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An original technique for histological study of the human temporal bone is presented. It allows faster and better results than previous methods. It becomes obvious that the systematic study of the temporal bone may give important data in the field of pathology, foeto-pathology and forensic medicine.
Sinus lift bone grafting has expanded the use of dental implants in reconstructions of the atrophic maxilla. Potential problems include sinus membrane tear, which can lead to graft infection and early failure. Attempts at managing sinus membrane perforations are often limited by difficulty of access, as well as by the friability of the soft tissue lining the sinus. Various techniques have been proposed for managing such membrane tears. The use of fibrin adhesive, however, may present a potential solution in such situations. This article reports our experience with the use of fibrin adhesive in sinus lift procedures, as well as on its autologous preparation.
Ossein was solubilized by the action of alkali and a resulting high-molecular-weight fraction isolated. The chemical and physical properties of this fraction were studied and compared with those of an acid-soluble collagen prepared from calf skin by conventional techniques. From the results it is concluded that the alkali-soluble protein exhibits only minor differences from acid-soluble collagen, and that these differences can be ascribed for the most part to a decrease in the inter- and intramolecular cross-linking.
AIM: This study used a modified tooth-clearing technique to allow observation of accessory canals following filling with a warm gutta-percha technique and one of two endodontic cements. METHODOLOGY: Ten extracted human maxillary molars with three roots were selected and divided into two equal groups of five teeth. Each group had 15 canals. Root canal preparation was performed with a modified double flared technique; irrigation with 5% NaOCl and lubrication with RC-Prep were used. The canals were then filled with gutta-percha and cement utilizing a warm vertical condensation technique in the apical third followed by thermo-mechanical compaction in the middle and coronal thirds. Pulp Canal Sealer or AH-Plus were used in the experimental groups. The teeth were demineralized with a modified buffered acid solution, cleared in methylsalicylate and examined under a stereomicroscope. Accessory canals were evaluated in the apical, middle and coronal thirds of each root canal and categorized as narrow or wide, following observation on four surfaces. The depth of penetration of gutta-percha and cement into lateral canals was scored using a 5-point system. RESULTS: Complete transparency of the roots was achieved. Accessory canals were detected in all specimens. In coronal ramifications, gutta-percha filled the empty spaces (coronal thirds, grades 3 and 4: 70.9% in AH-Plus group and 68.8% in Pulp Canal Sealer group). In the apical accessory canals, gutta-percha entered less frequently (apical thirds, grades 3 and 4: 17.9% in the AH-Plus group and 3.2% in the Pulp Canal Sealer group); cement without gutta-percha (grades 1 and 2) was present in 55.5% in the AH-Plus group and 38.7% of the Pulp Canal Sealer group. Analysis showed that AH-Plus cement resulted in significantly greater filling of the apical accessory canals compared to Pulp Canal Sealer. CONCLUSIONS: The modified tooth-clearing technique allowed observation of fine morphological details in all specimens. Effective gutta-percha filling was evident in most of the wide coronal lateral canals whilst the apical narrow ramifications were often incompletely filled by cement. Overall AH-Plus demonstrated better diffusion into lateral accessory canals compared to Pulp Canal Sealer.
The purpose of this study was to see if the root surface topography of teeth, stored in saline and subsequently treated with citric acid, differred from the root surface topography of teeth that were treated immediately upon extraction, 12 freshly extracted adult human permanent teeth, with proximal surfaces free of caries and periodontal disease, were treated in succession. The crowns were removed at the level of periodontal attachment, the teeth sectioned buccal-lingually and a treatment area deligniated on each proximal section. The treatment area of 6 teeth was root planed to expose dentin (D) and scaled to remove adherent tissue and leave a cementum surfaces (C) on the other 6 teeth. A coronal-apical groove down the middle of the treatment area divided it into approximately equal parts or experimental regions. One proximal section of each tooth was placed in physiologic saline (S) and treated after 6 weeks of storage while the other proximal section was freshly treated (F). Treatment consisted of applying a 30% citric acid (CA) solution (pH = 1.60) for 5 min. Cotton pellets soaked in the citric acid solution were placed (P) on one half of the experimental area and heavily burnished (B) on the other half. Treatment areas were subsequently prepared for scanning electron microscopy analysis. Assessment was made of (i) the % of surface area tufted, (ii) fibril tufting depth (0.3) and (iii) fibril tufting density (1.3). Similarities were found in the data for both storage methods (F and S) across each application technique (P or B) and each tooth surface (D or C) with respect to the (i) % area tufted and (ii) frequency distribution of tufting depth scores. As for the application techniques, the data for burnishing was greater than placed across each storage method (F or S) and each tooth surface (D or C) for the same two parameters. The results of the study indicated that 6-week physiologic saline storage does not affect root surface demineralization by citric acid, as assessed by SEM.
