Hard tissue formation in pulpotomized primary teeth in dogs with nanomaterials MCM-48 and MCM-48/hydroxyapatite: an in vivo animal study

BACKGROUND

This animal study sought to evaluate two novel nanomaterials for pulpotomy of primary teeth and assess the short-term pulpal response and hard tissue formation in dogs. The results were compared with mineral trioxide aggregate (MTA).

METHODS

This in vivo animal study on dogs evaluated 48 primary premolar teeth of 4 mongrel female dogs the age of 6-8 weeks, randomly divided into four groups (n = 12). The teeth underwent complete pulpotomy under general anesthesia. The pulp tissue was capped with MCM-48, MCM-48/Hydroxyapatite (HA), MTA (positive control), and gutta-percha (negative control), and the teeth were restored with intermediate restorative material (IRM) paste and amalgam. After 4-6 weeks, the teeth were extracted and histologically analyzed to assess the pulpal response to the pulpotomy agent.

RESULTS

The data were analyzed using the Kruskal‒Wallis, Fisher's exact, Spearman's, and Mann‒Whitney tests. The four groups were not significantly different regarding the severity of inflammation (P = 0.53), extent of inflammation (P = 0.72), necrosis (P = 0.361), severity of edema (P = 0.52), extent of edema (P = 0.06), or connective tissue formation (P = 0.064). A significant correlation was noted between the severity and extent of inflammation (r = 0.954, P < 0.001). The four groups were significantly different regarding the frequency of bone formation (P = 0.012), extent of connective tissue formation (P = 0.047), severity of congestion (P = 0.02), and extent of congestion (P = 0.01). No bone formation was noted in the gutta-percha group. The type of newly formed bone was not significantly different among the three experimental groups (P = 0.320).

CONCLUSION

MCM-48 and MCM-48/HA are bioactive nanomaterials that may serve as alternatives for pulpotomy of primary teeth due to their ability to induce hard tissue formation. The MCM-48 and MCM-48/HA mesoporous silica nanomaterials have the potential to induce osteogenesis and tertiary (reparative) dentin formation.

Histological evaluation of the regenerative potential of a novel photocrosslinkable gelatin-treated dentin matrix hydrogel in direct pulp capping: an animal study

BACKGROUND

To assess histologically the success of the pulp capping approach performed in traumatically exposed dogs' teeth using a novel injectable gelatin-treated dentin matrix light cured hydrogel (LCG-TDM) compared with LCG, MTA and TheraCal LC.

METHODS

Sixty-four dogs' teeth were divided into two groups (each including 32 teeth) based on the post-treatment evaluation period: group I: 2 weeks and group II: 8 weeks. Each group was further subdivided according to the pulp capping material into four subgroups (n = 8), with subgroup A (light-cured gelatin hydrogel) as the control subgroup, subgroup B (LCG-TDM), subgroup C (TheraCal LC), and subgroup D (MTA). Pulps were mechanically exposed in the middle of the cavity floor and capped with different materials. An assessment of periapical response was performed preoperatively and at 8 weeks. After 2 and 8-week intervals, the dogs were sacrificed, and the teeth were stained with hematoxylin-eosin and graded by using a histologic scoring system. Statistical analysis was performed using the chi-square and Kruskal-Wallis tests (p = 0.05).

RESULTS

All subgroups showed mild inflammation with normal pulp tissue at 2 weeks with no significant differences between subgroups (p ≤ 0.05), except for the TheraCal LC subgroup, which exhibited moderate inflammation (62.5%). Absence of a complete calcified bridge was reported in all subgroups at 2 weeks, while at 8 weeks, the majority of samples in the LCG-TDM and MTA-Angelus subgroups showed complete dentin bridge formation and absence of inflammatory pulp response with no significant differences between them (p ≤ 0.05). However, the formed dentin in the LCG-TDM group was significantly thicker, with layers of ordered odontoblasts identified to create a homogeneous tubular structure and numerous dentinal tubule lines suggesting a favourable trend towards dentin regeneration. TheraCal LC samples revealed a reasonably thick dentin bridge with moderate inflammation (50%) and LCG showed heavily fibrous tissue infiltrates with areas of degenerated pulp with no signs of hard tissue formation.

