Long-term follow-ups of revascularized immature necrotic teeth: three case reports.

Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar treated with a revascularization technique. At a24-month follow-up, periapical radiolucency had disappeared and thickening of the root wall was observed. In cases 2 and 3, a10-year-old boy had his necrotic, immature, bilateral mandibular second premolars treated with the same modality. At 48-month(in case 2) and 42-month (in case 3) follow-ups, loss of periapical radiolucencies and increases in the root wall thickness were also observed.

Assessment of pulp blood flow in primary and permanent teeth using pulse oximetry.

Pulse oximetry (PO) is a well-accepted non-invasive method for assessing vascular health, based on oxygen saturation (SaO(2) ) measurements. The objectives of this study were to design and build a custom-made PO dental sensor holder, to evaluate the effectiveness of PO in determining pulp blood flow in primary and permanent teeth, and to compare the SaO(2) levels obtained in teeth and on the little finger of patients. The PO sensor adapted to the custom-made sensor holder is termed as a device to position and hold the PO sensor. This study evaluated SaO(2) readings obtained in the pulp of 123 teeth of 84 children aged 4-13years. The teeth were divided into three groups: group I - primary teeth: 23 central incisors and 28 canines; group II - permanent teeth: 25 central incisors and 28 canines; and group III - endodontically treated teeth (control): 12 permanent central incisors and seven primary central incisors. The pulp blood flow and SaO(2) were measured and were compared with readings of the patient's finger. Data were analyzed by paired t-tests and Pearson's analysis method. The PO was able to identify all the clinically normal pulps contained in the sample, and all the endodontically treated teeth (controls) showed no response. The mean SaO(2) values were 85.27% in the teeth and 92.85% in the fingers. In conclusion, PO readings were effective in determining pulp blood flow in primary and permanent teeth. However, there was no correlation between the SaO(2) values in the fingers and in the teeth of the patients (P<0.05).

Evaluation of pulpal blood flow changes in primary molars with physiological root resorption by laser Doppler flowmetry and pulse oximetry.

AIM: The aim of this study was to undertake a comprehensive quantitative investigation ofpulpal bloodflow (PBF) changes in human non-carious primary molar teeth with variable degrees of root resorption by Laser Doppler Flowmetry (LDF) and Pulse Oximetry (PO) methods. MATERIALS AND METHODS: Data was collected from clinically and radiographically healthy 86 mandibular primary molars which have different physiological root resorption levels (PRRLs). PRRLs for each of the teeth were assessed using periapical radiographs and teeth were subdivided into three groups. RESULTS: The LDF values demonstrated a significant diference (p = 0.0001) between all groups although PO did not demonstrate any difference (p = 0.109). Statistical analysis of LDF values demonstrated significant differences between Groups A and C (p = 0.0001) and Groups B and C (p = 0.008). Furthermore, positive correlations were determined between LDF values and PRRL groups (p = 0.0001) and patients' ages (p = 0.0001). CONCLUSIONS: In our study, it was observed that the PBF values of human primary molars measured by LDF tended to increase with the progress of physiological root resorption and age. LDF was found to be a more effective method than PO to assess the pulpal vascularity changes of human primary molars.

Vascular status in human primary and permanent teeth in health and disease.

The present study sought to compare the vascular status of human primary teeth with that of human permanent teeth, and to determine whether caries or painful pulpitis was associated with changes in vascularity. Coronal pulps were removed from 62 primary and 62 permanent mandibular molars with a known pain history. Teeth were categorized as intact, moderately carious or grossly carious. Pulp sections were labelled with Ulex europaeus I lectin (UEIL), which is a marker of human vascular endothelium. Image analysis was then used to quantify the percentage area of UEIL-labelled tissue (vascularity) and the number of blood vessels present within three regions: the pulp horn, the subodontoblastic region, and the mid-coronal pulp. Only the mid-coronal region of the primary tooth pulp was found to be significantly more vascular than the corresponding area of the permanent tooth pulp. Both dentitions showed a significant increase in vascularity within the pulp horn region with caries progression, but this was not accompanied by an increase in vessel number. There was no correlation between vascularity and pain symptoms. These findings suggest that the primary tooth pulp is more vascular than its successor within the mid-coronal region. However, the functional and clinical significance of this finding remains speculative.

Human dental pulp vasculogenesis evaluated by CD34 antigen expression and morphological arrangement.

Vasculogenesis describes the process by which endothelial precursor cells form new blood vessels. To characterize the topography and the cellular processes underlying vascularization of human dental pulp, we examiend the expression of the human hematopoietic progenitor cell antigen CD34. Dental pulps, obtained from deciduous and permanent teeth, were morphologically examined at light- and electron-microscope levels and by expression of CD34. The findings indicate that vasculogenesis of dental pulp is a complicated process starting from single CD34(+) cells. These subsequently coalesce to form solid vascular cords inside the developing connective tissue, which later hollows. Pericytes were embedded within the fully formed microvessels' basement membrane. The presence of CD34(+) endothelial cells in permanent teeth reveals that the process of vasculogenesis persists into adult life, where it contributes to continuous adjustment of vessel and network structures in response to functional needs and dental tissue homeostasis.

