Francisco Javier Manzano-Moreno

Risk factors associated with early implant failure: A 5-year retrospective clinical study

STATEMENT OF PROBLEM The replacement of lost teeth with dental implants is a widespread treatment whose associated problems are also frequently encountered. Nevertheless, the factors associated with early implant failure have not been well documented. Further analyses of the factors influencing osseointegration establishment are required to maximize the predictability of the procedure and minimize implant failures. PURPOSE The purpose of this retrospective clinical study was to explore the association between possible risk factors and early implant failure. MATERIAL AND METHODS This retrospective clinical study evaluated 142 participants who received 276 external connection BTI implants between 2007 and 2011. Participant variables (age, sex, systemic disease, tobacco use, alcohol consumption, bruxism, and degree of periodontal disease), implant variables (type of edentulism, localization, area, diameter, length, and bone quality), intervention variables (expansion mechanisms, sinus augmentation techniques, bone regeneration, and implant insertion), and postoperative variables (presence of pain/inflammation at 1 week postsurgery) were studied. A multilevel logistic regression model (mixed effects-type model) was used to determine the influence of variables on early implant failure. RESULTS Early implant failure was significantly associated with the male sex (P=.001), severe periodontal disease (P=.005), short implants (P=.001), expansion technique (P=.002), and postoperative pain/inflammation at 1 week postsurgery (P<.001). CONCLUSIONS Early dental implant failure is more frequent in men and in individuals with severe periodontal disease, short implants, pain/inflammation at 1 week postsurgery, or bone expansion treatment.

Repercussions of NSAIDS drugs on bone tissue: the osteoblast.

Non-steroidal anti-inflammatory drugs (NSAIDs) can act by modulating the behavior of osteoblasts, including their proliferation, differentiation, adhesion, and migration, but not all NSAIDs have these effects. Our objective was to update the information on this issue in a review of the literature in order to offer guidance on the prescription of the appropriate NSAID(s) to patients requiring bone tissue repair. To review current knowledge of this issue by searching for all relevant publications since 2001 in the MEDLINE, EMBASE and Cochrane Library databases, we used the following descriptors: bone tissue, osteoblast, NSAIDs, Anti-inflammatory drugs. Published studies show that most NSAIDs have an adverse effect on osteoblast growth by cell cycle arrest and apoptosis induction. The effect on differentiation varies according to the drug, dose, and treatment time. Osteoblast adhesion is increased and migration decreased by some NSAIDs, such as indomethacin and diclofenac. The antigenic profile or phagocytic function can also be modulated by NSAIDs. In general, NSAIDs have an adverse effect on bone tissue and given the routine administration of NSAIDs to individuals requiring bone repair, in which the osteoblast has an essential role, this effect on bone should be borne in mind.

The effect of low-level diode laser therapy on early differentiation of osteoblast via BMP-2/TGF-β1 and its receptors.

OBJECTIVES The objective of this study was to determine the effect of LLDL therapy on the gene expression of osteoblast markers of growth and differentiation. MATERIALS AND METHODS The MG-63 cell line was exposed to diode laser (ezLase) of 940 nm at 1-1.5 W and 3-4 J, and gene expressions (Runx-2, alkaline phosphatase [ALP], type I collagen [Col-I], osterix [OSX], osteocalcin [OSC], osteoprotegerin [OPG], bone morphogenetic protein [BMP]-2 and -7, transforming growth factor-β1 [TGF-β1], and TGF-β receptors [TGF-β R1, TGF-β R2; TGF-β R3]) were evaluated by quantitative RT-PCR. RESULTS LLDL treatment stimulated the expression of osteoblast differentiation markers ALP, Col-I, Runx-2, and OSX in relation to the doses applied (P < 0.05), but no changes were detected in OSC, OPG, or BMP-7 at any study dose. This effect may be mediated by TGF-β1 and BMP-2, given that the treatment increased their expression and that of TGF-β receptors R1, R2, and R3 (P < 0.001). CONCLUSION These results suggest that the biostimulatory effect of laser therapy on osteoblasts may be attributable to the release of autocrine factors in response to the irradiation. A clinical trial is warranted to test its therapeutic usefulness in bone tissue regeneration and to define a treatment protocol.

Factors Affecting Dental Implant Stability Measured Using the Ostell Mentor Device: A Systematic Review.