CONCLUSIONS

LCG-TDM, as an extracellular matrix-based material, has the potential to regenerate dentin and preserve pulp vitality, making it a viable natural alternative to silicate-based cements for healing in vivo dentin defects in direct pulp-capping procedures.

A comparative study of efficacy of single rooted and double rooted teeth in age estimation using dentin translucency

BACKGROUND

Among various methods of age estimation using dental tissues, measurement of root dentin translucency (RDT) is said to be the most accurate. Numerous studies have estimated age by measuring RDT in single and double rooted teeth and have shown conflicting results. Only few studies have compared efficacy of using single and double rooted teeth for RDT measurement in age estimation.

AIM

To analyze the efficacy of single rooted teeth (SRT) and double rooted teeth (DRT) for measurement of sclerotic dentin (SD) and age estimation.

METHOD

Study was conducted on 120 freshly extracted SR and DR teeth with 60 teeth in each group. Ground sections of 150 µ thickness were observed under stereomicroscope and photographed. The sclerotic dentin length was measured on the images captured using image analysis software.

RESULTS AND CONCLUSION

The present study did not reveal significant difference (p = 0.012) between SRT and DRT when RDT was used for age estimation. However DRT provided more accurate age estimation than SRT with less mean age difference.

Complication After Extraction of Natal Teeth with Continued Growth of a Dental Papilla

The purposes of this case report were to describe a growing two-cm gingival mass that developed after natal teeth were extracted in a four-month-old female patient, present a review of the literature on the growth of a gingival mass after the extraction of natal teeth, and illustrate the clinical and histological features that differentiate this condition from other types of gingival masses in infants. Histological examination of the excised mass revealed that it contained tooth-like hard tissue (regular and irregular dentin) that intermingled with bone, dental pulp, and fibrous tissue. We found eight cases from 1962 to 2009 in which a soft-tissue mass with dentin-like hard tissue or a tooth-like structure had developed after the extraction of natal teeth. Based on clinical and histological findings, we deduced that the mass was the result of abnormal growth of a residual dental papilla, including mesenchymal stem cells. Consequently, dentists, obstetricians, gynecologists, and pediatricians should be aware of this potential complication and observe caution before they extract natal teeth.

Preliminary Evaluation of Platelet Rich Fibrin-Mediated Tissue Repair in Immature Canine Pulpless Teeth

OBJECTIVE

To evaluate the use of platelet-rich fibrin (PRF) in the regenerative therapy of immature canine permanent teeth.

METHODS

Eight immature premolars of beagle dogs were pulp extracted and cleaned with irrigation, then divided into two groups of empty root canals and those filled with a PRF clot. All of the eight premolars were sealed with mineral trioxide aggregate and glass ionomer cement. Two premolars were left naturally grown as a positive control. The root development was assessed radiographically and histologically after 12 weeks.

RESULTS

The radiological findings showed greater increases in the thickness of lateral dentinal wall in the PRF group than in the vacant group. Histologically, dental-associated mineral tissue, connective tissue, and bone-like mineral tissue grew into the root canals independent of PRF clot use. The PRF was able to increase the thickness of dental-associated mineral tissue. However, the vital tissue differed from the pulp dentin complex.

CONCLUSION

Our study demonstrated the feasibility of using PRF-mediated regenerative therapy in pulpless immature teeth for improving tissue repair.

[Enamel pearls]

Enamel pearls are paraplasia. This refers to the formation of enamel at an atypical localisation. Enamel pearls are roundish or crescent-shaped structures. They are most frequently found in the root area of deciduous molars and molars. A distinction is made between true and compound enamel pearls.

