Pink Spot - Literature Review and Case Report.

BACKGROUND: Pink spots in teeth were first described by Mummery in 1920, and were related to resorption. Resorption is a pathologic process that often eludes the clinician with its varied etiologic factors and diverse clinical presentations. Resorption can be generally classified as internal and external resorption. Internal resorption has been described as a rare occurrence as compared to external resorption. CASE REPORT: This article describes a pink spot that was diagnosed as a progressing resorption process. Early diagnosis enabled a successful management of the lesion. CONCLUSION: Early diagnosis and treatment of an internal resorption, clinically seen as a pink spot, in a primary central incisor may prevent its fast progress and subsequent loss.

Human pulp responses to in-office tooth bleaching.

OBJECTIVE: To evaluate and compare the responses of human incisor and premolar pulps after bleaching. STUDY DESIGN: A bleaching agent with 38% hydrogen peroxide (H(2)O(2)) was applied on the buccal surface of 10 sound lower teeth (G1: 6 premolars; G2: 4 incisors) for 45 minutes. Three premolars and 3 incisors that received only rubber/pumice prophylaxis were used as control groups G3 and G4, respectively. Two days after the bleaching procedure, the teeth were extracted and processed for histologic evaluation. RESULTS: Only in G2 (4 incisors) were any changes in the pulp detected. In the coronal pulp there was a large zone of coagulation necrosis. The radicular pulp showed mild inflammatory changes manifested as an accumulation of mononuclear cells around congested and dilated blood vessels. No pulpal damage was seen in either of the control groups (G3 and G4) or in group G1. CONCLUSION: Bleaching with 38% H(2)O(2) for 45 minutes causes irreversible pulp damage in lower incisors but not in premolars.

Apexification of non-vital pre-molar stemming from possible dens evaginatus.

Dens evaginatus is a dental anomaly that occurs more commonly in pre-molar teeth. Although not a cause for alarm in most instances, it can lead to serious consequences if it is damaged. This paper explores the treatment of a necrotic pre-molar with an open apex that caused serious facial swelling in an adolescent patient. It is believed that this swelling was the result of an enamel tubercle, or dens evaginatus, which was knocked off or traumatized.

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.

The current opinions and use of MTA for apical barrier formation of non-vital immature permanent incisors by consultants in paediatric dentistry in the UK.

The purpose of the study was to assess the current opinions and usage of mineral trioxide aggregate (MTA) for apical barrier formation of non-vital immature permanent teeth by consultants in paediatric dentistry in the UK. A semi-structured postal questionnaire was sent to all known consultants in paediatric dentistry in the UK. The response rate was 78.6% (44 of 56). Thity-eight consultants (86.3%) agreed that the use of this material was a good idea with 68.2% having used or arranged for its use in apical barrier formation. Forty-two consultants (95.5%) agreed that reduced number of visits was an advantage to the technique, with only 34.1% agreeing that this procedure was less likely to weaken the tooth and 63.6% agreed that material and equipment costs were a drawback and 50% agreed that lack of available evidence was a disadvantage to its use. The results from this study give an indication of the extent of MTA use by consultant-led services in paediatric dentistry in the UK and highlights the need for a multi-centre randomised controlled clinical trial.

Evaluating a method of artificially hypermineralizing dentin to simulate natural conditions in bonding studies.

PURPOSE: This study tested an in vitro model of dentin hypermineralization, aiming to simulate naturally hypermineralized dentin for bond strength studies. The effect on bond strength of a double-etching treatment on the artificially hypermineralized substrate was also evaluated. MATERIALS AND METHODS: Extracted human third molars were selected and 2 groups were formed: a group of 3 teeth, called N (normal dentin) and a group of 6 teeth, called H (hypermineralized dentin). Occlusal surfaces were ground flat to expose midcoronal dentin. Group H was subjected to artificial hypermineralization and subdivided into 2 subgroups: Ht and Hd. The exposed dentinal surfaces of group N and subgroup Ht were etched with 37% phosphoric acid for 15 s prior to bonding with Single Bond adhesive. Dentin of the subgroup Hd was etched twice (double etching) prior to bonding with Single Bond. A 4-mm-high Z100 composite buildup was created on each tooth and, after 24 h water storage, bond strengths were evaluated by the microtensile method. The data between group N and subgroup Ht and between subgroups Ht and Hd were compared using the Student's t test (alpha = 0.05). RESULTS: No significant difference was observed between bond strengths of group N and subgroup Ht (p = 0.108). Subgroup Hd was statistically different from Ht (p < 0.0001). CONCLUSIONS: Bond strengths of Single Bond to artificially hypermineralized dentin did not differ statistically from those to normal dentin substrate. The double etching approach significantly reduced bond strengths of artificially hypermineralized dentin.

