Histological evaluation of the effect of intrapulpal anesthesia in pulpotomies

Abstract The effect of intrapulpal anesthesia prior to pulpotomies was histologically studied on 12 young human premolars. In 9 teeth (75%) a mineralized bridge adjacent to the remaining pulp tissue containing dilated blood vessels was observed. The rest (25%) had no mineralized bridge and the remaining pulp tissue showed inflammation with hemorrhage as well as necrotic areas.     

Partial pulpotomy in young permanent teeth with deep carious lesions

Abstract The material comprised 37 young posterior teeth with deep carious lesions and exposed pulps, treated with partial pulpotomy and dressed with calcium hydroxide. The teeth were divided into two groups. Group 1 consisted of 31 teeth with no clinical or radiographic symptoms before treatment, Group 2 of 6 teeth with temporary pain, widened periodontal space periapically and/or productive osteitis, i.e. increased density of the surrounding alveolar bone. After an observation time of 24 to 140 months (x?= 56 months), healing had occurred in 29 of 31 teeth in Group 1 (93.5%) and in 4 of 6 teeth in Group 2. It was concluded that the present, as well as previously reported results indicate that partial pulpotomy may be an adequate treatment for young permanent molars with a carious exposure, although more studies are needed before the treatment can be recommended for routine clinical use.     

双糊剂型自凝氢氧化钙水门汀的研制和性能评价

目的 :研制一种双糊剂型自凝氢氧化钙水门汀并对其物理、化学、力学和生物学性能进行评价。方法 :由水杨酸甲酯和 1,3-丁二醇在催化剂的作用下通过酯交换制成凝固螯合剂水杨酸 1,3-丁二醇酯 ,参照国外有关配方配制成Calar双糊剂型自凝氢氧化钙水门汀。以Dycal自凝氢氧化钙水门汀为对照 ,测定了Calar的凝固时间、抗压强度、直径抗张强度、溶解率、pH值、抑菌性能和动物牙齿盖髓试验。 结果 :Calar的凝固时间为 (3.5± 0 .5 )min、抗压强度为 (2 9.5± 4 .2 )MPa、直径抗张强度为 (2 .4± 0 .3)MPa、水中 2 4h溶解率为 (2 .5± 0 .2 ) %、pH值为 11.3± 0 .5、抑菌 (变形链球菌MRa)圈直径为 (13.8± 1.7)mm ,在活体狗牙上用Calar盖髓 70d后可见盖髓点牙髓组织内形成较厚且完整的牙本质桥将露髓点封闭 ,显示出良好的盖髓效果。以上各项性能与对照材料Dycal无明显差异。 结论 :Calar自凝氢氧化钙水门汀是一种性能优良、安全可靠的氢氧化钙类盖髓、垫底材料 ,具有可凝固性 ,凝固后具有一定的强度 ,可在临床推广试用     

Reparative hard tissue formation following calcium hydroxide application after partial pulpotomy in cariously exposed pulps of permanent teeth

In a prospective study, partial pulpotomy was performed on six permanent molars with deep carious lesions and pulpal involvement. The bleeding pulp was irrigated with normal tap water until bleeding had stopped and the exposed pulp was covered with calcium hydroxide followed by zinc oxide eugenol, and finally covered with a semipermanent restoration. All teeth showed hard tissue barrier formation, both clinically and radiographically, within three months and were free from subjective and objective symptoms through the observation period (average observation period was 26 months). The patients also experienced the therapy positively. These findings and those of others have helped gain more recognition for partial pulpotomy as a strong possible alternative therapy when pulps are exposed by deep carious lesions and a bleeding pulp is exposed during the excavation process. The rationale for this therapy is to remove the infected and/or inflamed pulpal areas beneath the carious lesion and disintegrated tissue. A rapid and simplified procedure would allow the general practitioner to perform this procedure when necessary at dental clinics, without specialist facilities under conditions that avoid unnecessary contamination of the pulp.     