Objectives:The aim of this study was to review the literature on factors that may affect dental implant stability as measured with the Ostell mentor device. Materials and Methods:A systematic search of the literature was performed in Pubmed, Scopus, and Cochrane databases using dental implants, stability, and resonance frequency analysis as key words. Results:The most relevant randomized controlled trials and clinical trials (n = 39) were selected from among 264 articles. Conclusions:Many factors can affect dental implant stability as measured with the Ostell mentor device. This may be a useful instrument for deciding the timing of implant loading, but additional research is required to establish the reliability and predictability of resonance frequency analysis for the future osseointegration of dental implants, which remains controversial.

Human fibroblast-like cultures in the presence of platelet-rich plasma as a single growth factor source: clinical implications.

OBJECTIVE: The purpose of this study was to compare the proliferation, morphology, and antigenic expression of human fibroblast–like cells between primary cultures treated with platelet-rich plasma (PRP) or fetal bovine serum (FBS) as the growth factor source. DESIGN: Cells from human gingival tissue samples obtained from healthy volunteers during oral surgery were studied. Isolated cells were cultured in media supplemented with 10% PRP or FBS. Platelet-rich plasma was prepared from the venous blood of each patient. The authors studied short- and long-term cell cultures in the presence of PRP or FBS as the sole growth factor source in order to determine (a) cell growth rate, by MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay; (b) cell morphology, by electronic microscopy; and (c) antigenic expression, by flow cytometry and confocal microscopy. RESULTS: In short-term cultures, the cell growth rate was higher with PRP versus FBS treatment. No differences in morphology or expression of vimentin, fibronectin, or &agr;-actin antigens were observed between PRP and FBS cultures. In long-term cultures, PRP and FBS did not significantly differ in cell growth rate but differed in morphology and in the expression of vimentin, fibronectin, and &agr;-actin. CONCLUSION: The PRP enhances cell proliferation over the short term and induces cell differentiation of fibroblast-like cells to myofibroblast-like cells over the long term, suggesting that fibroblast differentiation to myofibroblasts may underlie the action mechanism of PRP in soft tissue regeneration.

Long-Term Survival of Dental Implants with Different Prosthetic Loading Times in Healthy Patients: A 5-Year Retrospective Clinical Study

PURPOSE To compare survival rates among dental implants restored with immediate, early, and conventional loading protocols, also comparing between maxillary and mandibular implants, and to evaluate the influence of implant length and diameter and the type of prosthesis on treatment outcomes. MATERIALS AND METHODS This retrospective cohort study initially included all 52 patients receiving dental implants between July 2006 and February 2008 at a private oral surgery clinic in Granada (Southern Spain). Clinical and radiographic examinations were performed, including periapical or panoramic radiographs, and incidences during completion of the restoration were recorded at 1 week, 3 months, 6 months, and at 1, 2, 3, 4, and 5 years. After a 5-year follow-up, 1 patient had died, 3 were lost to follow-up, and 6 required grafting before implant placement; therefore, the final study sample comprised 42 patients with 164 implants. RESULTS Variables associated with the survival/failure of the restoration were: number of implants (higher failure rate with fewer implants), bone type (higher failure rate in type III or IV bone), and type of prosthesis (higher failure rate with single crowns). No significant association was found in univariate or multivariate analyses between survival rate and the loading protocol, implant length or diameter, or maxillary/mandibular location. CONCLUSIONS Immediate occlusal loading, immediate provisionalization without occlusal loading, and early loading are viable treatment options with similar survival rates to those obtained with conventional loading. Bone quality and number of implants per patient were the most influential factors.