Management of Class III crown fractures in the permanent dentition.

Management of Class III crown fractures in the permanent dentition can be both challenging and rewarding for practitioners. Several of the techniques described require further investigation to determine clinical efficacy based on scientific research. In addition to evidence-based protocols, treatment outcomes will continue to be related to the technical proficiency of the dentist, including diagnostic acumen and appropriate treatment planning decisions. A treatment planning decision paradigm, as described in this article for management of Class III fractures to permanent teeth, is summarized in Table 1.

An in vivo evaluation of hemorrhage control using sodium hypochlorite and direct capping with a one- or two-component adhesive system in exposed nonhuman primate pulps.

OBJECTIVE: This study evaluated the biologic ability of sodium hypochlorite to control hemorrhage via chemical amputation of the coagulum, to remove dentin chips, to assist healing, and to facilitate formation of a dentinal bridge under two adhesive systems. METHOD AND MATERIALS: Ninety Class V cavities with mechanical pulpal exposures were placed in the teeth of five adult monkeys and histologically observed. All exposures were prepared with a No. 330 bur, and hemorrhage was controlled with 3% sodium hypochlorite. Twenty-two exposures were capped with All-Bond 2 and AElitefil, and 26 exposures were capped with One-Step (OS) and Resinomer (RS). Two pulps were excluded from the final data. Forty-two exposures were capped with calcium hydroxide and amalgam as controls. At 7, 27, and 90 days, tissues were obtained by perfusion fixation, demineralized, sectioned, stained, and histologically graded according to published qualitative criteria. RESULTS: For both adhesives, at 7 days, 12 of 16 pulps showed no coagulum remnants or dentin chips at the material interface. No necrotic pulps were observed. At 27 and 97 days, 26 of 30 capped pulps had dentinal bridges at the adhesive interface. Reparative dentin was present in 28 pulps. Four 97-day pulps exhibited necrosis associated with stained bacteria. One 97-day pulp contained dentin chips throughout the pulp and demonstrated no healing, no reparative dentin, and no stained bacterial profiles. CONCLUSION: Normal soft tissue reorganization and dentinal bridge formation were observed in 86% of pulps treated with sodium hypochlorite and either adhesive system.

Pulpal response to different pulp capping methods after pulp exposure by air abrasion.

Air abrasion is regaining popularity especially in the area of pediatric dentistry due to its ease of use and its advantages. Due to the lost of tactile information, while using this technique, there is an increased risk for pulpal exposure. On the other hand, Ca(OH)2 medicament has been proven to induce dentin bridge formation, but an adequate sealing seems to be even more important that the capping material used. The purpose of this study was two fold: to assess the pulpal response after pulpal exposure by air abrasion and to evaluate the healing potential after using Ca(OH)2 medicament or Liner Bond II as a capping agent. Two hundred sixteen teeth from mixed-bred dogs were used in this study. The teeth were divided into three groups, A) pulpal exposure by air-abrasion followed by sealing of the cavity with Liner Bond II, B) pulpal exposure by air-abrasion and Ca(OH)2 pulp capping and C) pulpal exposure by high-speed followed by air-abrasion and Ca(OH)2 pulp capping as a control group. The animals were sacrificed after 7, 14, 30 and 60 days and a histopathological evaluation was undertaken. After applying Analysis of Variance to compare the groups, it was observed that at earlier observation periods, the inflammatory criteria near the exposure site were different among the groups. As time elapsed, the inflammation was resolved in the pulp tissue, however, the odontoblastic layer and the dentin bridge formation had a highly statistically significant difference (p<0.001) among the various groups at all observation periods. In addition, a positive correlation was observed between the organization of the odontoblastic layer and the dentin bridge formation mainly after 30 days. It could be concluded that dentin bridge formation could be achieved with the use of Ca(OH) or Liner Bond II as capping agent with an adequate sealing. However, the formation is delayed especially when Liner Bond II is used as capping agent.

