Therapeutic effect of laser on pediatric oral soft tissue problems: a systematic literature review.

In recent years, extensive evidence has been published about usage of laser in oral lesions. The aim of the present study was to review the effectiveness of laser radiation in the treatment of pediatric oral soft tissue problems. The relevant keywords were searched in EBSCO, Medline (via Ovid), PubMed, Scopus, and Web of Science (WOS) databases. Then, eligible case series and controlled clinical trial studies, which published up to the end of 2018, were extracted and scrutinized. In this study, the age range of ≤ 21 years or the average age of ≤ 21 years was considered as the pediatric group. After limiting the search results, removing duplicate titles and eligibility evaluation, 17 papers were enrolled to the study (seven controlled clinical trials and ten case series). Er:YAG (2940 nm), CO2 (10,600 nm), Er,Cr:YSGG (2780 nm), and diode (650, 660, and 975 nm) lasers indicated successful clinical results on mucocele excision, frenectomy, gingival incision and re-contouring, and treatment of vascular malformations. In addition, 660-nm diode laser radiation was an effective adjuvant treatment for halitosis and gingivitis induced by multi-bracket appliances. Reduction or absence of pain and bleeding, suitable homeostasis, reduction of operation time, less analgesic consumption, and antibacterial effect were among the advantages of the laser radiation in the studies. Laser as a main or adjuvant tool can have an effective role in surgical and non-surgical treatments of pediatric oral soft tissue problems. Conducting further randomized controlled trial studies on different soft tissue lesions can contribute to drawing better conclusions.

Comparison of Tissue Density in Hounsfield Units in Computed Tomography and Cone Beam Computed Tomography.

OBJECTIVES: Bone quality and quantity assessment is one of the most important steps in implant treatment planning. Different methods such as computed tomography (CT) and recently suggested cone beam computed tomography (CBCT) with lower radiation dose and less time and cost are used for bone density assessment. This in vitro study aimed to compare the tissue density values in Hounsfield units (HUs) in CBCT and CT scans of different tissue phantoms with two different thicknesses, two different image acquisition settings and in three locations in the phantoms. MATERIALS AND METHODS: Four different tissue phantoms namely hard tissue, soft tissue, air and water were scanned by three different CBCT and a CT system in two thicknesses (full and half) and two image acquisition settings (high and low kVp and mA). The images were analyzed at three sites (middle, periphery and intermediate) using eFilm software. The difference in density values was analyzed by ANOVA and correction coefficient test (P<0.05). RESULTS: There was a significant difference between density values in CBCT and CT scans in most situations, and CBCT values were not similar to CT values in any of the phantoms in different thicknesses and acquisition parameters or the three different sites. The correction coefficients confirmed the results. CONCLUSIONS: CBCT is not reliable for tissue density assessment. The results were not affected by changes in thickness, acquisition parameters or locations.

Designing of a Computer Software for Detection of Approximal Caries in Posterior Teeth.

BACKGROUND: Radiographs, adjunct to clinical examination are always valuable complementary methods for dental caries detection. Recently, progressing in digital imaging system provides possibility of software designing for automatically dental caries detection. OBJECTIVES: The aim of this study was to develop and assess the function of diagnostic computer software designed for evaluation of approximal caries in posterior teeth. This software should be able to indicate the depth and location of caries on digital radiographic images. MATERIALS AND METHODS: Digital radiographs were obtained of 93 teeth including 183 proximal surfaces. These images were used as a database for designing the software and training the software designer. In the design phase, considering the summed density of pixels in rows and columns of the images, the teeth were separated from each other and the unnecessary regions; for example, the root area in the alveolar bone was eliminated. Therefore, based on summed intensities, each image was segmented such that each segment contained only one tooth. Subsequently, based on the fuzzy logic, a well-known data-clustering algorithm named fuzzy c-means (FCM) was applied to the images to cluster or segment each tooth. This algorithm is referred to as a soft clustering method, which assigns data elements to one or more clusters with a specific membership function. Using the extracted clusters, the tooth border was determined and assessed for cavity. The results of histological analysis were used as the gold standard for comparison with the results obtained from the software. Depth of caries was measured, and finally Intraclass Correlation Coefficient (ICC) and Bland-Altman plot were used to show the agreement between the methods. RESULTS: The software diagnosed 60% of enamel caries. The ICC (for detection of enamel caries) between the computer software and histological analysis results was determined as 0.609 (95% confidence interval [CI] = 0.159-0.849) (P = 0.006). Also, the computer program diagnosed 97% of dentin caries and the ICC between the software and histological analysis results for dentin caries was determined as 0.937 (95% CI=0.906-0.958) (P < 0.001). Bland-Altman plot showed an acceptable agreement for measuring the depth of caries in enamel and dentin. CONCLUSIONS: The designed software was able to detect a significant number of dentin caries and acceptable measuring of the depth of carious lesions in enamel and dentin. However, the software had limited ability in detecting enamel lesions.

