Why can't you achieve adequate regional anesthesia in the presence of infection?

Association between single nucleotide polymorphisms in candidate genes and success of pulpal anesthesia following inferior alveolar nerve block

INTRODUCTION

The present study aimed to investigate the possible association between the single-nucleotide polymorphisms (SNPs) in the SCN9A, SCN10A, SCN11A, OPRM1, and COMT genes and the success rate of pulpal anesthesia after inferior alveolar nerve block (IANB).

METHODS

A total of 70 patients (45 females and 25 males) presenting mandibular molar teeth with symptomatic irreversible pulpitis were included. Saliva samples were collected from the participants before the application of IANB. A standard IANB was performed with 1.8 mL 4% articaine with 1:100,000 epinephrine. Endodontic treatment was initiated 15 minutes after injection, and the patients were asked to report their pain level during the procedure on a 170-mm Heft-Parker visual analog scale. If the patient recorded a pain level of lower than 54 on the visual analog scale (no pain or mild pain), the anesthesia was considered successful. The DNA isolation and genotyping were performed, and the association between rs4286289, rs6746030, rs6795970, rs6801957, rs11709492, rs1799971, rs1799973, rs4680, rs6269, rs4633, and rs740603 SNPs and the success rate of anesthesia was investigated.

RESULTS

The anesthesia success rate was significantly lower for the GG genotypes (45%) than the GA and AA genotypes (90%) for rs6795970 in the SCN10A gene. Additionally, the A allele for rs6795970 and the T allele for rs6801957 in the SCN10A gene were significantly associated with higher anesthesia success rates.

CONCLUSIONS

SNPs in the SCN10A gene affect the success rate of pulpal anesthesia after IANB.

Effect of precooling injection site and cold anesthetic administration on injection pain, onset, and anesthetic efficacy in maxillary molars with symptomatic irreversible pulpitis: a randomized controlled trial

OBJECTIVE

This randomized controlled clinical trial assessed the analgesic and anesthetic effects of precooling the injection site and administration of refrigerated 2% lignocaine HCl with 1:100,000 epinephrine (LE) in maxillary molars with symptomatic irreversible pulpitis (SIP).

MATERIALS AND METHODS

Sixty patients diagnosed with SIP (preoperative pain score ≥ 85 mm) in maxillary first molars were randomly allocated to two groups. In group I (control), topical gel was applied for a minute followed by conventional LE infiltration, whereas in group II (experimental), topical ice application for 15 s and refrigerated (4-6 °C) LE administration was done prior to endodontic treatment. The primary outcome measure was anesthetic efficacy that was defined as none to weak pain (≤ 36 mm) as measured on Heft Parker visual analog scale (HP-VAS) following access cavity preparation. Pain on injection and onset constituted the secondary outcome measures. The pain on injection was measured using HP-VAS, whereas the onset of anesthesia was assessed using an electric pulp tester (EPT) which was applied on the experimental tooth every minute until no response was elicited. Mann-Whitney U test was performed to analyze the data (p < 0.01).

RESULTS

Experimental group reported a success rate of 86.6% when compared to control group (26.6%) and a statistically significant reduction on injection pain (20.0 mm vs 54.5 mm) (p < 0.01). The onset of anesthesia for experimental group was 2.4 min which was also significantly lower than control group (4.5 min) (p < 0.01).

CONCLUSIONS

Cryotherapy can serve as an effective alternative to conventional anesthesia for achieving success, reduced pain, and faster onset during endodontic treatment of maxillary molars with SIP.

CLINICAL RELEVANCE

Precooling the injection site and cold LE administration can result in effective pulpal anesthesia during endodontic management of maxillary molars in SIP patients.

Postanesthetic Cold Sensibility Test as an Indicator for the Efficacy of Inferior Alveolar Nerve Block in Patients with Symptomatic Irreversible Pulpitis of Mandibular Molars

Materials and Methods

This study was conducted on the mandibular first molars of 54 patients (35 males and 19 females) with signs and symptoms of SIP. To anesthetize the affected molars, all patients received a single carpule of 2% lidocaine with 1 : 100000 epinephrine using a standardized inferior alveolar nerve block (IANB) technique. The cold test was conducted before beginning the endodontic procedures and after gaining lip numbness, and the results were reported as either positive or negative response. The root canal preparation (RCP) was then initiated and the patients' responses were documented (Gold standard test). True pulpal anesthetic failure was described as a pain perception during the access cavity and pulp tissue removal. True pulpal anesthesia was defined as no pain or discomfort during the access cavity and pulp extirpation. The qualitative variables frequencies and percentages of patients with true/false positive and negative responses were determined and then compared using the Chi-square test. The pain perception of male and female patients during the cold test and gold standard was compared using the Fisher exact test. The following diagnostic parameters were calculated using an online statistical calculator: sensitivity, specificity, predictive values, accuracy, and Youden index. In addition, a receiver operating characteristic curve (ROC) was constructed and the area under the curve (AUC) was calculated.

