Revascularization of traumatized teeth assessed by laser Doppler flowmetry: case report

Microbiological aspects of traumatic injuries

After traumatic injuries to teeth, microorganisms may invade the compromised pulp tissue and initiate pulp infection and periapical inflammation. In addition to bone resorption that typically accompanies pulp necrosis, root resorption frequently occurs. Root resorption has several variants that may occur shortly after the trauma or at a later stage. The pathological changes seen after traumatic injuries to teeth are invariably linked to the presence of microbial irritants. The presence of bacterial biofilms in the dental pulp space can be treated with regenerative or therapeutic endodontic procedures. However, necrosis of periodontal ligament is usually terminal for the tooth involved. In this review, the sources of bacteria after traumatic injuries are discussed. The types and role of microorganisms involved in the pathogenesis of endodontic pathosis after traumatic injuries are presented, and contemporary approaches for the management of these conditions are reviewed. Contemporary antimicrobial strategies are discussed. The rationale for the use of systemic and topical antimicrobials is presented. Finally, novel approaches to the use of antimicrobial therapies, particularly in regenerative procedures, are reviewed.

The Efficacy of Laser Doppler Flowmetry, Electric Pulp Test and Cold Test in Diagnosing Revascularization of Extrusively Luxated Immature Maxillary Incisors

Objective:

To evaluate the effect of extrusion on immature permanent tooth PBF values during a 6-month post-trauma period and to compare the accuracy of cold tests on pulp sensibility of traumatized teeth with that of electric pulp tests (EPT).

Methods:

The study group comprised of 26 extruded immature maxillary incisors in 25 trauma patients. The respective contralateral homologous teeth (n=25) were included as a positive control group. Teeth in the study group were treated by repositioning and splinting. Pulp vitality readings for traumatized and control teeth were taken with LDF, EPT and cold test on the day of splint-removal (2-3 weeks after trauma–T1) as well as 6 weeks (T2), 3 months (T3) and 6 months (T4) post-trauma. Student t and Mann-Whitney U-tests were used to compare data among groups. Statistical significance was set at P< 0.05.

Results:

LDF gave positive vitality readings (>4.5 PU) in all patients from T1 to T4 (with the exception of 1 patient at T1).

Conclusions:

LDF was able to accurately identify vitality in traumatized immature teeth even during the first few weeks following trauma, whereas conventional sensibility tests were unable to accurately recognize vitality shortly after trauma.

Dental Pulp Revascularization in a Replanted Avulsed Immature Maxillary Permanent Central Incisor

An 8-year-old girl sustained an accidental traumatic avulsion of her right maxillary permanent central incisor. She arrived with her mother at a hospital dental clinic with the right maxillary central incisor tooth wrappe in a wet paper towel over 1 hour after the injury. Replantation was accomplished without root surface alteration or root canal intervention. Clinical and radiographic follow-up examinations for over 1 year revealed continued root growth and apical development of the replanted avulsed immature maxillary central incisor with no signs or symptoms of pulpal or periapical pathosis. Excellent outcomes were achieved for periodontal ligament reattachment without removal of the periodontal membrane and pulp revascularization without endodontic intervention.

A multidisciplinary approach to the management of traumatic intrusion in immature permanent teeth

Intrusion in a developing permanent tooth is an extremely complicated traumatic injury and is rarely seen in the permanent dentition. The damage caused by the trauma to the surrounding tooth structures results in a multitude of complications during the healing process. Careful repositioning of the intruded tooth by orthodontic means, revascularisation of the immature tooth to regain vitality, and periodontal treatment to provide the most acceptable aesthetic outcome are described in this case report. It outlines the treatment options to overcome the complications and variable outcomes. The present report emphasises the importance of a multidisciplinary approach to provide complete rehabilitation of a traumatically intruded developing tooth.

Diagnosis of acute dental trauma: the importance of standardized documentation: a review

In 1985 Andreasen and Andreasen published a paper on the diagnosis of luxation injuries and outlined the importance of standardized clinical, radiographic, and photographic techniques. Now 30 years later, these recommendations remain current in the International Association of Dental Traumatology (IADT) guidelines for the management of dental trauma and describe circumstances surrounding the time of injury, the extent of trauma (e.g., type of luxation injury), healing potential (e.g., stage of root development) as well as information concerning subsequent treatment. The purpose of this review was to include findings for other types of trauma and to discuss more recent studies that augment and/or improve on the original findings from 30 years ago. The present review discusses the use of a standardized clinical registration (pulpal sensibility testing, laser Doppler flowmetry, mobility testing), radiographic survey, and photographic registration of the traumatized patient. Moreover, the value of digital radiographs and recent developments in computer tomography with respect to possible enhancement of the trauma diagnosis are discussed.

