The efficacy of infiltration anaesthesia for adult mandibular incisors: a randomised double-blind cross-over trial comparing articaine and lidocaine buccal and buccal plus lingual infiltrations.

AIM: To compare the efficacy of 2% lidocaine and 4% articaine both with 1:100,000 adrenaline in anaesthetising the pulps of mandibular incisors. METHODS: Thirty-one healthy adult volunteers received the following local anaesthetic regimens adjacent to a mandibular central incisor: 1) buccal infiltration of 1.8 mL lidocaine plus dummy lingual injection (LB), 2) buccal plus lingual infiltrations of 0.9 mL lidocaine (LBL), 3) buccal infiltration of 1.8 mL articaine plus dummy lingual injection (AB), 4) buccal plus lingual infiltrations of 0.9 mL articaine (ABL). Pulp sensitivities of the central incisor and contralateral lateral incisor were assessed electronically. Anaesthetic efficacy was determined by two methods: 1) Recording the number of episodes with no responses to maximal electronic pulp tester stimulation during the course of the study period, 2) recording the number of volunteers with no response to maximal pulp tester stimulation within 15 min and maintained for 45 min (defined as sustained anaesthesia). Data were analysed by McNemar, chi-square, Mann-Whitney and paired t-tests. RESULTS: For both test teeth, the number of episodes of no sensation on maximal stimulation was significantly greater after articaine than lidocaine for both techniques. The split buccal plus lingual dose was more effective than the buccal injection alone for both solutions (p <0.001). 4% articaine was more effective than 2% lidocaine when comparing sustained anaesthesia in both teeth for each technique (p <0.001), however, there was no difference in sustained anaesthesia between techniques for either tooth or solution. CONCLUSIONS: 4% articaine was more effective than 2% lidocaine (both with 1:100,000 adrenaline) in anaesthetising the pulps of lower incisor teeth after buccal or buccal plus lingual infiltrations.

Examination of tunnelled haemodialysis catheters using scanning electron microscopy.

Tunnelled haemodialysis catheters (t-HDC) are prone to colonization by microorganisms, resulting in increased morbidity and mortality. A previous study concluded that all culture-negative catheters removed from cancer patients were colonized by microbial biofilms when examined by scanning electron microscopy (SEM). Examination of t-HDC by SEM has not been published before. A total of 44 segments (0.5 cm each) from 11 ex-vivo t-HDC were examined by SEM prior to endoluminal brushing and quantitative culture to determine their colonization status. Endoluminal brushing yielded a positive culture from two catheters. Methicillin-sensitive Staphylococcus aureus was grown from one catheter and a Streptococcus species was cultured from the second. SEM examination revealed universal endoluminal coverage by adherent biological material (ABM), which was composed of fibrin, platelets and other host-derived products. However, bacterial cells were visible on the two culture-positive catheters and on two out of nine culture-negative catheters, and were possibly present on one culture-negative catheter. In conclusion, in this study the prevalence of microbial colonization of ex vivo t-HDC was 18% using the endoluminal brushing technique and 36% when examined by SEM. The previously reported universal microbial colonization of central venous catheters is likely to represent coverage by ABM rather than by microbial biofilms.

Articaine buccal infiltration enhances the effectiveness of lidocaine inferior alveolar nerve block.