A slicing technique for the preparation of a tooth specimen is described. A low speed saw (ISOMET) was used for this modified technique. It is a slicing machine fitted with a diamond-impregnated cutting disc of 0.5 mm in thickness. The formalin was used for lubrication to serve as both a coolant and a fixative simultaneously. It is thought that the preparation will not damage or disturb the surface of the tooth specimen by careful management under 200 rpm with a loading of 50 grams. The cutting of slices can be controlled by adjusting the specimen arm with a micrometer to the desired thickness. A high quality histological preparation can be obtained when the specimen is sliced as mentioned above soon after it is removed from the living body before decalcification. By the observation of specimens such as the resected jaw bone or other large hard tissue specimens, it is suggested that the sliced specimens of 2 mm in thickness can be obtained routinely for histological study by using this method.
The otic labyrinth presents one of the most difficult objects for histological investigations as it is situated in the thick layer of the temporal bone and has a very complex structure. At the same time, a method for treating this object is not given in general hand-books on pathological techniques. The methods for histological treatment of the otic labyrinth elaborated by Wittmaack and later on modified are presented in the article. Methods for fixation, vital fixation including, decalcination, dehydratation and saturation of the objects prepared for histological investigation are described in details. Methods for the temporal bone orientation in order to obtain sections of the internal otic structures in the most advantageous plane depending on the purpose and aim of the investigation are recommended.
Lymph nodes from guinea pigs inoculated with Mycobacterium tuberculosis were fixed in buffered formalin, then treated for the recommended times in Gooding and Stewart's fluid, EDTA, aqueous nitric acid, von Ebner's fluid, and rapid decalcifier (RDC). The blocks were processed to paraffin wax and sections were stained by the Ziehl-Neelsen technique. Only in sections of the blocks treated with RDC were no acid alcohol fast bacilli demonstrable. Hydrochloric acid is a known constituent of RDC and it was found that Myco. tuberculosis is altered by treatment with 2-5M solutions of hydrochloric acid and above and cannot subseuqently be demonstrated by the Ziehl-Neelsen stain. From these results it is recommended that calcified tissue from patients in whom there is a suspicion of tuberculosis should be decalcified with an agent other than RDC.
Several different staining procedures were carried out on decalcified histological sections from human femoral heads to demonstrate the nerves in subchondral bone. The femoral heads were obtained at surgery from patients with fractures of the femoral neck or osteoarthritic hip joints. The Bodian technique was found to be the most suitable. Serial sections were used in order to disclose the various sources of error. It was not possible to demonstrate nerves in the bone matrix, but they were easily seen in the subchondral bone marrow, after related to the vessels. A comparison of the fracture and osteoarthritic cases revealed an obvious difference; more nerves were seen in osteoarthritis. The method described is considered suitable for further study of the nerves in osteoarthritic femoral heads.
OBJECTIVES: This study investigated the ultrastructure of the resin-dentine interface when a two-bottle primer system containing NTG-GMA (N(p-tolyl)glycine-glycidyl methacrylate) and BPDM (biphenyl dimethacrylate) was used with different concentrations of water as a part of the primer solvent: (I) an experimental version of All-Bond 2 with no water in primer A; (II) a commercial version of All-Bond 2 (Bisco, Itasca, IL, USA) with 5% water in primer A; and (III) a former version of All-Bond 2 with 17% water in primer A. METHODS: Thirty-six 1-mm thick dentine discs prepared from third permanent molar teeth were each conditioned with 10% phosphoric acid for 20 s and rinsed for 20 s. They were randomly divided into three groups: Group A, conditioned dentine surface air-dried for 30 s; Group B, air-dried for 3 s; and Group C, blot-dried so that the dentine surface remained visibly moist. The three categories of primers were applied to each disc in 8-10 coats, resulting in nine sub-groups. Discs in each sub-group were bonded together to form disc-pairs using a chemical cure resin, demineralized in ethylene diamine tetraacetic acid (EDTA) and prepared for transmission electron microscopic examination. RESULTS: With the use of the water-free primer version, sub-optimal hybridization was observed whenever dentine was dried prior to bonding (Groups IA and IB). In the 5% water version, prolonged desiccation resulted in compromised hybridization (Group IIA), while resin globules were observed on the surface of the hybrid layer when a moist technique was employed (Group IIC). In the 17% water version, surface blisters and globules characteristic of the 'overwet phenomenon' were observed in Groups IIIB and IIIC. CONCLUSION: Between the two extremes of a morphological spectrum of bonding conditions, the different primer versions exhibited different sensitivity ranges. There was a shift in the 'window of opportunity' for optimal hybridization and tubular seal depending on the water content of the primer system investigated.