Continued root formation after delayed replantation of an avulsed immature permanent tooth

Introduction. Tooth avulsion in the young permanent dentition is a frequent finding, and its prognosis depends on the treatment of the avulsed tooth before replantation, the extra-alveolar time, the storage medium, and the patient's general health. The present report describes management of an immature avulsed lower central incisor 90 minutes after the accident. Methods. A right lower central incisor of a 7-year-old girl was avulsed, and it was soaked in a glass of milk. 90 minutes after avulsion, replantation was performed, and the tooth was splinted; but after two weeks the replanted tooth's pulp was necrotic. Thus, endodontic treatment was performed and root canal was filled using a calcium hydroxide and iodoform paste (Metapex). Three months later, the intracanal medication was washed out and the canal was sealed using an apical plug of calcium enriched mixture (CEM) cement. Results. 20 months after replantation the tooth was completely asymptomatic, with physiologic mobility. Also, continued root formation including an apical segment beyond the artificial apical plug was observed. Conclusion. Creation of an appropriate apical barrier following the disinfection of root canal system promoted continued root-end growth in a replanted immature permanent tooth.

Pulp and periradicular testing

Pulp and periradicular testing is crucial to the initial trauma evaluation and to subsequent monitoring of the traumatized teeth and supporting structures. An accurate diagnosis serves as the basis for therapeutic intervention and helps to ensure that destruction of the dental structures will be minimized and function will be regained. The purpose of this review is to present the current best evidence for accurate diagnostic testing of the pulp and periapex of traumatized teeth. Five databases were searched for literature pertaining to pulpal testing and trauma. Widely recognized textbooks were also consulted. Currently used pulp vitality testing is constrained by its subjective character and by the fact that it is a measure of neuronal status and not true pulpal viability. Tests that measure tissue perfusion more accurately reflect pulpal vitality, but they are not available commercially. This review discusses the specificity, sensitivity, and accuracy of commonly used tests, with emphasis on the applicability of certain tests to specific patient presentations in trauma. Factors that influence test selection are discussed, and specific recommendations are made on the basis of best evidence. Although differences exist between the various studies as to the accuracy of commonly used pulpal and periradicular tests, most of these have acceptable predictive value. Pulpal and periradicular tests in the trauma patient should be used in conjunction with clinical and radiographic observations to arrive at a diagnosis and treatment plan.

Doppler flowmetry as a tool of predictive, preventive and personalised dentistry

Periodontal lesions are considered a major problem in the global burden of oral diseases due to their high frequency and negative impact on quality of life. Periodontal inflammation is accomplished by a breakdown of microcirculatory function. Early detection of gingival microvessel dysfunction helps diagnose and prevent the progression of initial periodontal pathology. Doppler flowmetry is a useful tool in the diagnosis, monitoring, prognosis and management of periodontal patients which allows access not only of gingival blood flow but also of pulpal microcirculation. Doppler flowmeters might help to realise the ultimate target of predictive, preventive and personalised periodontology tailored with respect to the particular patient. This article highlights the main working principles of laser Doppler flowmeters and the ultrasonic Doppler flowmeters. The advances in blood flow measurement by ultrasonic flowmetry are discussed.

Revascularization for a necrotic immature permanent lateral incisor: a case report and literature review

BACKGROUND

Revascularization is a valuable treatment in immature necrotic teeth that allows the continuation of root development.

CASE REPORT

This article describes the successful revascularization treatment of an immature maxillary lateral incisor that was initially diagnosed with apical periodontitis. The tooth was asymptomatic and functional clinically and radiographically during the follow-up period of 5 years.

CONCLUSION

The follow-up showed evidence of progressive thickening of the dentinal walls, development of root length and apical closure. The article also discusses the currently available literature regarding revascularization of immature permanent teeth.

Revitalization of tooth with necrotic pulp and open apex by using platelet-rich plasma: a case report

INTRODUCTION

A growing body of evidence is demonstrating the possibility for regeneration of tissues within the pulp space and continued root development in teeth with necrotic pulps and open apexes. The purpose of this case report is to add a regenerative endodontic case to the existing literature about using platelet-rich plasma (PRP).

