Image quality assessment of three cone beam computed tomography scanners-an analysis of the visibility of anatomical landmarks.

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate large field of view (FoV) subjective image quality of three cone-beam computed tomography (CBCT) machines to assess the threshold for reliable diagnostic perceptibility when lowering exposure settings. MATERIALS AND METHODS: One entire cadaver's head was scanned using three CBCT scanners. The largest available FoV of each device, imaging orthodontic relevant structures, was applied. CBCT datasets with different image quality based on standard to minimum scanning parameters were acquired. Five dentists evaluated the visibility of selected anatomical structures of the upper and lower jaw using a 5-point rating scale. RESULTS: Image quality depends on parameters such as a minimum voxel size of 0.2 to 0.4mm or a minimum of 4mA. A reduction in number of images (scanning protocol) reduces image quality. Visualization of different anatomical structures for orthodontic treatment planning requires distinct scanning protocols to support adequate perception of these structures. LIMITATIONS: This study does not account for the evaluation of paediatric anatomical structures due to the availability of cadaver's head. CONCLUSIONS: CBCT scans performed for orthodontic purposes using a large FoV with reduced parameters (400 µm, 2 to 4 mA and low dose protocols) are acceptable for visualization of large anatomical structures. Further lowering these parameters will not be sufficient to view small anatomical structures. Orthodontic indications will have to define specific anatomical structures to choose adequate scanning protocols to reduce dose and ensure reliable diagnostic visibility.

Morphometric characteristics of the sphenoid sinus and potential influencing factors: a retrospective assessment using cone beam computed tomography (CBCT).

The present study aimed to evaluate the morphological characteristics of the sphenoid sinus (SS), and the impact of potential influencing factors on the morphometric features using CBCT imaging. CBCT scans of 148 patients, aged between 15 and 85 (32.88 ± 15.33) years were retrospectively evaluated. DICOM files from the CBCT scans were imported into semi-automatic software and the SS of each patient was assessed for the morphological characteristics including configuration, symmetry, extension, shape, septation, volume, and maximum diameter. Furthermore, potential influencing factors such as age, gender, side, and sinus condition were analysed. A significant association was observed between sinus extension and age. Septation was also found to be significantly associated with age, gender and sinus condition. Besides, sinus volume was significantly associated with gender and sinus condition. No significant influence of shape and side on the morphometric features was noticed. The average volume and diameter of the SS were 6576.92 ± 3748.12 mm3 and 30.48 ± 9.28 mm, respectively. In conclusion, the present findings indicate that age, gender and sinus condition have a significant impact on the morphometric characteristics of the SS. Mature sinuses exhibit a post-sellar extension pattern until middle age. In addition, males, and sinuses with healthy sinus condition have larger volumes compared to females and pathological sinuses.

A Systematic Review of WTA-WTP Disparity for Dental Interventions and Implications for Cost-Effectiveness Analysis.

Cost-effectiveness analysis is widely adopted as an analytical framework to evaluate whether health care interventions represent value for money, and its use in dentistry is increasing. Traditionally, in cost-effectiveness analysis, one assumes that the decision maker's maximum willingness to pay (WTP) for health gain is equivalent to his minimum willingness to accept (WTA) monetary compensation for health loss. It has been documented in the literature that losses are weighted higher than equivalent gains, i.e., that WTA exceeds WTP for the same health condition, resulting in a WTA/WTP ratio greater than 1. There is a knowledge gap of published WTA/WTP ratios for dental interventions in the literature. We therefore conducted a (i) systematic review of published WTA-WTP estimates in dentistry (MEDLINE, Web of Science, Cochrane Library, London, UK) and (ii) a patient-level analysis of WTA/WTP ratios of included studies, and (iii) we demonstrate the impact of a WTA-WTP disparity on cost-effectiveness analysis. Out of 55 eligible studies, two studies were included in our review. The WTA/WTP ratio ranged from 2.58 for discontinuing water fluoridation to 5.12 for mandibular implant overdentures, indicating a higher disparity for implant rehabilitations than for dental public health interventions. A WTA-WTP disparity inflates the cost-effectiveness of dental interventions when there is a substantial risk of both lower costs and health outcomes. We therefore recommend that in these cases the results of cost-effectiveness analyses are reported using different WTA/WTP ratios in a sensitivity analysis.

