General medicine and surgery for dental practitioners: part 3. Management of specific medical emergencies in dental practice

In this paper, the actions needed to manage specific medical emergencies are discussed. Each emergency requires a correct diagnosis to be made for effective and safe management. Contemporary management in dental practice avoids the intravenous route when drugs are required to treat the emergency.

Effect of massage on the efficacy of the mental and incisive nerve block

The purpose of this trial was to assess the effect of soft tissue massage on the efficacy of the mental and incisive nerve block (MINB). Thirty-eight volunteers received MINB of 2.2 mL of 2% lidocaine with 1 : 80,000 epinephrine on 2 occasions. At one visit the soft tissue overlying the injection site was massaged for 60 seconds (active treatment). At the other visit the crowns of the mandibular premolar teeth were massaged (control treatment). Order of treatments was randomized. An electronic pulp tester was used to measure pulpal anesthesia in the ipsilateral mandibular first molar, a premolar, and lateral incisor teeth up to 45 minutes following the injection. The efficacy of pulp anesthesia was determined by 2 methods: (a) by quantifying the number of episodes with no response to maximal electronic pulp stimulation after each treatment, and (b) by quantifying the number of volunteers with no response to maximal pulp stimulation (80 reading) on 2 or more consecutive tests, termed anesthetic success. Data were analyzed by McNemar, Mann-Whitney, and paired-samples t tests. Anesthetic success was 52.6% for active and 42.1% for control treatment for lateral incisors, 89.5 and 86.8% respectively for premolars, and 50.0 and 42.1% respectively for first molars (P = .344, 1.0, and .508 respectively). There were no significant differences in the number of episodes of negative response to maximum pulp tester stimulation between active and control massage. A total of 131 episodes were recorded after both active and control massage in lateral incisors (McNemar test, P = 1.0), 329 (active) versus 316 (control) episodes in the premolars (McNemar test, P = .344), and 119 (active) versus 109 (control) episodes respectively for first molars (McNemar test, P = .444). Speed of anesthetic onset and discomfort did not differ between treatments. We concluded that soft tissue massage after MINB does not influence anesthetic efficacy.

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.

General medicine and surgery for dental practitioners. Part 2--metabolic disorders

It is important for dental practitioners to have a basic knowledge of the more common metabolic disorders as some may impact on the practice of dentistry. Many of these disorders do not have overt clinical signs. Taking a thorough medical history and where necessary, liaising with the patient's physician, is particularly important.

Aspirations and solutions--a 20 year journey through dental local anaesthetics

This paper describes clinical and laboratory investigations concerned with the delivery, comfort, systemic effects and efficacy of dental local anaesthesia. Factors influencing the aspirating ability of dental local anaesthetic delivery systems are discussed. The effects of adrenaline in dental local anaesthetic solutions on plasma potassium levels and on the transplanted heart are described. The use of an infiltration technique as an alternative to the inferior alveolar nerve block in the mandible is discussed.

General medicine and surgery for dental practitioners. Part 5--Psychiatry

There are a significant number of patients in society who have some form of psychiatric disorder. It is important that dental practitioners have an awareness of the more common psychiatric disorders and their potential implications as they are likely to encounter them in clinical practice.

General medicine and surgery for dental practitioners. Part 4 - skin disorders part B

Skin disorders are potentially important to dentists in diverse ways. The skin disease itself might have oral manifestations, and drugs used to treat skin disorders may impact on dental management. This second paper on skin disorders continues with a consideration of those disorders, and aspects of their treatment, which could have relevance to dental practitioners.

Prescribed medication taken by patients attending general dental practice: changes over 20 years

INTRODUCTION

Drug therapy can influence treatment planning and provision of dental care by general dental practitioners. There is little published information regarding the types of drug therapy taken by patients presenting for dental treatment in the United Kingdom.

OBJECTIVE

To record the drug therapy taken by patients presenting to general dental practice in 1995 and 2005 and compare to data reported in 1984.

SETTING

General dental practice.

STUDY DESIGN

Prospective cross-sectional study.

METHOD

Patients presenting to general dental practices in 1995 and 2005 were questioned regarding their current drug therapy. Patients' general medical practitioners were contacted if their drug history was unclear.