METHODS

An 11-year-old boy whose maxillary second premolar tooth had been accidently extracted and immediately replanted developed pulpal necrosis and symptomatic apical periodontitis. After preparing an access cavity, its necrotic pulp was removed. The canal was irrigated with 5.25% NaOCl solution and dried with paper points. A triple antibiotic mixed with distilled water was packed in the canal and left for 22 days. Twenty milliliters of whole blood was drawn from the patient's forearm for preparation of PRP. After removal of the antibiotic mixture, the PRP was injected into the canal space up to the cementoenamel junction level. Three millimeters of grey mineral trioxide aggregate was placed directly over the PRP clot. Three days later, the tooth was double-sealed with permanent filling materials.

RESULTS

Clinical examination 5 1/2 half months later revealed no sensitivity to percussion or palpation tests. Radiographic examination of this tooth showed resolution of the periapical lesion, further root development, and continued apical closure. Sensitivity tests with cold and an electric pulp test elicited a positive response similar to those found in the first premolar tooth.

CONCLUSIONS

On the basis of short-term results of the present case, it appears that regeneration of vital tissues in a tooth with necrotic pulp and a periapical lesion is possible; PRP is potentially an ideal scaffold for this procedure.

Laser physics and a review of laser applications in dentistry for children

AIM

The aim of this introduction to this special laser issue is to describe some basic laser physics and to delineate the potential of laser-assisted dentistry in children.

REVIEW

A brief review of the available laser literature was performed within the scope of paediatric dentistry. Attention was paid to soft tissue surgery, caries prevention and diagnosis, cavity preparation, comfort of the patient, effect on bacteria, long term pulpal vitality, endodontics in primary teeth, dental traumatology and low level laser therapy. Although there is a lack of sufficient evidence taking into account the highest standards for evidence-based dentistry, it is clear that laser application in a number of different aetiologies for soft tissue surgery in children has proven to be successful. Lasers provide a refined diagnosis of caries combined with the appropriate preventive adhesive dentistry after cavity preparation. This will further lead to a new wave of micro-dentistry based on 'filling without drilling'.

CONCLUSION

It has become clear from a review of the literature that specific laser applications in paediatric dentistry have gained increasing importance. It can be concluded that children should be considered as amongst the first patients for receiving laser-assisted dentistry.

Pulpal blood flow changes due to rapid maxillary expansion

OBJECTIVE

To determine the pulpal blood flow (PBF) changes in anchorage teeth associated with the high forces of a rapid maxillary expansion (RME) appliance.

MATERIALS AND METHODS

The study was performed with 14 girls and 7 boys for a total of 21 patients between 10 and 15 years of age (mean, 13.1 +/- 1.39 years). A modified acrylic bonded RME appliance was used as an expansion appliance. Laser Doppler flowmetry was used for the pulpal perfusion measurements. Records were taken from 42 upper central incisors, 28 canines, and 42 first molars at the following time intervals: just before expansion (T1); at the first week of expansion (T2); at the end of the expansion process (T3); and at the third (T4), seventh (T5), and 12th weeks of retention (T6). The data gained were statistically evaluated by parametric tests.

RESULTS

PBF values of the anchorage teeth were doubled at the first week of expansion; however, these values began to decrease because of separation of the median palatal suture. PBF values tended to reach their initial values during the retention period. Pulpal perfusion changes of all examined anchorage teeth were similar to each other from the beginning to the end of the evaluation.

CONCLUSION

PBF changes that occur with RME are reversible.

The use of likelihood ratio methodology to find predictors of treatment outcome in patients with dental injury diagnoses

The purpose of this prospective, cohort study of patients with dental injuries was to develop prediction rules to predict treatment response related to the management of dental injuries. The study comprised of 130 patients with a single permanent incisor affected by a dental displacement (n = 100) or fracture injury (n = 30). Laser Doppler flowmetry (LDF) measurements of pulpal blood flow (PBF) were taken 6 and 18 weeks after dental injury Treatment response (success or failure) was categorized based on findings of clinical and radiographical evaluation after 9 months. Forty-four (34%) subjects were categorized as treatment success (absence of loss of sensitivity, periapical radiolucency and grey discolouration of crown), 43 (33%) as treatment failures (loss of sensitivity, and periapical radiolucency and/or grey discolouration of crown) and 43 (33%) as acceptable outcome (loss of sensitivity). After using univariate analysis to determine the association between potential clinical and LDF predictor variables and treatment response status, preliminary prediction rules were developed for prediction of success [positive likelihood ratio (LR), 29.0; 95% confidence interval (CI), 1.7-496.4] and failure (negative LR, 0.55; CI, 0.4-0.7). The most important variables were subluxation, root fracture, baseline PBF level and change in PBF level at 3-month follow-up. Outcome following the management of dental injuries may be predicted from variables collected from LDF and physical examination. Predictive modelling may provide clinicians with the opportunity to identify 'at-risk' patients early and initiate specific treatment approaches.

