Prophylactic penicillin: effect on posttreatment symptoms following root canal treatment of asymptomatic periapical pathosis

Flare-ups After Nonsurgical Retreatments: Incidence, Associated Factors, and Prediction

INTRODUCTION

The aims of this study were to determine the incidence, associated factors, and predictability of flare-ups after nonsurgical retreatments (NSRetx).

METHODS

All patients (n = 3,666) who received NSRetx by 3 endodontists in 2 endodontic offices during a period of 6 years (2016-2022) were included. Demographic, diagnostic, and procedural data were collected. A flare-up was defined as moderate-severe pain with/without swelling that took place within 14 days of initiation of NSRetx and resulted in an unscheduled appointment. Bivariate analyses on the entire cohort and multivariable analyses on cases with complete dataset (n = 2,846) were performed to identify significant associations. A Random Forest algorithm was used to make a prediction model.

RESULTS

Incidence of flare-ups was 3.95% (n = 145). Increased risk of flare-ups was associated with diabetes (adjusted odds ratio [AOR] = 2.01; 95% confidence interval [CI], 1.01-3.97), mandibular teeth (AOR = 1.67; 95% CI, 1.11-2.52), moderate-severe preoperative pain on percussion (AOR = 2.13; 95% CI, 1.31-3.50), and pain on palpation (AOR = 1.63; 95% CI, 1.01-2.64). Lower risk of flare-up was associated with high blood pressure (AOR = 0.44; 95% CI, 0.21-0.82) (P < .05). The prediction model was not able to predict flare-ups with sufficient confidence (precision = 0.13).

CONCLUSIONS

Incidence of flare-ups following NSRetx was low (∼4%) and had a weak but significant association with the history of diabetes. Moderate-severe pain on percussion, pain on palpation (any intensity), and mandibular teeth had a significant association with flare-ups. The history of high blood pressure was associated with lower risk of flare-ups. Flare-ups were difficult to predict in this clinical setting.

Understanding painful versus non-painful dental pain in female and male patients: A transcriptomic analysis of human biopsies

Dental pain from apical periodontitis is an infection induced-orofacial pain condition that presents with diversity in pain phenotypes among patients. While 60% of patients with a full-blown disease present with the hallmark symptom of mechanical allodynia, nearly 40% of patients experience no pain. Furthermore, a sexual dichotomy exists, with females exhibiting lower mechanical thresholds under basal and diseased states. Finally, the prevalence of post-treatment pain refractory to commonly used analgesics ranges from 7-19% (∼2 million patients), which warrants a thorough investigation of the cellular changes occurring in different patient cohorts. We, therefore, conducted a transcriptomic assessment of periapical biopsies (peripheral diseased tissue) from patients with persistent apical periodontitis. Surgical biopsies from symptomatic male (SM), asymptomatic male (AM), symptomatic female (SF), and asymptomatic female (AF) patients were collected and processed for bulk RNA sequencing. Using strict selection criteria, our study found several unique differentially regulated genes (DEGs) between symptomatic and asymptomatic patients, as well as novel candidate genes between sexes within the same pain group. Specifically, we found the role of cells of the innate and adaptive immune system in mediating nociception in symptomatic patients and the role of genes involved in tissue homeostasis in potentially inhibiting nociception in asymptomatic patients. Furthermore, sex-related differences appear to be tightly regulated by macrophage activity, its secretome, and/or migration. Collectively, we present, for the first time, a comprehensive assessment of peripherally diseased human tissue after a microbial insult and shed important insights into the regulation of the trigeminal system in female and male patients.

The effect of antibiotic use on endodontic post-operative pain and flare-up rate: a systematic review with meta-analysis

Aim Antibiotics are widely used to prevent flare-ups after endodontic treatment of non-vital teeth. This systematic review assessed the effect of antibiotic administration on post-endodontic treatment pain and flare-up rate.Methods Five major databases including Web of Science, Cochrane Library, PubMed, Scopus and Embase were searched to identify randomised clinical trials (RCTs) published until September 2020. Retrieved papers were critically appraised using the revised Cochrane risk of bias tool (RoB 2). To reduce the clinical heterogeneity, the included studies were divided into two groups: studies on symptomatic non-vital teeth and studies on asymptomatic non-vital teeth. The primary outcomes were 'post-operative pain' and 'flare-up rate'. The data of included studies were statistically combined through meta-analysis using random-effect model. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence.Results Six RCTs involving two RCTs (N = 61) on symptomatic teeth and four RCTs (N = 310) on asymptomatic teeth were included. In two RCTs on asymptomatic teeth, prophylactic antibiotic had been used, while in the remaining two RCTs, antibiotics had been administered after treatment. Quantitative synthesis of the RCTs showed that antibiotic administration following endodontic treatment of symptomatic non-vital teeth has no effect on pain severity at 24 hours following treatment (weighted mean difference [WMD] = -0.03; 95% confidence interval [CI]: -0.53 to 0.47), and the use of antibiotics before endodontic treatment of asymptomatic non-vital teeth has no effect on flare-up rate (relative risk [RR] = 0.58; 95% CI: 0.22-1.54). The GRADE approach revealed that the overall quality of evidence on the topic is low.Conclusions The antibiotic administration following endodontic treatment of symptomatic non-vital teeth has no effect on pain severity at 24 hours following treatment. Also, prophylactic antibiotics are ineffective in reducing the flare-up rate following treatment of asymptomatic non-vital teeth. However, to evaluate the effect of post-treatment antibiotics on flare-up rate in asymptomatic non-vital teeth, more high-quality RCTs are needed.