Fracture resistance of cementum-extended composite fillings in severely damaged deciduous incisors: An in vitro study.

OBJECTIVE: The aim of this study was to comparatively assess the fracture resistance of the cementum-extended and conventional composite fillings with or without intracanal composite posts in severely damaged deciduous incisors. MATERIALS AND METHODS: This in vitro study was performed on 60 extracted deciduous maxillary incisors that were randomly divided into four groups: Group 1: Composite filling (CF); Group 2: Composite filling with composite posts (CF + CP); Group 3: Composite filling extended 0.5 mm to cementum (ceCF); Group 4: Composite filling extended 0.5 mm to cementum with composite posts (ceCF + CP). The fracture resistance was assessed by exerting a progressively increasing load with a cross-head speed of 0.5 mm/min in a Universal Testing Machine. STATISTICAL ANALYSIS: Data were analyzed by SPSS-18 using one-way analysis of variance at α < 0.05. RESULTS: The mean fracture resistance (MFR) values of the experimental groups were 410.57 ± 139.44 N, 564.44 ± 92.63 N, 507.5 ± 76.37 N and 601.08 ± 96.04 N. A significant difference was found between the MFR of Groups 1 and 2, Groups 1 and 4 and Groups 3 and 4 (P < 0.05). CONCLUSION: A superior outcome was achieved by intracanal composite posts in both conventional and cementum-extended composite fillings.

Efficacy of Er,Cr:YSGG laser in removing smear layer and debris with two different output powers.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in removing debris and the smear layer using two different output powers on the apical, middle, and coronal segments of root canal walls. BACKGROUND DATA: Previous literature has failed to evaluate the exclusive effect of Er,Cr:YSGG laser on the quality of smear layer and debris removal in all three segments of the root canal space. METHODS: Sixty extracted teeth were included in the study. After instrumentation, samples were divided into three experimental groups and one positive control group with no further treatment. In group 1, a final irrigation was performed using ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl), sequentially. In group 2, the samples were treated with a 2.78 µm Er,Cr:YSGG laser with an output power of 1.5 W. The same laser was used in group 3, but with an output power of 2.5 W. Scanning electron microscope (SEM) images from the coronal, middle, and apical thirds of the roots were prepared and evaluated for both smear layer and debris removal by three blinded observers. RESULTS: The results showed no differences between groups 1 and 2 regarding the quality of smear layer removal in all areas. However, the 2.5 W laser failed to remove the smear layer effectively. Regarding debris removal, the EDTA and NaOCl irrigation showed significantly better outcomes (adjusted p<0.05) in all areas. CONCLUSIONS: This study raises questions about the overall cleaning abilities of Er,Cr:YSGG lasers.

Diagnostic accuracy of magnetic resonance imaging versus clinical staging in cervical cancer.