Sinus floor elevation or referral for further diagnosis and therapy: A comparison of maxillary sinus assessment by ENT specialists and dentists using cone beam computed tomography.

OBJECTIVES: To compare ear, nose, and throat (ENT) specialists and dentists assessing health or pathology of maxillary sinuses using cone beam computed tomography (CBCT). MATERIAL AND METHODS: Two ENT specialists and two oral surgeons assessed 100 CBCT datasets of healthy patients referred for dental implant placement in the posterior maxilla and decided on the possibility of sinus floor elevation or the necessity for further diagnostic examinations based solely on radiographic findings. Inter-rater agreements within the same specialty were calculated with Cohen's kappa and overall agreements with Fleiss kappa, and factors influencing the decisions taken were evaluated using regression analyses. RESULTS: The correlation between all four raters was generally fair to moderate. The intra-specialty comparison showed a lower correlation between dentists than between ENT specialists. Absence of membrane thickening and total or subtotal sinus opacification showed the highest predictive value for a consensus in favor of sinus floor elevation and ENT referral, respectively. Flat membrane thickening with an irregular surface morphology was associated with disagreement between the examiners. Dome-shaped membrane thickenings were often considered as to be referred by dentists but not by ENTs. CONCLUSION: The assessment of maxillary sinuses using CBCT imaging exhibited unsatisfactory agreement between ENT specialists and oral surgeons. Referral guidelines based on accidental CBCT findings that aim to diagnose relevant sinus pathologies early and avoid unnecessary diagnostics and/or therapies are needed, and an initial proposal for such recommendations is provided. Further research on correct interpretation of sinus findings and a validation of the present recommendations are required.

Radiographic Assessment of Bone Healing Using Cone-beam Computed Tomographic Scans 1 and 5 Years after Apical Surgery.

INTRODUCTION: The objective of this long-term study was to evaluate radiographic healing in cone-beam computed tomographic (CBCT) scans taken 1 and 5 years after apical surgery. METHODS: In the context of a prospective clinical study, postsurgical CBCT scans were taken 1 and 5 years after apical surgery. Three calibrated observers independently assessed buccolingual CBCT images oriented along the longitudinal axis of the treated roots. Radiographic periapical healing was categorized as "fully, partially, or not healed" for each of the following study parameters: the resection plane, the cortical plate, the apical area, and the overall bone healing. The analysis included the interobserver agreement (Fleiss kappa values), the comparison of 5- and 1-year ratings, and the changes of healing categories from 1-5 years (McNemar-Bowker tests). Data were analyzed statistically for the detection of significant differences. RESULTS: CBCT images of 41 teeth (in 41 patients) with 47 treated roots were evaluated. At 5 years, all studied parameters had higher rates of fully healed cases compared with the rate at 1 year. The resection plane and apical area parameters each were judged in 72.3% as fully healed at 5 years, whereas the cortical plate and overall bone healing parameters showed clearly lower fully healed rates (42.6% and 38.3%, respectively). Fully healed cases at 1 year remained so at 5 years in 87.5%-100% depending on the study parameter. CONCLUSIONS: This 5-year CBCT follow-up study of apical surgery showed a marked improvement of radiographic healing from 1-5 years but to a varying degree regarding the different study parameters. Although new hard tissue formation at the resection plane and within the former apical defect was advanced in most cases at 5 years, the reestablishment of the cortical bone plate clearly lagged behind.

Cone beam computed tomography in implant dentistry: recommendations for clinical use.