Pharmacological Management of Acute Endodontic Pain

Pain associated with infections of the tooth pulp and periapical tissues is intense and often the most common reason for patients seeking emergency dental care. Effective management of acute dental pain requires a deep understanding of pain mechanisms, which enables accurate diagnosis and definitive treatment. While drugs are only used as an adjunct to definitive dental treatment, a thorough understanding of their mechanism of action and effectiveness enables clinicians to effectively control intra-operative and post-operative pain and prevent persistent pain. This review describes how pain is detected, processed, and perceived. It also provides information on evidence-based strategies on the use of different classes of drugs to effectively manage endodontic pain.

Antibiotic prescribing practices of dentists for endodontic infections; a cross-sectional study

Objective

The indiscriminate prescription of antibiotics has led to the emergence of resistance microbes worldwide. This study aimed to investigate the antibiotic prescribing practices amongst general dental practitioners and specialists in managing endodontic infections in the United Arab Emirates (UAE).

Design

General dental practitioners and specialists in the UAE were invited to participate in an online questionnaire survey which included questions on socio-demographics, practitioner’s antibiotic prescribing preferences for various pulpal and periapical diseases, and their choice, in terms of the type, dose and duration of the antibiotic. The link to the survey questionnaire was sent to 250 invited dentists. Data were analyzed by descriptive statistics and chi-square tests for independence and level of significance was set at 0.05.

Results

A total of 174 respondents participated in the survey (response rate = 70%). The respondents who prescribed antibiotics at least once a month were 38.5% while 17.2% did so, more than three times a week; amoxicillin 500 mg was the antibiotic of choice for patients not allergic to penicillin (43.7%), and in cases of penicillin allergies, erythromycin 500 mg (21.3%). There was a significant difference in the antibiotic prescribing practices of GDPs compared to endodontists and other specialties especially in clinical cases such as acute apical abscesses with swelling and moderate to severe pre-operative symptoms and retreatment of endodontic cases (p<0.05). Approximately, three quarters of the respondents (78.7%) did not prescribe a loading dose when prescribing antibiotics. About 15% respondents prescribed antibiotics to their patients if they were not accessible to patients due to a holiday/weekend.

Conclusions

In general, the antibiotic prescribing practices of UAE dentists are congruent with the international norms. However, there were occasions of inappropriate prescriptions such as in patients with irreversible pulpitis, necrotic pulps with no systemic involvement and/or with sinus tracts.

Apical periodontitis-induced mechanical allodynia: A mouse model to study infection-induced chronic pain conditions

Infection-induced chronic pain is an under-studied pain condition. One example is apical periodontitis, which evokes considerable mechanical allodynia that persists after treatment in 7% to 12% of patients. Available analgesics often provide incomplete relief. However, a preclinical model to study pain mechanisms associated with apical periodontitis is not available. Here, we report a mouse model of apical periodontitis to facilitate studies determining mechanisms mediating persistent infection-induced pain. Mice were anesthetized and the left first molar was exposed to the oral environment for six weeks. Bone resorption, as an indicator of apical periodontitis, was quantified using microcomputed tomography. Mechanical allodynia was determined using extraoral von-Frey filaments in both male and female mice. The expression of c-fos in the medullary dorsal horn was assessed using immunohistochemistry. Mice with apical periodontitis developed significant mechanical allodynia by day 7 that was maintained for 42 days. Mechanical thresholds were significantly lower in females compared to males. Administration of ibuprofen, morphine, or MK-801 reversed mechanical allodynia. Finally, apical periodontitis triggered an upregulation of c-fos in the medullary dorsal horn. Collectively, this model simulates signs of clinical pain experienced by patients with apical periodontitis, detects sex differences in allodynia, and permits the study of peripheral and central trigeminal pain mechanisms.

