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Biomedical subjects

J Hebling

Publications and source records attributed to J Hebling.

15 recordsLinked to original sources
PubMed2006

Extravasation mucocele involving the ventral surface of the tongue (glands of Blandin-Nuhn).

BACKGROUND: Mucocele is a lesion that involves the salivary glands and respective current ducts caused mainly by traumas in the affected area. Two different histological forms can be found: extravasation phenomenon and mucus-retention cyst where the former is the most frequently observed involving minor salivary glands such as the glands present in the anterior portion of the ventral surface of the tongue (glands of Blandin-Nuhn). CASE REPORT: This report describes a large lesion involving the ventral surface of the tongue that was definitively diagnosed by histological examination as extravasation mucocele. CONCLUSION: Important concepts are reviewed to help clinicians correctly diagnose and treat this pathology.

Biopsy↗
PubMed2006

Reactionary dentinogenesis after applying restorative materials and bioactive dentin matrix molecules as liners in deep cavities prepared in nonhuman primate teeth.

OBJECTIVE: The aim of this in vivo study was to evaluate the response of the pulp-dentin complex following application of resin-modified glass-ionomer cement, calcium hydroxide hard-setting cement and EDTA-soluble preparation of dentine matrix proteins (ESDP) in deep cavities prepared in non-human primate teeth. METHODS: Eighteen deep Class V buccal cavities were prepared in premolars of four capuccin monkeys. In Groups 1 and 2, the cavity floor was lined with ESDP or a resin-modified glass-ionomer cement (Vitrebond - 3M ESPE), respectively. In Group 3 (control), the cavity was lined with a hard setting calcium hydroxide cement (Dycal - Dentsply). The cavities were subsequently filled with amalgam. After 6 months, the animals were sacrificed and the teeth were prepared for microscopic assessment. Six-micron thick serial sections were stained with H/E, Masson's trichrome and Brown & Brenn techniques. RESULTS: No inflammatory pulpal response was observed for all experimental and control Groups. However, the amount of reactionary dentin deposition differed between groups in the rank order ESDP (Group 1) > calcium hydroxide (Group 3) > resin-modified glass-ionomer (Group 2). These differences were statistically significant. CONCLUSIONS: All materials were biocompatible when applied in deep cavities. ESDP stimulated higher deposition of reactionary dentin matrix than Vitrebond and Dycal.

Animals↗
PubMed2006

In vivo evaluation of the biocompatibility of three current bonding agents.

The aim of this in vivo study was to evaluate the biocompatibility of three current bonding agents and calcium hydroxide cement. Sixty polyethylene tubes filled with the following materials: Group 1: Prime & Bond NT (PB-Dentsply, US; Group 2: Bond 1 (BO-Jeneric/Pentron, US); Group 3: Optibond Solo (OP-Kerr, US); and Group 4 (control): calcium hydroxide cement - Dycal (CH-Dentsply, US) were implanted into the connective tissue of 30 rats. After 15, 30 and 60 days, the implants were excised and the animals sacrificed. The biopsies were immersed in Karnovsky (pH, 7.2) fixative solution for 48 hours, and processed using routine histological technique. Six-micron-thick sections were cut and stained with hematoxilin and eosin and Masson's trichome technique. Microscopic evaluation was used to compare the connective tissue reactions caused by the experimental and control materials adjacent to the tube opening. At 15 days, the experimental and control materials triggered a moderate to intense inflammatory response which gave rise to a thick capsule adjacent to the tube opening. With time, the inflammatory reaction decreased. At 60 days, the connective tissue adjacent to the bonding agents exhibited a persistent inflammatory response mediated by macrophages and giant cells which were engulfing displaced resin components. On the other hand, for the control group (calcium hydroxide) no inflammatory response associated with a thin capsule adjacent to the material was observed even at the 30-day period. The hard-setting calcium hydroxide cement allowed complete healing and was considered more biocompatible than the bonding agents.

Animals↗
PubMed2005

Chlorhexidine arrests subclinical degradation of dentin hybrid layers in vivo.

The recent paradigm that endogenous collagenolytic and gelatinolytic activities derived from acid-etched dentin result in degradation of hybrid layers requires in vivo validation. This study tested the null hypothesis that there is no difference between the degradation of dentin bonded with an etch-and-rinse adhesive and that in conjunction with chlorhexidine, an MMP inhibitor, applied after phosphoric-acid-etching. Contralateral pairs of bonded Class I restorations in primary molars of clinical subjects were retrieved after a six-month period of intra-oral functioning and processed for transmission electron microscopy. Hybrid layers from the chlorhexidine-treated teeth exhibited normal structural integrity of the collagen network. Conversely, abnormal hybrid layers were seen in the control teeth, with progressive disintegration of the fibrillar network, to the extent that it was beyond detection by collagen staining. Self-destruction of collagen matrices occurs rapidly in resin-infiltrated dentin in vivo and may be arrested with the use of chlorhexidine as an MMP inhibitor.

Acid Etching, Dental↗
PubMed2003

Biocompatibility of resin-based materials used as pulp-capping agents.

AIM: To evaluate and compare the response of pulps of rats capped with resin-modified glass-ionomer cement (RMGIC) or self-etching adhesive system. METHODOLOGY: Class I cavities were prepared on the occlusal surface of 54 maxillary first molars of 27 rats. Pulp exposure was performed on the cavity floor. The following resin-based materials were applied as pulp-capping agents: G1, Clearfil Liner Bond 2V (CLB 2V; Kuraray Co., Japan); G2, Vitrebond (VIT; 3M/ESPE, USA). In group 3 (control group), a calcium hydroxide/saline paste (CH; Labsynth, Brazil) was used. The cavities were restored with amalgam. After 7, 30 and 60 days, the animals were sacrificed and the jaws were processed for microscopic evaluation. RESULTS: Despite the inflammatory response caused by the experimental and the control materials at 7 days, pulpal healing associated with calcified barrier formation was observed at 60 days following the pulp therapy. Both resin-based materials promoted a large zone of cell-rich fibrodentine matrix deposition on the pulp horn related to the pulp exposure site, which was larger to VIT than to CLB 2V specimens. Tertiary dentine underneath the fibrodentine matrix was deposited by a layer of elongated pulpal cells. The remaining pulpal tissue exhibited normal histological characteristics. In the control group, healing and dentine-bridge formation was observed at 30 days. Pulpal breakdown occurred only when bacterial infection occurred. CONCLUSION: Both experimental pulp-capping agents allowed pulpal healing characterized by cell-rich fibrodentine and tertiary dentine deposition as well as calcified barrier formation.

Animals↗
PubMed2000

Current status of pulp capping with dentin adhesive systems: a review.

Several studies have assessed the morphology and thickness of hybrid layer, the dentin bond strengths as well as sealing ability of dentin adhesive systems. However, few in vivo studies have evaluated the biocompatibility of the adhesive systems following application to deep dentin or directly to the pulp of human teeth. Many studies performed in non-human primate teeth or teeth of rats have reported pulp healing and dentin bridging following pulp capping with bonding agents. In addition, a few clinical and radiographical reports of the success of resin pulp capping have been described in the dental literature. OBJECTIVES: The aim of this review was to evaluate the literature on pulp responses following total acid etching and application of adhesive resins on deep cavities or pulp exposures. In addition, the clinical/radiographical evidence for the apparent success of vital pulp therapy and results obtained from animal and human studies were compared and discussed. SIGNIFICANCE AND CONCLUSIONS: The self-etching adhesive systems may be useful and safe when applied on dentin. In contrast, persistent inflammatory reactions as well as delay in pulpal healing and failure of dentin bridging were seen in human pulps capped with bonding agents. The results observed in animal teeth cannot be directly extrapolated to human clinical conditions. Consequently, vital pulp therapy using acidic agents and adhesive resins seems to be contraindicated.

Acid Etching, Dental↗
PubMed2000

Biocompatibility of two current adhesive resins.

The purpose of the study was to evaluate the biocompatibility of two current adhesive resins and a calcium hydroxide cement. Fifty-four polyethylene tubes were filled with these dental materials, which were hand-mixed or light-cured according to the manufacturer's directions: group 1--Clearfill Liner Bond 2 (Kuraray); group 2--Single Bond (3 M); and group 3--calcium hydroxide cement (Dycal-Dentsply). The materials were implanted into dorsal connective tissue of rats, which were killed 7, 30, and 60 days after the implantation procedure. The implant sites were excised, immersed in buffered Karnovsky's fixative, and processed using routine histological techniques. Sections of 6 microns thickness were stained with hematoxylin and eosin and assessed under light microscopy. Both adhesive resins at 7 days elicited a moderate/intense inflammatory reaction that decreased over time. Fibrous capsules surrounding the tubes were observed at 30 days. Half of the samples in groups 1 and 2 showed thin fibrous capsule formation containing macrophages, capillaries, lymphocytes, fibroblasts, and collagen fibers. Connective tissue healing was observed even though many specimens exhibited a persistent inflammatory reaction mediated by macrophages and giant cells at the 60-day evaluation. Dycal allowed complete healing at 30 days with only a thin fibrous capsule. In conclusion, all experimental materials were successfully walled off by the connective tissue of the rat. However the adhesive resins may release particulates that may, in turn, induce a persistent local inflammatory reaction. Consequently, in this specific condition, these materials cannot be regarded as biocompatible. Dycal was less irritating than the adhesive resins and was better tolerated by the connective tissue.

Animals↗
PubMed2000

Improved sealant retention with bonding agents: a clinical study of two-bottle and single-bottle systems.

Recent in vitro work and a short clinical study suggest that adding a bonding agent layer between sealant and saliva-contaminated enamel allows for adequate bond strength and retention of resin sealants and may improve success of all sealant applications. This five-year clinical study scored 617 occlusal and 441 buccal/lingual molar sealants, with use of a split-mouth design, with half receiving sealant alone and half bonding agent plus sealant. Treatment effects and potential risk factors for sealant failure were tested by means of a Cox regression model. Three bonding agent groups were analyzed for treatment effect: Tenure primer, Scotchbond Multi-Purpose, and 3 single-bottle dentin bonding agents as a third group. The single-bottle group was successful in reducing risk of sealant failure, with a hazard ratio (HR) of 0.53 (p = 0.014) for occlusal and 0.35 (p = 0.006) for buccal/lingual sealants. Scotchbond was detrimental to occlusal sealant success, with a HR of 2.96 (p = 0.0003). Tenure primer was neutral, showing HRs close to 1.0. Variables that affected success differed between occlusal and buccal/lingual sealants, suggesting that failures on these two surfaces may be dependent upon differing factors. Early eruption stage was a significant risk factor for both surfaces (HR = 2.91, p = 0.00001, occlusal; and HR = 1.52, p = 0.015, buccal/lingual). Behavior (HR = 1.96, p = 0.0007), salivary problems (HR = 1.73, p = 0.002), and visually apparent variations in enamel (HR = 1.51, p = 0.018) were significant risk factors for occlusal sealants only. In addition to completing detailed analyses of risk factors for sealant survival, this study shows that single-bottle bonding agents protect sealant survival, yielding half the usual risk of failure for occlusal sealants and one-third the risk of failure for buccal/lingual sealants.

Child↗
PubMed2000

Use of one-bottle adhesive as an intermediate bonding layer to reduce sealant microleakage on saliva-contaminated enamel.

PURPOSE: To evaluate the influence of three different adhesives, each used as an intermediary layer, on microleakage of sealants applied under condition of salivary contamination. MATERIALS AND METHODS: Six different experimental conditions were compared, 3 with adhesives and 3 without. After prophylaxis and acid etching of enamel, salivary contamination was placed for 10 s. In Group SC the sealant was applied after saliva without bonding agent and then light-cured. In Group SCA, after saliva, the surface was air dried, and then the sealant was applied and cured. In Groups ScB, SB and PB, a bonding agent (Scotchbond Dual Cure/3M, Single Bond/3M and Prime & Bond 2.1/Dentsply, respectively) was applied after the saliva and prior to the sealant application and curing. After storage in distilled water at 37 degrees C for 24 hrs, the teeth were submitted to 500 thermal cycles (5 degrees C and 55 degrees C), and silver nitrate was used as a leakage tracer. Leakage data were collected on cross sections as percentage of total enamel-sealant interface length. Representative samples were evaluated under SEM. RESULTS: Sealants placed on contaminated enamel with no bonding agent showed extensive microleakage (94.27% in SC; 42.65% in SCA). The SEM revealed gaps as wide as 20 microm in areas where silver nitrate leakage could be visualized. In contrast, all bonding agent groups showed leakage less than 6.9%. Placement of sealant with a dentin-bonding agent on contaminated enamel significantly reduced microleakage (P < 0.0001). The use of a bonding agent as an intermediary layer between enamel and sealant significantly reduced saliva's effect on sealant microleakage.

Acid Etching, Dental↗
PubMed2000

Pulp response to direct capping with an adhesive system.

PURPOSE: To evaluate the pulp response following direct pulp capping with an adhesive system (Prime & Bond 2.0 - PB 2.0) and a zinc-oxide eugenol cement (ZOE) on pulp exposures in rat molar teeth. MATERIALS AND METHODS: Forty-eight Class I cavities were prepared on the occlusal surface of molar teeth of rats (Rattus Norvegicus, Holtzman). Pulp exposures performed on the cavity floor were capped either with the adhesive system P&B 2.0 or ZOE. After 7, 15, 30, and 60 days, the specimens were processed through H & E and Brown & Brenn staining techniques. RESULTS: Both pulp capping materials allowed pulp repair, characterized by reorganization of a new odontoblast cell layer underlying the dentin bridge formation. However, P&B 2.0 promoted a large zone of cell-rich fibrodentin matrix deposition between the pulp capping material and the dentin bridge, which was deposited far from the pulp exposure site. On the other hand, pulps capped with ZOE showed dentin bridging immediately subjacent to the pulp capping material. In those samples in which microleakage occurred between dental material and cavity walls there was a persistent inflammatory reaction and lack of complete pulp repair.

Animals↗
PubMed1999

Biocompatibility of an adhesive system applied to exposed human dental pulp.

Human pulp tissue was directly capped with All Bond 2, or calcium hydroxide and evaluated 7, 30, or 60 days after the procedures. Histological analysis was performed to assess the inflammatory cell response, tissue disorganization, dentin bridging, and the presence of bacteria. At 7 days, with All Bond 2 capping, there was a large area of neutrophilic infiltrate underlying the pulp capping material, and the death of adjacent odontoblasts, was observed. However, with time, the neutrophilic reaction was replaced by fibroblastic proliferation with macrophages and giant cells surrounding globules of resin scattered in the coronal pulp tissue. The persistent inflammatory reaction and hyaline alteration of extracellular matrix inhibited complete pulp repair or dentin bridging. In contrast, at 7 days, the pulp tissue capped with calcium hydroxide exhibited odontoblast-like cells organized underneath coagulation necrosis. Pulp repair evolved into apparent complete dentin bridge formation at 60 days. All Bond 2 did not appear to allow any pulp repair and does not appear to be indicated for direct pulp capping of human teeth.

Adolescent↗
PubMed1999

Human pulp response after an adhesive system application in deep cavities.

OBJECTIVES: To evaluate the pulpo-dentin complex response to a dentin adhesive application in deep cavities performed in human teeth. METHODS: Deep class V cavities were prepared on the buccal surface of 46 premolars. The remaining dentin of the axial wall received 10% phosphoric acid and dentin adhesive (group DA), or was protected before the acid and dentin adhesive application with calcium hydroxide cement (group CH). Half of the teeth, which received the acid application directly over the axial wall, were contaminated prior to the procedures with dental plaque collected from the patient's own teeth (group DAC). The plaque was placed on the dentin for 5 min and then the cavity was washed. All teeth were restored with a light-cured composite resin. The teeth were extracted after 7, 30 or 60 days and prepared according to normal histologic techniques. Serial sections were stained with H/E, Masson's trichrome and Brown & Brenn technique for demonstration of bacteria. RESULTS: The histopathologic evaluation showed that in groups DA and DAC, the inflammatory response was more evident than in group CH. Also, the intensity of the pulp reaction increased as the remaining dentin thickness decreased. There was no statistical difference in the inflammatory response between the groups DA and DAC. CONCLUSION: Based on the experimental conditions, we concluded that the All Bond 2 adhesive system, when applied on dentin in deep cavities, showed an acceptable biocompatibility. However, the intensity of the pulpo-dentin complex response depends on the remaining dentin thickness.

Acid Etching, Dental↗
PubMed1995

Charge displacement in bacteriorhodopsin during the forward and reverse bR-K phototransition.

Dried oriented purple membrane samples of Halobacterium salinarium were excited by 150 fs laser pulses of 620 nm with a 7 kHz repetition rate. An unusual complex picosecond electric response signal consisting of a positive and a negative peak was detected by a sampling oscilloscope. The ratio of the two peaks was changed by 1) reducing the repetition rate, 2) varying the intensity of the excitation beam, and 3) applying background illumination by light of 647 nm or 511 nm. All of these features can be explained by the simultaneous excitation of the bacteriorhodopsin ground form and the K intermediate. The latter was populated by the (quasi)continuous excitation attributable to its prolonged lifetime in a dehydrated state. Least-square analysis resulted in a 5 ps upper and 2.5 ps lower limit for the time constant of the charge displacement process, corresponding to the forward reaction. That is in good agreement with the formation time of K. The charge separation driven by the reverse phototransition was faster, having a time constant of a 3.5 ps upper limit. The difference in the rates indicates the existence of different routes for the forward and the reverse photoreactions.

Bacteriorhodopsins↗
PubMedDate not supplied

Biocompatibility of an adhesive system and 2-hydroxyethylmethacrylate.

The aim of the study was to evaluate the biocompatibility of an adhesive system and a resin component when implanted into connective tissue of rats. Forty sponges embedded in both materials: Scotchbond MP (SBMP/ 3M-Group A) and 2-hydroxyethylmethacrylate (HEMA-Group B), were implanted into dorsal connective tissue of 20 animals. After 7, 15, 30, or 60 days of the implantation, the animals were sacrificed; implant sites were excised and immersed for 24 hours in Kamovisky's fixative. The samples were processed under routine histologic technique, being stained with H & E. Histological evaluation showed that both materials promoted at 7 days intense inflammatory response with predominance of neutrophils and macrophages. The intense connective reaction was replaced for fibroblastic proliferation associated with macrophages and foreign body giant cells over time. The persistent moderate inflammatory reaction adjacent to scattered fragments of materials was greater to HEMA than to the SBMP. Both experimental materials did not show acceptable biocompatibility with connective tissue of rats in spite of allowing an evident connective tissue healing.

Animals↗