Dental pulp testing: a review

Dental pulp testing is a useful and essential diagnostic aid in endodontics. Pulp sensibility tests include thermal and electric tests, which extrapolate pulp health from sensory response. Whilst pulp sensibility tests are the most commonly used in clinical practice, they are not without limitations and shortcomings. Pulp vitality tests attempt to examine the presence of pulp blood flow, as this is viewed as a better measure of true health than sensibility. Laser Doppler flowmetry and pulse oximetry are examples of vitality tests. Whilst the prospect is promising, there are still many practical issues that need to be addressed before vitality tests can replace sensibility tests as the standard clinical pulp diagnostic test. With all pulp tests, the results need to be carefully interpreted and closely scrutinised as false results can lead to misdiagnosis which can then lead to incorrect, inappropriate, or unnecessary treatment.

Treatment of complex dentoalveolar injury--avulsion and loss of periodontal tissue: a case report

Dental avulsion is a common and complex injury which affects multiple oral tissues. In this case report, a 9-year-old girl patient with two traumatically avulsed maxillary central incisors with loss of periodontal tissue was presented. Treatment guidelines for avulsed permanent teeth with open apex were carried out. Bilateral laterally sliding flap procedure was performed, to repair loss of gingival soft tissue. Conventional immobilization was carried out for 6 weeks. Five months follow-up of the patient in whom replantation was performed resulted in positive sensitivity test, no symptoms of infection, pain or any discomfort and good periodontal wound healing. In conclusion, this report presents successful replantation and periodontal treatment of a patient with complex dentoalveolar injury.

Outcomes of dental fracture injury as related to laser Doppler flow measurements of pulpal blood-flow level

Laser Doppler flowmetry (LDF) is a non-invasive method to assess pulpal blood flow (PBF). Dental fracture injuries have been associated with significant PBF reduction The purpose of this study was: (i) to evaluate whether the severity of outcomes of dental fracture injuries may be related to LDF measurements of PBF, and (ii) to investigate whether outcomes of dental fracture injuries may predict PBF levels. The relationship between outcomes and PBF measurements was analyzed in 72 permanent maxillary incisors of 52 consecutive dental trauma patients. The diagnostic outcome group comprised 72 incisors with a type I (absence of sensitivity, periapical radiolucency, and grey discoloration of crown) (n = 42), type II (loss of sensitivity) (n = 16), or type III (loss of sensitivity, periapical radiolucency, and/or grey discoloration of crown) diagnosis. At each session, when an injured permanent maxillary incisor was recorded, a contralateral homologous tooth was used as a control. An ordinal stepwise regression was completed to assess the degree of association between PBF measurements and diagnostic outcomes. A logistic regression analysis was used to compute the odds ratios for the outcome features for incisor non-injury controls vs two outcome groups: type II (n = 16) and type III (n = 14). PBF measurements that were significantly associated with more severe outcome were PBF levels of <or=6 perfusion units (PU) (106.70 odds ratio) (P = 0.000). Significant increase in the risk of a PBF level of <or=6 PU occurred with a type III outcome (32.49 odds ratio) (P = 0.004). PBF measurements were related to the severity of adverse outcomes. Diagnoses of treatment outcomes predicted the presence of specific PBF levels.

Evaluation of the ability of laser Doppler flowmetry for the assessment of pulp vitality in general dental practice

OBJECTIVES

In this study we investigated pulpal blood flow (PBF) values and moving blood cell velocity (MBCV) curves recorded by laser Doppler flowmetry (LDF) for pulpal vitality diagnosis in general dental practice and to compare MBCV curves to standard diagnostic tests in traumatology.