Genetic Variants in Cyclooxygenase-2 Contribute to Post-treatment Pain among Endodontic Patients

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) have a well-established analgesic efficacy for inflammatory pain. These drugs exert their effect by inhibiting the enzyme cyclooxygenase (COX) and are commonly used for the management of pain after endodontic treatment. There are 2 distinct isoforms of COX: COX-1, which is constitutively expressed, and COX-2, which is primarily induced by inflammation. Previous studies have shown that functional human genetic variants of the COX-2 gene may explain individual variations in acute pain. The present study extends this work by examining the potential contribution of the 2 COX isoforms to pain after endodontic treatment.

METHODS

Ninety-four patients treated by endodontic residents at the University of North Carolina School of Dentistry were enrolled into a prospective cohort study. Data on potential predictors of post-treatment pain were collected, and all patients submitted saliva samples for genetic analysis. Nonsurgical root canal therapy was performed, and participants recorded pain levels for 5 days after.

RESULTS

In this study, 63% of patients experienced at least mild pain after root canal therapy, and 24% experienced moderate to severe pain. The presence of pretreatment pain was correlated with higher post-treatment pain (P = .01). Elevated heart rate (P = .02) and higher diastolic blood pressure (P = .024) were also correlated with decreased post-treatment pain. Finally, we identified genetic variants in COX-2 (haplotype composed of rs2383515 G, rs5277 G, rs5275 T, and rs2206593 A) associated with post-treatment pain after endodontic treatment (P = .025).

CONCLUSIONS

Understanding the genetic basis of pain after endodontic treatment will advance its prevention and management.

Efficacy of Prophylactic use of Antibiotics to Avoid Flare up During Root Canal Treatment of Nonvital Teeth: A Randomized Clinical Trial

OBJECTIVES

Flare-up during root canal treatment of non vital teeth is a common clinical incident. The aim of the present study was to assess the effect of prophylactic use of antibiotics to avoid flare up during root canal treatment of the teeth having asymptomatic necrotic pulp.

MATERIALS AND METHODS

A randomized double blind clinical trial with parallel design was conducted on 100 subjects with asymptomatic non vital teeth. They were randomly divided into two groups. The first group (50 participants) was given two gram amoxicillin one hour before the first visit of root canal treatment; the second group (50 participants) did not receive any treatment (control group). In both groups, root canal treatment was performed in two visits. The flare up was assessed by the pain visual analogue scale and based on the swelling criteria. The data were processed and analyzed using SPSS statistical software 17. A p-value of 0.05 or less was considered statistically significant.

RESULTS

A total of 80% of participants in the experimental group had flare up while 12% of participants had flare up in the control group. Prophylactic Amoxicillin had no effect on inter-appointment flare up (p > 0.05). There was no relationship between flare up and patient's age, gender and tooth type (p > 0.05).

CONCLUSION

Prophylactic use of Amoxicillin in asymptomatic non vital teeth before root canal treatment had no effect on the incidence of flare-up.

Microbiology and treatment of acute apical abscesses

Acute apical abscess is the most common form of dental abscess and is caused by infection of the root canal of the tooth. It is usually localized intraorally, but in some cases the apical abscess may spread and result in severe complications or even mortality. The reasons why dental root canal infections can become symptomatic and evolve to severe spreading and sometimes life-threatening abscesses remain elusive. Studies using culture and advanced molecular microbiology methods for microbial identification in apical abscesses have demonstrated a multispecies community conspicuously dominated by anaerobic bacteria. Species/phylotypes commonly found in these infections belong to the genera Fusobacterium, Parvimonas, Prevotella, Porphyromonas, Dialister, Streptococcus, and Treponema. Advances in DNA sequencing technologies and computational biology have substantially enhanced the knowledge of the microbiota associated with acute apical abscesses and shed some light on the etiopathogeny of this disease. Species richness and abundance and the resulting network of interactions among community members may affect the collective pathogenicity and contribute to the development of acute infections. Disease modifiers, including transient or permanent host-related factors, may also influence the development and severity of acute abscesses. This review focuses on the current evidence about the etiology and treatment of acute apical abscesses and how the process is influenced by host-related factors and proposes future directions in research, diagnosis, and therapeutic approaches to deal with this disease.

Placebo interventions for all clinical conditions

BACKGROUND

Placebo interventions are often claimed to substantially improve patient-reported and observer-reported outcomes in many clinical conditions, but most reports on effects of placebos are based on studies that have not randomised patients to placebo or no treatment. Two previous versions of this review from 2001 and 2004 found that placebo interventions in general did not have clinically important effects, but that there were possible beneficial effects on patient-reported outcomes, especially pain. Since then several relevant trials have been published.

