Annular closure device for disc herniation: meta-analysis of clinical outcome and complications.

BACKGROUND: Lumbar intervertebral disc herniation is a common cause of lower back and leg pain, with surgical intervention (e.g. discectomy to remove the herniated disc) recommended after an appropriate period of conservative management, however the existing or increased breach of the annulus fibrosus persists with the potential of reherniation. Several prosthesis and techniques to reduce re-herniation have been proposed including implantation of an annular closure device (ACD) - Barricaid™ and an annular tissue repair system (AR) - Anulex-Xclose™. The aim of this meta-analysis is to assist surgeons determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications. METHODS: Four electronic full-text databases were systematically searched through September 2017. Data including outcomes of annular closure device/annular repair were extracted. All results were pooled utilising meta-analysis with weighted mean difference and odds ratio as summary statistics. RESULTS: Four studies met inclusion criteria. Three studies reported the use of Barricaid (ACD) while one study reported the use of Anulex (AR). A total of 24 symptomatic reherniation were reported among 811 discectomies with ACD/AR as compared to 51 out of 645 in the control group (OR: 0.34; 95% CI: 0.20,0.56; I2 = 0%; P < 0.0001). Durotomies were lower among the ACD/AR patients with only 3 reported cases compared to 7 in the control group (OR: 0.54; 95% CI: 0.13, 2.23; I2 = 11%; P = 0.39). Similar outcomes for post-operative Oswestry Disability Index and visual analogue scale were obtained when both groups were compared. CONCLUSION: Early results showed the use of Barricaid and Anulex devices are beneficial for short term outcomes demonstrating reduction in symptomatic disc reherniation with low post-operative complication rates. Long-term studies are required to further investigate the efficacy of such devices.

Symptomatic annulus-repair-device loosening due to a low-grade infection.

We report the unusual case of a young patient with reoperation after annuloplasty using the Barricaid® (Intrinsic Therapeutics, Woburn, MA, USA) closure device. Our patient, a 32-year-old man underwent lumbar discectomy and annuloplasty of the level L5-S1. Five years later, the patient presented with a new onset of low-back pain radiating into the right leg. Imaging revealed loosening of the annulus repair device. The device was removed surgically and the patient was pain free thereafter. Annular closure devices such as the Barricaid system aim to improve outcome after lumbar discectomy by reducing the risk of recurrent disc herniation of the same level. Data on long-term follow-up are missing. Here we present, to our knowledge, the first case of symptomatic device loosening.

Sodium-phosphorylated chitosan/zinc oxide complexes and evaluation of their cytocompatibility: an approach for periodontal dressing.

The aim of this study was to evaluate the possibility of metal complex formation between sodium-phosphorylated chitosan (PCTS) and ZnO. The polymer-metal complex formation was investigated in terms of thermal degradation. The structure deduction of the PCTS/ZnO complex was investigated by means of Fourier transform infrared spectroscopy and X-ray diffraction (XRD). The PCTS/ZnO complexes were formed by the sharing of lone pairs of electrons from the N atoms in the amine groups and O atoms in the phosphate and hydroxyl groups of PCTS to the protonated hydroxyl species on the ZnO surface. Because complex formation occurred at the surface of ZnO particles, it did not change the ZnO crystalline structure. Cytotoxicity, evaluated by a direct contact test with primary human gingival fibroblast cells, revealed that PCTS was biocompatible and reduced the cytotoxicity of ZnO by complexation, making PCTS/ZnO complexes potentially biocompatible. Within the limits of these data, it appears that PCTS could be used as a reaction rate-modifying agent in periodontal dressings.

An investigation into asbestos related disease in the dental industry.

This article discusses the dangers of the asbestos-based disease mesothelioma and the possible origins of this form of cancer in dental professionals. The potential for an increase in diagnosed cases of mesothelioma among dentists and technicians in future is highlighted.

Evaluation of tissue response to periodontal dressings: histological study in tooth sockets of rats.