BACKGROUND: In implant dentistry, three-dimensional (3D) imaging can be realised by dental cone beam computed tomography (CBCT), offering volumetric data on jaw bones and teeth with relatively low radiation doses and costs. The latter may explain why the market has been steadily growing since the first dental CBCT system appeared two decades ago. More than 85 different CBCT devices are currently available and this exponential growth has created a gap between scientific evidence and existing CBCT machines. Indeed, research for one CBCT machine cannot be automatically applied to other systems. METHODS: Supported by a narrative review, recommendations for justified and optimized CBCT imaging in oral implant dentistry are provided. RESULTS: The huge range in dose and diagnostic image quality requires further optimization and justification prior to clinical use. Yet, indications in implant dentistry may go beyond diagnostics. In fact, the inherent 3D datasets may further allow surgical planning and transfer to surgery via 3D printing or navigation. Nonetheless, effective radiation doses of distinct dental CBCT machines and protocols may largely vary with equivalent doses ranging between 2 to 200 panoramic radiographs, even for similar indications. Likewise, such variation is also noticed for diagnostic image quality, which reveals a massive variability amongst CBCT technologies and exposure protocols. For anatomical model making, the so-called segmentation accuracy may reach up to 200 µm, but considering wide variations in machine performance, larger inaccuracies may apply. This also holds true for linear measures, with accuracies of 200 µm being feasible, while sometimes fivefold inaccuracy levels may be reached. Diagnostic image quality may also be dramatically hampered by patient factors, such as motion and metal artefacts. Apart from radiodiagnostic possibilities, CBCT may offer a huge therapeutic potential, related to surgical guides and further prosthetic rehabilitation. Those additional opportunities may surely clarify part of the success of using CBCT for presurgical implant planning and its transfer to surgery and prosthetic solutions. CONCLUSIONS: Hence, dental CBCT could be justified for presurgical diagnosis, preoperative planning and peroperative transfer for oral implant rehabilitation, whilst striving for optimisation of CBCT based machine-dependent, patient-specific and indication-oriented variables.

Three-dimensional Frankfort horizontal plane for 3D cephalometry: a comparative assessment of conventional versus novel landmarks and horizontal planes.

Background: To assess the reproducibility of landmarks in three dimensions that determine the Frankfort horizontal plane (FH) as well as two new landmarks, and to evaluate the angular differences of newly introduced planes to the FH. Methods: Three-dimensional (3D) surface models were created from CBCT scans of 26 dry human skulls. Porion (Po), orbitale (Or), internal acoustic foramen (IAF), and zygomatico-maxillary suture (ZyMS) were indicated in the software by three observers twice with a 4-week interval. Angles between two FHs (FH 1: Or-R, Or-L, mid-Po; FH 2: Po-R, Po-L, mid-Or) and between FHs and new planes (Plane 1-6) were measured. Coordinates were exported to a spreadsheet. A statistical analysis was performed to define the landmark reproducibility and 3D angles. Results: Intra- and inter-observer landmark reproducibility showed mean difference more than 1 mm for x-coordinates of all landmarks except IAF. IAF showed significantly better reproducibility than other landmarks (P < 0.0018). The mean angular difference between FH 1 and FH 2 was 0.7 degrees. Plane 3, connecting Or-R, Or-L and mid-IAF, and Plane 4, connecting Po-R, Po-L and mid-ZyMS, both showed an angular difference of less than 1 degree when compared to FHs. Conclusions: This study revealed poor reproducibility of the traditional FH landmarks on the x-axis and good reproducibility of a new landmark tested to replace Po, the IAF. Yet, Or showed superior results compared to ZyMS. The potential of using new horizontal planes was demonstrated. Future studies should focus on identification of a valid alternative for Or and ZyMS and on clinical implementation of the findings.

Measuring the Monetary Value of Dental Implants for Denture Retention: A Willingness to Pay Approach.

PURPOSE: Two interforaminal dental implants in is a common treatment option for denture retention in edentulous patients. Economic methods to assess the patient's quality of life include the willingness to pay (WTP) for implant treatment and willingness to accept (WTA) to forgo implant treatment. The purpose of this study was to assess the monetary value of implant retained complete dentures using WTP and WTA. METHODS: We included a convenience sample of 16 patients from a previously published cohort study on the survival of immediately loaded implants in edentulous patients to assess WTP and WTA for this treatment option. RESULTS: The average maximum WTP for implant treatment was 4606 (95% CI: 2991-6222) Swiss Francs. Out of the 16 patients, only 5 were willing to trade their implants for money, with a mean WTA of CHF 33'500 (range: 3000-100'000).All patients would agree to undergo the implant surgery procedure again. CONCLUSION: The results of the present study show that most patients are not willing to trade the increase in quality of life after implant surgery against money, suggesting that WTA exceeds by large WTP for the same health condition.

Scarring of Soft Tissues Following Apical Surgery: Visual Assessment of Outcomes One Year After Intervention Using the Bern and Manchester Scores.

The successful outcome of apical surgery is usually defined by absence of clinical signs and symptoms and resolution of previous periapical radiolucencies. However, little attention is given to soft tissue scarring. The present study evaluated the severity of gingival and mucosal scarring 1 year following apical surgery of 52 teeth. Clinical pictures taken at the 1-year examination were rated by three observers using specific scarring scores. The overall repeatability of the two scores was high (85.3%), whereas the overall reproducibility was relatively low (44.2%). None of the tested variables proved significant for influencing scar severity.