OBJECTIVES

Our primary aims were to assess the effect of placebo interventions in general across all clinical conditions, and to investigate the effects of placebo interventions on specific clinical conditions. Our secondary aims were to assess whether the effect of placebo treatments differed for patient-reported and observer-reported outcomes, and to explore other reasons for variations in effect.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 4, 2007), MEDLINE (1966 to March 2008), EMBASE (1980 to March 2008), PsycINFO (1887 to March 2008) and Biological Abstracts (1986 to March 2008). We contacted experts on placebo research, and read references in the included trials.

SELECTION CRITERIA

We included randomised placebo trials with a no-treatment control group investigating any health problem.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. Trials with binary data were summarised using relative risk (a value of less than 1 indicates a beneficial effect of placebo), and trials with continuous outcomes were summarised using standardised mean difference (a negative value indicates a beneficial effect of placebo).

MAIN RESULTS

Outcome data were available in 202 out of 234 included trials, investigating 60 clinical conditions. We regarded the risk of bias as low in only 16 trials (8%), five of which had binary outcomes.In 44 studies with binary outcomes (6041 patients), there was moderate heterogeneity (P < 0.001; I(2) 45%) but no clear difference in effects between small and large trials (symmetrical funnel plot). The overall pooled effect of placebo was a relative risk of 0.93 (95% confidence interval (CI) 0.88 to 0.99). The pooled relative risk for patient-reported outcomes was 0.93 (95% CI 0.86 to 1.00) and for observer-reported outcomes 0.93 (95% CI 0.85 to 1.02). We found no statistically significant effect of placebo interventions in four clinical conditions that had been investigated in three trials or more: pain, nausea, smoking, and depression, but confidence intervals were wide. The effect on pain varied considerably, even among trials with low risk of bias.In 158 trials with continuous outcomes (10,525 patients), there was moderate heterogeneity (P < 0.001; I(2) 42%), and considerable variation in effects between small and large trials (asymmetrical funnel plot). It is therefore a questionable procedure to pool all the trials, and we did so mainly as a basis for exploring causes for heterogeneity. We found an overall effect of placebo treatments, standardised mean difference (SMD) -0.23 (95% CI -0.28 to -0.17). The SMD for patient-reported outcomes was -0.26 (95% CI -0.32 to -0.19), and for observer-reported outcomes, SMD -0.13 (95% CI -0.24 to -0.02). We found an effect on pain, SMD -0.28 (95% CI -0.36 to -0.19)); nausea, SMD -0.25 (-0.46 to -0.04)), asthma (-0.35 (-0.70 to -0.01)), and phobia (SMD -0.63 (95% CI -1.17 to -0.08)). The effect on pain was very variable, also among trials with low risk of bias. Four similarly-designed acupuncture trials conducted by an overlapping group of authors reported large effects (SMD -0.68 (-0.85 to -0.50)) whereas three other pain trials reported low or no effect (SMD -0.13 (-0.28 to 0.03)). The pooled effect on nausea was small, but consistent. The effects on phobia and asthma were very uncertain due to high risk of bias. There was no statistically significant effect of placebo interventions in the seven other clinical conditions investigated in three trials or more: smoking, dementia, depression, obesity, hypertension, insomnia and anxiety, but confidence intervals were wide.Meta-regression analyses showed that larger effects of placebo interventions were associated with physical placebo interventions (e.g. sham acupuncture), patient-involved outcomes (patient-reported outcomes and observer-reported outcomes involving patient cooperation), small trials, and trials with the explicit purpose of studying placebo. Larger effects of placebo were also found in trials that did not inform patients about the possible placebo intervention.

AUTHORS' CONCLUSIONS

We did not find that placebo interventions have important clinical effects in general. However, in certain settings placebo interventions can influence patient-reported outcomes, especially pain and nausea, though it is difficult to distinguish patient-reported effects of placebo from biased reporting. The effect on pain varied, even among trials with low risk of bias, from negligible to clinically important. Variations in the effect of placebo were partly explained by variations in how trials were conducted and how patients were informed.

Incidence and factors related to flare-ups in a graduate endodontic programme

AIM

To investigate the incidence and factors related to endodontic flare-ups in nonsurgical root canal treatment (NSRCT) cases completed by graduate endodontic residents at University of Pennsylvania, USA.

METHODOLOGY

Residents at University of Pennsylvania enter all clinical patient records into an electronic database called PennEndo database. Analysis of records of 6580 patients treated from September 2000 to July 2005 revealed a total of 26 patients with flare-ups (0.39%). Patients were categorized to have undergone flare-up when they attended for an unscheduled visit and active treatment, and when they suffered from severe pain and or swelling after initiation or continuation of NSRCT. SAS software was used to develop a logistic regression model with flare-up as a dependent variable. Independent variables included in the model were: history of previous pain, one vs. two visit NSRCT, periapical diagnosis, tooth type, rotary versus hand instrumentation, and lateral versus vertical compaction of gutta-percha.