Results

The overall percentage of actual failure of pupal anesthesia was 57%. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and Youden index for the cold test were 0.87, 0.91, 0.93, 0.84, 0.89, and 0.78, respectively. There was no statistically significant difference between male and female patients regarding their responses to cold testing and the gold standard test (P > 0.05). Besides, the patients' reactions to the cold test were significantly matched with their reactions to the gold standard test (P < 0.05). The area under the ROC was mostly 0.9.

Conclusion

The cold test could be a valuable and accurate method for predicting the potential pupal anesthesia before beginning the endodontic treatment of mandibular molars with symptomatic irreversible pulpitis, particularly after obtaining postanesthetic soft tissue numbness.

Retromolar canal infiltration as a supplement to the inferior alveolar nerve block injection: an uncontrolled clinical trial

OBJECTIVES

This study aimed to determine the success rate of retromolar canal (RMC) infiltration following the failure of inferior alveolar nerve block (IANB) injections for the anesthesia of mandibular first molars with acute irreversible pulpitis.

MATERIALS AND METHODS

An IANB injection was administered for 50 patients with acute irreversible pulpitis. Lip numbness was set as the sign of anesthesia and further evaluated and confirmed with pulp sensibility tests after 10-15 min. Access cavity preparation was commenced unless the patient felt any pain; in this case, an RMC infiltration injection was given. The success rate was determined through the patients' recording of the presence, absence, or reduction of pain severity during access cavity preparation using the Heft-Parker visual analog scale.

RESULTS

Seven patients (14%) did not experience any pain by pulp sensibility tests and during access cavity preparation after IANB injection. Twenty-five (58.1%) of the remaining 43 patients who had the RMC infiltration injection had reduced pain, and four patients (9.3%) experienced no pain after the RMC infiltration. Fourteen patients (32.5%) experienced no change in pain. Chi-squared test results revealed that the percentage of patients with reduced pain was higher than that of other patients (P < 0.001).

CONCLUSIONS

RMC infiltration, along with IANB, significantly reduced the pain felt by patients and increased the success of the anesthetic technique for root canal treatment of mandibular first molars with acute irreversible pulpitis.

CLINICAL RELEVANCE

The administration of RMC infiltration can enhance the success of the IANB technique for anesthetizing mandibular first molars exhibiting acute irreversible pulpitis.

Irreversible pulpitis and achieving profound anesthesia: Complexities and managements

Dental pain management is one of the most critical aspects of modern dentistry. Irreversible pulpitis and further root canal therapy might cause an untolerated pain to the patients. The improvements in anesthetic agents and techniques were one of the advantages of studying nerve biology and stimulation. This article tried to overview of the nerve activities in inflammatory environments or induced pain. Furthermore, the proper advises, and supplementary techniques were reviewed for better pain management of irreversible pulpitis.

Effect of pulp inflammation on nerve impulse quality with or without anesthesia

Absence of complete anesthesia in teeth with acutely inflamed pulp is a well-known clinical symptom, but the mechanism behind this symptom is poorly understood. In the current electrophysiologic study, afferent nerve fiber responses of the inflamed tooth with and without anesthesia were compared with normal teeth. Seventeen cats were used in this experimental study. After inducing inflammation in one canine tooth, the responses of afferent nerves from the inflamed and control contralateral canine tooth neurons were compared before and after application of anesthesia. In most cases, 2 distinct responses in both normal and inflamed sites were recorded. The conduction velocity was significantly lower in the nerve to the inflamed side compared with the control side. In contrast, the response intensity was significantly higher in the inflamed side compared with the control side. It was also found that it was markedly more difficult to inhibit impulse transmission by using anesthesia on the inflamed side, whereas there was no trouble inhibiting impulses on the control side.