Bisphosphonate Modulation of the Gene Expression of Different Markers Involved in Osteoblast Physiology: Possible Implications in Bisphosphonate-Related Osteonecrosis of the Jaw

The aim of the present study was to elucidate the role of osteoblasts in bisphosphonates-related osteonecrosis of the jaw (BRONJ). The specific objective was to evaluate the effect on osteoblasts of two nitrogen-containing BPs (zoledronate and alendronate) and one non-nitrogen-containing BP (clodronate) by analyzing modulations in their expression of genes essential for osteoblast physiology. Real-time polymerase chain reaction (RT-PCR) was used to study the effects of zoledronate, alendronate, and clodronate at doses of 10-5, 10-7, or 10-9 M on the expression of Runx-2, OSX, ALP, OSC, OPG, RANKL, Col-I, BMP-2, BMP-7, TGF-β1, VEGF, TGF-βR1, TGF-βR2, and TGF-βR3 by primary human osteoblasts (HOBs) and MG-63 osteosarcoma cells. Expression of these markers was found to be dose-dependent, with no substantive differences between these cell lines. In general, results demonstrated a significant increase in TFG-β1, TGF-βR1, TGF-βR2, TGF-βR3, and VEGF expressions and a significant reduction in RUNX-2, Col-1, OSX, OSC, BMP-2, BMP-7, ALP, and RANKL expressions, while OPG expression varied according to the dose and cell line. The results of this in vitro study of HOBS and MG-63 cell lines indicate that low BP doses can significantly affect the expression of genes essential for osteoblast growth and differentiation and of genes involved in regulating osteoblast-osteoclast interaction, possibly by increasing TGF-β1 production. These findings suggest that osteoblasts may play an important role in BRONJ development, without ruling out other factors.

Bacterial contamination levels of autogenous bone particles collected by 3 different techniques for harvesting intraoral bone grafts.

PURPOSE The aim of this study was to compare levels of bacterial contamination of autogenous bone collected when using low-speed drilling, a back-action chisel, and a bone filter. MATERIALS AND METHODS Bone tissue samples were taken from 31 patients who underwent surgical extraction of their third lower molars. Before surgical removal of the molar, bone particles were collected by a low-speed drill or a back-action chisel. Then, a stringent aspiration protocol was applied during the ostectomy to collect particulate bone by a bone filter. Processing of samples commenced immediately by incubation in an anaerobic or a CO2-rich atmosphere. The number of colony-forming units (CFUs) was determined at 48 hours of culture. RESULTS No significant difference in the number of CFUs per milliliter was observed between the low-speed drilling group and the back-action chisel group in the anaerobic or CO2-rich condition (P = .34). However, significantly more micro-organisms were found in the bone filter group than in the low-speed drilling group or the back-action chisel group in the anaerobic and CO2-rich conditions (P < .001). CONCLUSIONS Particulate bone harvested with low-speed drilling or a back-action chisel is safer for use as an autograft than are bone particles collected with a bone filter. These results suggest that bone obtained from low-speed drilling is safe and straightforward to harvest and could be the method of choice for collecting particulate bone. Further research is needed to lower the bacterial contamination levels of autogenous bone particles used as graft material.

Effect of olive oil phenolic compounds on osteoblast differentiation

Osteoporosis is a skeletal disorder characterized by compromised bone strength that predisposes individuals to an increased risk of fracture. Previous in vivo and in vitro studies have reported that phenolic compounds present in extra virgin olive oil have a beneficial effect on osteoblasts in terms of increase cell proliferation. The aim of this study was to determine whether phenolic compounds present in olive oil could modify the expression of cell differentiation markers on osteoblasts.

Cultured Human Fibroblast Biostimulation Using a 940 nm Diode Laser

Background: Fibroblasts are the main cells involved in regeneration during wound healing. The objective was to determine the effect of 940 nm diode laser on cultured human fibroblasts using different irradiation regimens. Methods: The CCD-1064Sk human epithelial fibroblast cell line was treated with a 940 nm diode laser at different energy doses (power: 0.2–1 W and energy density: 1–7 J/cm2) using different transmission modes (continuous or pulsed). The effect on cell growth at 24 and 72 h post-treatment was examined by measuring the proliferative capacity, the impact on the cell cycle, and the effect on cell differentiation. Results: fibroblast proliferative capacity was increased at 24 and 72 h post-treatment as a function of the energy dose. The greatest increase was observed with a power of 0.2 or 0.5 W and energy density between 1 and 4 J/cm2; no difference was observed between continuous and pulsed modes. There were no significant differences in cell cycle between treated groups and controls. α-actin expression was increased by treatment, indicating enhanced cell differentiation. Conclusion: The 940 nm diode laser has biostimulating effects on fibroblasts, stimulating proliferative capacity and cell differentiation without altering the cell cycle. Further researches are necessary to explore its potential clinical usefulness in wound healing.