OBJECTIVETo evaluate shrinkage range of cleared teeth caused by nitric acid with different temperature and concentration.

METHODS48 human teeth were root canal-prepared and filled, then randomly and averagely divided into six groups on the basis of temperature and density of nitric acid and the condition of whether or not added the oscillate. Group A was 20 degrees C with 6% nitric acid, group B was 20 degrees C with 6% nitric acid and oscillate, group C was 20 degrees C with 3% nitric acid, group D was 20 degrees C with 3% nitric acid and oscillate, group E was 30 degrees C with 6% nitric acid and oscillate, group F was 30 degrees C with 3% nitric acid and oscillate. After achieving the standard of the decalcification, all the specimens were gradually dehydrated, and then cleared and conserved using methyl salicylate. Time-consumed and shrinkage range of all the specimens were recorded and analyzed.

RESULTSThe time of decalcification in group E was the fastest, then was group F, group B. Group C was the last one. The anastole of the specimens was group E > group B > group A, group F > group D > group C, group B > group D, group E > group D, there was significant difference (P < 0.05). Group C had significant difference with other groups (P < 0.05). The anastole rate of the specimens had no significant difference between group A and group B, group C and group D, group B and group F, group D and group F.

CONCLUSIONIn 20 degrees C, 3% nitric acid with oscillate to carry out the decalcification can use less time and get less anastole. The result of the tooth-clearing technique is the best.

PURPOSE: This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. MATERIALS AND METHODS: Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. RESULTS: The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. CONCLUSION: Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.
Cone-Beam Computed Tomography* ; Decalcification Technique ; Dental Pulp Cavity ; Humans ; Molar* ; Tooth, Deciduous ; X-Ray Microtomography

BACKGROUND: In 1951, Ardran reported that metastatic bone lesions could be detectable on plain radiography with 30% to 50% of decalcification. Authors performed experimental study for minimum level of decalcification to detect the osteolytic bone metastasis of long bone with recent technique of radiographs. METHODS: One pair of fibula and humerus from two cadavers was cut into specimen 1 inch in length. Distal half of specimen was dipped into hydrochloride (HCl) with 15 min interval. All 16 specimens were checked by film-type radiography (FR), computed radiography (CR), digital radiography (DR). To exclude inter-observer's variance, 3 radiologists evaluated images. Calcium amount before and after decalcification was measured and expressed in percentage of decalcification. RESULTS: Osteolytic changes were detectable with 11% to 16% of decalcification for fibula and 3% to 8% for humerus on plain radiography with FR, CR, and DR. CONCLUSIONS: Our study showed that minimum of 3% and maximum of 16% of decalcification is necessary when osteolytic metastatic bone lesions of long bone could be detected on plain radiography.
Cadaver ; Calcium ; Decalcification Technique ; Fibula ; Humerus ; Neoplasm Metastasis* ; Osteolysis ; Radiographic Image Enhancement ; Radiography*

Calcinosis ; complications ; Decalcification Technique ; Humans ; Meningeal Neoplasms ; complications ; Meningioma ; complications ; Specimen Handling ; methods ; Ultrasonics

OBJECTIVETo study the methods of decalcification for making united slices of tooth and affiliated periodontic tissues.

METHODSTwenty-one samples containing dog molars and affiliated periodontic tissues were divided into seven mean groups. The pH value of solution, time of decalcification, weight and volume of samples, and content of decalcified calcium were detected. The slices were observed by HE, specific, and immunohistochemical stain.

RESULTSThe velocity of decalcification increased with decrease of solution pH. The weight of samples lightened by 37.61%, the volume reduced by 25.97% on average, and calcium decalcified was 174.49 mg per gram humid samples. The EDTA decalcification was slowest, but it was best. Decalcification was fast in Plank-Rycho solution while the section was worst, and faster in the formyl solution containing aluminium chloride than in EDTA, and the section was better.

CONCLUSIONSThe 50% formyl solution containing aluminium chloride is an ideal decalcifying solution.

