Work-Related musculoskeletal pain among lebanese dentists: An epidemiological study.

INTRODUCTION: The aim of this study was to evaluate the prevalence of musculoskeletal disorders and identify their associated factors among a group of Lebanese dentists. MATERIALS AND METHODS: A total of 314 Lebanese, dentists completed an anonymous questionnaire that focused on occupational health problems. This study was approved by the ethics committee of Saint-Joseph University of Beirut, Lebanon. The statistical analyses were performed using SPSS for windows. The alpha error was set to 0.05. RESULTS: The mean age of the participants was 39.2 (±11.66) years. The results showed that 61.5% of the surveyed dentists complained of spinal pain: 31.6% of cervical pain, 22.3% of lumbar pain and 13.0% of dorsal pain. Moreover, the pain was continuous in 20.7% and, occasional in 65.8%. Our statistics showed that 7.6% had a problem with the carpal tunnel. A total of 22.3% suffered from tendinitis and 9.2% from arthritis of shoulder, elbow, wrist and hand. The frequency of headaches was 30.6%. Concerning sports activity, 49.7% practiced it occasionally and 3.6% did so frequently. CONCLUSIONS: The occurrence of musculoskeletal pain in the upper extremities is a serious concern that affects Lebanese dentists. Most of them often complained of tendinitis and headaches because they do not practice sports; thus, encouraging them to practice sports may reduce or solve such health problems. Issuing brochures that include exercises to perform and hiring trained assistants could help reduce the risk of musculoskeletal disorders. Finally, these occupational health problems should be highlighted at all clinical and research symposia to increase awareness.

[Status of health and oral health of the elderly population in Lebanon]. / État des lieux sanitaire et bucco-dentaire de la population gériatrique libanaise.

Lebanon is in demographic transition as more people reach increasingly older age; 10% of the population in Lebanon is elderly. The incidence of chronic diseases and oral diseases increases significantly with age. However, 55% of the elderly have no health insurance and 82% have no dental insurance. Both noncommunicable diseases (NCDs) and oral diseases are a major health burden in the country and share the same risk factors. The WHO strategy for prevention and control of noncommunicable diseases should therefore be a new approach for the prevention and control of dental diseases among Lebanese elderly. This paper aims to increase the awareness of the medical community in Lebanon about the interrelationship between general and oral health in the elderly and concludes with the need for the Ministry of Health to develop policies and national action plans against NCDs to reduce not only mortality from NCDs but also morbidity from oral diseases.

Vertical bone regeneration with deproteinised bovine bone mineral or biphasic calcium phosphate in the rabbit calvarium: effect of autologous platelet lysate.

Although bone substitutes associated with platelet concentrates are widely used to vertically reconstruct alveolar ridges, their respective and specific contribution remain controversial. The aim of this study was to evaluate the benefit of using either biphasic calcium phosphate (BCP) or demineralised bovine bone mineral (DBBM) alone or with autologous platelet lysate (APL) in vertical bone regeneration. The study involved fourteen New Zealand rabbits. Autologous APL was prepared by freeze-thawing from a platelet suspension (10(9) platelets/ml). Four CP titanium (cpTi) cylinders were fixed to each calvarium; one cylinder was empty, one was filled with APL alone and the others were filled either with BCP or BCP + APL or DBBM or DBBM + APL. New bone formation and biomaterial resorption were evaluated using non-demineralised histology and histomorphometry. After 6 weeks, new bone formation was observed in all cylinders. The newly formed bone in the cylinders filled with APL alone, DBBM and BCP was significantly increased by (0.6-, 2.5- and 3.3-fold, respectively) (P < 0.0001) compared to results obtained with the empty cylinders. Vertical bone height in the cylinders filled with BCP was greater to that observed with DBBM. The residual material in the cylinders filled with BCP was significantly (P < 0.0001) lower (0.35-fold) than that with DBBM. Both newly formed bone and residual material in the cylinders filled with BCP + APL or DBBM + APL were similar to those filled with either BCP or DBBM, respectively. This study provided evidence that APL alone, as well as DBBM and BCP, have a beneficial effect on vertical bone formation and remodelling. APL associated with either DBBM or BCP did not provide additional benefits.

Biotribocorrosion (tribo-electrochemical) characterization of anodized titanium biomaterial containing calcium and phosphorus before and after osteoblastic cell culture.

The purpose of this study was to investigate the relationship between the osteoblastic cells behavior and biotribocorrosion phenomena on bioactive titanium (Ti). Ti substrates submitted to bioactive anodic oxidation and etching treatments were cultured up to 28 days with MG63 osteoblast-like cells. Important parameters of in vitro bone-like tissue formation were assessed. Although no major differences were observed between the surfaces topography (both rough) and wettability (both hydrophobic), a significant increase in cell attachment and differentiation was detected on the anodized substrates as product of favorable surface morphology and chemical composition. Alkaline phosphatase production has increased (≈20 nmol/min/mg of protein) on the anodized materials, while phosphate concentration has reached the double of the etched material and calcium production increased (over 20 µg/mL). The mechanical and biological stability of the anodic surfaces were also put to test through biotribocorrosion sliding solicitations, putting in evidence the resistance of the anodic layer and the cells capacity of regeneration after implant degradation. The Ti osteointegration abilities were also confirmed by the development of strong cell-biomaterial bonds at the interface, on both substrates. By combining the biological and mechanical results, the anodized Ti can be considered a viable option for dentistry.