The efficacy comparison of ibuprofen, acetaminophen-codeine, and placebo premedication therapy on the depth of anesthesia during treatment of inflamed teeth

The purpose of this study was to elucidate whether premedication therapy with acetaminophen-codeine or ibuprofen is able to increase the depth of anesthesia in inflamed teeth. Sixty patients with the diagnosis of irreversible pulpitis in 1 mandibular tooth requiring root canal therapy (RCT) were selected. Two other teeth in the same quadrant were selected as controls. An electric pulp tester (EPT) was used to evaluate pulp sensitivity at the baseline and after drug administration and anesthesia injection. The subjects were divided into 3 groups randomly, and in each group 1 of the 3 drugs including acetaminophen-codeine, ibuprofen, and placebo were administered 1 hour before anesthesia delivery. After 1 hour, anesthesia was injected and after a waiting period, the EPT measurement was recorded. The reversed EPT scale was used to evaluate the depth of anesthesia achieved during RCT. Data were analyzed to statistically compare the results before and after intervention in cases and controls of each group and among different groups. Significanly lower tooth sensitivity levels (TSLs) were observed after intervention in acetaminophen-codeine and ibuprofen groups, which was more significant in the ibuprofen group. The comparison of inflamed teeth TSLs in the acetaminophen-codeine group and the placebo group after anesthesia and drug administration showed significant differences (P = .001). This comparison between ibuprofen and placebo groups also showed significant differences (P approximately 0). Also, significantly lower TSL of inflamed teeth was observed in the ibuprofen group in comparison with the acetaminophen-codeine group (P = .002). This study reflected preoperative administration of ibuprofen, if not contraindicated, as a drug of choice 1 hour before local anesthesia injection as an effective method for achieving a deep anesthesia during RCT of teeth with irreversible pulpitis.

Effectiveness of computerized delivery of intrasulcular anesthetic in primary molars

BACKGROUND

Pain measures associated with computerized delivery of intrasulcular anesthestic have not been reported. The authors evaluated a computerized delivery system for intrasulcular (CDS-IS) anesthesia in primary molars. METHODS; The study population consisted of children aged 2 to 13 years who received CDS-IS injections, 159 in mandibular molars and 48 in maxillary molars. Children were treated by one of three modes of behavioral management: behavior modification (BM) only, inhalation of nitrous oxide (N2O) in addition to BM or intrarectal sedation. Variables evaluated included the subjective perception of the child's well-being before and after administration of the anesthetic, the child's pain behavior during anesthetic administration, effectiveness of the anesthetic during dental treatment, incidence of reported postoperative dental pain (PDP) and analgesic use after the CDS-IS injections.

RESULTS

The effectiveness of CDS-IS anesthesia in mandibular molars was 97 percent, 92 percent, 63 percent and 71 percent for restorations, preformed stainless steel crowns, extractions and pulpal therapies, respectively (mean effectiveness, 89 percent). The effectiveness of CDS-IS anesthesia in maxillary molars was 96 percent, 50 percent, 92 percent and 78 percent, respectively (mean effectiveness, 90 percent). CDS-IS was less effective in children aged 2 to 4 years who received sedation than it was in older children. The authors found no differences between children's subjective self-reports of well-being before and after anesthetic administration, between the sexes and/or between modes of behavioral management (that is, BM or N2O). Most children exhibited low pain-related behavior during anesthetic administration, with no differences between boys and girls. The overall incidence of PDP was 31.4 percent; 64.9 percent of these patients received pain-relieving medications as a result, with no correlation to age, tooth treated, effectiveness of anesthesia or type of treatment.

CONCLUSIONS

CDS-IS is effective for anesthetizing primary molars, mainly for amalgam, resin-based composite and stainless steel crown restorations.

Comparing The Quality Of Anaesthesia In Normal And Inflamed Teeth By Pulp Testing

Failure to achieve complete anaesthesia of teeth with acutely inflamed pulps is a well-known clinical symptom. In this study, we compared the quality of anaesthesia in intact and inflamed mandibular teeth by using an electric pulp tester. Thirty patients with inflamed lower teeth, which had spontaneous or night pain, were selected; two healthy teeth in the same quadrant were used as control teeth. Electric pulp testing and thermal tests were made on each inflamed and control tooth. Teeth were then anaesthetised by inferior alveolar nerve block and electric pulp tests were repeated on inflamed and control teeth. Significant differences were found between electrical stimulation of inflamed and intact pulp (p approximately 0). There was no significant difference between the responses of inflamed teeth to electric pulp testing before and after anaesthesia (p = 0.327), which showed that the teeth could become resistant to anaesthesia due to the inflammation.

Effectiveness of local anesthesia in pediatric dental practice

BACKGROUND

Pain control in dental treatment for children is very important. The purpose of this study is to describe the characteristics of local anesthetic use by pediatric dentists and to examine factors related to its effectiveness in children.