Histological comparison of alendronate, calcium hydroxide and formocresol in amputated rat molar

Abstract –  The purpose of this study was to evaluate the potential of alendronate sodium (ALN), a biphosohonate to stimulate hard tissue formation in pulpotomized (amputated) rat molars. Two commonly used pulpotomy materials, calcium hydroxide (CH) and formocresol (FC) were utilized for comparisons. Histological evaluations were performed by observers blinded to treatment allocation on days 7, 15, 30 and 60, followed by statistical analysis of selected histological criteria. In all evaluation periods, hard tissue deposition was evident along the radicular dentin in ALN and CH groups. In days 30 and 60, the latter two groups showed no differences in inflammatory cell response and hard tissue deposition scores ( P  > 0.05). ALN appears to be capable of maintaining pulpal vitality, while promoting hard tissue formation, similar to CH.     

Scanning electron microscopy evaluation of the hard tissue barrier after pulp capping with calcium hydroxide,mineral trioxide aggregate (MTA) or ProRoot MTA

The aim of this study was to investigate the morphology and localisation of calcium hydroxide‐ and mineral trioxide aggregate (MTA)‐induced hard tissue barriers after pulpotomy in dogs' teeth. Pulpotomies were performed on maxillary and mandibular premolars of five dogs. The teeth were assigned into three groups according to the pulp‐capping agent used. The pulpal wounds were capped with calcium hydroxide (Ca(OH)₂– control), MTA or ProRoot MTA, and the cavities were restored with amalgam. After a 90‐day follow‐up period, the dogs were euthanised and the teeth were examined under scanning electron microscopy (SEM). An image‐processing and analysis software was used to delimit the perimeters of the root canal area and the hard tissue barrier to determine the percentage of root canal obliteration. SEM data were used to assess the morphology, localisation and extension of the reparative hard tissue barriers. ProRoot MTA was statistically different from MTA and Ca(OH)₂ (P < 0.05) regarding tissue barrier morphology. Localisation data showed that ProRoot MTA was significantly different from Ca(OH)₂ (P < 0.05) and similar to MTA (P > 0.01; P > 0.05). No statistically significant difference (P > 0.01; P > 0.05) was observed between MTA and Ca(OH)₂. A larger number of complete (centroperipheral) hard tissue barriers with predominance of dentinal tubules was observed to the ProRoot MTA when compared with the Ca(OH)₂ group.     

Odontoblast differentiation: a response to environmental calcium?

Abstract— The response of the dental pulp to calcium hydroxide has been well described but the process of pulpal repair leading to dentinal bridge formation appears complex and the mechanisms remain incompletely understood. Through the precise regulation of the free calcium ion in the cytosol, cells have been able to utilize anions such as phosphates for a wide range of activities such as energy production (oxidative phosphorylation). As anions are abundant in the cytosol, intracellular levels of calcium ions are kept low, several orders of magnitude less than that of the surrounding extra cellular matrix. Consequently, cells are able to use calcium ions for the regulation of many cellular events. The binding of extracellular molecules such as cytokines, hormones or antibodies, with receptors on the plasma membrane may result in short- or long-term modifications to cellular metabolism, including the mechanisms of intracellular calcium homeostasis. Cell survival depends upon the ability to adapt to changes in the cell's micro-environment. Adaptation in turn results in altered cellular activity that may be interpreted as showing that the cell has become more or less specialised. In some instances this may include the resumption of mitotic activity. If the rate or magnitude of change exceeds a cell's adaptive capacity, the cell dies. Responses of cells to alterations in their environment are reviewed as they may provide an explanation for the success of calcium hydroxide in facilitating pulpal repair and the differentiation of odontoblasts.     