AIM: To compare mandibular tooth pulpal anaesthesia and reported discomfort following lidocaine inferior alveolar nerve block (IANB) with and without supplementary articaine buccal infiltration. METHODOLOGY: In this prospective randomized double-blind cross-over study, thirty-six healthy adult volunteers received two IANB injections of 2 mL lidocaine 2% with epinephrine 1 : 80,000 over two visits. At one visit, an infiltration of 2 mL of articaine 4% with epinephrine 1 : 100,000 was administered in the mucobuccal fold opposite a mandibular first molar. At the other visit, a dummy injection was performed. Injection discomfort was recorded on 100 mm visual analogue scales. Pulpal anaesthesia of first molar, premolar, and lateral incisor teeth was assessed with an electronic pulp tester until 45 min post-injection. A successful outcome was recorded in the absence of sensation on two or more consecutive maximal pulp tester stimulations. Data were analysed using McNemar and Student's t-tests. RESULTS: The IANB with supplementary articaine infiltration produced more success than IANB alone in first molars (33 volunteers vs. 20 volunteers respectively, P < 0.001), premolars (32 volunteers vs. 24 volunteers respectively, P = 0.021) and lateral incisors (28 volunteers vs. 7 volunteers respectively, P < 0.001). Buccal infiltration with articaine or dummy injection produced less discomfort than IANB injection (t = 4.1, P < 0.001; t = 3.0, P = 0.005 respectively). CONCLUSIONS: The IANB injection supplemented with articaine buccal infiltration was more successful than IANB alone for pulpal anaesthesia in mandibular teeth. Articaine buccal infiltration or dummy buccal infiltration was more comfortable than IANB.

Pulpal anaesthesia for mandibular permanent first molar teeth: a double-blind randomized cross-over trial comparing buccal and buccal plus lingual infiltration injections in volunteers.

AIM: To compare the efficacy of buccal and buccal plus lingual infiltration anaesthesia for permanent mandibular first molars. METHODOLOGY: Thirty one healthy adult volunteers received each of the following methods of anaesthesia for a mandibular first molar tooth in a randomised order, 1) Buccal infiltration of 1.8 mL and needle penetration lingually. 2) Buccal infiltration of 0.9 mL, plus lingual infiltration of 0.9 mL. Two percent lidocaine with 1:100,000 epinephrine was used. Electrical pulp testing was performed before, and every 2 minutes for 30 minutes after injection. A successful outcome was recorded as the absence of pulp sensation on two or more consecutive maximal pulp tester stimulations (80 microA). Injection discomfort was assessed using visual analogue scales. Data were compared with McNemar and Wilcoxon Signed Ranks tests. RESULTS: Buccal infiltration was successful in 38.7% of cases compared to 32.3% after combined infiltrations; the difference was not significant (P = 0.63). Buccal infiltration produced more episodes of no response to maximum stimulation than buccal and lingual infiltrations (129 and 114 respectively), this difference was not significant (P = 0.11). Peak anaesthetic effect occurred around 10-14 minutes after injection. There was no difference in injection discomfort between buccal injections of 0.9 mL and 1.8 mL of solution (P = 0.90). Lingual injection was more uncomfortable than lingual penetration (P = O.O02). CONCLUSIONS: Buccal and buccal plus lingual infiltrations did not differ in their efficacy in producing anaesthesia of permanent first molar teeth.

Possible link between extraction of wisdom teeth and temporomandibular disc displacement with reduction: matched case control study.

We undertook a case control study that compared 220 patients diagnosed with disc displacement with reduction at the Dental Hospital of Manchester with 1100 controls drawn from participants in the 1998 Adult Dental Health Survey. We found that patients were not significantly more likely to have had extraction of third molars than controls; odds ratio: 1.28, 95% CI: 0.96-1.71. Also only 21 patients (9.5%) reported having had extraction of third molars in the 5 years before their diagnosis. We conclude that for most patients extraction of third molars is unlikely to have caused disc displacement with reduction.

Scrotal ulceration during all-trans retinoic (ATRA) therapy for acute promyelocytic leukaemia.

We report the development of painful scrotal ulceration in two patients during treatment with all-trans-retinoic acid (ATRA) for acute promyelocytic leukaemia (APL). ATRA 45 mg/m2 was administered orally for 8 days prior to the addition of standard induction chemotherapy. Painful scrotal ulceration developed in both cases within 2 weeks of therapy (9 and 13 days) and responded slowly to drug withdrawal and systemic, or topical, corticosteroids. A total of 17 APL patients have been treated with ATRA at our institution during the last 10 years, giving an incidence of approximately 12%. The present report, together with a review of literature, suggests that scrotal ulceration is a specific adverse effect of ATRA therapy and that this complication may be more common than previously documented.