Primary teeth show less protecting factors against root resorption

International Journal of Paediatric Dentistry 2011; Background. Physiological root resorption differentiates primary from permanent teeth. The understanding of what protects and regulates root resorption might help to develop therapies to its control. Aim. To verify the presence and distribution of ECRM and the expression of CK14, OPG, TRAP and COX‐2 in the periodontal ligament (PDL) of human primary and permanent teeth. Design. Eight primary teeth undergoing physiological or pathological root resorption and 4 permanent teeth were immunohistochemically processed for CK14, TRAP, COX‐2 and OPG expression. Results. PDL from primary and permanent teeth showed similar morphological features; however, fewer ECRM clusters and higher immunoreactivity to CK14 were found in primary PDL. In permanent teeth, ECRM were distributed along the entire PDL tissue. Howship′s lacunae were found only in primary teeth, associated with the presence of TRAP‐positive cells and increase in COX‐2 expression. OPG expression in primary PDL was detected in nonresorptive cervical areas and in lacunae showing reparative tissue. It was observed higher expression of OPG in all permanent teeth when compared to primary specimens. Conclusions. It may be concluded that PDL from primary teeth shows less ECRM clusters and lower expression of OPG. These features may be associated with lower protection against root resorption in primary teeth.     

Morphological characteristics of the depository surface of alveolar bone of diabetic mice

Sharpey's fibers support teeth by attachment of periodontal ligament fibers to alveolar bone. The effects of diabetes mellitus on this support mechanism have not been described and were the subject of this study. Male Swiss mice were rendered diabetic by streptozotocin. Mandibles were removed 9 weeks after injections, the mineralizing front of the depository surface of the interdental septum was exposed by fracture through the periodontal ligament, rendered anorganic, and examined by scanning electron microscopy. No significant reduction in alveolar crest height was evident in diabetic as compared to control animals; however, significant changes in the a) mineralization patterns of bone depository surfaces and Sharpey's fibers, and b) number of Sharpey's fibers inserting into alveolar bone were evident in diabetics. Unmineralized fissures, characteristic of Sharpey's fibers of control, were nearly obliterated by mineralized tissue in diabetic animals. The mineralizing front of the middle and apical thirds of the diabetic alveolar wall was covered by numerous large calcified globules resembling enlarged calcospherites, which were not evident over the cervical third or control tissues. The mean Sharpey fiber density was greater in controls than in diabetics (p less than 0.001); however, there was no significant difference between their mean diameters. These observations suggest that, in early diabetes, Sharpey's fibers and depository surfaces of the middle and apical thirds of the interdental septum have morphologic evidence of aging, which precedes significant reduction in alveolar crest height. These changes may weaken the attachment of periodontal ligament fibers to bone and reduce resistance of the periodontium to intrusive forces.     

The influence of dental alloys on three-body wear of human enamel and dentin in an inlay-like situation

This in vitro study evaluated the effect of metal alloys on three-body wear resistance of enamel and dentin, and vice versa. Three-body wear of human enamel, dentin, a soft gold alloy (BiOcclus Inlay), a CoCr alloy (Remanium 2000), a resin cement (Variolink II) and a zinc oxide phosphate cement (Harvard) was investigated using the ACTA-machine. Sample chambers of eight sample wheels were prepared with pure materials or combinations of human tooth substance, alloys and cement, simulating an inlay-like situation. After 100,000 and 200,000 cycles in a millet suspension with a spring force of 20 N, the amount of abraded material was profilometrically measured and evaluated by 3D surface data analysis. After 200,000 cycles, the materials demonstrated a mean loss of 0.41 microm for CoCr, 51 microm for gold, 57 microm for enamel, 164 microm for dentin, 79 microm for Variolink and 369 microm for Harvard. Using ANOVA and the Games-Howell-test, resin cement, enamel and gold were a subset not shown to differ, as was zinc phosphate cement and dentin. CoCr demonstrated the least wear and differed significantly from all materials. Enamel wear was significantly reduced in mixed chambers with CoCr, and gold after 200,000 cycles compared to enamel in pure chambers. In summary, a soft gold alloy can be recommended for inlays when considering three-body abrasion since the wear rate of the "soft" gold alloy corresponded to that of human enamel.     

Management and outcomes of small bowel obstruction in older adult patients: a prospective cohort study

Background

The purpose of this research was to examine the morbidity, mortality and rate of recurrent bowel obstruction associated with the treatment of small bowel obstruction (SBO) in older adults.

Methods

We prospectively enrolled all patients 70 years or older with an SBO who were admitted to a tertiary care teaching centre between Jul. 1, 2011, and Sept. 30, 2012. Data regarding presentation, investigations, treatment and outcomes were collected.