钙乐(Calar)光固化氢氧化钙盖髓垫底材料的临床应用研究

目的：评价钙乐光固化氢氧化钙（VLC Calar）盖髓垫底的临床效果。方法：在临床选择深龋近髓（61牙），重度楔状缺损（33牙）、深龋穿髓（32牙）和意外穿髓（22牙），用VLC Calar进行垫底及盖髓，并以氢氧化钙制剂作为对照，其上用玻璃离子水门汀垫底，银汞合金或玻璃离子水门汀充填修复。术后半年复查。结果：应用VLC Calar后的成功率为：深龋近髓间接盖髓88.9%，重度楔状缺损间接盖髓95.5%，深龋穿髓直接盖髓52.2%，意外穿髓直接盖髓85.7%，成功率与对照材料无显著性差异，但VLC Calar黏附性好，易充填，能快速固化。结论：钙乐（Calar）光固化氢氧化钙用于间接盖髓及意外穿髓的盖髓效果较好，但用于深龋穿髓的直接盖髓效果较差。     

Histological observations of hard tissue barrier formation in amputated dental pulp capped with α-tricalcium phosphate containing calcium hydroxide

Abstract This study was performed to evaluate the pulpal response to α-tricalcium phosphate (αTCP) containing calcium hydroxide (Ca(OH)₂). The dental pulps of monkeys were amputated and dressed with four agents: αTCP, αTCP containing 1% Ca(OH)₂, αTCP containing 5% Ca(OH)₂, and Ca(OH)₂ being used as a control. The pulpal responses were histologically evaluated after 4 and 8 weeks. The pulp tissue treated with αTCP proliferated above the level of the original wound surface, and a thin layer of hard tissue barrier was formed directly against the capping agent. The barrier demonstrated atubular matrix lined with flattened or cuboidal cells, but occasionally appeared irregular in form. Ca(OH)₂ dressing resulted in destruction of pulp tissue, with a thick hard tissue barrier being formed below the level of the exposure site. The barrier consisted coronally of osteodentin and pulpally of tubular dentin lined with odontoblast-like cells. By contrast, 1% Ca(OH)₂ added to αTCP produced a slight proliferation of pulp tissue. An atubular matrix barrier, pulpally lined with cuboidal cells, formed above the exposure site. It was later followed by the formation of tubular matrix lined with columnar cells. Teeth treated with 5% Ca(OH)₂, showed a thin necrotic layer and a thick barrier formation. The barrier was composed of tubular dentin-like tissue lined with odontoblast-like cells. It would appear that αTCP containing a small amount of Ca(OH)₂ may be clinically useful as a capping agent, as it induced consistent hard tissue formation, without excessive destruction of underlying pulp tissue.     

Pulp capping with calcium hydroxide: diagnostic value of radiographic findings

Abstract We compared the radiographic and histologic findings 2, 4 and 13 weeks after pulp-capping dog teeth with 2 hard-setting calcium hydroxide-containing agents and with calcium hydroxide powder mixed with physiologic saline. Radiopacity of the treated pulp regions was observed in all teeth showing dentin bridge formation. In most teeth that histologically exhibited a zone of pulp necrosis subjacent to the capping material, a radiopaque zone beneath the exposure site was also observed.     

Cytotoxicity of substances leached or dissolved from pulp capping materials

AIM: To evaluate the cytotoxic effects of substances leached or dissolved from pulp capping materials on human pulp fibroblasts. METHODOLOGY: The substances were applied to cell cultures in conditioned media. The experimental groups were: GI (control; n = 24)--cultures treated with fresh medium; GII (n = 24)--cultures treated with calcium hydroxide cement; GIII (n = 24)--cultures treated with adhesive resin and GIV (n = 24)--cultures treated with 37% orthophosphoric acid. The media were conditioned by placing the crude materials in contact with fresh culture medium for 1 h. The cytotoxicity analysis was performed using the Trypan blue dye exclusion assay at times of 0, 6, 12 and 24 h for cell viability assay, and at 1, 3, 5 and 7 days for survival assay. Data were treated by anova (P < 0.05) and Tukey's test (P < 0.05). RESULTS: GI and II presented similar cell viability and cell growth. GIII and IV exhibited statistically significant lower percentages of cell viability: GIV only at the 0 h experimental time, whereas in GIII this viability markedly diminished reaching values of 10% by 12 h. Cell growth was impaired only in cultures of GIII. CONCLUSIONS: Substances dissolved from the adhesive system tested were cytotoxic for human dental pulp fibroblasts in culture, whilst substances leached from calcium hydroxide were biocompatible.     