STUDY DESIGN

LDF tests performed with the PeriFlux System 5000 were applied to vital and nonvital (endodontic treatment) teeth of healthy students (n = 52) and on 24 luxated teeth of patients.

RESULTS

The PBF values were not reproducible and no statistically significant differences were observed between vital and nonvital teeth. MBCV curves in contrast could distinguish between the 2 tooth types. Tests on luxated teeth showed that while 62.5% of MBCV curves correlated with conventional vitality tests, only 12.5% of MBCV curves could help in vital diagnosis.

CONCLUSION

When applied to luxated teeth, the MBCV curve appeared to be accurate when the standard vitality tests indicated a nonvital diagnosis.

A retrospective evaluation of crown-fractured permanent teeth treated in a pediatric dentistry clinic

A retrospective study was carried out on the dental trauma records of 93 patients (55 boys, 38 girls) with 129 crown-fractured teeth. The patients' average age was 9.57 years (SD 1.57), ranging between 7 and 15 years. Uncomplicated crown facture (comprising enamel-dentin) was the most observed type of injury (n = 107, 83%). Only 15 patients (16.13%) sought treatment in less than 24 h following the injury. Of 41 injured teeth (31.79%) the apices were open at the time of presentation at the clinic. The initial treatment of these injured teeth were interim restoration with acid-etch and composite (69%), Cvek amputation (2.33%), fragment reattachment (1.55%), apexification (APX, 10.07%), and root-canal treatment (RCT, 17.05%). Out of 94 teeth, which were diagnosed as vital on admittance, 23 (24.46%) later developed pulp necrosis and required APX or RCT depending on their apical status. In 66 teeth (51.16%) definitive treatment was provided with only esthetic restoration (ER), while in 15.50% and 26.68% of injured teeth ER was carried out following APX and RCT, and RCT, respectively. Definitive treatment was provided in 3-6 months for 29.45% of the injured teeth, while 27.13% and 20.16% of teeth received definitive treatment within 1-3 months and 6 months to 1 year, respectively. Type of crown-fracture, elapsed time following injury, and vitality of the tooth on admittance and pulp necrosis observed were significantly related to the total time spent for definitive treatment (P < 0.05).

Use of laser Doppler flowmetry to predict vitality of luxated or avulsed permanent teeth

OBJECTIVE

Splinting of traumatically displaced or avulsed permanent teeth has been described as an effective modality in the treatment of patients with dental injuries. The purpose of this study was to investigate whether laser Doppler flowmetry (LDF) measurements of pulpal blood flow (PBF) and/or dental injury type may predict treatment outcome of splinting of permanent maxillary incisors.

STUDY DESIGN

The study comprised 64 patients undergoing dental trauma splinting, who were characterized by the presence of a single permanent maxillary incisor affected by a subluxation, luxation, or avulsion type injury. Perfusion units (PU) were taken in 2 sessions, on the day of splint removal (6 weeks after trauma; session I) and 12 weeks after splint removal (session II). At each session, when an injured permanent maxillary central incisor was recorded, the respective contralateral homologous tooth was used as a control. An adverse outcome occurring 36 weeks after splint removal was defined as the presence of "periapical radiolucency and/or grey discoloration." A multiple logistic regression analysis was used to compute the odds ratio for session-related PBF characteristics and dental injury type for adverse outcome (n=22) versus nonadverse outcome (n=42).

RESULTS

There was a significant increase in PBF values from session I to session II (P=.047) for teeth without an adverse outcome, whereas teeth affected by an adverse outcome showed a significant decrease in PBF values (P=.001). PBF measurements did not change over time for the control group of contralateral incisors (P=.185). For the outcome criterion of "presence of periapical radiolucency and/or grey discoloration," there was a significant association between the treatment outcome groups and the variables of dental injury type (P=.049), session-related PBF difference (P=.000), and session II-related PBF level (P=.000). Significant increase in risk of an adverse outcome occurred with a session-related PBF difference (PBF(Session I) - PBF(Session II)) of >/=0 PU (8.6 odds ratio) (P=.014), and a session II-related PBF level of </=2.8 PU (20.2 odds ratio) (P=.030).

CONCLUSION

The data suggest the LDF test to be a valuable diagnostic adjunct for luxated teeth showing signs of adverse outcomes. Predictive modeling may provide clinicians with the opportunity to identify "at-risk" teeth early and initiate specific treatments.