MM-MTA for direct pulp capping: a histologic comparison with ProRoot MTA in rat molars

AIM

To compare the histomorphological response of rat dental pulps capped with MM-MTA and ProRoot MTA at 1, 2 and 4 weeks postoperatively.

MATERIALS AND METHODS

Direct pulp capping with MM-MTA and ProRoot MTA, overlaid with light-cured composite resin, was performed on right and left maxillary first molars of 20 Wistar rats. Animals were killed at 1, 2 and 4 weeks postoperatively. Biopsy samples were stained and viewed by light microscopy to determine dentin bridge formation. Data were statistically evaluated with the Kruskal-Wallis test (p < 0.05).

RESULTS

Absence of dentin bridge formation at 1 week, partial dentin bridge formation at 2 weeks and complete dentin bridge formation at 4 weeks are observed with MM-MTA and ProRoot MTA. The results showed no statistically significant difference between both materials at 4 weeks.

CONCLUSION

Both materials produced similar responses in the pulp when used for pulp capping in intact, caries-free molars of rats.

Incomplete caries removal and indirect pulp capping in primary molars: a randomized controlled trial

PURPOSE

To compare the effect of incomplete caries removal (ICR) and indirect pulp capping (IPC) with calcium hydroxide (CH) or an inert material (wax) on color, consistency and contamination of the remaining dentin of primary molars.

METHODS

This double-blind, parallel-design, randomized controlled trial included 30 children presenting one primary molar with deep caries lesion. Children were randomly assigned after ICR to receive IPC with CH or wax. All teeth were then restored with resin composite. Baseline dentin color and consistency were evaluated after ICR, and dentin samples were collected for contamination analyses using scanning electron microscopy. After 3 months, restorations were removed and the three parameters were re-evaluated. In both groups, dentin became significantly darker after 3 months.

RESULTS

No cases of yellow dentin were observed after 3 months with CH compared to 33.3% of the wax cases (P < 0.05). A statistically significant difference over time was observed only for CH regarding consistency. CH stimulated a dentin hardening process in a statistically higher number of cases than wax (86.7% vs. 33.3%; P = 0.008). Contamination changed significantly over time in CH and wax without significant difference between groups. It was concluded that CH and wax arrested the carious process of the remaining carious dentin after indirect pulp capping, but CH showed superior dentin color and consistency after 3 months.

Strategy for apexification of wide-open apex associated with extensive periapical lesion in a weakened root

This case report describes successful apexification for a challenging case involving a 30-year-old man, who suffered from dental trauma involving tooth No. 7 (which had occurred several years earlier) and recently experienced acute periapical abscess in this region. Radiographic analysis revealed incomplete root formation, a wide-open apex, thin root canal walls, and an extensive periapical lesion. Chemomechanical debridement was performed gently using K-files and irrigation with a 1% sodium hypochlorite solution. The root canal was filled with a calcium hydroxide paste, which was replaced periodically. At 18 months post-treatment, an apical barrier tissue and significant reduction of periapical radiolucency were observed; at that time, the entire root canal was filled with gray mineral trioxide aggregate (MTA). At a follow-up 16 months later, the tooth had normal function and periapical repair was complete.

Resorption pattern and radiographic diagnosis of invasive cervical resorption. A correlative microCT, scanning electron and light microscopic evaluation of a case series

