Mechanisms underlying the adaptive pulp and jaw bone trabecular changes in sickle cell anemia.

OBJECTIVE: Mechanisms underlying the oral outcomes in sickle cell anemia (HbSS) have been less explored. This study aimed to investigate the association of morbimortality indicators and hydroxyurea use with adaptive pulp and jaw bone trabecular changes in HbSS. METHODS: This cross-sectional study included 123 individuals with HbSS. The exposures were the morbimortality indicators of HbSS (number of vaso-occlusive crises, organ damage, hemoglobin level, and leukocyte count) and the use of hydroxyurea for HbSS treatment. The outcomes were adaptive pulp and jaw bone trabecular changes confirmed by radiographic examination. Associations were estimated by Poisson regression in crude and adjusted analyses for sex, skin color, socioeconomic class, and age. RESULTS: The vaso-occlusive crises (mean ratio (MR) = 3.5, p = 0.045), lower hemoglobin (MR = 2.4, p = 0.037), and higher leukocyte count (MR = 2.17, p = 0.036) were risk factors, while the use of hydroxyurea was inversely associated with adaptive pulp changes (MR = 0.23, p = 0.024). The vaso-occlusive crises were associated with jaw bone trabecular changes (MR = 1.33, p = 0.02). CONCLUSION: Adaptive pulp changes may be a potential clinical marker of chronic vasculopathy in HbSS. The use of hydroxyurea may reduce the frequency of adaptive pulp changes.

Predicting pre- and postoperative pain of endodontic origin in a southern Brazilian subpopulation: an electronic database study.

AIM: To determine the prevalence of preoperative endodontic pain (PREP) and the incidence of postoperative endodontic pain (POEP), identifying the predictors of PREP and POEP in a southern Brazilian subpopulation, using clinical data from an electronic chart database (ECD). METHODOLOGY: This retrospective observational study included 563 consecutive individuals presenting for root canal treatment (RCT). Patients were treated by undergraduate and graduate students, following standard RCT protocols. Demographic, medical and dental variables were extracted from a pre-structured and standardized ECD. The main outcomes PREP and incident POEP were collected through a 0-10 numeric rating scale, dichotomized as none/mild (<4) or moderate/severe (≥4) pain. Predictive models calculating the prevalence ratios (PR) of PREP and the relative risks (RR) of incident POEP were carried out with Poisson regression analysis, estimating the relationship between clinical factors, PREP and incident POEP. RESULTS: Mean age at baseline was 49.2 ± 17.1 years, with 68.4% women. The prevalence and incidence of moderate/severe PREP and POEP were 44.4% and 3.8%, respectively. RCT intervention significantly reduced PREP (P < 0.001). Multivariate analysis revealed that group of teeth, location (mandibular teeth), pulpitis, necrotic pulp, preoperative swelling and periapical radiolucency were independently associated with moderate/severe PREP, whilst age ≥60 years and root canal retreatments were independent protective factors to PREP (P < 0.05). No demographic, medical or dental variables were associated with POEP, although molar teeth (RR = 4.23, 95%CI = 0.93-19.2, P = 0.056) had a borderline nonsignificant association. CONCLUSIONS: Moderate/severe PREP was independently associated with age, group of teeth, location, preoperative swelling, retreatments and pulp and periapical status. No demographic, medical or dental variable predicted moderate/severe POEP following RCT amongst this subpopulation.

Pain associated with root canal treatment.