Laser Doppler flow measurements of pulpal blood flow and severity of dental injury

AIM

To evaluate laser Doppler flowmetry (LDF) measurements of pulpal blood flow (PBF) and severity of dental injury.

METHODOLOGY

The relationship between adverse outcomes and PBF measurements was analysed in 94 permanent maxillary incisors of 71 consecutive dental trauma patients. The diagnostic adverse outcome group was comprised of 72 incisors in 52 patients with a type I (loss of sensitivity), type II (loss of sensitivity and periapical radiolucency), or type III (loss of sensitivity, periapical radiolucency and grey discoloration of crown) diagnosis. The nonadverse outcome group consisted of 22 incisors in 19 patients with the finding of an absence of an adverse outcome. At each session, when an injured permanent maxillary incisor was recorded, a contralateral homologous tooth was used as a control. An ordinal stepwise regression was completed to assess the degree of association between PBF measurements and adverse outcomes

RESULTS

Using chi-square analysis for pairwise comparison, a significant relationship between PBF measurements and types of adverse outcomes (chi(2) =119.635, d.f. = 12, P = 0.000) was observed. PBF measurements that were significantly associated with more severe outcome were PBF levels of </=3 perfusion units (PU) (119.1 odds ratio) (P = 0.000), and those of >3 PU and </=6 PU (12.7 odds ratio) (P = 0.000).

CONCLUSIONS

PBF measurements were related to the severity of adverse outcomes. Further studies are required to evaluate whether PBF measurements can predict dental injuries that progress to adverse treatment outcomes.

Assessing revascularization of avulsed permanent maxillary incisors by laser Doppler flowmetry

BACKGROUND

Laser Doppler flowmetry, or LDF, is a noninvasive method used to assess pulpal blood flow, or PBF. Dental avulsion is associated with loss of pulpal sensitivity. The authors conducted this study to assess whether LDF could be used to detect revascularization of replanted teeth.

METHODS

The authors used LDF to assess the PBF values of avulsed permanent maxillary incisors treated using replantation and splinting in 17 subjects. They took measurements at four sessions: on the day of splint removal and at 12 weeks, 24 weeks and 36 weeks after splint removal. Five vital control teeth and five nonvital control teeth were used to assess the background signal. At 36 weeks, the authors determined clinically and radiographically whether revascularization had occurred.

RESULTS

LDF readings correctly predicted the pulp status in 88.2 percent of the readings. Of the readings for vital teeth, 100 percent were correct, and of the readings for nonvital teeth, 80 percent were correct. Univariate analysis of variance demonstrated that in revascularized teeth, the PBF value increased significantly from splint removal to week 12 after splint removal and from week 24 to week 36 after splint removal. In the teeth that failed to revascularize, the PBF value dropped significantly from week 24 to week 36 after splint removal.

CONCLUSIONS

The results of this study suggest that LDF accurately diagnoses revascularization of avulsed maxillary incisors after replantation and splinting.

CLINICAL IMPLICATIONS

LDF may become useful in detecting revascularization much earlier than standard sensitivity tests.

Laser Doppler flow investigation of fractured permanent maxillary incisors

Laser Doppler flowmetry (LDF) is a non-invasive method to assess pulpal blood-flow (PBF). Dental injury has been associated with losses of pulpal sensibility. The purpose of this study was to assess the outcome of splint therapy on tooth fracture type-related PBF values. In 15 trauma patients, a single maxillary incisor treated by repositioning and splinting was investigated by LDF to assess local PBF values. Perfusion units were taken in four sessions, on the day of splint removel, and 12, 24 and 36 weeks after splint removal. Analysis of the tooth fracture type-related PBF measurements revealed root fractures to be associated with a significant decrease (P < 0.05) and uncomplicated crown fractures to be associated with a significant increase in PBF values (P < 0.05), while complicated crown fractures showed no significant difference between the session-related values (P > 0.05). The main findings of this study suggest splint therapy of root fractures of the central maxillary incisor to be associated with a short- and long-term decrease in PBF values. The LDF may become useful in the detection of transient ischaemic episodes and the identification of teeth at risk for adverse sequelae such as avascular necrosis and tissue loss.