RESULTS

The odds for developing a flare-up in teeth with a periapical radiolucency were 9.64 times greater than teeth without a periapical radiolucency (P = 0.0090). There was no statistically significant difference in flare-ups between one and two visits NSRCT. The odds of developing a flare-up increased 40 fold when NSRCT was completed in three or more visits. However, this result may have been confounded by addition of an unscheduled visit in patients suffering from flare-ups. Other independent variables did not have any statistically significant correlations.

CONCLUSIONS

A low percentage of patients experienced flare-ups during NSRCT procedures. The presence of a periapical lesion was the single most important predictor of flare-ups during NSRCT.

Flare-ups in endodontics and their relationship to various medicaments

The purpose of this research is to investigate the frequency of endodontic flare-ups using a visual analogue scale. Definitions of flare-ups vary widely as does their reported frequency. A flare-up was defined as an increase of 20 or more points on the visual analogue scale for a given tooth, within the periods of 4 h and 24 h after the initial treatment appointment. The data from a previous study were used to determine the incidence of flare-ups after using three modalities (Ledermix, calcium hydroxide and no medication) to manage patients presenting for relief of pain of endodontic origin. A statistical analysis showed that there were no significant differences in flare-up rates at both the 4-h and 24-h periods between the three modalities. Further research is required using the above definition of a flare-up and standardising treatment protocols.

Prevalence of and factors affecting postpreparation pain in patients undergoing two-visit root canal treatment

AIM

This longitudinal, prospective study (i) investigated the prevalence of postpreparation pain during root canal treatment and (ii) evaluated the influence of factors affecting the pain experience.

METHODOLOGY

Twenty practitioners, comprising general dental practitioners, MSc graduates and endodontists, participated in this study. The patient sample (n=272) was derived from consecutive patients attending the practitioners' surgeries for a two-visit root canal treatment on a single tooth. Demographic, medical history, preoperative and intraoperative data as well as pain experience on days 1 and 2 after root canal preparation were recorded. Intensity of pain experienced was recorded on a visual analogue scale (VAS) of 0-5. The data were analysed using logistic regression models.

RESULTS

The prevalence of postpreparation pain within 48 h after treatment was 64.7% (n=176), but less than 10% of patients experienced severe pain (VAS 4 or 5) on either day 1 or day 2. The presence of preoperative pain (OR=2.841, P<0.001), tooth type (OR=2.008, P=0.009), systemic steroid therapy for other medical reasons (OR=0.181, P=0.023) and preoperative swelling (OR=2.433, P=0.040) were the only factors to significantly influence postpreparation pain experience.

CONCLUSIONS

The prevalence of postpreparation pain was high, and the important prognostic determinants were presence of preoperative pain, tooth type, systemic steroid therapy and preoperative swelling.

Placebo interventions for all clinical conditions

BACKGROUND

Placebo interventions are often claimed to improve patient-reported and observer-reported outcomes, but this belief is not based on evidence from randomised trials that compare placebo with no treatment.

OBJECTIVES

To assess the effect of placebo interventions.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2002), MEDLINE (1966 to 2002), EMBASE (1980 to 2002), Biological Abstracts (1986 to 2002), and PsycLIT (1887 to 2002). We contacted experts on placebo research, and read references in the included trials.

SELECTION CRITERIA

We included randomised placebo trials with a no-treatment control group investigating any health problem.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Outcome data were available in 156 out of 182 included trials, investigating 46 clinical conditions. We found no statistically significant pooled effect of placebo in 38 studies with binary outcomes (4284 patients), relative risk 0.95 (95% confidence interval (CI) 0.89 to 1.01). The pooled relative risk for patient-reported outcomes was 0.95 (95% CI 0.88 to 1.03) and for observer-reported outcomes 0.91 (95% CI 0.81 to 1.03). There was heterogeneity (P=0.01) but the funnel plot was symmetrical. There was no statistically significant effect of placebo interventions in the four clinical conditions investigated in three trials or more: pain, nausea, smoking, and depression, but confidence intervals were wide. We found an overall effect of placebo treatments in 118 trials with continuous outcomes (7453 patients), standardised mean difference (SMD) -0.24 (95% CI -0.31 to -0.17). The SMD for patient-reported outcomes was -0.30 (95% CI -0.38 to -0.21), whereas no statistically significant effect was found for observer-reported outcomes, SMD -0.10 (95% CI -0.20 to -0.01). There was heterogeneity (P<0.001) and large variability in funnel plot results even for big trials. There was an apparent effect of placebo interventions on pain (SMD -0.25 (95% CI -0.35 to-0.16)), and phobia (SMD -0.63 (95% CI -1.17 to -0.08)); but also a substantial risk of bias. There was no statistically significant effect of placebo interventions in eight other clinical conditions investigated in three trials or more: nausea, smoking, depression, overweight, asthma, hypertension, insomnia and anxiety, but confidence intervals were wide.