RESULTS

35%, 21.1% and 43.8% of patients were taking medications in 1984, 1995 and 2005 respectively. Statistically significant increases in the proportion taking three or more medications were evident in both 1995 and 2005.

DISCUSSION

In 2005 more patients presenting to dental practice were taking medications compared to 1984. There is an increasing trend toward polypharmacy. Therefore it is important to maintain a contemporaneous knowledge of pharmacology and drug interactions to ensure the provision of safe dental care.

Tutor perceptions of the use of a reflective portfolio within a pastoral tutor system to facilitate undergraduate personal development planning

All Higher Education Institutions in the UK are now required to provide transcripts of student activity and outcomes of summative assessments. In addition, the student should be able to reflect on their learning and plan their own development. This article reports on the staff evaluation of the use of a reflective portfolio facilitating the production of highly individualised personal development plans within an existing tutor system. A number of significant issues are highlighted; tutor systems adopting this approach must maintain flexibility for managing student crises when they arise, the difference between appraisal and assessment needs clear definition for both students and tutors, training in basic mentoring skills should be provided for all tutors, tutors should be aware of the difficulties many students experience with reflection and also be alert to the over reflective learner.

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.

Recent advances in local anaesthesia

This paper describes developments in the field of dental local anaesthesia. Recently introduced injectable agents, advances in the field of topical anaesthesia and new delivery systems are discussed.

A survey of local anaesthetic use among general dental practitioners in the UK attending postgraduate courses on pain control

OBJECTIVE

The aim of this study was to identify which local anaesthetic solutions were used by general dental practitioners in the United Kingdom and to determine selection criteria. In addition, differences in anaesthetic choice between recent graduates (< or = 5 years) and more experienced practitioners were investigated.

MATERIAL AND METHODS

Five hundred and six general dental practitioners attending postgraduate courses on pain control in dentistry completed a questionnaire. Participants were asked to indicate year and place of qualification, anaesthetic solutions available in their surgeries and criteria used in the choice of anaesthetic. In addition, the respondents were asked to indicate choice of local anaesthetic in a number of common medical conditions. Questionnaires were distributed and collected immediately prior to the start of the course presentation and participants were not asked to indicate whether the selection decisions were teaching, experience or evidence based. Data were analysed by using the Chi-square test.

RESULTS

Lidocaine with epinephrine was the most widely available solution among this group of practitioners (94%), the second most common solution was prilocaine with felypressin (74%). The majority of practitioners had two or more solutions available. Practitioners who qualified within the last five years (14%) were more likely to have articaine available, the most recently introduced local anaesthetic into the UK (p = 0.04, one degree of freedom). Common medical conditions lead to a modification in anaesthetic selection: the use of prilocaine/felypressin increases in the majority of circumstances, although it is avoided in pregnant females by recent graduates.

CONCLUSIONS

Lidocaine/epinephrine continues to be the most common anaesthetic solution used by this group of UK general practitioners. The primary criterion for selection of an anaesthetic agent was perceived efficacy. Prilocaine/felypressin is commonly selected as an alternative solution in the presence of common medical conditions.

Factors influencing the discomfort of intraoral needle penetration

This study with 24 volunteers compared the discomfort produced by needle penetration in different parts of the palatal mucosa. In addition, comparing a fresh needle to one that was used for a previous penetration in the same patient, we assessed the influence of the status of the needle on insertion discomfort during buccal mucosal penetration. The results showed that needle penetration in the anterior hard palate was more uncomfortable than in the posterior palate. Although men could not differentiate between fresh and used needles for a second buccal mucosal penetration, women reported a significant increase in discomfort with used needles.

Pressures generated in vitro during Stabident intraosseous injections

AIM

To test the hypothesis that the Stabident intraosseous injection is a potentially high-pressure technique, which carries serious risks of anaesthetic cartridge failure.

METHODOLOGY

A standard Astra dental syringe was modified to measure the internal pressure of local anaesthetic cartridges during injection. Intra-cartridge pressures were measured at 1 s intervals during slow (approximately 15 s) and rapid (<10 s) injections of 2% Xylocaine with 1:80,000 adrenaline (0.25 cartridge volumes) into air (no tissue resistance), or into freshly prepared Stabident perforation sites in the anterior mandible of freshly culled young and old sheep (against tissue resistance). Each injection was repeated 10 times over 3 days. Absolute maximum pressures generated by each category of injection, mean pressures at 1 s intervals in each series of injections, and standard deviations were calculated. Curves of mean maximum intra-cartridge pressure development with time were plotted for slow and rapid injections, and one-way anova (P<0.05) conducted to determine significant differences between categories of injection.