Pulp response in primary teeth with deep residual caries treated with silver fluoride and glass ionomer cement ('atraumatic' technique)

Histological assessment of the dental pulps of 55 carious primary teeth was carried out 3 to 58 months after treatment by the 'atraumatic' technique involving application of 40 per cent silver fluoride to residual caries followed by restoration with glass ionomer cement. Fifty of the 55 teeth examined showed a favourable pulpal response, inducing presence of abundant reparative dentine and a wide odontoblast layer. Histological comparisons were made between these teeth and others not treated with silver fluoride but restored with glass ionomer cement, amalgam or zinc oxide and eugenol. Possible mechanisms of the action of silver fluoride in arresting residual caries are discussed. The question of whether or not treatment of carious dentine with silver fluoride represents a biologically acceptable clinical procedure cannot be answered on the basis of pulpal histology alone. The very high concentration of fluoride in commercial preparations of silver fluoride raises several questions concerning its clinical safety.

Experiments in pigs on the sources of laser Doppler blood-flow signals recorded from teeth.

A laser Doppler blood-flow meter (Moor Type MBF3D) was used to record from the crowns of eight deciduous mandibular incisors in three anaesthetized pigs. The flow-meter probe was attached to the crown either 2 or 6 mm from the gingival margin. Recordings were made from each tooth with the supporting tissues intact, after exposing the root pulp, after cutting the pulp, and after death of the animal. At each stage the effect of wrapping the crown in aluminium foil was determined. There was no significant change in the signals when the root pulp was exposed (p > 0.05, paired t-test). Without foil, cutting the pulp reduced the signal recorded 2 mm from the gingival margin by an average of 85.1 percent (n = 8, p < 0.001) and at 6 mm by 87.9 percent (n = 4, p < 0.001). There were further significant reductions (p < 0.01) equivalent to 12.9 percent and 9.0 percent, respectively, of the control values when the animal was killed. The foil increased the average blood-flow signals recorded from intact teeth at both 2 and 6 mm from the gingival margin by 77.8 percent and 98.3 percent (p < 0.05), respectively. It also had a similar effect after pulp exposure. With foil, cutting the pulp reduced the signal by 86.2 percent and 92.8 percent at the two sites, respectively, and post mortem there was a further reduction of 12.4 percent and 6.1 percent. Thus, under all conditions the major part of the signal recorded from an intact tooth was from the pulp but a significant component (an average of between 14.9 percent and 7.2 percent depending on the conditions) was from tissues outside the tooth. The best performance was obtained with foil and with the probe 6 mm from the gingival margin.

Vascular pathways within pulpal tissue of human primary teeth.

The vascular distribution within pulps of human primary teeth has not been as well studied as those within human permanent teeth. Such information is useful to those who diagnose and treat dental conditions in children. The purpose of this study was to determine the architecture of the vascular structures, in contrast to the histological appearances, of noncarious human primary teeth during root completion, root resorption and dental caries attack. Following extraction, primary teeth were perfused with an opaque injection mass and photographed to trace the courses of the arterioles, venules and capillaries within the crowns and roots. The architectural morphology of similar vascular structures in permanent pulps are included to provide a comparative reference. Arterioles entered the apical foramina and traveled throughout the root canal(s) to the pulpal chamber, giving off branches which passed toward the dentinal walls. Within the pulpal chamber, the arterioles passed toward the occlusal and proximal surfaces and arborized profusely to form a subodontoblastic plexus of capillaries. The capillaries lead to larger diameter venules, which exited the pulp through apical foramina. Many unusual vascular pathways existed within the root structure. No communication existed between the pulp chamber and periodontal membrane through the furcation dentin and cementum. Many lateral canals were seen along the root structures.

[Structural organization of the microcirculatory bed of the primordia of human deciduous teeth]. / Strukturnaia organizatsiia mikrotsirkuliatornogo rusla zachatkov molochnykh zubov cheloveka.

By means of injection and noninjection techniques structural organization of microcirculatory bed in the deciduous (milk) teeth germs have been studied in human fetuses, newborns and children. A definite dependence of the angioarchitectonics on the developmental stage of every tooth has been stated. Morphological differentiation of separate parts of the microcirculatory ways in the dental papilla is connected with dentinogenesis, and in the dental saccule--with amelogenesis, periodontum and alveolar wall formation. Those dental germ zones which have a peculiar functional importance (peripheral parts of the dental papilla, dental saccule in the area of the epithelial dental organ) are characterized by the presence of certain structural-functional apparatuses which provide increasing contact areas between blood and the tissues. Intraorganic circulatory bed of the dental papilla consists of identically constructed vascular complexes. The conformity coefficient between the arteriolar inlet and the venular outlet of the dental papilla microcirculatory ways during dentinogenesis is between 0.16--0.3. It has been stated that devices regulating the blood stream in the deciduous tooth germs (anastomoses, sphincters, arcades, etc.) are forming during the antenatal and early postnatal periods.