METHODS

The authors observed 361 patients in 17 pediatric dental practices in Washington state while each child received restorative or surgical dental treatment. The authors recorded data concerning local anesthetic use and effectiveness. The children's mean age was 87 months, and 181 (50.1 percent) of the patients were girls. A pediatric dentist observer rated each child's anxiety before the initial injection of local anesthetic and the effectiveness of pain control during restorative treatment. The observing dentist asked the treating dentist about the effectiveness of pain control after completion of treatment.

RESULTS

Forty-two of 361 children (11.6 percent) were observed to experience ineffective pain control. Fourteen of 17 dentists (82.4 percent) were observed to have at least one patient in whom pain control was ineffective. Lidocaine (2 percent with 1:100,000 epinephrine) was used by 15 of 17 dentists (88.2 percent) and in 312 of 361 cases (86.4 percent). The average amount of agent was one cartridge (36 milligrams of lidocaine). Children who were anxious, who had symptoms before treatment, and who underwent more invasive operative and endodontic procedures were more likely to experience ineffective pain control.

CONCLUSIONS

The data suggest that painful treatment is relatively frequent even in specialized pediatric practice. Variability in general practice is likely to be greater.

CLINICAL IMPLICATIONS

The incidence of ineffective pain control may be less if clinicians use methods to reduce anxiety and perioperative infection and symptoms.

Failure of inferior alveolar nerve block in endodontics

Analgesia is essential for successful completion of modern dental procedures. Standard inferior alveolar nerve block (IANB) is the primary method used to achieve mandibular analgesia. Difficulty experienced in obtaining satisfactory analgesia after IANB, especially of an acutely inflamed mandibular molar, remains a common clinical problem. Even when a proper technique is employed, clinical studies show that IANB fails in approximately 30% to 45% of cases. The reasons for failure are not fully understood. Anatomical considerations and abnormal physiological responses in the presence of inflammation as explanations for IANB failure are discussed in this paper.

Endodontic anesthesia in mandibular molars: a clinical study

Sixty-one mandibular molar teeth with clinically manifest pulpitis, which required endodontic therapy, were studied. Twenty-seven subjects received standard inferior alveolar nerve block (IANB) with 2% lidocaine HCI with 1:100,000 epinephrine and 34 subjects received IANB with 3% mepivacaine with no vasoconstrictor. Pulpal anesthesia was assessed with dichlorodifluormethane (DDM). Subjects who gave a positive response to DDM were given a periodontal ligament injection with 2% lidocaine with 1:100,000 epinephrine. This study showed that 3% mepivacaine HCI is as effective as 2% lidocaine HCI in achieving pulpal anesthesia in mandibular molars with IANB. Of a total 61 IANB with lip anesthesia, 23 subjects required periodontal ligament injection to achieve a negative response to DDM. It was concluded that lip anesthesia is not a reliable indicator of pulpal anesthesia. The use of DDM is a reliable method of determining true pulpal anesthesia.

The role of intracanal medication in root canal treatment

The role of intracanal medication as a root canal dressing is re-examined. In pulpectomy and some root canal treatments, where the root canal contains vital pulp tissue, it is doubtful whether a routine intracanal medicament is needed. In infected root canals, intracanal medication has been advocated for many purposes. An intracanal medicament is used to: (i) eliminate any remaining bacteria after canal instrumentation; (ii) reduce inflammation of periapical tissues and pulp remnants; (iii) render canal contents inert and neutralize tissue debris; (iv) act as a barrier against leakage from the temporary filling; (v) help to dry persistently wet canals. However, most of the indications for intracanal medicaments are questionable. Intracanal medicaments should only be used for root canal disinfection as part of controlled asepsis in infected root canals, and their role is secondary to cleaning and shaping of the root canal. Thorough canal debridement and adequate canal preparation are more pertinent, and their importance is emphasized. Bacteriological sampling may be necessary if a tooth does not respond to treatment, to help in the choice of intracanal medicament.

Plaque and systemic disease: a reappraisal of the focal infection concept

The review presented here covers metastatic local and systemic disease secondary to the accumulation of plaque or the formation of other pathogenic microbial depots in the mouth. At least 3 pathways may link oral infection to secondary disease, to wit metastatic infection due to transient bacteremia, metastatic immunological injury, and metastatic toxic injury. The available evidence is presented and examples are provided. They concern among others such divergent diseases as acute bacterial myocarditis, infective endocarditis, brain abscess, uveitis and iridocyclitis, trigeminal and atypical facial neuralgia, unilateral facial paralysis, fever of "unknown' origin, and neutrophil dysfunction.