The aim of this study was to evaluate, whether and how the histologic structure of invasive cervical resorption (external granulomas) affect their clinical radiographic diagnosis. For this purpose, nine more or less intact extracted teeth, of which intraoral radiographs were available, were processed for examination in the scanning electron (SEM) and light microscope. From some of the specimens non-decalcified ground sections were prepared and some were decalcified for preparation of histologic sections. Five teeth were scanned in an X-ray microtomography (microCT) device and digitally reconstructed in three dimensions. Three histologic characteristics, namely (1) the location and extension of the resorptive defect, (2) the size of the communication with the periodontium, and (3) the amount of mineralized substitution tissue formed in the lesion affected the radiographic diagnosis. At early and advanced stages, invasive cervical resorption had encircled the pulp cavities, however, without destroying the innermost dentin. Even if the dentinal wall adjacent to the pulp was histologically intact and thick, this important diagnostic feature frequently could not be recognized in conventional radiographs. Also, the communication between the resorptive lesion and the periodontium often was not visible radiographically, although it could always be identified in the microscopic evaluation, particularly at early stages when it proved to be very small. Invasive cervical resorption lesions containing large amounts of mineralized substitution tissue were difficult to recognize and, therefore, could easily be overseen. Thus, three features which are deemed essential for the differential diagnosis of invasive cervical resorption were not readily apparent in conventional radiographs. From these three features, the dentinal wall against the pulp cavity and the communication to the peri-odontium were, however, clearly visible in the microCT reconstructions.

A new index to measure tooth wear--methodolgy and practical advice

A new tooth wear index, designed to measure stages of tooth wear in enamel and dentine is presented. The index measures the lateral spread of wear in enamel and the depth of tooth wear in dentine. The index scores enamel loss at 5 levels and 6 levels in dentine and provides a more sensitive index for monitoring the progression of wear than older indices. The protocols and methods of the index are described and incorporate refinements based on the combined experiences of two independent studies conducted on adults and children. The findings of both studies are summarised and recommendations are made for future studies which investigate the prevalence of tooth wear in adults or children.

Nanohydroxyapatite used as a pulpotomy and direct pulp capping agent in primary pig teeth

PURPOSE

Recently, a fully Nanocrystalline Hydroxyapatie (NHA) paste has been introduced for augmentation procedures in osseous defects and is attracting increasing interest in medicine and dentistry. The purpose of the present study was to assess and compare the pulp response of pig primary teeth after capping with NHA and formocresol in pulpotomy and NHA and calcium hydroxide in direct pulp capping.

METHODS

Forty teeth of two 4-month old pigs were pulpotomized and capped with these materials. Four weeks later, the animals were euthanized and the specimens were prepared for histological examination.

RESULTS

In the pulpotomy groups, there was a significant difference between NHA and FC in terms of pulp response, hard tissue formation and normal pulp tissue preservation. In the direct pulp capping groups, there was no significant difference between NHA and Ca(OH)2 in terms of criteria mentioned above.

CONCLUSIONS

The results of the present histological study show that, in the short term and in non-carious pig teeth, NHA appears to be biocompatible and provokes no moderate or severe inflammatory reaction in pulp tissue in both pulpotomy and direct pulp capping treatments.

Mechanical characterization of sclerotic occlusal dentin by nanoindentation and nanoscratch

PURPOSE

To evaluate the mechanical properties of occlusal wear lesions identified as sclerotic.

METHODS

Nanoindentation and nanoscratch techniques have been applied to determine elastic modulus (E), hardness (H) and wear resistance of different types of sclerotic dentin. Nanoscratch testing was applied to evaluate the tribological behavior. Mechanical properties of sclerotic dentin were evaluated together with scanning electron micrographs to show the different degree of tubular occlusion.

RESULTS

The higher the degree of sclerosis, the lower were the measured mechanical properties. The highest values (E = 20 GPa and H = 0.67 GPa) were obtained in normal dentin, and the lowest (E = 11.4 GPa and H = 0.51 GPa) in severe sclerotic lesions. These differences were statistically significant (P<0.05). The groove width in the nanoscratch tests was also higher for moderate or severe sclerosis than for normal dentin.

A histologic investigation of direct pulp capping in rodents with dentin adhesives and calcium hydroxide

OBJECTIVE

To investigate reactions of pulp tissue when in contact with the dentin adhesives Resulcin AquaPrime + MonoBond (RAPMB, Merz Dental), Scotchbond 1 (SB1, 3M ESPE), and Gluma Comfort Bond (GCB, Heraeus Kulzer) in comparison with calcium hydroxide after 1 to 70 days.