AIM: To determine the pain experienced by patients during root canal treatment and to correlate with age and gender, pulpal diagnosis, previous periapical status, dental characteristics and length of treatment. METHODOLOGY: One hundred and seventy-six patients (68 men and 108 women), with ages ranged from 6 to 83 years, were randomly recruited. Patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain experienced during root canal treatment. RESULTS: The mean pain level during root canal treatment was 1.2 +/- 0.8 in a VAS between 0 and 10. Fifty-four per cent of patients did not experience pain. There were no significant differences in relation to gender or age groups. Mandibular teeth had a significantly (P < 0.05) higher percentage incidence of pain in comparison with maxillary teeth. Pain was absent in 63% of anterior teeth compared with 44% in posterior ones (P < 0.01). Interventions shorter than 45 min resulted in a significantly higher percentage of pain absence (P < 0.05). Root canal treatment was significantly (P < 0.05) more painful in teeth with irreversible pulpitis and acute apical periodontitis compared to the group with necrotic pulps and chronic apical periodontitis (P = 0.049). CONCLUSIONS: Root canal treatment in teeth with irreversible pulpitis and acute apical periodontitis was more painful. Age, tooth type and length of the treatment were factors associated with increased risk for pain experienced during the procedure. Knowledge of pain levels endured by patients will allow dentists to decide when to use supplemental local anaesthesia.

The role of pathophysiological explanations in clinical case representations of dental students and experts.

INTRODUCTION: Teaching of biomedical knowledge lays the foundations for the understanding and treatment of diseases. However, the representation of pathophysiological explanations in the management of clinical cases differs for various levels of medical expertise and different theories have been proposed to explain this phenomenon. The present study investigated for the first time how biomedical knowledge is used in clinical reasoning in dental medicine. MATERIALS AND METHODS: In an experimental study 20 experts in the field of Periodontology and 61 students of different levels of training produced written pathophysiological explanations after having studied three different clinical cases. By comparing the written protocols to a visualised expert-made 'canonical' explanation the concepts used in the pathophysiological explanation were counted and classified as well as the links between concepts. RESULTS: The statistical analysis by MANOVA showed significant differences between third- and fourth-year students, students of intermediate expertise level (fifth-year) and experts for various parameters qualifying concepts or links of the written pathophysiological explanations. The participants of intermediate expertise level produced a high rate of concepts and links; however, characteristic findings for knowledge encapsulation in the different levels of expertise were not evident. The analysis showed that the design of the clinical cases and of the canonical explanations significantly influenced the outcomes. CONCLUSION: The present study demonstrated the pathophysiological representations of clinical cases in dental students and experts to be different from other medical disciplines. It could be assumed that this observation is based on different contents for teaching of practical skills and diagnostic procedures in dental compared with medical education.

Endodontic medicine: interrelationships among apical periodontitis, systemic disorders, and tissue responses of dental materials.

Endodontic medicine, which addresses the bidirectional relationship between endodontic infections and systemic diseases, has gained prominence in the field of endodontics. There is much evidence showing that while systemic disease may influence the pathogenesis of endodontic infection, endodontic infection can also cause systemic alterations. These alterations include more severe bone resorption and inflammation in the periapical area as well as enhanced systemic disease symptoms. Similarly, many reports have described the impact of systemic diseases on the tissue responses to dental materials. Conversely, the local use of dental materials may show systemic effects in the form of altered production of biomarkers. Thus, studies to better understand the mechanisms related to those connections are extremely important. In this context, the objective of this review was to analyze and discuss the current literature regarding the connections among these three factors-systemic diseases, endodontic infection, and endodontic dental materials-and determine how these connections may interfere in the systemic health status and the endodontic treatment outcomes, which are represented by periapical wound healing.

[The influence of age upon circadian rhythm of human pulp sensibility].

OBJECTIVE: To explore the influence of age on the circadian rhythm of pulp sensibility, guide the diagnosis and treatment of dental and endodontic diseases. METHODS: The first lower molars of young, middle-aged, and aged volunteers were inspected for the threshold of pulp sensitivity. Each inspection was implemented every 4 hours earlier, totally 7 times during 24 hours. All values of pulp sensibility threshold from each volunteer were analyzed by Halberg methods for cosinor-rhythmometry. The chronobiology characteristics of pulp sensibility were compared among young, middle-aged, and aged. RESULTS: The pulp sensibility threshold values of the young, middle-aged, and aged indicated to have the circadian rhythm alternation in period of 24 hours, with fitting well to a cosine curve. The trend of rhythm curve was similar to all three age groups. The acrophase and bathyphase appeared at 0:00 and 12:00 separately. The values and amplitudes of pulp threshold sensibility showed to be: young>aged> middle-aged. CONCLUSION: The circadian rhythm of pulp sensibility changes according with age. The pulp sensibility threshold value is lower in aged people than in the young, and the lowest sensibility threshold is in middle-aged people. Besides, the extent of rhythm fluctuation is the least in middle-aged people.