Although the use of periodontal dressings is currently limited, there are some indications for their use. Selection of any material that will have direct contact with live tissues, such as periodontal dressings, should be careful in order to allow surgical wound healing. The aim of this study was to evaluate the intensity of inflammatory response and bone formation in tooth sockets of rats after implantation of three periodontal dressings. After removal of the right maxillary incisors of 84 male rats, each tooth socket received implantation of a polyethylene tube, 63 of which were filled with non-eugenol periodontal dressing and the remaining 21 tubes remained empty (control group). Histological evaluation assessed the intensity of inflammatory response and presence and location of bone tissue formation at postoperative periods of 7, 14 and 28 days. Statistical analysis was performed by the Kruskal-Wallis test at 5% significance level. Regarding the inflammatory infiltrate, at 28 days, there was statistically significant difference between one of periodontal dressings and control group (p<0.05). Analysis of postoperative periods, showed that the control group presented statistically significant reduction in the inflammatory infiltrate comparing the 14- and 28-day periods (p<0.05). Regarding bone tissue formation, there was difference in control group between the 7- and 28-day periods (p<0.05). Within the experimental conditions, it may be concluded that no differences were found in the inflammatory response among the groups at 7 and 14 days and that Voco pac dressing induced a more intensive inflammatory reaction at 28 days.

Post-surgical infections: prevalence associated with various periodontal surgical procedures.

BACKGROUND: Of the various adverse outcomes that may be encountered following periodontal surgery, the risk of infection stands at the forefront of concern to the surgeon, since infection can lead to morbidity and poor healing outcomes. This paper describes a large-scale retrospective study of multiple surgical modalities in a diverse periodontal practice undertaken to explore the prevalence of clinical infections post-surgically and the relationship between diverse treatment variables and infection rates. METHODS: A retrospective review of all available periodontal surgical records of patients treated in the Department of Periodontics at Wilford Hall Medical Center, San Antonio, Texas, was conducted. The sample comprised 395 patients and included 1,053 fully documented surgical procedures. Surgical techniques reviewed included osseous resective surgery, flap curettage, distal wedge procedures, gingivectomy, root resection, guided tissue regeneration, dental implant surgery, epithelialized free soft tissue autografts, subepithelial connective tissue autografts, coronally positioned flaps, sinus augmentations, and ridge preservation or augmentation procedures. Infection was defined as increasing and progressive swelling with the presence of suppuration. The impact of various treatment variables was examined including the use of bone grafts, membranes, soft tissue grafts, post-surgical chlorhexidine rinses, systemic antibiotics, and dressings. Results were analyzed using Fisher's exact test and Pearson's chi-square test. RESULTS: Of the 1,053 surgical procedures evaluated in this study, there were a total of 22 infections for an overall prevalence of 2.09%. Patients who received antibiotics as part of the surgical protocol (pre- and/ or post-surgically) developed eight infections in 281 procedures (2.85%) compared to 14 infections in 772 procedures (1.81%) where antibiotics were not used. Procedures in which chlorhexidine was used during post-surgical care had a lower infection rate (17 infections in 900 procedures, 1.89%) compared to procedures after which chlorhexidine was not used as part of post-surgical care (five infections in 153 procedures, 3.27%). The use of a post-surgical dressing demonstrated a slightly higher rate of infection (eight infections in 300 procedures, 2.67%) than non-use of a dressing (14 infections in 753 procedures, 1.86%). Despite these trends, no statistically significant relationship was found between post-surgical infection and any of the treatment variables examined, including the use of perioperative antibiotics. CONCLUSIONS: The results of this study confirm previous research demonstrating a low rate of postoperative infection following periodontal surgical procedures. Although perioperative antibiotics are commonly used when performing certain regenerative and implant surgical procedures, data from this and other studies suggest that there may be no benefit in using antibiotics for the sole purpose of preventing post-surgical infections. Further large-scale, controlled clinical studies are warranted to determine the role of perioperative antibiotics in the prevention of periodontal post-surgical infections.

Occupational respiratory hypersensitivity in dental personnel.