METHOD AND MATERIALS

An occlusal cavity was prepared in 152 molars of 76 Wistar rats. The pulps were exposed and dentin adhesives placed on the pulp tissue of 10 molars for each dentin adhesive group and time period. Eight molars per time period served as controls and were capped with calcium hydroxide. All cavities were restored with composite resin. The animals were sacrificed 1, 3, 7, and 70 days after pulp capping. Pulp tissue was histologically evaluated for the following criteria: bacterial infection, inflammatory cells, necrosis, and reparative dentin. The data were statistically evaluated using the Kruskal-Wallis test (P < .05).

RESULTS

Overall, significantly more bacterial infections were detected 1, 3, 7, and 70 days after pulp capping with dentin adhesive (P < .05). In all dentin adhesive groups, 1 day after direct pulp capping, significantly more inflammatory cells were found, whereas after 7 days, this was only the case for the SB1 group (P < .05). After 70 days, capping with calcium hydroxide resulted in significantly less necrosis than with RAPMB and SB1 (P < .05). Regarding necrosis, SB1 showed the worst results: Pulp necrosis occurred significantly more often than with calcium hydroxide and GCB (P < .05). After the application of calcium hydroxide, significantly more reparative dentin formation occurred (P < .05).

CONCLUSION

Direct pulp capping with calcium hydroxide seems to produce remarkably better results than with dentin adhesive.

[Comparative study on dogs between CO2 laser and conventional technique in direct pulp capping]

Three dogs have been used in this experiment. Class V cavities were made in sixty teeth. A pulpal communication was provoked intentionally in these cavities. Teeth were randomly split in 2 groups (30 teeth for each). On first group, the pulp bleeding was stopped until appearance of coagulum on exposed pulp surfaces by means of CO2 laser irradiation (Output Power: 3 W, Pulse duration: 0.1 sec, frequency: 1 Hz, spot size diameter: 0.3 mm, Energy density: 425 J/cm2). Calcium Dihydroxide was deposited followed by a temporary filling (IRM, Dentsply, De Trey, Germany). In the second group, the calcium Dihydroxide was deposited directly on exposed bleed pulp (conventional technique) followed by the same temporary filling. Ten weeks later, all teeth were extracted and prepared for histological study.

RESULTS

93% of treated teeth preserved their pulp vitality in the group treated with CO2 laser for direct pulp capping versus 82% in the group treated by conventional technique. The average of the thickness of the dentinal bridge newly formed was 391.5 +/- 33 microm for teeth irradiated with laser and 294.1 +/- 28 microm for teeth treated by conventional technique. The thickness of the dentinal bridge newly formed in teeth treated by means of CO2 laser was 33% more important than in those treated by the conventional technique. Statistical analysis showed a significant difference between the averages of values in all groups (p < 0.05). To conclude, CO2 Laser use in the direct pulp capping increases significantly the percentage of pulp vitality preservation and the thickness of the dentinal bridge newly formed after pulp exposition.

Cytotoxic effects and pulpal response caused by a mineral trioxide aggregate formulation and calcium hydroxide

PURPOSE

To evaluate the in vivo pulpal response after pulpotomy with different capping agents. In addition, the in vitro cytotoxic effects of both materials were assessed by applying them on culture of pulp cells.

METHODS

For the in vivo test, the coronal pulp of 28 teeth of dogs was mechanically removed and the root pulps were capped with the following dental materials: Group 1: Pro-Root MTA (PRMTA); and Group 2 (control): calcium hydroxide saline paste (CH). After 60 days, the animals were sacrificed and the teeth processed for histological analysis. In the in vitro test, experimental extracts obtained from both capping agents were applied on the cultured MDPC-23 odontoblast-like cells.