Investigations of the prevalence and virulence of Candida albicans in periodontal and endodontic lesions in diabetic and normoglycemic patients.

OBJECTIVE: The aim of this study was to investigate the prevalence of isolated Candida albicans from periodontal endodontic lesions in diabetic and normoglycemic patients, and the fungi's virulence in different atmospheric conditions. MATERIAL AND METHODS: A case-control study was conducted on 15 patients with type 2 diabetes mellitus (G1) and 15 non-diabetics (G2) with periodontal endodontic lesions. Samples of root canals and periodontal pockets were plated on CHROMagar for later identification by polymerase chain reaction (PCR) and virulence test. RESULTS: C. albicans was identified in 79.2% and 20.8% of the 60 samples collected from diabetic and normoglycemic patients, respectively. Of the 30 samples collected from periodontal pockets, 13 showed a positive culture for C. albicans, with 77% belonging to G1 and 23% to G2. Of the 11 positive samples from root canals, 82% were from G1 and 18% from G2. Production of proteinase presented a precipitation zone Pz<0.63 of 100% in G1 and 72% in G2, in redox and negative (Pz=1), under anaerobic conditions in both groups. Hydrophobicity of the strains from G1 indicated 16.4% with low, 19.3% with moderate, and 64.3% with high hydrophobicity in redox. In G2, 42.2% had low, 39.8% had moderate, 18% had high hydrophobicity in redox. In anaerobic conditions, G1 showed 15.2% with low, 12.8% with moderate, and 72% with high hydrophobicity; in G2, 33.6% had low, 28.8% had moderate, and 37.6% had high hydrophobicity. There was statistical difference in the number of positive cultures between G1 and G2 (p<0.05) with predominance in G1. There was statistical difference for all virulence factors, except hemolysis (p=0.001). CONCLUSIONS: Candida albicans was isolated more frequently and had higher virulence in diabetic patients.

Chitosan monomer promotes tissue regeneration on dental pulp wounds.

The present study was undertaken to evaluate the applicability of chitosan monomer (D-glucosamine hydrochloride) as a pulp capping medicament. Both in vitro and in vivo experiments were carried out to study the cell metabolism and wound healing mechanisms following the application of chitomonosaccharide. After 3 days of osteoblast culture, alkaline phosphatase (ALP) activity significantly increased in the chitosan group. Reverse transcription polymerase chain reaction analysis revealed that chitosan induced an increase in the expression of ALP mRNA after 3 days and bone morphogenetic protein-2 mRNA after 7 days of osteoblast incubation. Inflammatory cytokine, interleukin (IL)-8, synthesis in fibroblasts was strongly suppressed in the medium supplemented with chitosan monomer. Histopathological effects were evaluated in rat experiments. After 1 day, inflammatory cell infiltrations were observed to be weak when compared with the application of chitosan polymer. After 3 days, a remarkable proliferation of fibroblasts was seen near the applied chitosan monomer. The inflammatory cell infiltration had almost completely disappeared. After 5 days, the fibroblastic proliferation progressed, and some odontoblastic cells appeared at the periphery of the proliferated fibroblasts. These findings indicate that the present study is the first report that chitosan monomer acts as a biocompatibility stable medicament even at the initial stage of wound healing in comparison with the application of chitosan polymer.

Influence of pulpal treatments on cell and tissue reactions in the marginal periodontium.

