant placement when placing single implants in bone types II and III.

Material And Methods: 12 private dental clinics in Spain agreed to participate in this trial. A total of 105 patients were recruited. Patients were randomised for consumption orally of 2g amoxicillin or identical placebo tablets. Only patients needing single implants were included. Outcome measures were post-operative infections, adverse events and implant failures. Characteristics of the saprophytic flora were also studied in all patients. Patients were seen 3 days, 10 days, 1 month and 3 months postoperatively.

Results: A total of 105 patients (n = 52 in the amoxicillin group and n = 53 in the placebo group) were evaluated and none were excluded from the study at 3 months. Six post-operative infections occurred and two implants were lost in each group. There were no statistically significant differences for postoperative infection, adverse events, implant failures and the characteristics of saprophytic flora between groups. The use of amoxicillin did not either alter or modify the characteristics of the saprophytic flora nor provoke remarkable side effects.

Conclusions: Antibiotic prophylaxis may not be needed when placing single implants in patients with bone types II and III.
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June 2010

The effects of PRGF on bone regeneration and on titanium implant osseointegration in goats: a histologic and histomorphometric study.

J Biomed Mater Res A 2009 Oct;91(1):158-65

Biotechnology Institute I MAS D, San Antonio 15, 01005 Vitoria, Spain.

The effect of local application of scaffold-like preparation rich in growth factors (PRGF) on bone regeneration in artificial defects and the potential effect of humidifying titanium dental implants with liquid PRGF on their osseointegration were investigated. The PRGF formulations were obtained from venous blood of three goats and applied either as a 3D fibrin scaffold (scaffold-like PRGF) in the regeneration of artificial defects or as liquid PRGF via humidifying the implants before their insertion. Initially, 12 defects were filled with scaffold-like PRGF and another 12 were used as controls. The histological analysis at 8 weeks revealed mature bone trabeculae when PRGF was used, whereas the control samples showed mainly connective tissue with incipient signs of bone formation. For the second set of experiments, 26 implants (13 humidified with liquid PRGF) were placed in the tibiae of goats. Histological and histomorphometric results demonstrated that application of liquid PRGF increased the percentage of bone-implant contact in 84.7%. The whole surface of the PRGF-treated implants was covered by newly formed bone, whereas only the upper half was surrounded in control implants. In summary, PRGF can accelerate bone regeneration in artificial defects and improve the osseointegration of titanium dental implants.
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October 2009

Intravenous human plasma-derived augmentation therapy in alpha 1-antitrypsin deficiency: from pharmacokinetic analysis to individualizing therapy.

Ann Pharmacother 2008 May 15;42(5):640-6. Epub 2008 Apr 15.

Pharmacy Service, Hospital Vall d'Hebron, Barcelona, Spain.

Background: Severe forms of alpha(1)-antitrypsin (AAT) deficiency require augmentation therapy by intravenous administration of purified preparations of AAT concentrate. Although standard AAT treatment schedules are widely available, pharmacokinetic studies characterizing AAT serum decay are scarce, and data on the variability of individual patients are almost nonexistent.

Objective: To establish individual AAT pharmacokinetics and develop a predictive model based on simple pharmacokinetic characterization that can be used to optimize individual AAT dosing regimens.

Methods: Seven patients with severe hereditary AAT deficiency (PI(*)ZZ phenotype) with serum AAT levels less than 0.50 g/L initially received AAT 180 mg/kg every 3 weeks. At 7, 14, and 21 days after AAT administration, serum samples were taken for quantitative AAT analysis and further one-compartment pharmacokinetic analysis. Subsequently, patients were rescheduled (dose and dosing interval) according to their individual responses. The influence of baseline AAT level, age, sex, body weight, and commercial AAT preparation was evaluated.

Results: The mean +/- SD AAT pharmacokinetic profile was: volume of distribution 127.6 +/- 31.9 mL/kg, clearance 10.13 +/- 1.84 mL/kg/day, and half-life 8.7 +/- 1.0 days. Hence, the mean optimized final AAT dose was 123.1 mg/kg every 2 weeks (range 118.5-125.6). AAT concentrations differed by a mean (geometrical) value of 3.9% (range -4.2% to 6.7%) from the minimum desired AAT serum trough of 0.50 g/L. The impact of baseline AAT levels and commercial AAT preparation used was statistically significant (p = 0.033 and p = 0.035, respectively). Differences between estimated and actual values were slightly lower when baseline AAT levels were taken into consideration, with a mean value of 3.3% (range -4.2% to 6.1%).

Conclusions: AAT augmentation therapy can be effectively individualized on a pharmacokinetic basis with a simple, easily executed method.
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May 2008