RESULTS

In the root pulps capped with PRMTA or CH, coagulation necrosis partially replaced by dystrophic calcification as well as tubular dentin matrix laid down by elongated pulp cells was observed. None or mild inflammatory response occurred beneath the capped pulpal wound. Regarding the pulpal response, PRMTA and CH presented no statistical difference. However, the teeth capped CH presented greater healthy pulp loss which resulted in convex shape of the hard barrier than PRMTA. When applied on the cultured cells, it was demonstrated that PRMTA and CH solutions decreased the cell metabolic activity by 9.9% and 29.4%, respectively. CH caused higher cytotoxic effects to the MDPC-23 cells as well as deeper healthy pulp tissue loss than PRMTA. However, similar sequence of healing occurred after pulpotomy with both dental materials.

Histological evaluation of mineral trioxide aggregate and calcium hydroxide in direct pulp capping of human immature permanent teeth

PURPOSE

To evaluate histological findings in human immature permanent premolars scheduled for extraction for orthodontic reasons, in which mechanical pulp exposures were capped with white ProRoot Mineral Trioxide Aggregate (WMTA) or calcium hydroxide (CH).

METHODS

Forty-eight human immature premolars in 23 patients (age 10-18 years) were randomly treated with WMTA or CH. After rubber dam isolation Cl I cavities were prepared and the pulps exposed. After hemostasis the pulps were capped with either material. The preparations were restored using an acid etch, bonding agent, flowable composite and composite resin technique. The teeth were extracted after 47 to 609 days and processed for routine histological examination, stained with hematoxylin and eosin and Brown and Brenn for recognition of bacteria. Statistical analyses of inflammation, bridge formation and bacterial leakage were performed using a Chi-square test and ANOVA.

RESULTS

Forty-four of 48 teeth were suitable for microscopic evaluation, 30 with WMTA, 14 with CH. Of the WMTA group, 29 teeth were vital, 28 had formed a bridge, and one specimen had failed. Twelve of 14 teeth with CH were vital, while three teeth failed to form a bridge. No statistically significant differences between WMTA and CH were found, except for superficial and deep inflammatory cell response (P < or = 0.05). Pulp capping of intentionally exposed human immature premolars performed slightly better when using MTA.

The caries process and its effect on the pulp: the science is changing and so is our understanding

The understanding of the caries process and its effect on the pulp is presented in the context that caries does develop in various rates of progression. Early in the caries process, the pulp reflects changes within lesion activity. Thus, the early pulp response is reversible. Later, the rate of caries progression is reflected by the quality of the tertiary dentin. Slowly progressing lesions create tertiary dentin resembling normal tubular dentin. Rapidly progressing lesions lead to the production of a tubular dentin or complete absence of tertiary dentin, as well as pulp necrosis and apical pathology Finally, the nature of the untreated deep carious lesion is on ecosystem that might undergo significant changes. The untreated lesion is temporarily converted from an active and closed lesion environment into one that is open and slowly progressing. The analysis of untreated carious lesions has transformed the treatment philosophy of deep carious lesions.

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.

Effects of hemostatic agents on the histomorphologic response of human dental pulp capped with calcium hydroxide

OBJECTIVE

To evaluate the response of human pulps capped with a calcium hydroxide [Ca(OH)2] cement after bleeding control with 2 hemostatic agents.

METHOD AND MATERIALS

Pulps were exposed on the occlusal floor, and the bleeding was controlled either with saline solution (SS) or 2.5% sodium hypochlorite (NaOCl) (SH). After that, the pulp was capped with Ca(OH)2 cement and restored with resin composite. After 30 (groups SS30 and SH30) and 60 (groups SS60 and SH60) days, the teeth were extracted and processed with hematoxylin-eosin and categorized in a histologic score system. The data were subjected to Kruskal-Wallis and Mann-Whitney tests (alpha = .05).

RESULTS

Regarding dentin bridge formation, an inferior response of SH60 group was observed when compared to SS60 (P < .05). The response of the SH30 group generally was similar to that of the groups treated with saline solution. However, after 60 days, 2.5% NaOCl showed a trend toward having an inferior response.

CONCLUSION

Using saline solution as a hemostatic agent before pulp capping with Ca(OH)2 resulted in a significantly better histomorphologic response than using 2.5% NaOCl as a hemostatic agent before capping with Ca(OH)2.

