Diagnostic and Clinical Factors Associated with Pulpal and Periapical Pain

Pulpal and periapical pains are two of the reasons why patients seek dental care. Pain experienced before, during or after endodontic therapy is a serious concern to both patients and endodontists (1). Although pain receives substantial attention from all healthcare providers, many patients consider pain and dentistry to be synonymous (2). Pain is a complex phenomenon, and dental pain, a multifactorial or multidimensional experience, involves sensory responses and emotional, conceptual, and motivational aspects (3). Moreover, the pain threshold of intradental nerves may be affected by inflammation, detected by receptors expressed on pulpal nociceptors (2), or local changes in intrapulpal pressure (4). In the United States, about 22% of adults aged 18 Diagnostic and Clinical Factors Associated with Pulpal and Periapical Pain


INTRODUCTION
Pulpal and periapical pains are two of the reasons why patients seek dental care.Pain experienced before, during or after endodontic therapy is a serious concern to both patients and endodontists (1).Although pain receives substantial attention from all healthcare providers, many patients consider pain and dentistry to be synonymous (2).Pain is a complex phenomenon, and dental pain, a multifactorial or multidimensional experience, involves sensory responses and emotional, conceptual, and motivational aspects (3).Moreover, the pain threshold of intradental nerves may be affected by inflammation, detected by receptors expressed on pulpal nociceptors (2), or local changes in intrapulpal pressure (4).
In the United States, about 22% of adults aged 18

Diagnostic and Clinical Factors Associated with Pulpal and Periapical Pain
clinical factors during and after root canal treatment (13,14), others have determined the association of periapical and pulpal symptoms with bacteria, enzymes and toxins (15)(16)(17)(18).Few epidemiological studies have focused on urgencies that occur before the beginning of endodontic treatment (7).Knowledge of the frequency and clinical factors associated with pulpal and periapical pain may provide important information to the planning of preventive or therapeutic strategies, as well as to the understanding of the outcomes of urgent endodontic treatment.Thus, this study aimed to determine the frequency and clinical factors associated with pulpal and periapical pain experienced before dental treatment.

MATERIAL AND METHODS
A retrospective survey evaluated patients who sought treatment at the Dental Urgency Service of the Dental School of the Federal University of Goiás, Brazil, in 2005 and 2006 due to odontogenic discomfort or pain associated with inflammation, infection, or both.After approval by the University Ethics Committee (Protocol number 055/2005), a consecutive sample of 1,765 patients (675 males) of low socioeconomic status with mean age of 32 years and history of severe odontogenic pain or swelling, was formed.Inclusion criterion was pulpal or periapical diseases that occurred before dental treatment (minimum of 6 months after the last dental appointment), and the exclusion criteria were teeth with odontogenic developmental anomalies and missing information or incomplete records.Data were collected by two professors of the institution, who discussed the diagnostic criteria.When a consensus was not reached, a third professor made the final decision.
The analysis of pulpal and periapical pain followed guidelines for the clinical diagnosis of pulpal and periapical diseases: hyperreactive pulpalgia, symptomatic pulpitis, symptomatic apical periodontitis of traumatic or infectious origin, periapical abscess without sinus tract, periapical abscess with sinus tract (7).During the clinical examination, data about medical and dental history were collected together with the following clinical characteristics of the pain: type (provoked, spontaneous), duration (short, long), frequency (continuous, intermittent) and site (local, diffuse).The clinical examination included the evaluation of all visual biophysical characteristics of the tooth and surrounding tissues, palpation, percussion and pulpal vitality tests, and radiographic studies.Dental urgencies associated with other odontogenic problems, such as traumatic dental injuries, periodontal pain, temporomandibular joint (TMJ) pain, and postoperative pain, were classified into the "other" category.
Frequency of pulpal and periapical pain was calculated based on the clinical classification of inflamed pulpal and periapical tissues.Chi-square test assessed the clinical factors associated with pulpal and periapical pain, and multiple logistic regression tested the association of pulpal and periapical pain with independent clinical factors.Data were analyzed using the SPSS for Windows 15.0 statistical software (SPSS Inc., Chicago, IL, USA).

RESULTS
Of the studied teeth, 889 were mandibular and 876 were maxillary, including.They were permanent molars (n=974), premolars (n=399), permanent canines (n=95), permanent incisors (n=203) and primary teeth (n=94); 93 had root canal treatment, and 1,672 did not.Of all odontogenic urgencies, the highest frequency rates were 28.3% for symptomatic pulpitis and 26.4% for apical periodontitis of infectious origin.The lowest frequency rate was 0.6% for symptomatic apical periodontitis of traumatic origin (Table 1).Clinical factors of odontogenic pain are shown in Tables 2 and 3 4).