OBJECTIVE: The aim was to study the causes of respiratory hypersensitivity in dental personnel based on the statistics of the Finnish Register of Occupational Diseases (FROD; 1975-1998) and the patient material of the Finnish Institute of Occupational Health (FIOH; 1990-1998). METHODS: Details about the cases of respiratory hypersensitivity were compiled from the FROD. The occupational rhinitis diagnoses studied at the FIOH were based on work-related symptoms and a change in the status of the nasal mucosa during challenge testing; and the diagnosis of occupational asthma based on reactions in challenge testing, or on IgE positivity and peak flow monitoring at work and during days off. RESULTS: A total of 64 cases of occupational respiratory diseases (ORDs) was diagnosed in dental personnel during 1975 to 1998 according to the FROD; two cases in 1975 to 1989, and 62 in 1990 to 1998. Twenty-eight cases were of occupational asthma (18 caused by methacrylates), 28 occupational rhinitis (six caused by methacrylates), seven allergic alveolitis and one organic dust toxic syndrome (ODTS). The non-acrylate-material diagnosed in 1990-1998 at the FIOH comprised three cases of asthma and one of rhinitis caused by chloramine-T (sodium- N-chlorine- p-toluene sulphonamide); as well as one case of asthma, seven cases of rhinitis, and two cases of combined rhinitis and conjunctivitis caused by natural rubber latex (NRL). Furthermore, one case of occupational rhinitis caused by Nobetec containing colophony was diagnosed. The incidence rate (IR) of ORD increased from 0 in 1988 to a peak of 105.1 new cases per 100,000 working years in 1995. During the last observation year, i.e. 1998, the IR was 55 new cases per 100,000 workers. The IR in dental personnel was lower than in the whole working population in Finland up until 1992, but since then has been greater than in the whole population, peaking in 1995 when the IR of dental personnel was 2.55 times greater than in the whole population. CONCLUSION: The present study shows the increasing frequency of respiratory hypersensitivity among dental personnel. Besides methacrylates, important causes of respiratory hypersensitivity are NRL and chloramine-T.

Cytocompatibility of periodontal dressing materials in fibroblast and primary human osteoblast-like cultures.

Purpose of this investigation was to determine the cytocompatibility of various periodontal dressing materials by means of human primary gingival fibroblasts (HGF), human osteoblast-like cells (HObl) derived from the alveolar bone, and permanent 3T3 mouse fibroblasts (3T3). Cell culture medium extracts (time periods of extraction: day 1 and between day 2 and day 8 after setting) as well as solid specimens of the following materials were investigated: Coe-pak, Voco pac, Peripac, and Barricaid. Responses of cultures exposed for 24 h and 48 h to these materials were monitored by the fluorescent dyes H33342 and sulforhodamin 101 as well as by light microscopy. It was found that most extracts of Voco pac, Peripac, and Barricaid did not inhibit growth of HGF. Coe-Pak, however, clearly reduced the proliferation of HGF compared to untreated controls. Peripac decreased growth of HObl whereas Coe-Pak, Voco pac, and Barricaid caused no cytotoxic alterations in any of the test assays. Contrary to HGF and HObl, 3T3 cells were much more irritated by the test materials. But the light-curing resinous material Barricaid reduced proliferation of 3T3-fibroblasts only slightly. Our data indicate that Barricaid is exceedingly cytocompatible, whereas all other materials revealed moderate or severe cytotoxic effects according to the cell type.

The effect of a light-cured periodontal dressing material on HeLa cells and fibroblasts in vitro.

The effect which a visible light-curing periodontal dressing material based upon a urethane dimethacrylate resin has upon HeLa cells and fibroblasts in its uncured and fully cured states has been studied in vitro. Fully-cured material has no effect on either cell type. Uncured material produces a surrounding zone of growth inhibition and cell death on direct contact. Inhibition is caused by the release into the medium of substances toxic to cells. However, this growth inhibition is overcome in time (5 days). It is suggested that partly-cured material containing residual free monomer in contact with a healing gingival site could impede rapid repair. Nuclear magnetic resonance microimaging has shown that in places where there is a greater depth of material (e.g., interproximal regions) this underlying material may be partly cured. Increasing the exposure to the curing light will prevent (or minimize) the presence of partly-cured material; the fully-cured material being compatible with the cells.