Reaction of rat connective tissue to implanted dentin tubes filled with a white mineral trioxide aggregate.

The purpose of this paper was to study the reaction of rat subcutaneous connective tissue to the implantation of dentin tubes filled with white mineral trioxide aggregate (MTA), a material that will be marketed. The tubes were implanted into rat subcutaneous tissue and the animals were sacrificed after 7 and 30 days. The undecalcified pieces were prepared for histological analysis with polarized light and von Kossa technique for mineralized tissues. Granulations birefringent to polarized light and an irregular structure like a bridge were observed next to the material; both were von Kossa positive. Also, in the dentin wall tubules a layer of birefringent granulations was observed. The results were similar to those reported for gray MTA, indicating that the mechanisms of action of the white and gray MTA are similar.

Location, arrangement and possible function of interodontoblastic collagen fibres in association with calcium hydroxide-induced hard tissue bridges.

AIM: To assess the location, arrangement and possible function of interodontoblastic collagen fibres in association with calcium hydroxide-induced hard tissue bridges by using light and transmission electron microscopy techniques and immunohistochemical staining localization. METHODOLOGY: Prior to the study, an animal use protocol form was reviewed and approved by the Screening Committee for Animal Research of the Tokyo Medical and Dental University. Exposed monkey pulps were capped with a hard-set calcium hydroxide and histopathologically evaluated at 3, 14, 21, 30 and 90 days, using light microscopy with silver staining and transmission electron microscopy to differentiate structural features of interodontoblastic collagen fibres. In addition, an attempt was made to identify and to differentiate between several types of collagen and fibronectin using immunohistochemical localization techniques. RESULTS: At 14 days, interodontoblastic collagen fibres were observed extending from the original dentine, passing through the odontoblasts, and consisted of two portions: a thick fibril and a thin fibril. At 21 days, interodontoblastic collagen fibres were seen penetrating into the predentine and becoming incorporated into the mineralized dentine. At 30 days, interodontoblastic collagen fibres reached the cell process. Although interodontoblastic collagen fibres were no longer observed near the odontoblastoid cells at the area of the newly formed tubular dentine, interodontoblastic collagen fibres were observed embedded within the primary formed dentine bridge. Immunohistochemical staining demonstrated type I collagen and fibronectin within the interodontoblastic collagen fibres. CONCLUSIONS: Interodontoblastic collagen fibres were routinely detected throughout early dentine bridges. Interodontoblastic collagen fibres are thought to be important for initial dentine bridging to induce and support a dentinogenesis framework.

Calcium hydroxide in endodontic retreatment after two nonsurgical and two surgical failures: report of a case.

AIM: To describe the role of calcium hydroxide in infection control during complex endodontic retreatment. SUMMARY: A case is presented in which two conventional endodontic treatments and two surgical interventions failed to bring periapical healing. Despite this history, a further conventional treatment augmented by long-term disinfection with calcium hydroxide finally delivered a successful outcome. KEY LEARNING POINTS: Periapical healing follows proper intracanal infection control. Despite repeated surgical and nonsurgical intervention, careful retreatment can often bring healing. Calcium hydroxide has long-acting antimicrobial and soft-tissue dissolving activity. It is a helpful adjunct in endodontic retreatment.

Reaction of rat connective tissue to implanted dentin tube filled with mineral trioxide aggregate, Portland cement or calcium hydroxide.