The inhibiting effect of a 24 hours application of a fluoridated varnish with various fluoride contents on demineralization of human sound enamel was evaluated in vitro. The varnishes used had the same polyurethane base (Fluor Protector) and contained 0.7; 0.1; 0.05 and 0 wt% fluoride, resp. A constant composition technique was used to demineralize varnished and non-varnished specimens at a pH of 5 for periods upto 2 weeks. Microhardness measurements were carried out after several time intervals to follow mineral loss in time longitudinally. At the end of each experimental run microradiography was carried out to investigate 1) lesion type, 2) lesion depth and 3) mineral loss. It is shown in this study that the fluoride releasing varnishes applied on the enamel for 24 hours can inhibit demineralization completely. No demineralization inhibition with the 0% fluoride varnish application was observed.
When lesion formation in dental enamel or dentine is studied in vitro, a well-defined area of the material, a 'window', is exposed to the demineralization medium. In the present experiments, we report the effect of window width on lesion formation in enamel and dentine. Rectangular windows, longest dimension always 5 mm and shortest dimension varying from 0.5 to 5 mm, were exposed to demineralization media. Lesions in dentine were formed by placing the specimens in an acidified unstirred 6% carboxymethyl cellulose (CMC) gel, an unstirred 0.5% CMC gel, a mildly stirred 0.5% CMC gel, or in a mildly stirred demineralization solution. Lesions in enamel were formed only in an unstirred acidified 6% CMC gel. pH in the demineralization media was 5.0 in all experiments. The microradiographic technique was used to assess lesion depth and mineral loss (vol% x microm) of lesions formed. Lesions formed in the unstirred gels were deeper, and there was a larger mineral loss, the narrower the window. There was no effect of window size on lesions formed in stirred systems. These effects can be explained by the strong dependence of concentration gradient in stirred gels just outside the exposed window on the window size. The phenomenon found here in vitro may at least partly explain why secondary caries may lead to localized, but relatively deep, lesions.
PURPOSE: To determine if alteration of any of the following factors could reduce microleakage following placement of Class II resin-based composites (RBC) at intraoral temperature: cavity preparation (vertical wall bevels), finishing technique (delayed vs. immediate), or postoperative re-bonding (marginal sealing). An additional purpose was to determine if a decalcification/clearing protocol was a valid technique for assessing three-dimensional microleakage. MATERIALS AND METHODS: Twenty recently extracted human molars had standardized Class II slot cavities prepared on the mesial and distal surfaces with the gingival floor located on dentin. The teeth were imbedded in a stone template, warmed to 37 degrees C and restored immediately upon removal from the oven with visible light-cured (VLC) adhesive (All-Bond 2) and three horizontal increments of VLC RBC (Bisfil P) using a metal matrix. Teeth were placed into one of four groups: (1) Control; (2) The preparation was modified to include 0.5-1.0 mm enamel bevels on the vertical walls (facial and lingual); (3) Finishing of the RBC was delayed 24 hours; (4) Following immediate finishing, all margins of the RBC restorations were sealed by dentin bonding agent application. Teeth were stored at 37 degrees C for 2 weeks, thermocycled 1000x at 5/55 degrees C, stained with silver nitrate, underwent a decalcification and clearing protocol, and evaluated for three-dimensional dye penetration. RESULTS: Axial-occlusal enamel margins exhibited minimal leakage and no differences among the groups. Vertical walls without bevels exhibited pronounced microleakage. Beveled vertical proximal walls exhibited significantly less facial and lingual wall microleakage compared to all other groups, and less gingival marginal leakage compared to the control group.