REVIEWERS' CONCLUSIONS

There was no evidence that placebo interventions in general have clinically important effects. A possible small effect on continuous patient-reported outcomes, especially pain, could not be clearly distinguished from bias.

The relationship of intracanal medicaments to postoperative pain in endodontics

AIM

To investigate the relationship of postoperative pain to three different medicaments placed in the root canal after a complete biomechanical debridement of the root canal system in patients presenting for emergency relief of pain.

METHODOLOGY

Two hundred and twenty-three teeth belonging to 221 patients presenting as emergencies to the Royal Dental Hospital of Melbourne were included in the study. Inclusion was limited to patients with a diagnosis of pulp necrosis and acute apical periodontitis. All teeth underwent conventional root canal treatment, which involved the instrumentation to the apices of each canal at the first visit. Canals were instrumented using a stepback technique and hand-files along with irrigants using Milton's (1% sodium hypochlorite) solution followed by 15% EDTAC. The canals were dried and one of the following three medicaments was inserted into the canal in random sequence: Group 1: Ledermix paste (Lederle Pharmaceuticals, Division of Cyanamid, Wolfratshausen, Germany); Group 2: calcium hydroxide paste (Calcipulpe, Septodont, France); and Group 3: no dressing. Before dismissal, the preoperative pain experienced on the previous night was recorded using a visual analogue pain scale. Patients were then instructed to record the degree of pain experienced 4 h after treatment and daily for a further 4 days.

RESULTS

The mean score pain for all three groups was between 42 and 48 prior to treatment being commenced. After 4 days, the pain score for Group 2 was 10, for Group 3 was 7 and for Group 1 was 4. Mean preoperative pain level was 44.4 (of a maximum 100) for all groups, and declined by 50% (to 22.1) after 24 h. Patients in Group 1 (Ledermix) experienced significantly less (P = 0.04) postoperative pain than those in the other two groups. There was no significant difference between Group 2 (calcium hydroxide) and Group 3 (no dressing).

CONCLUSION

Under the conditions of this study, painful teeth with acute apical periodontitis that had been dressed with Ledermix paste gave rise to less pain than that experienced by patients who had a dressing of calcium hydroxide or no dressing at all. Ledermix is an effective intracanal medicament for the control of postoperative pain associated with acute apical periodontitis, with a rapid onset of pain reduction.

Placebo treatment versus no treatment

BACKGROUND

Placebo interventions are often believed to improve patient reported and observer reported outcomes, but this belief is not based on evidence from randomised trials that compare placebo with no treatment.

OBJECTIVES

To assess the effect of placebo interventions.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (The Cochrane Library, issue 3, 1998), MEDLINE (Jan 1966 to Dec 1998), EMBASE (Jan 1980 to Dec 1998), Biological Abstracts (Jan 1986 to Dec 1998), PsycLIT (Jan 1887 to Dec 1998). Experts on placebo research were contacted and references in the included trials were read.

SELECTION CRITERIA

Randomised placebo trials with a no-treatment control group investigating any health problem were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Outcome data were available in 114 out of 130 included trials, investigating 40 clinical conditions. Outcomes were binary in 32 trials (3795 patients) and continuous in 82 (4730 patients). We found no statistically significant pooled effect of placebo in studies with binary outcomes, relative risk 0.95 (95 per cent confidence interval 0.88 to 1.02). The pooled relative risk for subjective (patient reported) outcomes was 0.95 (0.86 to 1.05) and for objective (observer reported) outcomes 0.91 (0.80 to 1.04). There was statistically significant heterogeneity (P < 0.03), but no evidence of sample size bias (P = 0.56). We found an overall positive effect of placebo treatments in trials with continuous outcomes, standardised mean difference -0.28 (95 per cent confidence interval -0.38 to -0.19). The standardised mean difference for subjective outcomes was -0.36 (-0.47 to -0.25), whereas no statistically significant effect was found for objective outcomes, standardised mean difference -0.12 (-0.27 to 0.03). There was statistically significant heterogeneity (P < 0.001), and evidence of sample size bias (P = 0.05). There was no statistically significant effect of placebo interventions in eight out of nine clinical conditions investigated in three trials or more (nausea, relapse in prevention of smoking and depression, overweight, asthma, hypertension, insomnia and anxiety), but confidence intervals were wide. There was a modest apparent analgesic effect of placebo interventions, standardised mean difference -0.27 (-0.40 to -0.15), but also a substantial risk of bias.