Results

Of the 104 patients admitted with an SBO, 49% were managed nonoperatively and 51% underwent surgery. Patients who underwent surgery experienced more complications (64% v. 27%, p = 0.002) and stayed in hospital longer (10 v. 3 d, p < 0.001) than patients managed nonoperatively. Nonoperative management was associated with a high rate of recurrent SBO: 31% after a median follow-up of 17 months. Of the patients managed operatively, 60% underwent immediate surgery and 40% underwent surgery after attempted nonoperative management. Patients in whom nonoperative management failed underwent surgery after a median of 2 days, and 89% underwent surgery within 5 days. The rate of bowel resection was high (29%) among those who underwent delayed surgery. Surgery after failed nonoperative management was associated with a mortality of 14% versus 3% for those who underwent immediate surgery; however, this difference was not significant.

Conclusion

These data suggest that some elderly patients with SBO may be waiting too long for surgery.     

Differential expression of perforin in muscle-infiltrating T cells in polymyositis and dermatomyositis.

Polymyositis (PM) and dermatomyositis (DM) are the prototypical inflammatory diseases of skeletal muscle. In PM, CD8+ T cells invade and destroy muscle fibers, whereas humoral effector mechanisms prevail in DM. We studied the expression of the cytotoxic mediator perforin in inflammatory cells in PM and DM muscle by semiquantitative PCR, immunohistochemistry and confocal laser microscopy. Similar levels of perforin mRNA were expressed in PM and DM, and abundant perforin-expressing CD3+CD8+ and CD3+ CD4+ T cells were observed in both diseases. However, there was a striking difference in the intracellular localization of perforin. In DM, perforin was distributed randomly in the cytoplasm of the inflammatory T cells. In contrast, 43% of the CD8+ T cells that contacted a muscle fiber in PM showed perforin located vectorially towards the target muscle fiber. The results suggest (a) that the random distribution of perforin in the cytoplasm of muscle-infiltrating T cells observed in DM reflects nonspecific activation, and (b) that the vectorial orientation observed only in PM reflects the specific recognition via the T cell receptor of an antigen on the muscle fiber surface, pointing to a perforin- and secretion-dependent mechanism of muscle fiber injury.     

Critical impact of patient knowledge and bone density testing on starting osteoporosis treatment after fragility fracture: secondary analyses from two controlled trials

Summary

Most patients are not treated for osteoporosis after their fragility fracture “teachable moment.” Among almost 400 consecutive wrist fracture patients, we determined that better-than-average osteoporosis knowledge (adjusted odds?=?2.6) and BMD testing (adjusted odds?=?6.5) were significant modifiable facilitators of bisphosphonate treatment while male sex, working outside the home, and depression were major barriers.

Introduction

In the year following fragility fracture, fewer than one quarter of patients are treated for osteoporosis. Although much is known regarding health system and provider barriers and facilitators to osteoporosis treatment, much less is understood about modifiable patient-related factors.

Methods

Older patients with wrist fracture not treated for osteoporosis were enrolled in trials that compared a multifaceted intervention with usual care controls. Baseline data included a test of patient osteoporosis knowledge. We then determined baseline factors that independently predicted starting bisphosphonate treatment within 1 year.

Results

Three hundred seventy-four patients were enrolled; mean age 64 years, 78 % women, 90 % white, and 54 % with prior fracture. Within 1 year, 86 of 374 (23 %) patients were treated with bisphosphonates. Patients who were treated had better osteoporosis knowledge at baseline (70 % correct vs 57 % for untreated, p?Conclusions The most important modifiable facilitators of osteoporosis treatment in patients with fracture were knowledge and BMD testing. Specifically targeting these two patient-level factors should improve post-fracture treatment rates.     

Painful bone metastases: a prospective observational cohort study

Incident pain related to bone metastases is a problematic symptom to treat. The difficulty in treating this type of pain is reflected in the wide variety of treatment modalities recommended. The aims of this prospective observational study were to determine the patterns of pain severity at rest and on movement over time and which treatment modalities are employed. In addition, we were interested in ascertaining any correlations between bone pain at rest, bone pain on movement and functional ability. Thirty-two patients were followed up for a mean of 22 weeks (range: 2-52). In total, there were 704 patient follow-up weeks. Patients were followed up for one year or until death. A total of 19 different treatment modalities were employed. There were strong correlations between pain at rest and pain on movement. There were no significant correlations between functional ability and pain at rest or movement. Our study demonstrates the complex management of patients with bone pain. This is the first study that highlights the correlation between pain at rest and pain on movement in patients with bone metastases in a palliative care population. It highlights the need for intensive follow-up of these patients, as they require multiple interventions to help control their pain. These data can also be used to power further interventional studies.