DISCUSSION
The distribution, prevalence, frequency and severity of diseases, especially when associated with pain, can be favored by epidemiological data (20,21).Planning preventive or therapeutic strategies and evaluating outcomes, depend on these data (22,23).
Data for this retrospective survey were carefully collected by professors who work at the Dental Urgency Service of the Federal University of Goiás, Brazil and are prepared to use the same clinical diagnosis guidelines (7).Although different classification systems for pulpal and periapical diseases are found in the literature (1,2,6,7,9,11,24), there seems to be evidence to support the consensus about the absence of correlation between clinical events, radiographic assessment and histopathological characteristics (1,2,9,10,12,19).Therefore, a clinical classification of pulpal and periapical disease, which the authors were familiar with, was used in our study (7).
Previous studies (13,14) have found an association of several factors The combination of various factors of the same clinical situation may interfere in research outcomes.Therefore, clinical criteria should be carefully standardized.Based on inclusion criteria, this study only determined pulpal and periapical pain that developed before dental treatment.The higher frequency of odontogenic pain indicated the occurrence of symptomatic pulpitis and apical periodontitis of infectious origin.These common symptomatic diseases are caused by microorganisms, as previously described (15)(16)(17)(18)(19)(20).Khabbaz et al. (18) determined the presence or absence of endotoxins in the superficial and deep layers of carious lesions of symptomatic and asymptomatic teeth with vital pulps, measured the amount of endotoxin, and associated the presence of endotoxins with the acute pulpal pain caused by irreversible pulpitis.Greater amounts of endotoxin were found in caries of painful teeth compared with teeth without symptoms.Hahn and Liewehr (17) discussed the association between caries bacteria, host responses, and clinical signs and symptoms of pulpitis, and reported that caries bacteria and inflammatory responses (proinflammatory and antiinflammatory cytokines) in the dental pulp are important aspects to understand pulpitis pathogenesis.Recent advances in immunology and neurophysiology explain some clinical signs of pulpitis, such as the proinflammatory properties of lipoteichoic acid, which is a common virulence factor of Gram-positive bacteria found among caries bacteria.Sundqvist et al. ( 16) evaluated the ability of bacteria of pulpal necrosis to induce purulent infections, and found that certain acute exacerbations are caused by polymicrobial infections in which important microorganisms achieve pathogenicity by synergism.
In the present study, one important clinical factor for pulpal pain was caries.This result is in agreement with those reported in other studies that correlated caries with symptomatic pulpitis (17,18).The significant clinical factor for periapical pain was open pulp chamber, which may be explained because of the continuous root canal contamination that promotes polymicrobial infection, increases the number of microorganisms (15,16), and favors bacterial synergism (16).Horiba et al. (15) showed that teeth with clinical symptoms have great amounts of endotoxin.The endotoxin detection rates and the mean endotoxin content were higher for teeth with exudations than for teeth with dry root canals.Jacinto et al. (19) also found high endotoxin concentrations in root canals of symptomatic teeth.There was a positive correlation between endotoxin concentration in root canals and the presence of endodontic signs and symptoms.
The type of restoration most often associated with pulpal pain was amalgam, while temporary and resin restorations were most frequently associated with periapical pain.Fracture of amalgam restorations with microbial leakage or not, may cause pulpal pain.Resin restorations were a clinical factor for periapical pain.This type of restoration without adequate pulp protection, may injure pulp tissue (7).In this situation, pulp necrosis often occurs slowly.Pain is more frequent when teeth have periapical lesions.It is important to consider that differences in apical periodontitis image interpretation by using cone beam computed tomography (CBCT) and conventional periapical radiography have been identified (25).CBCT has provided promising results with a more accurate detection of apical periodontitis.
This study found a higher frequency of pulpal and periapical pain in women than in men, and the mean age of the sample was 32 years, in agreement with previous investigations (5,14,20).Chung et al. (20) investigated the prevalence of orofacial pain symptoms in the Korean elderly population, and evaluated factors associated with orofacial pain and graded chronic pain.The results suggested that the 6-month prevalence of joint pain (15.5%), face pain (9.3%), toothache (26.8%), oral sores (26.2%), and burning mouth (14.2%) in Korean elders were higher than in studies on Caucasian populations.Painful oral sores and burning mouth had higher prevalence for females than for males.Subjects with joint pain, burning mouth or toothache pain were more likely to report high levels of a pain-related disability compared with subjects not reporting those symptoms.There were no age group differences in pain intensity, but the older age group reported a larger number of disability days because of their pain.Lipton et al. (5) evaluated the prevalence and distribution of orofacial pain among adults in the United States and found that toothache was the most frequent symptom, and that women experienced each symptom more often than men with only two exceptions -"toothache and oral sores" and "oral sores and burning mouth".
The prevention of caries and periodontal disease has received special attention in dentistry in the last years, but dental urgencies are often the result of clinical factors such as caries, restorations, coronal fractures, and open pulp chamber.In this study, traumatic dental injuries were included in the "other" category because of the number of cases treated in other University departments.Although, it is essential to mention that a limitation intrinsic in a retrospective study is associate the cause-and-effect relationships.Clinical experience is not sufficient to establish therapeutic guidelines, particularly in the case of odontogenic urgencies.Clinical and biological studies should be conducted to define the best therapeutic protocols.Several parameters should be considered, and it is essential to study endodontic pain, its frequency and clinical factors associated.In this study,

Table 4 .
Logistic regression analysis for each explanatory variable for pulpal and periapical pain in odontogenic urgencies (n=1765).