The effects of pulpal infection and intrapulpal application of calcium hydroxide and antibiotics were evaluated with special reference to cell and tissue reactions in the marginal hard/soft tissue interface in monkeys. Results indicate the pulpal conditions and endodontic dressings influence marginal healing and repair, provided an endodontic-periodontic pathway such as patent dentin tubules is present. These results suggest that permanent endodontic treatment, with an inert material, should be performed before the protective cementum layer is removed. Pulpally aggravated periodontal lesions should therefore not be overlooked in periodontal diagnosis and treatment.

The flare-up index: a quantitative method to describe the phenomenon.

Acute exacerbation of symptoms during the inter-appointment time interval of endodontic treatment is a well-known complication. The phenomenon is termed "flare-up" by most researchers and clinicians, although the exact definition of it differs from one author to another, making it difficult to compare the results of the studies. The suggested flare-up index may be the way to build a common language that will enable the dental community to measure and study more of this phenomenon.

Feline immunodeficiency virus model to study human immunodeficiency virus/acquired immune deficiency syndrome conditions.

This study was designed to induce rapid progression of the feline immunodeficiency virus (FIV) infection in cats. Predictably inducing the FIV disease state in the cat would yield an excellent tool to study endodontic disease processes under immunosuppressed conditions. Eight cats were immunosuppressed with steroids before infection with FIV. Another eight cats, age- and sex-matched littermates, served as uninoculated seronegative controls. Complete blood counts were taken for 10 mo in the FIV group, and 10 wk in the control group, including lymphocyte subsets. ELISAs were used to detect FIV infection. Statistical analysis was performed with generalized estimating equation models. All cats were positive at one point in time. The FIV group had significantly lower peripheral blood CD4+ counts compared with the control group. Therefore the FIV model presented gives the desired outcome and simulates what occurs in human immunodeficiency virus infection.

The endodontic-periodontal continuum revisited: new insights into etiology, diagnosis and treatment.

For many decades, investigators have conducted studies of the interrelationship between endodontics and periodontics. This review article examines previously held concepts regarding the endodontic-periodontal continuum in light of new research and explores promising advances in understanding etiology and in diagnosis and treatment.

Classification and diagnosis of pulpal pathoses.

The purpose of this article has been to review some concepts regarding the histophysiology and histopathology of the pulpodentinal complex and the "language of classification." Although there may not be agreement on the "language" presented here, there can be no disagreement that from a clinical perspective, knowledge and appreciation of the ideas presented can be helpful in determining pathologic presence. In reaching the ultimate clinical decision, the following questions must be answered: Are we dealing with a pulpal disease that is potentially reversible? If treatment is necessary do we treat the pulp or the pulp canal?

Prevalence of dental abscess in a population of children with vitamin D-resistant rickets.

A population of patients with vitamin D-resistant rickets whose present ages range from 4 to 22 years was examined to determine the prevalence of dental abscess associated with that condition. For those patients affected with abscesses in the primary dentition, four associated factors were examined: 1) the age at onset of the first abscess; 2) the tooth/teeth most commonly involved; 3) whether or not other teeth were involved over time; and 4) the order of occurrence of multiple abscesses. Six of 24 patients (25%) were affected with abscesses of the primary dentition; all had multiple abscesses. Males were more commonly involved than females. The sequence of involvement generally followed the pattern of tooth eruption; however, dental treatment in susceptible individuals shortened the time between eruption and abscess. Medication dose and measurement of radiographs were not reliable predictors of the occurrence of abscesses in this population; however, the results indicate that one abscess is a predictor of future abscesses for that patient.

Vitality of the dentin-pulp complex in health and disease: growth factors as key mediators.