Evaluation of New Cone-beam Computed Tomographic Criteria for Radiographic Healing Evaluation after Apical Surgery: Assessment of Repeatability and Reproducibility.

INTRODUCTION: Conventional 2-dimensional radiography uses defined criteria for outcome assessment of apical surgery. However, these radiographic healing criteria are not applicable for 3-dimensional radiography. The present study evaluated the repeatability and reproducibility of new cone-beam computed tomographic (CBCT)-based healing criteria for the judgment of periapical healing 1 year after apical surgery. METHODS: CBCT scans taken 1 year after apical surgery (61 roots of 54 teeth in 54 patients, mean age = 54.4 years) were evaluated by 3 blinded and calibrated observers using 4 different indices. Reformatted buccolingual CBCT sections through the longitudinal axis of the treated roots were analyzed. Radiographic healing was assessed at the resection plane (R index), within the apical area (A index), of the cortical plate (C index), and regarding a combined apical-cortical area (B index). All readings were performed twice to calculate the intraobserver agreement (repeatability). Second-time readings were used for analyzing the interobserver agreement (reproducibility). Various statistical tests (Cohen, kappa, Fisher, and Spearman) were performed to measure the intra- and interobserver concurrence, the variability of score ratios, and the correlation of indices. RESULTS: For all indices, the rates of identical first- and second-time scores were always higher than 80% (intraobserver Cohen κ values ranging from 0.793 to 0.963). The B index (94.0%) showed the highest intraobserver agreement. Regarding interobserver agreement, the highest rate was found for the B index (72.1%). The Fleiss' κ values for R and B indices exhibited substantial agreement (0.626 and 0.717, respectively), whereas the values for A and C indices showed moderate agreement (0.561 and 0.573, respectively). The Spearman correlation coefficients for R, A, C, and B indices all exhibited a moderate to very strong correlation with the highest correlation found between C and B indices (rs = 0.8069). CONCLUSIONS: All indices showed an excellent intraobserver agreement (repeatability). With regard to interobserver agreement (reproducibility), the B index (healing of apical and cortical defects combined) and the R index (healing on the resection plane) showed substantial congruence and thus are to be recommended in future studies when using buccolingual CBCT sections for radiographic outcome assessment of apical surgery.

The resection angle in apical surgery: a CBCT assessment.

OBJECTIVES: The primary objective of the present radiographic study was to analyse the resection angle in apical surgery and its correlation with treatment outcome, type of treated tooth, surgical depth and level of root-end filling. MATERIALS AND METHODS: In the context of a prospective clinical study, cone beam computed tomography (CBCT) scans were taken before and 1 year after apical surgery to measure the angle of the resection plane relative to the longitudinal axis of the root. Further, the surgical depth (distance from the buccal cortex to the most lingual/palatal point of the resection plane) as well as the level of the root-end filling relative to the most coronal point of the cut root face was determined. Treated teeth were categorized into four groups (maxillary and mandibular anterior and posterior teeth). The final material comprised 62 treated roots in 55 teeth. RESULTS: The mean calculated resection angle of all roots was 17.7° ± 11.4° (range -9.6° to 43.4°). Anterior maxillary roots presented the highest mean angle (25.8° ± 10.3°) that was significantly different from the mean angle in posterior maxillary roots (10.7° ± 9.4°; p < 0.001) and from the mean angle in posterior mandibular roots (15.1 ± 9.8°; p < 0.05). In roots with a shallow resection angle (≤20°), the rate of healed cases was higher than in roots with an acute resection angle (>20°), however without reaching statistical significance (p = 0.0905). Angles did not correlate either with the surgical depth or with the retrofilling length. CONCLUSIONS: Statistically significant differences were observed comparing resection angles of different tooth groups. However, the angle had no significant effect on treatment outcome. CLINICAL RELEVANCE: Contrary to common belief, the resection angle in maxillary anterior teeth was greater than in the other teeth. The surgeon is advised to pay attention to the resection angle when bevelling maxillary anterior teeth in apical surgery.

Assessment of smoking behaviour in a dental setting: a 1-year follow-up study using self-reported questionnaire data and exhaled carbon monoxide levels.