The subject of this study was to observe the rat subcutaneous connective tissue reaction to implanted dentin tubes filled with mineral trioxide aggregate, Portland cement or calcium hydroxide. The animals were sacrificed after 7 or 30 days and the undecalcified specimens were prepared for histological analysis with polarized light and Von Kossa technique for mineralized tissues. The results were similar for the studied materials. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was an irregular tissue like a bridge that was Von Kossa-positive. The dentin walls of the tubes exhibited in the tubules a structure highly birefringent to polarized light, usually like a layer and at different depths. The mechanism of action of the studied materials has some similarity.

Pulp capping with adhesive resin-based composite vs. calcium hydroxide: a review.

The results of some short-term experiments suggest that direct capping of a vital pulp with the modern resin-based composite systems may be as effective as capping with calcium hydroxide. Total cavity etching with 10% phosphoric acid seems to be safe for the exposed pulp, but unless annulled by calcium hydroxide 35% phosphoric acid may be disastrous. For hemostasis and cleaning of the pulp wound both sodium hypochlorite and saline seem suitable, whereas the effectiveness of a 2% chlorhexidine solution is questionable. Although hard-setting calcium hydroxide cements may induce the formation of dentin bridges, they appear not to provide an effective long-term seal against bacterial factors. Within a few years, the majority of mechanically exposed and capped pulps show infection and necrosis due to microleakage of such capping materials and tunnel defects in the dentin bridges. It is unknown whether newer types of resin containing calcium-hydroxide-products will act as a permanent barrier. The cytotoxicity of the resin-based composites and the temperature rise during polymerisation may not be of concern, but microleakage, sensitisation and allergic reactions may pose problems. Based on available data, pulp capping with resin-based composites may be said to be promising, but more and long-term research is mandatory before the method can be recommended.

Bone sialoprotein-induced reparative dentinogenesis in the pulp of rat's molar.

Bone sialoprotein (BSP), an osteogenic protein (OP), mixed with a carrier, was implanted in the pulp of rat first upper molars (OP group). Cavities were prepared with dental burs and pulp perforation was carried out by pressure with the tip of a steel probe. After 8, 14, and 30 days, the rats were killed and the pulps of the OP group were compared with (1) a sham group (S group), (2) a group where the carrier was implanted alone (C group), and (3) capping with calcium hydroxide (Ca group). After 8 days, a few inflammatory cells were seen, mostly located at the pulp surface near the perforation. In the Ca group, a dentin bridge started to form, in contrast to the other groups. After 15 days, globular structures were seen in the pulps of the S and C groups. A reparative osteodentin bridge isolated the pulp from the cavity in the Ca group. Variable reactions were seen in the OP group, with some evidence of cell and matrix alignments or plugs of osteodentin in continuity with an inner layer of reparative dentin. After 30 days, irregular osteodentin formation was observed in the pulps of the S and C groups, with a tendency for globular structures to merge, but with interglobular spaces filled by pulp remnants. In the Ca group, osteodentin was observed in the mesial part of the pulp chamber. In the BSP-implanted group, the osteogenic protein stimulated the formation of a homogeneous dentin-like deposit occupying most of the mesial part of the pulp. Apparently, BSP stimulates the differentiation of cells which secrete an organized extracellular matrix more efficiently than any other capping material used so far. Altogether, the results reported here support that bone sialoprotein displays novel bioactive properties and is capable of stimulating in 1 month's time the development of a thick reparative dentinal tissue in the pulp, occluding the perforation and filling the mesial third of the pulp chamber.

Tools for tissue engineering of mineralized oral structures.

This paper presents a short review of three groups of tools which can be or are used for the tissue engineering of mineralized oral structures: growth factor delivery systems (GFDS) and surface bioactivation with covalent bound peptides or with nanomechanically linked proteins. According to the reported personal experience of the authors, GFDS have to face the following challenging issue before being used routinely in dentistry, e.g., as a tool for reparative dentinogenesis or bone healing: adaptation of the GFDS design to the tissue where it will be implanted in order to deliver the right dose of growth factor (GF) at the right time. The bioactivation of surfaces, for example of dental implants, with covalent bound peptides or nanomechanically linked proteins represents a second innovative way to improve dental health in the future. Here we report on the experimental use of cyclic RGD peptides grafted on polymethylmethacrylate to improve osteoblast adhesion. Furthermore, we show the potential advantage of immobilizing and incorporating collagen I on titanium implant surfaces. These techniques or a combination of them will help to create improvements, for example, of dental implants in the near future. They will also help to promote bone and dentin regeneration.