Healing patterns of critical size bony defects in rats after grafting with bone substitutes soaked in recombinant human bone morphogenetic protein-2: histological and histometric evaluation.

The aim of the study was to evaluate the effect of different bone substitutes soaked in recombinant human bone morphogenetic protein-2 (rhBMP-2) on the healing of critical size defects in calvarial bone. Defects were created in 24 Sprague Dawley rats. The rhBMP-2 was diluted to obtain a final concentration of 0.2mg/ml. Rats were divided into four groups and treated as follows: in the first group the defect was filled with anorganic bovine bone mineral (ABBM) and rhBMP-2, the second group was treated with freeze-dried bone allograft (FDBA) and rhBMP-2, and the third group was treated with autogenous bone (AUTO). In the control group the defects were left untreated. Animals were killed after 8weeks and calcified histological sections prepared. Histometric measurements showed that mean (SD) bone formation was 4.00 (1.69)mm(2) in the ABBM group, 2.56 (1.06)mm(2) in the FDBA group, and 2.30 (0.34)mm(2) in the AUTO group. The difference between the ABBM group and the other 3 groups was significant (p<0.0001) with a mean bone formation of 0.82 (0.25)mm(2) in the control group. There was no significant difference between the FDBA and the AUTO groups (p=0.96). Within the limits of this study we concluded that the addition of rhBMP-2 to bone substitutes was efficacious in regenerating bone in critical size bone defects in calveria in rats.

[Amalgam, composite and compomer: microbiological study]. / Amalgames, composites et compomères. Etude microbiologique comparative.

Restorative materials have different consequences on the periodontium. The surface of these materials may influence gingival health and cause in some instances gingival inflammation. The purpose of this study was to investigate and compare, in a healthy periodontium, intracrevicular plaque bacteria (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis and Treponema denticola), at day 0 and at 6 months, around subgingivally located amalgam, composite and compomer fillings. All the tests were negative (less than 0.1% of the sum of 103 cells), since none of the investigated pathogens were detected. It has been concluded that the material used does not have direct effect on the bacteria species developed around the restorations at this short time period.

Expression of MMP-2, 9 and 13 in newly formed bone after sinus augmentation using inorganic bovine bone in human.

BACKGROUND AND OBJECTIVE: The aim of the present study was to analyse the expression of MMP-2, MMP-9 and MMP-13 in newly formed bone following maxillary sinus augmentation using inorganic bovine bone substitute, because these MMPs play a major role in bone remodeling and bone resorption. MATERIAL AND METHODS: Deproteinized bovine bone (Bio-Oss(®)) was used to fill cavities after elevating the sinus mucosa. Twenty patients with edentulous posterior maxilla were treated with 20 sinus-augmentation procedures using a two-stage technique. Forty-nine Straumann(®) endosseous implants were used to complete the implant-prosthetic rehabilitation. One cylinder-shaped bone biopsy from each patient was taken from the augmented maxillary region using trephine burs at the second stage of surgery, 8 months after grafting. A biopsy was also taken as a control from the upper molar region from six different patients who did not undergo the sinus procedure. All biopsies were subjected to biochemical analysis and staining for TRAP. RESULTS: No implant losses or failures occurred. The large number of TRAP-positive multinucleated osteoclasts in resorption lacunae indicated that the resorption was very active in all grafts, in contrast with the control group. Zymography and western blot analysis demonstrated a significantly increased expression of MMP-2, MMP-9 and MMP-13 in the newly formed bone compared with controls (p < 0.05). CONCLUSION: The quantity of osteoclastic cells and the increased expression of proteolytic enzymes suggest that 8 months after grafting, inorganic bovine bone is slowly resorbing and is the site of important remodeling of the newly formed bone by means of resorption and synthesis.

Pertinent cell population to characterize periodontal disease.

The purpose of this in situ study is to quantify the inflammatory cell subsets and the area fraction (AA%) occupied by collagen fibers in human healthy and diseased (four different stages) gingival connective tissue in order to establish a possible correlation between periodontal disease resulting in collagen breakdown and specific inflammatory cell subsets. Paraffin gingival tissue sections from eight healthy controls (group 0), 10 patients with gingivitis (group 1), 10 patients with moderate periodontitis (group 2) and 10 patients with severe periodontitis (group 3) were immunohistochemically investigated using antibodies against CD-45+, CD-3+, CD-8+, CD-20+, CD-68+, and EMA+ (plasma cells). The AA% occupied by gingival collagen fibers significantly decreased from 54.12% in group (0) to 38.58% in group (1), to 31.87% in group (2), and to 25.46% in group (3). In progressive lesions of periodontal disease, CD-3(+) and CD-8+ cell numbers were increased in early stages within the connective tissue, while CD-20+ cell numbers were increased only in late stages. On the other hand, EMA+, CD-68+ and CD-45+ cell numbers were progressively increased from group (0) to group (3). We demonstrated that CD-68+ monocyte/macrophages, CD-45+ leukocyte common antigen and notably EMA+ plasma cells are pertinently correlated with the severity of periodontal disease and related collagen breakdown.

