Experimental model of nervous anastomosis between intercostal and lumbar nerves in the rabbit

The authors propose a new experimental model of nervous anastomosis between intercostal and lumbar nerves in rabbit with the purpose of providing a technique to by-pass a spinal lesion. Before carrying out the surgical experiments, an histological study has been performed on the donor and receiver nerves which demonstrated the great difference in number of nervous fiber between these two nerves. The purpose of the method is thus to reinnerve a lumbar nerve by means of two intercostal nerves. Histological controls are performed on the 120th day.     

Copper-zinc superoxide dismutase activity in healthy and inflamed human dental pulp

AIM: To examine copper-zinc superoxide dismutase (Cu, Zn-SOD) activity in clinically healthy and symptomatic human dental pulps. METHODOLOGY: Twenty-five systemically healthy patients, 14 females and 11 males (age: 13.1-34.6 years; mean: 21.7 +/- 6.3), were the source of the pulp tissue. The condition of the pulps was assessed using clinical and radiographic evaluation. The pulp tissue was collected by longitudinally grooving and splitting the teeth (if extracted) or during endodontic treatment, and were age- and sex-matched between the healthy and the irreversible symptomatic pulpitis tissue groups. Cu, Zn-SOD activity was determined through spectrophotometric methods and a Mann-Whitney test assessed the significance of differences between the groups. RESULTS: The enzyme activities were 144.8 +/- 42.2 and 68.1 +/- 25.0 U mg(-1) in the healthy and irreversible symptomatic pulp tissue, respectively. The difference between the groups was statistically significant (P < 0.001). CONCLUSIONS: These results demonstrate a potential role for Cu, Zn-SOD during dental pulp inflammation in humans.     

Risultati clinici e istologici delle preparazioni subgengivali a lama di coltello. Casi clinici

Objectives

This article evaluates the correlation between clinical and histological results in teeth prepared for fixed prosthodontics using the Biologically Oriented Preparation Technique (BOPT).

Materials and methods

Clinical cases are presented to illustrate the main steps in the BOPT procedure and the clinical results. Six anterior teeth regarded as “hopeless” were used for histological analysis. Three were prepared according to the BOPT (test), and the other three were prepared with a rounded juxtagingival shoulder (control). Temporary acrylic resin restorations were immediately placed. The teeth were extracted after five weeks.

Results

The junctional epithelium (JE) measured 2.5 ± 0.4 mm (test) and 1.7 ± 0.3 mm (control) (p < 0.001). The area of connective tissue infiltrated by inflammatory cells was 2.7 ± 0.7 mm² (test) and 1.5 ± 0.3 mm² (control) (p < 0.001).

Conclusions

The BOPT appears to favor the formation of a long JE and inflammatory-cell infiltration of the connective tissue, so it should not be used on periodontically sound teeth.     

Histologic and ultrastructural analysis of regenerated bone in maxillary sinus augmentation using a porcine bone-derived biomaterial

BACKGROUND: The purpose of the present study was the histologic and ultrastructural evaluation of a biomaterial composed of cortical pig bone in the form of granules. METHODS: After maxillary sinus augmentation using this biomaterial, 10 specimens were retrieved after 5 months in 10 patients using this biomaterial. The specimens were processed to be observed under light microscopy (LM) and transmission electron microscopy (TEM). Histomorphometric measurements were presented by means +/- standard deviations. RESULTS: LM showed that most of the particles were surrounded by newly formed bone. In some areas, the osteoid matrix was present; however, mainly compact bone was present at the interface. There was no evidence of an acute inflammatory infiltrate. The newly formed bone was 36% +/- 2.8% and marrow spaces were 38% +/- 1.6%, whereas residual grafted material was 31% +/- 1.6%. Under TEM, all phases of bone formation (osteoid matrix, woven, and lamellar bone) were observed in proximity with the biomaterial particles. The bone-biomaterial interface showed a close contact between the porcine bone particles and the surrounding bone that had mainly features of mature bone with numerous osteocytes. A lamina limitans was sometimes present at this interface. CONCLUSIONS: According to our knowledge, this is the first study presenting data on TEM of a porcine bone-derived biomaterial used in sinus augmentation procedures in humans. Our findings show that this is a biocompatible biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes.