Evaluation of dentinogenesis inducer biomaterials: an in vivo study.

When exposure of the pulp to external environment occurs, reparative dentinogenesis can be induced by direct pulp capping to maintain pulp tissue vitality and function. These clinical situations require the use of materials that induce dentin repair and, subsequently, formation of a mineralized tissue. OBJECTIVE: This work aims to assess the effect of tricalcium silicate cements and mineral trioxide aggregate cements, including repairing dentin formation and inflammatory reactions over time after pulp exposure in Wistar rats. METHODOLOGY: These two biomaterials were compared with positive control groups (open cavity with pulp tissue exposure) and negative control groups (no intervention). The evaluations were performed in three stages; three, seven and twenty-one days, and consisted of an imaging (nuclear medicine) and histological evaluation (H&E staining, immunohistochemistry and Alizarin Red S). RESULTS: The therapeutic effect of these biomaterials was confirmed. Nuclear medicine evaluation demonstrated that the uptake of 99mTc-Hydroxymethylene diphosphonate (HMDP) showed no significant differences between the different experimental groups and the control, revealing the non-occurrence of differences in the phosphocalcium metabolism. The histological study demonstrated that in mineral trioxide aggregate therapies, the presence of moderate inflammatory infiltration was found after three days, decreasing during follow-ups. The formation of mineralized tissue was only verified at 21 days of follow-up. The tricalcium silicate therapies demonstrated the presence of a slight inflammatory infiltration on the third day, increasing throughout the follow-up. The formation of mineralized tissue was observed in the seventh follow-up day, increasing over time. CONCLUSIONS: The mineral trioxide aggregate (WhiteProRoot®MTA) and tricalcium silicate (Biodentine™) present slight and reversible inflammatory signs in the pulp tissue, with the formation of mineralized tissue. However, the exacerbated induction of mineralized tissue formation with the tricalcium silicate biomaterial may lead to the formation of pulp calcifications.

Evaluation of dentinogenesis inducer biomaterials: an in vivo study

Abstract When exposure of the pulp to external environment occurs, reparative dentinogenesis can be induced by direct pulp capping to maintain pulp tissue vitality and function. These clinical situations require the use of materials that induce dentin repair and, subsequently, formation of a mineralized tissue. Objective: This work aims to assess the effect of tricalcium silicate cements and mineral trioxide aggregate cements, including repairing dentin formation and inflammatory reactions over time after pulp exposure in Wistar rats. Methodology: These two biomaterials were compared with positive control groups (open cavity with pulp tissue exposure) and negative control groups (no intervention). The evaluations were performed in three stages; three, seven and twenty-one days, and consisted of an imaging (nuclear medicine) and histological evaluation (H&E staining, immunohistochemistry and Alizarin Red S). Results: The therapeutic effect of these biomaterials was confirmed. Nuclear medicine evaluation demonstrated that the uptake of 99mTc-Hydroxymethylene diphosphonate (HMDP) showed no significant differences between the different experimental groups and the control, revealing the non-occurrence of differences in the phosphocalcium metabolism. The histological study demonstrated that in mineral trioxide aggregate therapies, the presence of moderate inflammatory infiltration was found after three days, decreasing during follow-ups. The formation of mineralized tissue was only verified at 21 days of follow-up. The tricalcium silicate therapies demonstrated the presence of a slight inflammatory infiltration on the third day, increasing throughout the follow-up. The formation of mineralized tissue was observed in the seventh follow-up day, increasing over time. Conclusions: The mineral trioxide aggregate (WhiteProRoot®MTA) and tricalcium silicate (Biodentine™) present slight and reversible inflammatory signs in the pulp tissue, with the formation of mineralized tissue. However, the exacerbated induction of mineralized tissue formation with the tricalcium silicate biomaterial may lead to the formation of pulp calcifications

Efficacy of ferric sulphate as a pulpotomy medicament in primary molars: an evidence based approach.

AIM: To evaluate the available evidence on the efficacy of ferric sulphate (FS) compared to other pulpotomy medicaments in primary molars. METHODS: A comprehensive literature search was conducted through five databases (PubMed, Ovid®, EBSCOhost, Cochrane Library and ProQuest) and only those papers which met the inclusion criteria were accepted. The quality of the studies used for systematic review was rated by two independent researchers based on Fuks and Papagiannoulis (Eur Arch Paediatr Dent 7:64-71, 2006) criteria and graded as A (38-42), B1 (32-37), B2 (25-31), C (≤ 24). Inter-examiner reliability was measured using Kappa statistics. RESULTS: A total of 1371 studies were available, of which only two studies full-text articles were included for quality assessment with an excellent inter-researcher agreement (k = 0.9). The comprehensive search revealed that, none of the 20 studies obtained grade A. Only three studies were graded as B1, 5 studies received grade B2 and 12 studies attained grade C. Only 4 prospective randomised clinical trials reported high success rate with FS compared to other materials. Remaining 14 studies revealed low success rate with FS compared to other pulpotomy medicaments. CONCLUSION: There is insufficient evidence to support the application of FS as a pulpotomy medicament in primary molars in the existing English literature. Hence, properly planned randomised clinical trials with large sample size and long-term follow up are needed to support FS as an effective pulpotomy medicament compared to other traditional and new medicaments.

Histological Effects of Enamel Matrix Derivative on Exposed Dental Pulp.

INTRODUCTION: Direct pulp capping procedure is a therapeutic application of a drug on exposed tooth pulp in order to ensure the closure of the pulp chamber and to allow the healing process to take place. OBJECTIVE: The aim of this study was to examine the histological effects of Emdogain® on exposed tooth pulp of a Vietnamese pig (Sus scrofa verus). METHODS: The study comprised 20 teeth of a Vietnamese pig. After class V preparation on the buccal surfaces of incisors, canines and first premolars, pulp was exposed. In the experimental group, the perforations were capped with Emdogain® (Straumann, Basel, Switzerland), while in the control group pulp capping was performed with MTA® (Dentsply Tulsa Dental, Johnson City, TN, USA). All cavities were restored with glass-ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan). The observational period was 28 days, after which the animal was sacrificed and histological preparations were made. A light microscope was used to analyze dentin bridge formation, tissue reorganization and inflammation, and the presence of bacteria in the pulp. RESULTS: The formation of dentin bridge was observed in the experimental and control groups. Inflammation of the pulp was mild to moderate in both groups. Angiogenesis and many odontoblast-like cells, responsible for dentin bridge formation, were observed. Necrosis was not observed in any case, nor were bacteria present in the pulp. CONCLUSION: Histological analysis indicated a favorable therapeutic effect of Emdogain® Gel in direct pulp capping of Vietnamese pigs. Pulp reaction was similar to that of MTA®.

Dentinogenic responses after direct pulp capping of miniature swine teeth with Biodentine.

INTRODUCTION: The aim of this study was to evaluate pulpal responses after experimental direct pulp capping of mechanically exposed teeth with a new calcium silicate-based dentin replacement material. METHODS: Thirty-four anterior and posterior teeth of 3 miniature swine were used. Class V or I cavities were prepared on the buccal or occlusal surfaces, respectively. Pulpal exposures were further performed using a round carbide bur 0.8 mm in diameter. Exposures were treated with white MTA Angelus (Angelus, Londrina, PR, Brazil) or Biodentine (Septodont, Saint Maur des Fosses, France), and the cavities were further restored with Biodentine. The pulpal tissue responses were histologically assessed at postoperative periods of 3 and 8 weeks. Data were statistically analyzed using the Kruskal Wallis and the Mann-Whitney U tests. RESULTS: Inflammatory infiltration or pulp tissue necrosis was not found in any of the specimens. All teeth showed mineralized matrix formation in the form of a complete hard tissue bridge composed of osteodentin or osteodentin followed by a discontinuous or continuous reparative dentin zone. A significantly higher thickness of the hard tissue bridge was found in the group of teeth treated with Biodentine at both 3 and 8 weeks. A number of teeth, which were under root development at the onset of the experimental procedures, exhibited ectopic pulp calcification. CONCLUSIONS: The application of both calcium silicate-based materials in direct contact with the mechanically exposed pulp of healthy miniature swine teeth led to pulp repair with complete hard tissue bridge formation. The thickness of hard tissue bridges was significantly higher after pulp capping with Biodentine.

Iloprost induces tertiary dentin formation.

INTRODUCTION: Prostacyclin (PGI2), a member of the prostaglandin family, can promote angiogenesis and cell proliferation. METHODS: In this study, the effect of the application of a PGI2 analog (iloprost) on dentin repair was examined in vitro and in vivo. RESULTS: Iloprost significantly stimulated the expression of vascular endothelial growth factor and osteo-/odontogenic marker messenger RNA in human dental pulp cells (HDPCs) under osteoinductive conditions in vitro. In addition, iloprost enhanced HDPC alkaline phosphatase enzymatic activity and mineral deposition. An in vivo study was performed using a rat molar mechanical pulp exposure model. After 30 days, histologic analysis revealed that there was a dramatic tertiary dentin formation in the iloprost-treated group compared with the calcium hydroxide and the untreated control groups. Furthermore, vascular endothelial growth factor protein expression in dental pulp tissue was increased in the iloprost-treated group as determined by immunohistochemical staining. CONCLUSIONS: Taken together, the present study, for the first time, shows that iloprost induces the expression of osteo-/odontogenic markers in vitro and promotes angiogenic factor expression and enhances tertiary dentin formation in vivo. This implies the potential clinical usefulness of iloprost in vital pulp therapy.

Iloprost up-regulates vascular endothelial growth factor expression in human dental pulp cells in vitro and enhances pulpal blood flow in vivo.

INTRODUCTION: Prostacyclin (PGI2) is a biomolecule capable of enhancing angiogenesis and cellular proliferation. METHODS: We investigated the influence of a PGI2 analogue (iloprost) on dental pulp revascularization in vitro and in vivo by using human dental pulp cells (HDPCs) and a rat tooth injury model, respectively. Iloprost stimulated the human dental pulp cell mRNA expression of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and platelet-derived growth factor (PDGF) in a significant dose-dependent manner. This mRNA up-regulation was significantly inhibited by pretreatment with a PGI2 receptor antagonist and forskolin (a protein kinase A activator). In contrast, a protein kinase A inhibitor significantly enhanced the iloprost-induced mRNA expression of VEGF, FGF-2, and PDGF. Pretreatment with a fibroblast growth factor receptor inhibitor attenuated the VEGF, FGF-2, and PDGF mRNA expression, indicating opposing regulatory mechanisms. RESULTS: The effect of iloprost on the dental pulp was investigated in vivo by using a rat molar pulp injury model. The iloprost-treated group exhibited a significant increase in pulpal blood flow at 72 hours compared with control. CONCLUSIONS: The present study indicates that iloprost may be a candidate agent to promote neovascularization in dental pulp tissue, suggesting the potential clinical use of iloprost in vital pulp therapy.

Primate pulpal healing after exposure and TheraCal application.

AIM: The purpose of this in vivo study was to compare the effectiveness of a new light cured resin based dicalcium/tricalcium silicate pulp capping material (TheraCalLC, Bisco), pure Portland cement, resin based calcium hydroxide or glass ionomer in the healing of bacterially contaminated primate pulps. STUDY DESIGN: The experiment required four primates each having 12 teeth prepared with buccal penetrations into the pulpal tissues with an exposure of approximately 1.0 mm. The exposed pulps of the primate teeth were covered with cotton pellets soaked in a bacterial mixture consisting of microorganisms normally found in human pulpal abscesses. After removal of the pellet, hemostasis was obtained and the pulp capping agents applied. The light cured resin based pulp capping material (TheraCal LC) was applied to the pulpal tissue of twelve teeth with a needle tip syringe and light cured for 15 seconds. Pure Portland cement mixed with a 2% Chlorhexidine solution was placed on the exposed pulpal tissues of another twelve teeth. Twelve additional teeth had a base of GIC applied (Triage, Fuji VII GC America) and another twelve had a pulp cap with VLC DYCAL (Dentsply), a light cured calcium hydroxide resin based material. The pulp capping bases were then covered with a RMGI (Fuji II LC GC America). The tissue samples were collected at 4 weeks. The samples were deminerilized, sectioned, stained and histologically graded. RESULTS: There were no statistically significant differences between the groups in regard to pulpal inflammation (H = 0.679, P = 1.00). However, both the Portland cement and light cured TheraCal LC groups had significantly more frequent hard tissue bridge formation at 28 days than the GIC and VLC Dycal groups (H = 11.989, P = 0.009). The measured thickness of the hard tissue bridges with the pure Portland and light cured TheraCal LC groups were statistically greater than that of the other two groups (H = 15.849, P = 0.002). In addition, the occurrence of pulpal necrosis was greater with the GIC group than the others. Four premolars, one each treated according to the protocols were analyzed with a microCT machine. The premolar treated with the light cured TheraCal LC demonstrated a complete hard tissue bridge. The premolar treated with the GIC did not show a complete hard tissue bridge while the premolar treated with VLC Dycal had an incomplete bridge. The pure Portland with Chlorhexidine mixture created extensive hard tissue bridging. CONCLUSION: TheraCal LC applied to primate pulps created dentin bridges and mild inflammation acceptable for pulp capping.

MTA and ferric sulfate in pulpotomy outcomes of primary molars: a systematic review and meta-analysis.

OBJECTIVE: Methods of systematic review and meta analysis were employed to compare the success rate of pulpotomy of primary molars using mineral trioxide aggregate (MTA) and ferric sulfate (FS) as two regenerative and preservative agents, respectively. STUDY DESIGN: After raising a PICO question (In pulpotomy of vital carious-exposed primary molars, how does MTA compare to FS in terms of clinical and radiographic outcomes?) and determining the search strategy, MeSH-matching keywords were searched in four electronic databases and retrieved papers were examined in titles, and if necessary abstracts and full texts, to be relevant. Randomized clinical trials (RCTs) evaluating pulpotomy of vital primary molars after carious/traumatic exposure conducted with either FS or MTA, with at least a 6-month recall, tooth restorability, and those considering clinical and radiographic signs/symptoms, were included. The nonrandomized allocation and absence of comparison between the treatment groups caused the exclusion of the article. The quality of the RCTs and also their risk of bias (low, moderate, high), were assessed using a modification of van Tulder list; for meta-analysis of the matching studies, the extracted data were analyzed by Mantel Hanszel analysis. RESULTS: A total number of 620 articles were found. After exclusion of the common titles and application of the eligibility criteria, 4 RCTs [12-month follow-up: n=3, 24-month follow-up: n=4, in total: 264 teeth) comparing MTA and FS, were selected. It was showed that the 12-month outcome of both materials were similar [RR= 0.642 (CI 95%: 0.225-1.833, P=0.407)], while the two-year follow-up results revealed significant differences in treatment outcome, in favor of MTA [RR was 0.300 (CI 95%: 0.132-0.683, P=0.004)]. CONCLUSION: MTA demonstrated superior long-term treatment outcomes in pulpotomy of primary molars than FS.

The influence of different therapeutic modalities and platelet rich plasma on apexogenesis: a preliminary study in monkeys.

BACKGROUND: Traumatic injuries of permanent teeth with incomplete root formation are frequent during childhood. Adequate therapy is important for the further destiny of teeth with damaged pulp. OBJECTIVES: To evaluate the effect of pulpotomy and high pulpotomy on the pulp and on root development, and the effect of platelet rich plasma (PRP) with hydroxyapatite (HAP) as a carrier and hydroxyapatite alone on apexogenesis. MATERIAL AND METHODS: The study included eight monkeys (Cercopithecus aethiops) in which high pulpotomies were performed on the mandibular lateral incisors and canines, and pulpotomies were performed on the mandibular central incisors and premolars. The materials used in the study were commercial HAP (Apatec®, Stomygen) and PRP (prepared at the Torlak Institute of Immunology and Virology, Belgrade, Serbia.). Histological and radiological evaluations were done six months after the treatment. RESULTS: Considering the differences between HAP+PRP treated teeth in the pulpotomy group and teeth in the high pulpotomy group, two times more root growth retardation was observed in the high pulpotomy group. In the high pulpotomy group, root growth retardation was less common in HAP+PRP treated teeth (42.9%) than in HAP treated teeth (50%). In the pulpotomy group, retardation of root development was also less common in HAP+PRP treated teeth (25%) compared to HAP treated teeth (50%). There were differences between the pulpotomy and high pulpotomy groups, but without statistical significance. CONCLUSIONS: The application of endogenous growth factors in conjunction with the preservation of dental pulp vitality can result in a good outcome for pulp therapy of injured teeth, which means successfully completed apexogenesis.

Application of high-frequency radio waves to direct pulp capping.

INTRODUCTION: In vital pulp therapy such as direct pulp capping, clinical success rates depend on achieving hemostasis in exposed pulp tissue. For hemostasis of exposed pulp tissue, gentle pressure by cotton pellets moistened with sodium hypochlorite is most commonly used. However, more rapid and reliable methods are necessary. Therefore, we focused on high-frequency radio waves (HRW). METHODS: To evaluate reparative dentin induction by HRW, we used a rat direct pulp capping model and performed hemostasis by using HRW of several strengths, covering the pulp with calcium hydroxide as a direct capping agent. After 14 or 28 days, rats were killed, and reparative dentin and pulp inflammation were investigated histologically. RESULTS: Radio wave-induced hemostasis required less time when compared with the control group. Reparative dentin with regularly arranged dentinal tubules was observed in the HRW group. CONCLUSIONS: HRW induce hemostasis and produce high-quality reparative dentin and reduced pulpal inflammation.

Effects of folk medicinal plant extract Ankaferd Blood Stopper(®) in vital primary molar pulpotomy.

AIM: To compare the clinical and radiographic success rates of two vital pulpotomy agents: formocresol (FC) and Ankaferd Blood Stopper(®) (ABS), in primary molars during a 12-month follow-up period. STUDY DESIGN: A randomised, single-blind study design was used in a sample of 30 healthy 6-9 year old children with 60 carious primary molars without clinical or radiographic evidence of pulp degeneration. METHODS: The pulpotomy agents were assigned as follows: Group 1 was 1:5 diluted Buckley's formocresol (FC) and Group 2 was ABS. Clinical and radiographic follow-up at 3, 6, and 12 months used the following criteria: pain, swelling, sinus tract, mobility, internal root resorption, and furcation and/or periapical bone destruction. STATISTICS: The data were analysed using Chi-square tests. RESULTS: The clinical and radiographic evaluation at 3 months revealed total success rates of 100% in the FC and ABS groups. Success rates in FC and ABS groups at 6 months were 96.7% and 93.3% respectively. At the 12-month follow-ups, the total success rates in the FC, and ABS groups were 89.3% and 85.7%, respectively. When the groups were compared according to the time intervals, no significant differences were observed between the 3, 6, and 12 month values. The success rates of the materials decreased over time. CONCLUSIONS: FC and ABS were found successful as pulp dressings in primary molars. ABS appears to be an alternative pulpotomy agent but periodical follow-ups must be considered to evaluate long term success rates.

Effect of white mineral trioxide aggregate compared with biomimetic carbonated apatite on dentine bridge formation and inflammatory response in a dental pulp model.

AIM: To evaluate the effects of apatite precipitation on the biocompatibility and hard tissue induction properties of white mineral trioxide aggregate (WMTA) in a dental pulp model. METHODOLOGY: Pulp exposures were created on the axial walls of 32 sound canine teeth of eight dogs. Four additional sound teeth served as controls. The pulps were capped either with WMTA or apatite derivatives [biomimetic carbonated apatite (BCAp)] in the interaction of WMTA with a synthetic tissue fluid and restored with zinc oxide-eugenol cement. After 7 and 70 days, the animals were killed, and the histological specimens taken from the teeth were stained with haematoxylin and eosin for histomorphological evaluation. The Brown and Brenn technique was employed to stain bacteria. The data were subjected to nonparametric Kruskall-Wallis analysis and Mann-Whitney U_tests. RESULTS: Biomimetic carbonated apatite did not induce hard tissue bridge formation. WMTA performed significantly better than BCAp in this respect at both periods (P < 0.05). BCAp was associated with a significantly greater inflammatory response as compared with WMTA after 7 days (P < 0.05). Both materials were associated with similar reactions after 70 days (P >0.05). CONCLUSIONS: White mineral trioxide aggregate induced hard tissue formation via a mechanism other than that postulated via apatite formation.

Early response of mechanically exposed dental pulps of swine to antibacterial-hemostatic agents or diode laser irradiation.

OBJECTIVES: The purpose of this study was to compare the effectiveness of an antibacterial and hemostatic agent to diode laser irradiation in the healing of mechanically exposed porcine pulps. MATERIALS AND METHOD: The experiment required three adult swine (Sus scrofa domestica, Yorkshire) with 36 teeth prepared with occlusal penetrations into the pulpal tissues. The preparations were performed under general anesthesia and the pulps were exposed using high speed instrumentation with rubber dam isolation and a disinfected field. Following instrumentation the coronal pulpal tissue was amputated and immediately treated with ferric sulfate and chlorhexidine semi-gel (12), diluted Buckley' formocresol solution (12) for 5 minutes or laser irradiation with a diode laser (12). After treatment, hemostasis was obtained and a ZOE base applied to the treated pulps (36). The pulpal bases were all covered with a RMGI (Fuji II LC). The tissue samples were collected at 4 weeks (28 days). Following fixation, the samples were de-mineralized, sectioned, stained and histologically graded with a scale of 0-4. RESULTS: The treatment groups were statistically different with the Laser Treated Group demonstrating the least inflammation. CONCLUSION: Pulpotomy treatment with the KaVo Gentle Ray Diode Laser demonstrated significantly less inflammation than the other two pulpal therapy modalities. The ferric sulfate and chlorhexidine mixture demonstrated the greatest inflammation as histologically graded. Also, the histological sections of pulpotomized swine teeth treated with the ferric sulfate and chlorhexidine mixture presented with black pigmented areas in the pulp and surrounding tissue. The formocresol group (clinical standard) and the diode laser group did not present with the black precipitate.

Proliferation of rat molar pulp cells after direct pulp capping with dentine adhesive and calcium hydroxide.

The aim was to evaluate the proliferation of pulp cells 1, 3 and 7 days after direct pulp capping with the dentine adhesive Gluma Comfort Bond (GCB) and to compare it with calcium hydroxide (Ca(OH)(2)). An occlusal cavity was prepared in 72 molar teeth of 36 Wistar rats. Then GCB or Ca(OH)(2) was placed on the exposed pulp. All cavities were restored with composite. After 1, 3 and 7 days, the animals were sacrificed. One hour prior sacrification, 5-bromo-2'-desoxyuridine (BrdU) was injected into the intraperitoneal cavity for immunohistological analysis of 18 animals. BrdU was incorporated into the DNA to tag proliferating cells using an antibody staining. Three animals served as controls and were not further treated. The number of the tagged cells was statistically analysed by comparing the results of the three groups. In 18 rats, routine histological analysis was performed in order to evaluate the pulp tissue for bacterial infection, inflammatory cells and necrosis. The marked cells were identified as fibroblasts, endothelial cells (after 1, 3 and 7 days) and Höhl cells (after 7 days). One day after capping, significantly more cells were stained in the GCB than in the Ca(OH)(2) group (p < 0.05). After 3 days, significantly more cells were stained in the GCB than in the Ca(OH)(2) and the control group (p < 0.016). Direct contact of GCB with pulp tissue leads to an increased formation of granulation tissue (fibroblasts, endothelial cells) because of an inflammatory reaction. This may be explained by missing antibacterial effect and foreign body reactions. Also, GCB may have a negative effect on Höhl cells.

Tissue response to direct pulp capping with calcium hydroxide preceded by corticosteroid or corticosteroid/antibiotic dressing: a histological study in rats / Resposta do tecido pulpar à aplicação da pasta à base de hidróxido de cálcio precedida do emprego do curativo de corticosteróide ou corticosteróide/antibiótico: estudo histológico em ratos

Purpose: This study histologically evaluated the reaction of tooth pulp to treatment with calcium hydroxide in distilled water preceded by a corticosteroid (Decadron) or corticosteroid/antibiotic (Otosporin) dressing. Methods: Calcium hydroxide solution was applied to exposed tooth pulp for 5 min or for 72 h, using a sample of 120 molars of rats; histological examination was performed 7, 14, 30 and 60 days after treatment. Results: A mild inflammatory reaction was observed at 7 and 14 days whether the dressings were used for 5 min or for 72 h. When the corticosteroid/antibiotic dressing was used for 5 min, the tissue reaction and the mineralized barrier formed at 30 and 60 days were similar to those of animals in the control group. Use of the corticosteroid dressing for 5 min or 72 h or the corticosteroid/antibiotic dressing for 72 h delayed healing of the pulp tissue. Conclusion: Temporary dressings resulted in a milder inflammatory reaction during the early postoperative period. The tissue reaction and the quality of the barrier formed when the Otosporin temporary dressing was applied for 5 min were similar in the experimental and the control groups at longer postoperative periods. Temporary dressings of Decadron applied for 5 min or 72 h or Otosporin applied for 72 h caused a slight retardation of the healing process of the tissue that was apparent 30 days after the intervention.

Objetivo: Avaliar a reação pulpar à pasta de hidróxido de cálcio em água destilada, precedida de curativo de corticosteróide (Decadron) ou corticosteróide/antibiótico (Otosporin) por 5 min ou 72 h. Metodologia: Em 120 polpas de dentes de ratos expostas, a análise histológica foi realizada após 7, 14, 30 e 60 dias de cada tratamento. Resultados: Nos períodos iniciais observou-se leve reação inflamatória quando os curativos foram aplicados por 5 min ou 72 h. A reação tecidual e a barreira formada sob ação do hidróxido de cálcio após o curativo de Otosporin por 5 min foram semelhantes àquelas do grupo controle aos 30 e 60 dias. Os curativos de demora com Decadron por 5 min e 72 h e Otosporin por 72 h promoveram retardo no processo de reparação. Conclusão: Os curativos de demora promoveram reação inflamatória mais suave nos períodos iniciais de análise. A reação tecidual e a qualidade da barreira formada sob a ação do Otosporin por 5 min foram semelhantes àquelas do grupo controle nos períodos pós-operatórios mais longos. Os curativos de demora com Decadron por 5 min e 72 h e Otosporin por 72 h promoveram ligeiro retardo no processo de reparação tecidual a partir de 30 dias.

Histological evaluation of direct pulp capping with a self-etching adhesive and calcium hydroxide on human pulp tissue.

AIM: To evaluate human pulp tissue response following direct pulp capping with a self-etching adhesive: Clearfil SE BOND (SB). METHODOLOGY: Forty-five sound teeth from 20 subjects were used. Forty-one teeth had their pulp mechanically exposed at the base of a Class 1 cavity preparation and were divided into two groups: group 1, teeth were capped with SB (n = 21), and group 2, with calcium hydroxide cement (CH) (n = 20). Four teeth were maintained intact as an untreated control group. After 7, 30 and 90 days, respectively, 15 teeth were extracted and processed for light microscopic examination. Pulp healing and bacterial microleakage were assessed by haematoxylin and eosin, Masson trichrome and Brown and Brenn stain techniques. The data were analysed statistically by using the Mann-Whitney U test. RESULTS: After the 7-day observation period, the inflammatory reaction in the SB group was slight and significantly less severe than that of the CH group (P < 0.05). After the 30- and 90-day observation periods, the inflammatory reaction was slight in both groups, but specimens with dentine bridge formation in the SB group were significantly less common than those in the CH group (P < 0.05). CONCLUSIONS: Clearfil SB had good biocompatibility with human pulp tissue, but its ability to induce reparative dentine was significantly lower than that of calcium hydroxide.

Comparison of enamel matrix derivative versus formocresol as pulpotomy agents in the primary dentition.

The purpose of this study was to compare the clinical and radiographic success rates of two different pulpotomy agents: one novel agent, the biologically active odontogenic protein enamel matrix derivative (EMD) versus formocresol (FC). A randomized, single-blind, split-mouth study was used with a sample of 15 children aged 4 to 7 years (mean age, 5 +/- 0.73 years). A total of 15 pairs of teeth, 1 pair per child, were selected for treatment. One tooth from each pair was randomly assigned to either the EMD pulpotomy group or the FC pulpotomy group. All teeth were followed up clinically and radiographically at 2, 4, and 6 months. After 6 months, the clinical success rates for the FC and EMD groups were 67% and 93%, respectively. Although most likely clinically relevant, the clinical success rate difference after 6 months was not statistically significant. After 6 months, the radiographic success rates for the FC and EMD groups were 13% and 60 %, respectively. There was a statistically significant difference at p < or = 0.05. The clinical and radiographic assessment of EMD pulpotomized teeth in this study offers preliminary evidence that EMD is a promising material which may be as successful, or more so, than other pulpotomy agents.

Response of human pulps capped with different self-etch adhesive systems.

The aim of this study was to evaluate the response of human pulps capped with a calcium hydroxide hard-setting cement or with two-step self-etch adhesive systems. Pulp exposures were performed on the occlusal floor, and the bleeding control was performed with saline solution. The exposed pulp tissue was capped with Clearfil LB 2V (2V) or Clearfil SE Bond (SE) and restored with a composite resin. In control group, the pulpal wound was capped with Ca(OH)(2) cement and restored with Clearfil LB 2V or Clearfil SE Bond + composite resin. After 30 and 90 days, the teeth were extracted, processed for hematoxylin and eosin, and categorized in a histological score system. The pulpal response was worse for groups capped with the self-etch adhesive systems (2V and SE) in both periods of evaluation, when compared to their respective control groups at 90 days (p < 0.05). For both self-etch systems evaluated, the pulp tissue exhibited moderate to severe inflammatory cell infiltrate involving the coronal pulp with chronic abscesses. Dentin bridging was observed in a few specimens. For the calcium hydroxide groups, almost all specimens showed dentin bridge formation, with few scattered inflammatory cells and normal tissue below the pulp exposure site. Calcium hydroxide should be used as the material of choice for pulp capping, and the use of two-step self-etch adhesives for human pulp capping is contraindicated.

Formation of dentin-like particles in dentin defects above exposed pulp by controlled release of fibroblast growth factor 2 from gelatin hydrogels.

The induction of dentin formation on exposed dental pulp is a major challenge in research on the regeneration of the dentin-pulp complex. We examined the effects of fibroblast growth factor 2 (FGF2), which was delivered in either a collagen sponge (noncontrolled release) or incorporated into gelatin hydrogels (controlled release), on the formation of dentin in exposed rat molar pulps. During the early phase of pulp wound healing, pulp cell proliferation and invasion of vessels into dentin defects above exposed pulp were induced in both groups. In the late phase, the induction of dentin formation was distinctly different between the 2 types of FGF2 release. The noncontrolled release of free FGF2 from collagen sponge induced excessive reparative dentin formation in the residual dental pulp, although dentin defects were not noted. In contrast, controlled release of FGF2 from gelatin hydrogels induced the formation of dentin-like particles with dentin defects above exposed pulp. These results suggest the possibility of a novel therapeutic approach for dentin-pulp complex by controlled release of bioactive FGF2.