Transient apical breakdown following tooth luxation

Transient apical breakdown is a sequelae of certain dental traumatic injuries where the injured tissues undergo a spontaneous process of repair with no permanent damage to the pulp. Misdiagnosis of this condition may result in unnecessary endodontic treatment. Presented is a case of transient apical breakdown following a subluxation injury of a maxillary central incisor in a 15-year-old girl. Four months after injury, coronal discoloration, periapical radiolucency as well as negative pulp responses to cold and electric tests were still recorded. Subsequently, the tooth spontaneously regained its original shade and the pulp responded normally to pulp sensitivity tests. Methods for early diagnosis of transient apical breakdown are discussed.

Evaluation of pulpal blood flow after tooth splinting of luxated permanent maxillary incisors

Laser Doppler flowmetry (LDF) is a non-invasive method to assess pulpal blood flow (PBF). Dental injury has been associated with losses of pulpal sensibility. The purpose of this study was to assess whether LDF could be used to detect short- and long-term changes of PBF values of luxated permanent maxillary central incisors after repositioning and splinting. In 18 trauma patients, a single maxillary incisor treated by repositioning and splinting, and the respective contralateral homologous tooth were investigated by LDF to assess local PBF values. Perfusion units (PU) were taken in four sessions: on the day of splint removal, and 12, 24, and 36 weeks after splint removal. Analysis of the luxation type-related PBF measurements revealed intrusion type-related PBF values to be associated with a significant decrease in PBF values (P < 0.05), while lateral luxation and extrusion type-related PBF values showed no significant difference between the session-related values (P > 0.05). PBF measurements did not change over time for the contralateral incisors (P > 0.05). Teeth affected by an intrusion-type luxation injury remained unresponsive to sensitivity testing at follow up, while 3 (60%) developed grey discoloration of the crown. LDF may become useful in the detection of ischemic episodes of luxated maxillary central incisors after repositioning and splinting. Further studies are warranted to assess the validity of post-traumatic 'ischemic episodes' by comparing it to histological tooth pulp changes.

A two-probe laser Doppler flowmetry assessment as an exclusive diagnostic device in a long-term follow-up of traumatised teeth: a case report

The reliability of laser Doppler flowmetry in a two-probe assessment of pulpal blood flow is well known. The purpose of this case report was to determine its use as an exclusive and reliable tool for tooth vitality diagnosis in a long-term follow-up. As a result of a traumatic injury to a 24-year-old Caucasian female, tooth pulp vitality was studied in six maxillary front teeth over 30 weeks using two-probe laser Doppler flowmetry and current sensitivity tests. A similar assessment was repeated after 228 weeks. Confronted with an alveolar bone fracture with a tooth in the fracture line, one intrusion and several luxated teeth, current sensitivity tests are found not to be as reliable indicators of revascularisation, as significant results are obtained later (7 weeks) than using laser Doppler flowmetry tests (1 week). A pathway with ischaemia (3 weeks), hyperaemia (7 weeks) and restored blood supply in the pulp measured by laser Doppler flowmetry tests was found and avoided endodontic treatment. Teeth vascularisation evolved normally (228 weeks). Despite a strong indication in all sensitivity tests for endodontic treatment, the use of laser Doppler flowmetry tests was clear, more reliable than sensitivity tests and exclusive, as denervation was postponed and pulp vascularisation evident.

Clinical management of the avulsed tooth: present strategies and future directions

The aim of this review article is to supplement the recently published International Association of Dental Traumatology (IADT) guidelines on treatment of the avulsed tooth. A thorough discussion on the reasoning behind each guideline is presented. In addition, the author's views on alternate treatment strategies and future directions, along with recent research on the subject of the avulsed tooth, are also presented.

Revascularization of an immature permanent tooth with apical periodontitis and sinus tract

A necrotic immature mandibular second premolar with periapical involvement in a 13-year-old patient was treated. Instead of the standard root canal treatment protocol and apexification, antimicrobial agents were used in the canal, after which the canal was left empty. Radiographic examination showed the start of apical closure 5 months after the completion of the antimicrobial protocol. Thickening of the canal wall and complete apical closure was confirmed 30 months after the treatment, indicating the revascularization potential of a young permanent tooth pulp into a bacteria-free root canal space.

Efficacy of laser Doppler flowmetry for the diagnosis of revascularization of reimplanted immature dog teeth

This study was performed to assess if laser Doppler flowmetry (LDF) is an improved method for the detection of revascularization of replanted teeth. Teeth were extracted and reimplanted under different experimental conditions. LDF readings were taken before extraction and weekly for 3 months. In control teeth, LDF baseline readings were taken and then repeated after the apical blood vessels were cut surgically. At the end of 3 months it was determined radiographically and histologically whether revascularization had occurred, i.e. vitality had returned.