RESULTS

Pressures created when injecting into air were less than those needed to inject into tissue (P<0.001). Fast injection produced greater intra-cartridge pressures than slow delivery (P<0.05). Injection pressures rose more quickly and to higher levels in small, young sheep mandibles than in larger, old sheep mandibles. The absolute maximum intra-cartridge pressure developed during the study was 3.31 MPa which is less than that needed to fracture glass cartridges.

CONCLUSIONS

Stabident intraosseous injection conducted in accordance with the manufacturer's instructions does not present a serious risk of dangerous pressure build-up in local anaesthetic cartridges.

Differences Between Men and Women Regarding Attitudes Toward Dental Local Anesthesia Among Junior Students at a United Kingdom Dental School

The aim of this study was to assess the attitudes of junior dental students at a United Kingdom dental school regarding the administration and receipt of a local anesthetic injection. The effect of teaching on these attitudes was also evaluated. Data were collected by questionnaire. Previous experience with local anesthesia in a dental office did not affect students' attitudes toward administration and receipt of a local anesthetic injection from a classmate. Female students were more anxious about giving and receiving local anesthetic injections than male students. Didactic teaching decreased anxiety in relation to administration and receipt of a local anesthetic injection. The results showed that male and female students in a United Kingdom dental school differed in their attitudes toward local anesthesia.

A comparison of the aspirating abilities of re-usable and partly disposable dental cartridge syringes in vitro

OBJECTIVES

To compare the ability of re-usable and partly disposable dental cartridge syringes to aspirate in vitro.

METHODS

A laboratory investigation comparing two re-usable (Astra and Rotor) and one partly disposable (Ultra Safety-plus) dental cartridge syringes. Forces needed to move the cartridge plunger and forces required to produce aspiration of Bonney's Blue dye were measured using an Instron testing machine.

RESULTS

There were significant differences in the forces needed to produce aspiration in the different systems (F = 194, p<0.001). The Astra system needed the least force to produce aspiration. The forces required to aspirate in the Rotor and Ultra Safety-plus systems did not differ. Each system aspirated effectively in vitro at the initial aspiration manoeuvre. The forces available for subsequent aspiration attempts varied with the speed of cartridge plunger movement. The volume of local anaesthetic cartridge used did not affect the force needed to produce aspiration in the Ultra Safety-plus syringe. The method of testing free-flow of solution through the needle affected the force generated at subsequent plunger movements.

CONCLUSIONS

The re-usable and partly disposable syringes investigated aspirated effectively at the initial aspiration manoeuvre. The force available to produce aspiration at subsequent attempts varies with the speed of injection. The method of testing free-flow of solution through the needle in a loaded syringe affects the force available at the first aspiration manoeuvre.

Recent advances in local anaesthesia

This paper describes developments in the field of dental local anaesthesia. Recently introduced injectable agents, advances in the field of topical anaesthesia and new delivery systems are discussed.

Why Does Local Anaesthesia Not Work Every Time?

This paper describes the reasons why local anaesthesia may fail. It offers strategies to help overcome failure of local anaesthesia in dentistry.

General medicine and surgery for dental practitioners Part 9: Haematology and patients with bleeding problems

Disorders of the blood can affect the management of dental patients. Particular oral signs may be produced. In addition healing may be affected and the choice of anaesthesia for operative procedures will be influenced. Similarly, patients who have problems with haemostasis are a concern. Surgical procedures are obvious problems. However, restorative dentistry is not trouble-free as patients with bleeding problems may present difficulties regarding the choice of local anaesthesia, as regional block techniques may be contraindicated in some patients.