Equivalency study of histological responses to complete or partial pulpotomies in inflamed baboon immature first permanent molars

Partial pulpotomy is an accepted treatment for traumatised incisor teeth with exposed pulps. Clinical studies in humans suggest that this may also be an acceptable technique for carious exposed pulps in molar teeth, but objective histological evidence to support this perception is lacking.

OBJECTIVE

To compare histological responses to complete or partial pulpotomies of inflamed pulps in immature baboon first permanent molar teeth.

METHODS

An experimental study in the baboon (Papio ursinus). Pulpitis was induced with fresh Streptococcus mutans placed into occlusal cavities with a small pulpal exposure in 34 first permanent molars of 9 juvenile baboons. After 14 days a pulpotomy, either complete or partial, was performed on the same molars in contra-lateral quadrants using calcium hydroxide covered with IRM and amalgam. After 90 days specimens were harvested and examined under the light microscope with the examiner blind to the treatment.

RESULTS

Reaction frequencies in the complete and partial pulpotomy teeth were: dentine bridges 9/16 and 10/16, viable pulp in root canals 10/16 and 13/18, peri-apical abscesses 3/13 and 4/13. Fisher's exact probability test showed no statistically significant rates between the groups.

CONCLUSIONS

Complete or partial pulpotomy of inflamed pulps in immature baboon first permanent molars produced comparable reactions.

Histologic evaluation of pulpotomy performed with ethyl-cyanoacrylate and calcium hydroxide

The aim of this study was to evaluate histological aspects of the pulp-dentin complex of dogs submitted to pulpotomy and capped with ethyl-cyanoacrylate and calcium hydroxide. Thirty dog teeth were divided into 2 groups of 15 as follows: Group 1 - ethyl-cyanoacrylate; Group 2 - calcium hydroxide. The pulpotomies were carried out following all of the treatment precautions recommended for dogs. After 30 days the specimens were submitted to histological preparation and were then blindly evaluated by a histologist. Data were analyzed statistically by the Fisher exact test, comparing the two groups. After 30 days, the presence of a hard tissue barrier was observed in 83.3% of Group 1, and in 100% of Group 2 (p = 0.478). A continuous hard tissue barrier was observed in 50% of the ethyl-cyanoacrylate group and 75% of the calcium hydroxide group (p = 0.652). It can be concluded that both materials induced hard tissue barrier formation, but Group 2 had a higher percentage than Group 1, with no significant statistical differences; the differences observed between the different barriers (continuous/non-continuous) were not significant between groups and there was no pulpal necrosis in either group.

Find canals faster through basic research

Achieving access and finding canals are the key first steps in the endodontic procedure. This has always been a time-consuming, qualitative procedure that relies on the dentist's experience and feel. Recent basic research has been published that shows that the anatomic morphological measurements concerning the pulp chamber are very consistent in every tooth. This research points the way to a quantitative, predictable and quick technique for making endodontic access preparations without risk. The research and clinical technique are described in this article.

Human pulpal response to mineral trioxide aggregate (MTA): a histologic study

The purpose of this study was to study the histologic changes in the dental pulp following pulpotomy with Mineral Trioxide Aggregate (MTA) and Calcium hydroxide. Pulpotomies were performed on premolar teeth that were to be extracted for orthodontic reasons. The radicular pulp was capped with either MTA or Calcium hydroxide and restored with IRM. The teeth were extracted at 4 and 8 week intervals, fixed in 10% formalin and then kept in 5% nitric acid for 28 days for demineralization. Longitudinal sections were then prepared and viewed under light microscope. The pulps capped with MTA (at the end of 4 weeks and 8 weeks) showed dentin bridge formation which was more homogenous and continuous with the original dentin when compared to the pulps capped with calcium hydroxide. The pulpal inflammation was also less in the MTA group as compared to the calcium hydroxide group at the end of 4 and 8 weeks.