Autoantibodies in the serum of patients with inner ear disorders have been detected using the immunofluorescence technique. In the present study the results of the use of frozen sections of non-decalcified guinea pig cochlea in the indirect immunofluorescence test are described. Human sera with positive anti-mitochondrial (AMA), anti-nuclear (ANAS) and anti-nucleolar (ANAN) antibodies were utilized, as well as a negative serum control and sera from three patients suffering from chronic progressive sensorineural hearing loss. The positive reactions obtained were clear and specific. Autofluorescence was minimal and non-specific reactions were negligible. The fine structure of the inner ear tissue and the cellular antigenicity present were well preserved.
In the continuous search for the ideal grafting material in this study the authors used human demineralized freeze dried bone (DFDB) in the maxillary sinusfloor elevation surgery. In total 30 sinusgrafts were performed in 24 patients. Residual lateral maxillary bone height was less than 8 mm but more than 4 mm. The surgical technique used was according to the description of Tatum (1986). In those 30 grafted sinuses a total of 69 ITI full body screw implants were placed 6 months after grafting. Four sinuses exhibited a prolonged healing time. All implants were loaded 4 months after insertion. No implant losses or failures occurred. The rough surface ITI dental implant appeared to be a suitable implant following sinusgrafting with DFDB. According to the results of this study the limited sinusfloor elevation procedure with DFDB appears to be a clinical reliable pre-implant procedure.
Advances in neuroscience require better anatomical knowledge of neuronal architecture and structural details. Optimal embedding techniques are the basis for precise morphometric studies in section series as well as for the evaluation of tissue specimens or implants of differing hardness. There are very few methods for preparing large specimens by resin embedding, although resins such as polyethylene glycol (PEG) and methyl methacrylate (MMA) are presently in use. However, these methods have proven to be laborious and sometimes unsatisfactory for serial sectioning. While glycol methacrylate embedding (GMA) is suitable for smaller specimens, it results in inadequate infiltration and polymerization in blocks larger than 1 x 1 x 0.2 cm. We present an improved technique using GMA, which permits both standardized embedding of 4 x 2 x 2 cm blocks and preparation of section series. This method was developed for preserving skull-brain specimens from rats with polyester-mesh implants. The excellent preservation of cellular details allowed the assessment of local tissue reaction to foreign-body material in situ. Advantages of this method are: (1) No toxic catalysts or solvents are used (as opposed to MMA and current GMA processes); (2) Laborious routines in stretching and mounting of sections are not necessary (in contrast to PEG and MMA); (3) No deplastination is required before staining (in contrast to PEG and MMA); (4) Excellent morphologic preservation of various tissue is achieved.
Decalcified bone marrow biopsies containing metastatic tumor from 36 patients were stained for prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) using the avidin biotin complex (ABC) immunoperoxidase technique. Of these patients, 22 had known prostate primaries, ten had known nonprostatic, and four female patients had unknown primaries. Prostate-specific antigen was identified in 86% (19/22) of the metastatic prostatic carcinomas. Prostatic acid phosphatase was present in only 36% (8/22). None of the patients with nonprostatic primaries or unknown primaries showed positive staining for either antigen (0/14). This study indicates that immunoperoxidase staining for PSA is very sensitive and specific in the diagnosis of metastatic prostate carcinoma, while PAP was less sensitive using decalcified bone marrow specimens. We believe that immunostaining with PSA should be of great value in diagnosis of prostatic carcinoma metastatic to the bone.
The purpose of this study was to evaluate by different techniques the healing effect of demineralized allogeneic bone in parietal cranial defects in rats. 45Ca incorporation was measured for nine consecutive weeks in groups of control and implanted rats. Repeated 99mTc MDP uptake measurements were performed for nine weeks on the same group of rats. Each measurement was preceded by a cranial radiography. At the end of the study the animals were sacrificed for histologic evaluation. The results of the 45Ca incorporation, 99mTc MDP uptake measurements and the histologic pictures confirmed the osteogenic capacity of demineralized allogenic bone. From the results it can concluded that 99mTc MDP uptake measurements are a powerful tool in the evaluation of the healing process. It can be utilized sequentially in the same animal and gives detailed information about the progress of osteogenic activity over the entire implant area.