General medicine and surgery for dental practitioners. Part 8: Musculoskeletal system

Disorders of the musculoskeletal system may impact on dental management in diverse ways. Diseases of the bones may have a direct influence on treatment and joint disorders can also cause difficulties. Cervical spine involvement may lead to poor neck extension causing difficulties in providing dental treatment under local anaesthesia or allowing the provision of a safe general anaesthetic. Muscular disorders may mitigate against safe general anaesthesia. As with all medical disorders a thorough history can help to prevent many of the possible problems which may occur secondary to musculoskeletal diseases.

General medicine and surgery for dental practitioners. Part 7: renal disorders

Patients with kidney disorders are increasingly encountered in dental practice due to improvements in medical care leading to prolonged life expectancy. In order to provide appropriate and safe dental care for these patients it is important to have a working knowledge of renal disorders and related problems.

General medicine and surgery for dental practitioners. Part 5: liver disease

The liver has a number of important functions. It metabolises drugs and endogenous substances and contributes to their excretion by the body. Plasma proteins are synthesised in the liver which also acts as a storage organ for glycogen and vitamin B12. The liver is also important in the production of clotting factors for normal haemostatic function.

General medicine and surgery for dental practitioners. Part 3: gastrointestinal system

Diseases of the gastrointestinal (GI) system can be relevant to the dental surgeon for several reasons. The mouth may display signs of the disease itself, for example the cobblestone mucosa, facial or labial swelling of Crohn's disease, or the osteomata of Gardner's syndrome. These are well covered elsewhere and not discussed further here. The sequelae of GI disease, for example gastric reflux producing dental erosion, iron deficiency anaemia and treatment such as corticosteroid therapy may all have a bearing on management and choice of anaesthesia.

The interdisciplinary management of hypodontia: the relationship between an interdisciplinary team and the general dental practitioner

This paper will illustrate how the general dental practitioner can provide care for patients with hypodontia. It will demonstrate how an interdisciplinary team works for hypodontia patients and, in particular, for those with severe hypodontia.

The role of magnets in the management of unerupted teeth in children and adolescents

This case report describes the use of magnets in the management of teeth that fail to erupt. Eight children aged between 10 and 15 years were treated. Magnetic traction was applied to two premolars and six molars. Seven teeth (one premolar and six molars) erupted successfully (mean treatment time with magnetic traction: 7.5 months). One premolar failed to erupt; serial radiographic assessment over a 9-month period revealed no evidence of movement and so the magnetic fixture was removed. Histological evaluation of tissue samples taken from around the fixture revealed no evidence of abnormal pathology.

The interdisciplinary management of hypodontia: restorative dentistry

This paper considers the role of restorative dentistry in the management of hypodontia. The paper describes the general restorative considerations common to patients with hypodontia and illustrates the variety of restorative techniques available in the restorative management of hypodontia and oligodontia.

The interdisciplinary management of hypodontia: background and role of paediatric dentistry

This paper is the first of a series on the comprehensive management of young people with hypodontia. The paper looks at the background to the condition, the possible aetiological factors, the prevalence of hypodontia and other related conditions. Lastly there is consideration of the role of the paediatric dentist in interdisciplinary management of the affected child and adolescent patient.

Supplementary routes to local anaesthesia

The satisfactory provision of many dental treatments, particularly endodontics, relies on achieving excellent pain control. Unfortunately, the administration of a local anaesthetic solution does not always produce satisfactory anaesthesia of the dental pulp. This may be distressing for both patient and operator. Fortunately, failure of local anaesthetic injections can be overcome. This is often achieved by using alternative routes of approach for subsequent injections. Nerves such as the inferior alveolar nerve can be anaesthetized by a variety of block methods. However, techniques of anaesthesia other than the standard infiltration and regional block injections may be employed successfully when these former methods have failed to produce adequate pain control. This paper describes some supplementary local anaesthetic techniques that may be used to achieve pulpal anaesthesia for endodontic procedures when conventional approaches have failed. Although some of these techniques can be used as the primary form of anaesthesia, these are normally employed as 'back-up'. The methods described are intraligamentary (periodontal ligament) injections, intraosseous anaesthesia and the intrapulpal approach. The factors that influence the success of these methods and the advantages and disadvantages of each technique are discussed. The advent of new instrumentation, which permits the slow delivery of local anaesthetic solution has led to the development of novel methods of anaesthesia in dentistry. These new approaches are discussed.