REVIEWER'S CONCLUSIONS

There was no evidence that placebo interventions in general have clinically important effects. A possible moderate effect on subjective continuous outcomes, especially pain, could not be clearly distinguished from bias.

Antibiotic susceptibility of bacteria associated with endodontic abscesses

Antibiotics to treat endodontic infections are routinely prescribed based on previously published susceptibility tests. There is increased concern that bacteria have increased resistance to the currently recommended antibiotics. The purpose of this investigation was to perform antibiotic susceptibility tests on a panel of bacteria recently isolated from endodontic infections. The bacteria in this study were aseptically aspirated with a needle from endodontic abscesses, cultivated, and identified at the species level. Each of the 98 species of bacteria was tested for antibiotic susceptibility to a panel of six antibiotics using the Etest. The antibiotics were penicillin V, amoxicillin, amoxicillin + clavulanic acid, clindamycin, metronidazole, and clarithromycin. The percentages of susceptibility for the 98 species were penicillin V: 83/98 (85%), amoxicillin: 89/98 (91%), amoxicillin + clavulanic acid: 98/98 (100%), clindamycin: 94/98 (96%), and metronidazole: 44/98 (45%). Metronidazole had the greatest amount of bacterial resistance; however, if it is used in combination with penicillin V or amoxicillin, susceptibility of the combination with penicillin V or amoxicillin increased to 93% and 99%, respectively. Clarithromycin seems to have efficacy, but it is still considered an antibiotic under investigation because the minimum inhibitory concentration has not been established.

A comparison of placebo effects in clinical analgesic trials versus studies of placebo analgesia

A previous meta-analysis of clinical analgesic trial studies showed generally low magnitudes of placebo analgesia (N. Engl. J. Med. 344 (2001) 1594). However, as studies included in their analysis used only placebo as a control condition, we conducted two meta-analyses, one in which 23 studies used only placebo as a control condition, and one in which 14 studies investigated placebo analgesic mechanisms. Magnitudes of placebo analgesic effects were much higher in the latter (mean effect size=0.95) as compared to the former (mean effect size=0.15) and were significantly different (P=0.003). This difference as well as differences in effect sizes within studies of placebo mechanisms may be parsimoniously explained by differences in expected pain levels produced by placebo suggestions and by conditioning. Furthermore, some of the studies of placebo analgesic mechanisms indicate that the magnitude of placebo analgesia is higher when the placebo analgesic effect is induced via suggestion combined with conditioning than via suggestion alone or conditioning alone. Based on these findings, we suggest that placebo analgesic effects are most optimally conceptualized in terms of perception of the placebo agent, and therefore a new definition of placebo response is proposed.

Retreatment versus initial root canal treatment: factors affecting posttreatment pain

OBJECTIVE

The purpose of this study was to determine the factors associated with posttreatment pain in patients receiving root canal retreatment (RCR) and in those receiving initial root canal treatment (IRCT).

STUDY DESIGN

Eighty four patients scheduled for RCR or IRCT completed questionnaires on pretreatment pain levels (Visual Analogue Scale, 0-100) and demographic data. Diagnosis and original obturating material, if applicable, were also recorded, and treatment was initiated. At 4, 8, 12, 24, 48, 72, 96, and 120 hours, patients recorded posttreatment pain levels. Seventy one patients returned completed questionnaires.

RESULTS

There was no significant difference in posttreatment pain with respect to patients undergoing RCR and patients undergoing IRCT, type of original obturating material, or pretreatment diagnosis. Posttreatment pain levels were significantly increased at 4, 8, and 12 hours after treatment. Patients reporting higher levels of pretreatment pain (Visual Analogue Scale > 20) had significantly increased posttreatment pain (P <.05) up to 24 hours after the procedure.

CONCLUSIONS

Pretreatment pain level influenced posttreatment pain more than RCR or IRCT, the type of original obturating material, or the pretreatment diagnosis.

Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment

BACKGROUND

Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this finding has not been rigorously evaluated.

METHODS

We conducted a systematic review of clinical trials in which patients were randomly assigned to either placebo or no treatment. A placebo could be pharmacologic (e.g., a tablet), physical (e.g., a manipulation), or psychological (e.g., a conversation).