RESULTS

LDF readings correctly predicted the pulp status (vital vs. non-vital) in 83.7% of the readings. 73.9% (17 of 23) were correct for the vital teeth and 95% (19 of 20) were correct for the non-vital teeth. Fisher's exact test (2-tail) indicated that there was no significant association between the efficacy of LDF and tooth type (P = 0.166), although P2 was the least accurate tooth tested. Wilcoxon's matched-pair signed rank test demonstrated that in the revascularized (vital) teeth, the flux value between the baseline and week 2 dropped significantly (P = 0.0001), increased significantly from week 2 to week 4 (P = 0.0001) and then decreased steadily until week 12. However, at week 12 the flux was still significantly higher than at week 2 (P = 0.010). In the teeth that failed to revascularize, the flux value dropped significantly by weeks 1 and 2 (P = 0.004 and P = 0.0001, respectively). Flux values did not increase from week 2. A Fast Fourier Transform (FFT) analysis confirmed a pulse of dominant frequency of 2 Hz in the teeth that returned to vitality and the lack thereof in those that stayed non-vital. One tooth in which the flux value evaluation indicated a non-vital tooth but the radiographic/histologic findings showed vital (false negative) possessed a pulse of dominant frequency and proved by this method to have successfully revascularized.

The effect of wavelength, bandwidth, and probe design and position on assessing the vitality of anterior teeth with laser Doppler flowmetry

OBJECTIVES

To investigate the effect of four variables: wavelength (633 nm and 780 nm), bandwidth filter (3 kHz, 15 kHz, 22 kHz), probe fibre separation (250 microns) and 500 microns) and distance of the probe from the gingival margin (2-3 mm and 4-5 mm) when assessing the vitality of anterior teeth with a laser Doppler flowmetry system.

DESIGN

Split-mouth cohort clinical trial.

SETTING

Childrens dental clinic, Glasgow Dental Hospital and School.

SAMPLE AND METHODS

Sample included 11 non-vital maxillary incisors with necrotic pulps in 10 patients (mean age 12.25 years old). Recordings were taken from the non-vital tooth and from a vital maxillary incisor from the same patient, using all 24 combinations of the recording variables listed above. The vital/non-vital ratios of the signals from the 11 pairs of teeth were calculated and discriminant analysis applied to the data.

RESULTS

Of the variables investigated, the combination of a 633 nm laser source with a 3 kHz bandwidth filter using a probe with a 500 microns fibre separation placed 2-3 mm from the gingival margin was the most reliable, with 10 out of a possible 11 true positives for pulpal necrosis, no false positives, and one equivocal diagnosis, and was the only combination that recorded a smaller blood flow from the non-vital tooth compared with the vital control tooth for all 11 pairs of teeth investigated.

CONCLUSIONS

It was concluded, therefore, that laser Doppler flowmetry can be of use in assessing the vitality of anterior teeth and that this is the preferred combination of recording variables for further investigations.

Reliability of laser Doppler flowmetry in a 2-probe assessment of pulpal blood flow

OBJECTIVE

The reliability of using 2 probes with laser Doppler signals when adjacent teeth are being measured simultaneously to determine pulpal blood flow is unknown. The purpose of this study was to determine whether 2 probes are more reliable than 1 in a single-tool assessment.

STUDY DESIGN

Tooth pulp vitality was studied in 19 adults through use of laser Doppler flowmetry tests. In each subject, testing was carried out on 2 successive occasions with 2 probes positioned on the maxillary central incisors.

RESULTS

Significant mean differences of 31% for blood flux and 96% for concentration were found between the 2 probes, although they shared equal coefficients of variation. The reproducibility for each probe was found to be consistent, and the probes were highly correlated with each other. Flux and concentration, however, were not systematically correlated.

CONCLUSIONS

Simultaneous measurements with 2 probes were clearly more reliable. The necessity for a calibration control was evident.

Laser Doppler flowmetry: an aid in differential diagnosis of apical radiolucencies

The case of a patient having 2 teeth with associated apical radiolucencies that responded to conventional pulp tests is presented. A decision was made to reexamine the patient at intervals rather than perform root canal treatment. During a recall visit, use of an available laser Doppler flowmeter allowed detection of blood flow within the affected teeth. A diagnosis of periapical cemental dysplasia (cementoma) was made.