OBJECTIVES: This study analyses the changes in smoking habits over the course of 1 year in a group of patients referred to an oral medicine unit. MATERIALS AND METHODS: Smoking history and behaviour were analysed at baseline and after 1 year based on a self-reported questionnaire and on exhaled carbon monoxide levels [in parts per million (ppm)]. During the initial examination, all smokers underwent tobacco use prevention and cessation counselling. RESULTS: Of the initial group of 121 patients, 98 were examined at the follow-up visit. At the baseline examination, 33 patients (33.67 %) indicated that they were current smokers. One year later, 14 patients (42.24 % out of the 33 smokers of the initial examination) indicated that they had attempted to stop smoking at least once over the follow-up period and 15.15 % (5 patients) had quit smoking. The mean number of cigarettes smoked per day by current smokers decreased from 13.10 to 12.18 (p = 0.04). The exhaled CO level measurements showed very good correlation with a Spearman's coefficient 0.9880 for the initial visit, and 0.9909 for the follow-up examination. For current smokers, the consumption of one additional cigarette per day elevated the CO measurements by 0.77 ppm (p < 0.0001) at the baseline examination and by 0.84 ppm (p < 0.0001) at the 1-year follow-up. CONCLUSIONS: In oral health care, where smoking cessation is an important aspect of the treatment strategy, the measurement of exhaled carbon monoxide shows a very good correlation with a self-reported smoking habit. CLINICAL RELEVANCE: Measurement of exhaled carbon monoxide is a non-invasive, simple and objective measurement technique for documenting and monitoring smoking cessation and reduction.

[Cone beam computed tomography in endodontics: a review for daily clinical practice]. / Die digitale Volumentomographie in der Endodontologie. Eine Übersicht für den Praxisalltag.

Since the introduction of cone beam computed tomography (CBCT), this 3-dimensional diagnostic imaging technique has been established in a growing number of fields in dental medicine. It has become an important tool for both diagnosis and treatment planning, and is also able to support endodontic treatments. However, the higher effective dose of ionizing radiation compared to conventional 2-dimensional radiographs is not justifiable in every case. CBCT allows for a more precise diagnosis of periapical lesions, root fractures as well as external and internal resorptions. Concerning the utility of CBCT in treatment planning decisions, the gain of information through 3-dimensional imaging for any of these pathologies has to be evaluated carefully on an individual basis. Moreover, radioopaque materials such as root canal filling and posts often create artefacts, which may compromise diagnosis. The aim of this review is to summarize the possibilities and limits of CBCT imaging in endodontology as well as introduce guidelines for daily clinical practice. Furthermore, the article presents possible therapeutic advantages of preexisting CBCT scans for root canal treatments.

Assessment of bone channels other than the nasopalatine canal in the anterior maxilla using limited cone beam computed tomography.

PURPOSE: The anterior maxilla, sometimes also called premaxilla, is an area frequently requiring surgical interventions. The objective of this observational study was to identify and assess accessory bone channels other than the nasopalatine canal in the anterior maxilla using limited cone beam computed tomography (CBCT). METHODS: A total of 176 cases fulfilled the inclusion criteria comprising region of interest, quality of CBCT image, and absence of pathologic lesions or retained teeth. Any bone canal with a minimum diameter of 1.00 mm other than the nasopalatine canal was analyzed regarding size, location, and course, as well as patient gender and age. RESULTS: A total of 67 accessory canals ≥1.00 mm were found in 49 patients (27.8%). A higher frequency of accessory canals was observed in males (33.0%) than in females (22.7%) (p = 0.130). Accessory canals occurred more frequently in older rather than younger patients (p = 0.115). The mean diameter of accessory canals was 1.31 ± 0.26 mm (range 1.01-2.13 mm). Gender and age did not significantly influence the diameter. Accessory canals were found palatal to all anterior teeth, but most frequently palatal to the central incisors. In 56.7%, the accessory canals curved superolaterally and communicated with the ipsilateral alveolar extension of the canalis sinuosus. CONCLUSIONS: The study confirms the presence of bone channels within the anterior maxilla other than the nasopalatine canal. More than half of these accessory bone canals communicated with the canalis sinuosus. From a clinical perspective, studies are needed to determine the content of these accessory canals.

Assessment of smoking behaviour in the dental setting. A study comparing self-reported questionnaire data and exhaled carbon monoxide levels.