The defensive role of lysozyme in human gingiva in inflammatory periodontal disease.

BACKGROUND AND OBJECTIVE: The presence of lysozyme in human gingiva has not previously been demonstrated. In this study, we looked for evidence for the potential role of lysozyme as a protector of gingival elastic fibres. The objective of this study was also to determine the ex vivo susceptibility to hydrolysis of gingival elastic fibres from patients with or without periodontal disease by human leukocyte elastase and by human cathepsin G. MATERIALS AND METHODS: Using gingival tissue sections from eight control, 10 gingivitis and 10 periodontitis patients, we evaluated the area fraction occupied by gingival elastic fibres (after selective staining) by the use of automated image analysis. In the ex vivo experiments, serial tissue sections from four control, four gingivitis, four young periodontitis and four aged periodontitis patients were submitted to the action of human leukocyte elastase and cathepsin G, after which enzymatic activities were determined by image analysis. Indirect immunodetection of lysozyme was also done on tissue sections for all patients included in this study. RESULTS: Large variations of the area fraction occupied by elastic fibres were observed in human gingiva from young and aged patients with and without periodontal disease. In control and gingivitis patients, leukocyte elastase and cathepsin G had high comparable elastin solubilizing activities. With young and aged periodontitis patients, the two serine proteinases had weak elastin solubilizing activities. Lysozyme appeared to be present at the periphery of gingival elastic fibres in periodontitis patients. CONCLUSION: Lysozyme can be considered an important natural protector of elastic fibres in pathological gingiva.

Healing patterns of critical size bony defects in rat following bone graft.

PURPOSE: The aim of the present study was to evaluate the healing patterns of critical size calvarial bony defects treated with different bone substitutes and to compare them to an autogenous graft and an ungrafted control group. MATERIALS AND METHODS: Thirty-six Sprague-Dawley rats (200-230 g) were used. A periosteal flap was raised and an 8 mm defect was trephined. Rats were divided into six groups and treated as follows: group 1 was treated with a deproteinized bovine xenograft (XO), group 2 was treated with a bovine xenograft and covered with a resorbable membrane (XOCM), defects in group 3 were filled with a decalcified freeze-dried bone allograft (DFDBA), group 4 was treated with a composite bone substitute made of bovine xenograft and collagen (XOC), group 5 was filled with autogenous bone (AUTO), and group 6 was left untreated (control). The animals were euthanized at 2 months. RESULTS: Mean bone formation was 2.97 +/- 1.82 mm2 in group 5 (AUTO) followed by 2.93 +/- 1.93 mm2 in group 3 (DFDBA) and 2.25 +/- 1.94 mm2 in group 4 (XOC). Groups 1, 2, and 6 (XO, XOCM, and control, respectively) were not significantly different (p > 0.05) with a mean bone formation of 1.97 +/- 1.64, 1.87 +/- 1.07, and 1.85 +/- 1.04 mm2, respectively. CONCLUSIONS: This work confirmed the superiority of autogenous bone when it comes to bone grafting. Nevertheless, some bone substitutes can improve bone formation when compared to the control. New bone substitutes with growth factors to improve their abilities to induce bone formation should be experimented.

Bone formation with discs or particles of natural coral skeleton plus polyglactin 910 mesh: histologic evaluation in rat calvaria.

Several procedures have been used to regenerate localized bone defects around dental implants or to increase bone volume at an implant site, including bone grafting, placement of barrier membranes, and use of bone graft substitutes. This study sought to determine whether the bone graft substitute natural coral skeleton (NCS), with or without a protective polymer mesh, enhances bone formation in rat critical size craniotomy defects. The control group (1) had unfilled defects, while the defects in the four experimental groups (six rats each) were treated with: (2) an NCS disc of the size of the defect; (3) NCS granules; (4) NCS granules covered by a polyglactin 910 mesh; and (5) polyglactin 910 mesh alone. Undecalcified histologic sections were assessed by histomorphometric measurements 28 days later. The three NCS groups showed improved bone formation, which was statistically significant in groups (2) (NCS disc) and (4) (NCS granules covered by polyglactin 910 mesh). Group 4 had more bone formation than all the other groups. Polyglactin 910 mesh alone (group 5) produced no greater bone formation than the unfilled control. It is concluded that the bone formation obtained with NCS granules is enhanced when the particles are retained at the site of the defect with a protective mesh.