The quantification of tertiary dentine formation in response to materials commonly placed in deep cavities in general practice in the UK.

PURPOSE OF STUDY: To determine the rate of formation of tertiary dentine in dogs' teeth, in response to five commonly used lining materials. Also, to record the resulting differences in quality of the formed dentine. MATERIALS AND METHODS: Representatives of five types of materials commonly used in general practice in the UK were placed in deep standardised cavities with a remaining dentine thickness of 400-500 microns, and sealed to the cavo-surface with zinc oxide-eugenol. The daily rate of tertiary dentine formed in response to each material was measured over a period of 119 days using a tetracycline staining method. A concomitant study to show the quality of the formed dentine was undertaken using the same materials and experimental conditions. RESULTS: There was a significant difference between the rates of tertiary dentine formation for all materials except zinc oxide-eugenol and Ledermix paste. For each material there was a increased rate of tertiary dentine formation in the second period (29-49 days) compared to the first period (0-28 days). This is considered to be due, in part, to a lag period when damaged odontoblasts are differentiating from mesenchymal elements. The rate of tertiary dentine formation in response to all the test materials was always greater than that of normal physiological dentine formation in unprepared teeth. Qualitatively, there was difference in the formed tertiary dentine beneath each material. All the materials caused odontoblast destruction, altered ground substance production and alterations in the calcification process. CONCLUSION: None of the materials routinely used at present can be considered to be 'ideal' as odontoblast destruction, altered ground substance production and altered calcification occur beneath zinc oxide-eugenol preparations, calcium hydroxide preparations as well as in response to corticosteroid-containing materials such as Ledermix paste and cement.

Human pulp response after partial pulpotomy with two calcium hydroxide products.

Twenty human permanent teeth were used to study the pulpal response of two calcium hydroxide products, Dycal and Pulpdent Multi-Cal, after partial pulpotomy. Teeth were extracted at 4 months, fixed, and prepared for histologic examination. All 10 teeth treated with Dycal showed complete soft tissue healing and bridge formation. No stained bacteria were seen throughout the serial sections. One tooth treated with Dycal showed acceptable histologic results, dentin deposition in the root canal. Six cases dressed with Pulpdent Multi-Cal showed acceptable histologic results, whereas four teeth showed severe inflammation or necrosis associated with bacterial penetration into the pulp tissue. Clinically, one tooth treated with Pulpdent Multi-Cal showed pulpal pain and was extracted at 90 days. Our data support the thesis that human permanent pulps will promote tissue healing and dentin bridge formation as long as bacterial microleakage is excluded.

A new biological approach to vital pulp therapy.

Molecular biology is providing opportunities to develop new strategies or agents for the treatment of a wide variety of diseases. The availability of large amounts of highly purified proteins produced by recombinant DNA techniques is an obvious example. Recent evidence has implicated proteins belonging to the bone morphogenetic protein (BMP) subgroup of the transforming growth factor beta supergene family in tooth formation and dentinogenesis. It has long been known that bone and dentin contain bone morphogenetic protein activity. Recently, recombinant human BMP-2, -4, and -7 (also known as OP-1), have been shown to induce reparative dentin formation in experimental models of large direct pulp exposures in permanent teeth. The manner in which these agents act appears unique. New reparative dentin replaces the stimulating agents applied directly to the partially amputated pulp. Hence, the new tissue forms contiguous with, largely superficial to, and not at the expense of the remaining vital pulp tissue. This suggests a therapeutic approach permitting the induction of a predetermined and controlled amount of reparative dentin. Additionally, OP-1 has been associated with the formation of reparative dentin after application to a freshly cut but intact layer of dentin. These findings may provide future clinicians with additional options for the treatment of substantially damaged or diseased vital teeth.