European Society of Endodontology position statement: Management of deep caries and the exposed pulp

This position statement on the management of deep caries and the exposed pulp represents the consensus of an expert committee, convened by the European Society of Endodontology (ESE). Preserving the pulp in a healthy state with sustained vitality, preventing apical periodontitis and developing minimally invasive biologically based therapies are key themes within contemporary clinical endodontics. The aim of this statement was to summarize current best evidence on the diagnosis and classification of deep caries and caries‐induced pulpal disease, as well as indicating appropriate clinical management strategies for avoiding and treating pulp exposure in permanent teeth with deep or extremely deep caries. In presenting these findings, areas of controversy, low‐quality evidence and uncertainties are highlighted, prior to recommendations for each area of interest. A recently published review article provides more detailed information and was the basis for this position statement (Bjørndal et al. 2019, International Endodontic Journal, doi: 10.1111/iej.13128 ). The intention of this position statement is to provide the practitioner with relevant clinical guidance in this rapidly developing area. An update will be provided within 5 years as further evidence emerges.     

A retrospective study of direct pulp capping with calcium hydroxide compounds

Abstract Direct pulp capping with calcium hydroxide compounds was performed on 510 human teeth. Pulp had been exposed as a result of cavity preparation in 70% of cases, and by removal of carious dentine in 15%. For the remaining 15% of the cases no information on the cause of exposure was available. The teeth were clinically and radiographically controlled 1, 3, 6 and 12 months after treatment and at the stopping date. 245 cases were available for clinical examination. Information on the remaining cases was obtained from the records. Using the life table method, the trial time was calculated for each case as the time from dale of treatment to the date of failure, the date of last contact or the stopping date. The data were analyzed according to cause of perforation, age of patient and type of tooth. Five-year survival was 82% No significant difference in survival was observed between non-carious and small carious exposures. Young teeth and molars showed a higher survival rate when the longer observation periods were considered.     

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.     

Formation of a hard tissue barrier after experimental pulp capping or partial pulpotomy in humans: an updated systematic review

The aim was to update a systematic review of pulp capping and partial pulpotomy by Olsson et al. (2006), by evaluating new evidence on formation of a hard tissue barrier after pulp capping and partial pulpotomy of experimental exposures in humans. PubMed (01‐01‐2005 to 01‐03‐2014) and CENTRAL were searched using specific keywords. Hand searches were made and the level of evidence for each included article was evaluated by the authors. The evidence of the conclusions was graded as strong, moderately strong, limited or insufficient. The initial search in PubMed yielded 215 abstracts. Hand searches of reference lists yielded no additional original scientific articles. After a selection process and interpretation, 22 articles were included and rated for level of evidence: no article was rated as high and seven as moderate. Overall the methodological quality of studies has improved since the previous systematic review was published in 2006. The conclusions are that there is limited scientific evidence that application of calcium hydroxide or mineral trioxide aggregate to an exposed pulp frequently results in formation of a hard tissue barrier, whereas adhesives or enamel matrix derivatives do not. There is insufficient scientific evidence that mineral trioxide aggregate promotes hard tissue formation more frequently than calcium hydroxide.     

Influence of age on the behavior of dental pulp of dog teeth after capping with an adhesive system or calcium hydroxide

Abstract  – This study evaluated histomorphologically the influence of chronological age of the dog on the dental pulp-healing process after capping with the All Bond 2 system or with calcium hydroxide paste. The animals were divided according to age into young and adult groups. Class 5-type cavities were prepared, and the pulp was submitted to an exposure of a diameter of 0.5 mm. The pulp of the teeth was then protected with the adhesive system or with a calcium hydroxide paste. Sixty days after treatment, the results obtained with the adhesive system in the young group were significantly better than those in the adult group. With calcium hydroxide, the results were similar for both groups. The pulp treated with calcium hydroxide exhibited a complete hard tissue bridge and a pulp without inflammatory reaction, a fact not observed when the adhesive system was used. In conclusion, the chronological age of the pulp influenced the comparative results only for the adhesive system ( P  = 0.1), and the total results were better with calcium hydroxide than with the All Bond 2 system ( P  = 0.01).