The vitality of the dentin-pulp complex, both during tissue homeostasis and after injury, is dependent on pulp cell activity and the signalling processes, which regulate the behavior of these cells. Research, particularly over the last ten to fifteen years, has led to a better understanding of the molecular control of cellular behavior. Growth factors play a pivotal role in signalling the events of tissue formation and repair in the dentin-pulp complex. Sequestration of growth factors in the dentin matrix during tissue formation provides a pool of these molecules, which may be released during injury and contribute to signalling of reparative events. Therapeutic intervention with recombinant growth factors also provides possibilities for control of cell activity during repair. Harnessing both endogenous and exogenous sources of growth factors can provide exciting opportunities for novel biological approaches to dental tissue repair and the blueprint for tissue engineering of the tooth. These approaches offer significant potential for improved clinical management of dental disease and maintenance of tooth vitality.

Pulpal injury: pathology, diagnosis and periodontal reactions.

Diagnosis of pulpal disease can be difficult due to the lack of diagnostic signs and symptoms available to the practitioner. An understanding of the possible underlying pathological processes, combined with an exact assessment of the pain history, and appropriate clinical tests, should aid the practitioner in determining the nature of pulpal inflammation, and differentiating it from dentine sensitivity and cracked teeth. The responses of the pulp to traumatic injury to the periodontal membrane (PDM) require special consideration, particularly with respect to the assessment of pulp vitality, and the determination of cases requiring pulp extirpation in order to avoid inflammatory root resorption. Although the pulp is relatively isolated from the rest of the dentoalveolar complex by a dentine/cementum barrier, it is important to remember that it can communicate with the PDM through apical and lateral foramina, and areas of damaged cementum. Hence, it is a priority to both preserve the integrity of the cemental layer in cases of traumatic injury and periodontal disease, and to prevent the inflammation and resorption associated with periapical lesions by accurate diagnosis of irreversible pulpitis and pulp necrosis, followed by appropriate endodontic debridement procedures.

Pulp survival and hard tissue formation subsequent to dental trauma. A clinical and histological study of uncomplicated crown fractures and luxation injuries.

Traumatic injuries in children and adolescents are a common problem, and the prevalence of such injuries has increased over the last 10-20 years. The purpose of the present investigation was to evaluate long-term results following uncomplicated crown fractures and luxations involving subsequent pulp canal obliteration. A total of 198 patients with 488 injured permanent teeth were available for clinical examination (15 year follow-up), of which 102 also answered a questionnaire and were interviewed before oral examination. Further, 82 permanent incisors presenting with pulp canal obliteration (PCO) were followed for a period of 7 to 22 yr. (mean 16 yr.). The histological evaluation of luxation injuries was performed on 123 primary teeth from 98 patients. In the experimental study (crown fractures), 64 monkey permanent maxillary and mandibular central incisors and canines were subjected to different treatment alternatives at the time of fracture. The findings in the follow-up study showed very little pulpal response to crown fracture and subsequent restorative procedures as long as there was no concomitant periodontal injury. Approximately every fourth resin composite restoration was rated unacceptable at the clinical examination. The interview showed that half of the individuals were dissatisfied with the color and/or anatomic form of the composite restoration. PCO was found in all luxation categories, and according to the survival curve, the 20-year pulp survival rate diagnosed with X-ray was 84%. Although the risk for pulp necrosis (PN) increased with time, routine endodontic intervention of teeth with ongoing PCO of the root canal did not seem justified. The histological study showed that changes in dentin were represented by occlusion of the dentinal tubules and deposition of tertiary dentin. The tertiary dentin were classified as either dentin-like, bone-like or fibrotic. In the experimental study, few changes were observed in the pulp 3 months after crown fractures, irrespective of treatment alternative.

Occlusal considerations in determining treatment prognosis.

To function in occlusal harmony, the masticatory apparatus--composed of the teeth and its supporting structures, temporomandibular joints, and associated neuromusculoskeletal structures--must operate in an integrated and dynamic manner. Loss of integrated function, or of homeostasis in response to functional demand, may generate problems in occlusion. In health, adaptive changes occur with the teeth and periodontium in response to functional occlusal forces. With periodontal and endodontic disease, this adaptive capacity diminishes. The ability to foresee how these changes may influence dental treatment is important in the art of determining treatment prognosis.