RESULTS

We identified 130 trials that met our inclusion criteria. After the exclusion of 16 trials without relevant data on outcomes, there were 32 with binary outcomes (involving 3795 patients, with a median of 51 patients per trial) and 82 with continuous outcomes (involving 4730 patients, with a median of 27 patients per trial). As compared with no treatment, placebo had no significant effect on binary outcomes (pooled relative risk of an unwanted outcome with placebo, 0.95; 95 percent confidence interval, 0.88 to 1.02), regardless of whether these outcomes were subjective or objective. For the trials with continuous outcomes, placebo had a beneficial effect (pooled standardized mean difference in the value for an unwanted outcome between the placebo and untreated groups, -0.28; 95 percent confidence interval, -0.38 to -0.19), but the effect decreased with increasing sample size, indicating a possible bias related to the effects of small trials. The pooled standardized mean difference was significant for the trials with subjective outcomes (-0.36; 95 percent confidence interval, -0.47 to -0.25) but not for those with objective outcomes. In 27 trials involving the treatment of pain, placebo had a beneficial effect (-0.27; 95 percent confidence interval, -0.40 to -0.15). This corresponded to a reduction in the intensity of pain of 6.5 mm on a 100-mm visual-analogue scale.

CONCLUSIONS

We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.

Effect of prophylactic amoxicillin on endodontic flare-up in asymptomatic, necrotic teeth

The purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of prophylactic amoxicillin on the occurrence of endodontic flare-up in asymptomatic, necrotic teeth. Seventy patients participated and had a clinical diagnosis of an asymptomatic, necrotic tooth with associated periapical radiolucency. One hour before endodontic treatment, patients randomly received either 3 g of amoxicillin or 3 g of a placebo control in a double-blind manner. After endodontic treatment, each patient received: ibuprofen; acetaminophen with codeine (30 mg); and a 5 1/2-day diary to record pain, swelling, percussion pain, and number and type of pain medication taken. The results demonstrated 10% of the 70 patients had a flare-up characterized by moderate-to-severe postoperative pain or swelling that began approximately 30 h after endodontic treatment and persisted for an average of 74 h. Of the seven patients who had flare-ups, 4 were in the amoxicillin group and 3 were not. Prophylactic amoxicillin did not significantly (p = 0.80) influence the endodontic flare-up. We concluded that a prophylactic dose of amoxicillin before endodontic treatment of asymptomatic, necrotic teeth had no effect on the endodontic flare-up.

Endodontics in the adult patient: the role of antibiotics

OBJECTIVES

The aim of this study was to review the published work on the indications and efficacy for antibiotics in endodontic therapy.

DATA SOURCES

Published works in the medical and dental literature.

STUDY SELECTION

Evaluation of published clinical trials in endodontic and other pertinent literature.

CONCLUSIONS

Antibiotics are not routinely indicated in the practice of endodontics. Therapeutic antibiotics may be required as an adjunct to operative treatment when there is pyrexia and/or gross local swelling; they are only rarely indicated in the absence of operative intervention. Prophylactic antibiotics may be required for certain patients who are susceptible to serious infective sequaelae.

Penicillin as a supplement in resolving the localized acute apical abscess

PROBLEM

Antibiotics are often prescribed indiscriminately to treat endodontic emergencies.

OBJECTIVES

This study examined (1) the effect of penicillin supplementation on reduction of symptoms and (2) the course of recovery of localized acute apical abscess after emergency treatment.

STUDY DESIGN

Patients with pulp necrosis and periapical pain and/or localized swelling were considered. Those eligible did not have any signs of spreading infections. Patients received appropriate local treatment, and a double-blind protocol was used to randomly assign them to one of three groups: penicillin VK group, placebo group, or neither medication group. All received ibuprofen 600 mg four times daily for 24 hours. Patients entered their pre- and postoperative pain and swelling experience on a visual analog scale for up to 72 hours.

RESULTS

Resolution was fairly rapid in most patients. Statistical analysis of the scores of 32 respondents revealed no significant differences (at p < 0.05) between the three groups in course of recovery or symptoms at any time period.

CONCLUSIONS

Patients with localized periapical pain or swelling generally recovered quickly with local treatment. The data did not show a demonstrable benefit from penicillin supplementation.

Factors associated with endodontic flare-ups: a prospective study

The purpose of this prospective study was to assess the incidence of flare-ups (a severe problem requiring an unscheduled visit and treatment) among patients who received endodontic treatment by the two authors in their respective practices during a period of one year, and also to examine the correlation with pre-operative and operative variables. The results showed an incidence of 1.58% for flare-ups from 1012 endodontically treated teeth. Statistical analysis using the chi-square test (P<0.05) indicated that flare-ups were found to be positively correlated with multiple appointments, retreatment cases, periradicular pain prior to treatment, presence of radiolucent lesions, and patients taking analgesic or anti-inflammatory drugs. In contrast, there was no correlation between flare-up, and age, sex, different arch/tooth groups and the status of the pulp.