Polypharmacy and dentistry: 2. Interactions with analgesics and antimicrobials

In the first paper of this short series the principles involved in drug interactions and the influence of polypharmacy on dental local anaesthesia and sedation were discussed. This second paper will concentrate on interactions with analgesics and antimicrobials prescribed in dental practice.

Polypharmacy and dentistry: I. Introduction and interactions with local anaesthetics and sedative drugs

This series of two papers considers the effects of drug interactions in dentistry. In this first paper, the principles of drug interactions will be described. In addition, interactions with drugs used in local anaesthesia and sedation will be discussed. The second paper will concentrate on interactions with analgesics and antimicrobials prescribed in dental practice.

Pulpal anaesthesia for mandibular central incisor teeth: a comparison of infiltration and intraligamentary injections

AIM

This study compared the anaesthetic efficacy of infiltration and intraligamentary injections in the permanent mandibular central incisor.

METHODOLOGY

Twelve healthy volunteers received each of the following methods of anaesthesia for one of their mandibular central incisors over four visits. 1 Labial infiltration of 1.0 mL. 2 Lingual infiltration of 1.0 mL. 3 Labial infiltration of 0.5 mL plus lingual infiltration of 0.5 mL. 4 Intraligamentary injection of (118 mL. Two percent lidocaine with 1: 80 000 adrenaline and 30 gauge needles were used throughout. Electrical pulp testing was performed before injection and every 2 min up to 30 min after the injection. Injection discomfort was recorded on a 100-mm visual analogue scale. Data were compared with ANOVA, Student's t-test and chi2 tests.

RESULTS

Anaesthesia varied between techniques(F = 9.3, P < 0.001). The incidence of anaesthesia at any time was as follows: 50% success for labial infiltration; 50% success for lingual infiltration: 92% success for combined labial and lingual infiltration; 0% success for intraligamentary injections (chi2 = 20; P < 0.001). The mean (+/-SD) VAS score for intraligamentary injection discomfort was 28 +/- 12 mm, for buccal infiltrations 17 +/- 8 mm and for lingual infiltrations 16 +16 mm. Intraligamentary injections were more uncomfortable than buccal (t = 3.7: P < 0.01) and lingual infiltrations (t = 2.67: P < 0.05).

CONCLUSIONS

The most reliable method of the techniques investigated for obtaining pulpal anaesthesia in mandibular permanent central incisors was a combination of labial and lingual infiltration. Intraligamentary injections were unreliable and were more uncomfortable than infiltrations in the mandibular central incisor region.

A comparison of ropivacaine and lidocaine with epinephrine for intraligamentary anesthesia

OBJECTIVE

The purpose of this study was to compare the efficacy of 2 different concentrations of ropivacaine with lidocaine containing epinephrine for intraligamentary anesthesia.

STUDY DESIGN

Ethical approval was obtained and a randomized, double-blind, cross-over volunteer investigation was conducted. Twenty-four volunteers had intraligamentary injections of 2% lidocaine with 1:80,000 epinephrine, 0.75% ropivacaine, or 1% ropivacaine at the upper lateral incisor and lower first bicuspid teeth. The response of the test teeth to electrical pulp testing and the reaction of the gingiva to sharp probing were assessed up to 29 minutes after injection. Injection discomfort and side effects were also recorded. Data were analyzed by using the chi-square test and analysis of variance.

RESULTS

Lidocaine with epinephrine was more successful than the ropivacaine solutions in obtaining pulpal anesthesia (chi-square = 12; P <.002) and produced longer-lasting pulpal (F = 21; P <.001) and soft tissue (F = 16; P <.001) anesthesia. Injection discomfort and incidence of side effects were similar between solutions, and none produced serious adverse effects.

CONCLUSION

Lidocaine with epinephrine is more effective than ropivacaine as an intraligamentary anesthetic.

Effects of dental local anaesthetics in cardiac transplant recipients

OBJECTIVE

To investigate the cardiovascular responses of cardiac transplant recipients to dental local anaesthetic solutions with and without epinephrine (adrenaline).

MATERIALS AND METHODS

A clinical study employing 30 patients (20 cardiac transplant recipients and ten healthy) awaiting gingival or minor oral surgery under local anaesthesia receiving either 4.4 ml lidocaine (lignocaine) with 1:80,000 epinephrine or 4.4 ml 3% prilocaine with 0.031 U/ml felypressin.