Inhibition of plaque accumulation under periodontal dressing by sustained-release varnish of chlorhexidine.

Slow-release varnish containing chlorhexidine was applied prior to the application of a periodontal dressing. The ability of the slow-release varnish to inhibit accumulation of dental plaque under the dressing was compared to a placebo varnish. Seven volunteers were fitted with periodontal dressing on the lower and upper jaws. One jaw was pre-coated with slow-release varnish containing chlorhexidine, while the other was coated with a placebo. A week later the dressings were removed and the plaque under the dressing was scored. Significantly less plaque was found on teeth pre-coated with the slow-release varnish containing chlorhexidine as compared to the control. An increase in the amount of gingival fluid was observed in both the control and experimental groups after removing the periodontal dressing.

Formation of interdental soft tissue defects after surgical treatment of periodontitis.

This study monitored the development and repair of interdental soft tissue defects following surgical treatment of periodontitis in 21 patients. Open flap curettage was performed at 100 interdental areas with follow-up examinations 1, 3, and 6 months later. Interdental gingival contours were assessed both clinically and indirectly with silicone elastomer impressions from which stone models were obtained; defect depths were then calculated using the Reflex Microscope. Two types of defect were identified at the 1-month follow-up: 13 interdental clefts (mean depth, 1.8 mm); and 30 craters, (mean depth, 1.6 mm). Although clefts tended to persist, craters showed a strong tendency to repair. Thus, at the 6-month follow-up, the depths of clefts and craters were 1.3 mm and 0.7 mm respectively. The development of soft tissue defects did not appear to be related to the use of a periodontal dressing nor did the existence of an underlying bone defect appear to be of etiological importance. Pre-operative probing depths, however, were positively associated with the occurrence of soft tissue craters (P = 0.02). Pre-operatively, the overall mean probing depth and frequency of bleeding on probing were 5.3 mm and 100% respectively. At 6 months, these values were reduced to 2.0 mm and 22%. When clefts, craters, and interdental areas with no soft tissue defect were compared, no significant differences in probing depth reduction or frequency of bleeding were observed at any time point.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural pulmonary changes in mice exposed to aerosolized Periodontal Pack Powder.

An electron microscopic study was undertaken to investigate pulmonary ultrastructural changes in mice following exposure to an aerosolized Periodontal Pack Powder (PPP), and to determine if the asbestos fiber, which contains 7% PPP, is respirable. One hundred and sixty-five animals were used in this study. Seventy-two of the animals were exposed to the powder twice weekly for a minimum of two weeks and a maximum of four weeks. Fifty animals were exposed to the PPP (without asbestos), with the same exposure sequence used. Forty-three animals served as nonexposed controls. Randomly selected groups of exposed and control mice were killed at designated intervals between two and 12 weeks. Microscopic examination of the lungs revealed early interstitial pneumonia. These changes were seen in both treatment groups. Late changes included a generalized resolution of the pneumonia (seen in both treatment groups) with residual diffuse interstitial fibrosis, persistence of asbestos fibers within the tissue, and early asbestos body formation (seen only in animals exposed to asbestos-containing PPP). This study documents that the asbestos in Periodontal Pack Powder is both respirable and potentially pathogenic. Dentists who have used this product could conceivably be a population at risk for pulmonary fibrosis and/or obstructive airways disease.

Current status of periodontal dressings.

A comprehensive review of periodontal dressings is presented. The rationale for the application of dressings, their advantages and disadvantages are described. Tissue reactions to dressings and the therapeutic and adverse effects of antimicrobial agents used in dressings are discussed. The present status and value of a surgical dressing is critically assessed in view of recent studies which indicate that the routine use of dressings in postsurgical care may be either unnecessary or undesirable.

Acute allergic reaction to eugenol.

Eugenol has been widely used in the dental profession. It is an effective material that is incorporated into many dental products. Contact dermatitis due to this chemical is not unusual. However, true serious allergic reactions are extremely rare. This paper reports on such a case. Careful assessment of patients and of their dental and medical history is necessary to avoid disaster in the office.