Aluminum Compounds ; pharmacology ; Animals ; Bone and Bones ; drug effects ; metabolism ; Chlorides ; pharmacology ; Decalcification Technique ; methods ; Formates ; chemistry ; Humans

The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rabbits were co-cultured for 3-7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as control. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts, trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the surface of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good biocompatibility and ectopic induced osteogenic activity.
Animals ; Biocompatible Materials ; Bone Marrow Cells ; cytology ; Bone Matrix ; cytology ; Cells, Cultured ; Chondrocytes ; cytology ; Coculture Techniques ; Decalcification Technique ; Osteogenesis ; Rabbits ; Stem Cells ; cytology ; Stromal Cells ; cytology ; Tissue Engineering

BACKGROUND: Demineralized bone matrix (DBM) is used for bone healing due to its osteoinductivity, but it requires a carrier for clinical application. Here, we report the effects on the osteoinductivity of DBM by use of a poloxamer 407-based hydrogel as the carrier, compared to sterile water. METHODS: DBM-W and DBM-H represent 27 wt% of DBM with sterile water and DBM with a poloxamer 407-based hydrogel, respectively. Both of the compositions were applied to human mesenchymal stem cell (MSC) cultures, and monitored for alkaline phosphatase (ALP) staining and ALP activity. Six 10-week-old athymic nude rats were used for abdominal muscle grafting with either DBM-W or DBM-H, and were tested by plane radiography, microfocus X-ray computed tomography (CT), and decalcified histology to evaluate ectopic bone formation. RESULTS: The DBM-W group showed stronger ALP staining at 7, 14, and 21 days of treatment, and significantly higher ALP activity at 7 and 14 days of treatment, compared to the DBM-H group. Plane radiography could not confirm the radio-opaque lesions in the rat ectopic bone formulation model. However, ectopic bone formation was observed in both groups by micro-CT. Compared to the DBM-H group, the DBM-W group showed higher bone volume, percent bone volume and trabecular number, and the difference in percent bone volume was statistically significant. Decalcified histology found bony tissue with lamellation in both groups. CONCLUSIONS: Our results suggest that poloxamer 407-based hydrogel has efficacy as a DBM carrier since it shows ectopic bone formation, but its effects on the quality and quantity of osteoblastic differentiation in rat abdominal ectopic bone and MSC are considered negative.
Animals ; Bone Matrix/*physiology ; Cell Culture Techniques ; Decalcification Technique ; Excipients/*pharmacology ; Hydrogels/pharmacology ; Male ; Mesenchymal Stromal Cells/*drug effects ; Osteogenesis/*drug effects ; Poloxamer/*pharmacology ; Rats ; Rats, Nude

BACKGROUND: The conventional method for decalcification of bone specimens uses hydrochloric acid (HCl) and is notorious for damaging cellular RNA, DNA, and proteins, thus complicating molecular and immunohistochemical analyses. A method that can effectively decalcify while preserving genetic material is necessary. METHODS: Pairs of bilateral bone marrow biopsies sampled from 53 patients were decalcified according to protocols of two comparison groups: EDTA versus HCl and RDO GOLD (RDO) versus HCl. Pairs of right and left bone marrow biopsy samples harvested from 28 cases were allocated into the EDTA versus HCl comparison group, and 25 cases to the RDO versus HCl comparison group. The decalcification protocols were compared with regards to histomorphology, immunohistochemistry, and molecular analysis. For molecular analysis, we randomly selected 5 cases from the EDTA versus HCl and RDO versus HCl groups. RESULTS: The decalcification time for appropriate histomorphologic analysis was the longest in the EDTA method and the shortest in the RDO method. EDTA was superior to RDO or HCl in DNA yield and integrity, assessed via DNA extraction, polymerase chain reaction, and silver in situ hybridization using DNA probes. The EDTA method maintained intact nuclear protein staining on immunohistochemistry, while the HCl method produced poor quality images. Staining after the RDO method had equivocal results. RNA in situ hybridization using kappa and lambda RNA probes measured RNA integrity; the EDTA and RDO method had the best quality, followed by HCl. CONCLUSIONS: The EDTA protocol would be the best in preserving genetic material. RDO may be an acceptable alternative when rapid decalcification is necessary.
Biopsy* ; Bone Marrow* ; Decalcification Technique ; DNA ; DNA Probes ; Edetic Acid ; Humans ; Hydrochloric Acid ; Immunohistochemistry ; In Situ Hybridization ; Nuclear Proteins ; Polymerase Chain Reaction ; RNA ; RNA Probes ; Silver

The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rabbits were co-cultured for 3-7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as control. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts, trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the surface of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good biocompatibility and ectopic induced osteogenic activity.
Biocompatible Materials ; Bone Marrow Cells/*cytology ; Bone Matrix/*cytology ; Cells, Cultured ; Chondrocytes/cytology ; Coculture Techniques ; Decalcification Technique ; *Osteogenesis ; Stem Cells/cytology ; Stromal Cells/cytology ; *Tissue Engineering