The present study validated the accuracy of data from a self-reported questionnaire on smoking behaviour with the use of exhaled carbon monoxide (CO) level measurements in two groups of patients. Group 1 included patients referred to an oral medicine unit, whereas group 2 was recruited from the daily outpatient service. All patients filled in a standardized questionnaire regarding their current and former smoking habits. Additionally, exhaled CO levels were measured using a monitor. A total of 121 patients were included in group 1, and 116 patients were included in group 2. The mean value of exhaled CO was 7.6 ppm in the first group and 9.2 ppm in the second group. The mean CO values did not statistically significantly differ between the two groups. The two exhaled CO level measurements taken for each patient exhibited very good correlation (Spearman's coefficient of 0.9857). Smokers had a mean difference of exhaled CO values of 13.95 ppm (p < 0.001) compared to non-smokers adjusted for the first or second group. The consumption of one additional pack year resulted in an increase in CO values of 0.16 ppm (p = 0.003). The consumption of one additional cigarette per day elevated the CO measurements by 0.88 ppm (p < 0.001). Based on these results, the correlations between the self-reported smoking habits and exhaled CO values are robust and highly reproducible. CO monitors may offer a non-invasive method to objectively assess current smoking behaviour and to monitor tobacco use cessation attempts in the dental setting.

Comparison of intraoral radiography and limited cone beam computed tomography for the assessment of root-fractured permanent teeth.

AIM: To compare intraoral occlusal (OC) and periapical (PA) radiographs vs. limited cone beam computed tomography (CBCT) in diagnosing root-fractured permanent teeth. MATERIAL AND METHODS: In 38 patients (mean age 24 years, range 8-52 years) with 44 permanent teeth with horizontal root fractures, intraoral radiographs (PA and OC) and limited CBCT were used to evaluate the location (apical, middle, cervical third of the root) and angulation of the fracture line. Furthermore, the conventional radiographs and CBCT images were compared for concordance of fracture location. RESULTS: In the PA and OC radiographs, 28 fractures (63.6%) were located in the middle third of the root, 11 (25.0%) in the apical third and 5 (11.4%) in the cervical third. The PA/OC radiographs and the sagittal CBCT images (facial aspect) yielded the same level of root fracture in 70.5% of cases (31 teeth; 95% CI: 54.1-82.7%). The PA/OC radiographs and sagittal CBCT images (palatal aspect) showed the same level of root fracture in 31.8% of cases. There was a statistically significant association between the angle at which the root fracture line intersected the axis of the tooth and the level of root fracture in the facial aspect of the sagittal CBCT images. CONCLUSIONS: The diagnosis of the location and angulation of root fractures based on limited CBCT imaging differs significantly from diagnostic procedures based on intraoral radiographs (PA/OC) alone. The clinical significance for treatment strategies and for the prognosis of root-fractured teeth has to be addressed in future studies.

Laser Doppler flowmetry for assessment of anterior mandibular teeth in conjunction with bone harvesting in the symphysis: a clinical pilot study.

PURPOSE: To evaluate the pulp sensitivity and vitality of mandibular incisors and canines before and after bone harvesting in the symphysis. MATERIALS AND METHODS: In 20 patients requiring bone grafts from the symphysis, pulp sensitivity (carbon dioxide [CO2]) and pulpal blood flow (laser Doppler flowmetry [LDF]) of mandibular incisors and canines were evaluated preoperatively, postoperatively, and 6 months after surgery. Teeth were allocated to 1 of 3 groups according to their initial and final reaction to CO2 (group A = teeth with a positive reaction throughout the study, group B = teeth that exhibited a sensitivity change from positive to negative, and group C = teeth with a negative reaction throughout the study). RESULTS: Preoperative flux measurements (LDF) did not differ between groups A, B, and C. Teeth with sensitivity changes (group B) showed the greatest decrease (a statistically significant decrease) of pulpal blood flow over time, whereas teeth in groups A and C demonstrated an insignificant reduction of flux over time. DISCUSSION AND CONCLUSIONS: LDF was purely used as an experimental tool in the present study. Pulpal blood flow measurements using LDF demonstrated a decrease of flux over time in anterior mandibular teeth following bone harvesting in the symphysis. A significant change of flux, however, was only observed for teeth that also demonstrated a loss of pulp sensitivity during the same study period. Loss of pulp sensitivity appeared to be correlated to a significant decrease of blood flow assessed by LDF.