RESULTS

Cardiac transplant patients experienced a significant tachycardia 10 minutes after injection of the epinephrine-containing solution. No significant change in heart rate was detected after the injection of an epinephrine-free solution. Blood pressure was not affected. Periodontal surgery did not affect the responses to the local anaesthetics in the transplant recipients.

CONCLUSIONS

The cardiovascular response to dental local anaesthesia in cardiac transplant recipients is governed by the solution injected.

A comparison of intraoral injection discomfort produced by plain and epinephrine-containing lidocaine local anesthetic solutions: a randomized, double-blind, split-mouth, volunteer investigation

The authors report a clinical trial designed to compare the discomfort produced by plain and epinephrine-containing lidocaine solutions during local anesthesia in the maxilla. Twenty-four healthy volunteers were recruited; each received buccal and palatal infiltrations on each side of the maxilla in the premolar region. The solutions were 2% lidocaine and 2% lidocaine with 1:80,000 epinephrine. Allocation to side was randomized and operator and volunteer were blinded to the identity of the solutions. Volunteers recorded injection discomfort on a 100-mm visual analogue scale (VAS). Volunteers were included in the trial if a score of at least 30 mm was recorded for at least 1 of the matched pair of injections. Differences between treatments were measured using Student's paired t test. Twelve volunteers recorded a VAS score of at least 30 mm for 1 or both buccal injections, and 17 volunteers reached this score for palatal injections. Buccal injection pain was less when the plain solution was used (P = .04) and was not influenced by the order of the injection. Palatal injection discomfort did not differ between the solutions; however, the second palatal injection was more uncomfortable than the first palatal injection (P = .046). These results suggest that plain lidocaine produces less discomfort than lidocaine with epinephrine when administered into the maxillary premolar buccal sulcus in individuals who report moderate pain during this injection. Palatal injection discomfort does not differ between these solutions.

The effect of moisture and blood contamination on bond strength of a new orthodontic bonding material

The practice of orthodontics often requires the bonding of brackets under difficult conditions of moisture and/or blood contamination. Transbond MIP (3M Unitek, Monrovia, Calif) is a hydrophilic primer designed to bond in moist conditions. This study evaluated the bond strength of Transbond MIP under dry, moist, and blood-contaminated conditions. Ninety human premolars were bonded in 3 equal groups with Transbond MIP after acid etching; the enamel surfaces were either dry, moist, or contaminated with human blood. The shear bond strength was recorded. Dry bonding resulted in a significantly higher bond strength (15.69 MPa) than moist (12.89 MPa) or blood-contaminated (11.16 MPa) bonds. However, all bond strengths were in excess of previous reports of required clinical bond strength, and it was concluded that Transbond MIP is a suitable adhesive for bonding in conditions of poor moisture control or blood contamination.

The influence of two different dental local anaesthetic solutions on the haemodynamic responses of children undergoing restorative dentistry: a randomised, single-blind, split-mouth study

OBJECTIVES

This investigation was designed to study the haemodynamic effects of two different local anaesthetic solutions during restorative dental treatment in children.

DESIGN

A randomised, single-blind, split-mouth cross-over design was employed using children undergoing bilaterally similar restorative treatments over two visits.

SETTING

The study was performed in a dental hospital paediatric dentistry department.

METHODS

Ten children participated. At one visit the local anaesthetic was 2% lidocaine (lignocaine) with 1:80,000 epinephrine (adrenaline); at the other the anaesthetic was 3% prilocaine with 0.03IU/ml felypressin. Local anaesthetic was administered at a dose of 0.5 ml/10 kg body weight. Blood pressure and heart rate were measured before and during treatment with an automatic blood pressure recorder. Data were analysed by ANOVA and Student's paired t test.

RESULTS

Significant differences between treatments in diastolic blood pressure (F = 2.37; P = 0.05) and heart rate (F = 2.98; P< 0.02) were noted. The heart rate increased ten minutes following the injection of the epinephrine-containing solution. The diastolic blood pressure fell 20 minutes after injection of lidocaine with epinephrine.

CONCLUSION

The choice of local anaesthetic solution influences the haemodynamic response during restorative treatment in children.