BACKGROUND: Cervical cancer is the third most common gynecological cancer and a widespread malignancy in women, accounting for a large proportion of the cancer burden in developing countries. We compared accuracy of MRI staging with clinical staging and also concordance between the two methods for newly diagnosed patients with cervical cancer, using clinical staging as the reference. MATERIALS AND METHODS: This prospective study was conducted on 27 newly diagnosed patients with cervical cancer from Imam Khomeini hospital from June 2012 to Feb 2014. New cases of cervical cancer with positive PAP test were staged separately with a clinical exam based on the FIGO system by a gynecologist, oncologist and also with MRI by an expert radiologist. Then we compared the predicted stage for each patient with the two methods. RESULTS: Based on clinical staging 9 patients (33%) were observed at stage 1. MRI staging was in coordination with clinical staging in eight of them and for one patient MRI accorded stage 2B (88% concordance). CONCLUSIONS: MRI is a reliable noninvasive method with high accuracy for cervical cancer staging. Also presently it is easily obtainable, so we recommend using this technique along with clinical examination for staging cervical cancer patients. We also recommend to radiologists and residents of radiology to get experience with this method of staging.

Distraction osteogenesis for cleft palate closure: A finite element analysis.

BACKGROUND: Current methods of closure of the cleft palate result in the formation of scars and impairment of growth. Distraction osteogenesis (DO) might be an effective means to repair or at least reduce the size of wide clefts. This study investigates the biomechanical aspects of this process. MATERIALS AND METHODS: DO simulation was applied to reduce the size of a unilateral hard palate cleft on a three-dimensional (3D) model of the maxilla. For the position of osteotomy lines, two different models were assumed, with the osteotomy line on the affected side in model A and on the intact side in model B. In each model, DO screws were placed on two different positions, anteriorly (models A1 and B1) and posteriorly (models A2 and B2). Displacement pattern of the bony island in each of the four models, reaction forces at DO locations, and von Mises stress were estimated. Mesh generation and data processing were carried out in the 3D finite element analysis package (ABAQUS V6.7-1; Simulia Corp., Providence, RI, USA). RESULTS: In model B2, the island moved almost evenly, assuring a more complete closure of the cleft. The most uniform stress distribution was found in model B1. CONCLUSION: The results suggest that the best positions for the DO screw and the osteotomy line for closure of the cleft palate are posteriorly and on the intact side, respectively.

Clinical assessment of dizzy patients: the necessity and role of diagnostic tests.

Over administration of diagnostic tests in health care settings is a critical issue, imposing a great deal of expenditure on health sector. Vertigo and dizziness are common complaints of many patients who seek medical advice, and the vast majority of them undergo several evaluations, including Brain Magnetic Resonance Imaging (MRI), Laboratory tests, Pure Tone Audiometry (PTA), and Electrocardiography (ECG). The aim of this study was to investigate the performing rate of these diagnostic tests, and to evaluate their necessity and medical indications. This study was conducted on 270 dizzy patients referred to Apadana Dizziness and Vertigo Clinic, Ahvaz, Iran, from July 2008 to February 2013. Of these, 71.9% were diagnosed with peripheral lesions while laboratory assessment (58.1%) and brain MRI (38.1%) were the most requested tests. Age was an important factor, affecting the frequency of performing the ECG and Brain MRI. Medications were still administered widely even to those who seemed to respond well enough to vestibular rehabilitation. These findings revealed that many unnecessary and time-consuming diagnostic tests were performed, which had minor contribution to the final diagnosis and treatment of the patients. Therefore, a modification in the assessment methods of the dizzy patients with emphasis on history and clinical presentation seems essential.

Comparative evaluation of impression accuracy of tilted and straight implants in All-on-Four technique.

PURPOSE: The aim of this in vitro study was to compare the accuracy of implant impressions in parallel and nonparallel implants of All-on-Four treatment plan. MATERIALS AND METHODS: A reference model containing 4 internal-connection implant analogs was fabricated according to All-on-Four treatment plan (2 anterior implants at 0 degree and 2 posterior implants at 30 degrees in relation to the perpendicular line). Twenty impressions of this model were made using open-tray impression technique. Impressions were poured with American Dental Association type 4 stone, and the positional accuracy of the implant replica heads in x-, y-, and z- axes was evaluated using a coordinate measuring machine. These measurements were compared with the obtained measurements from the reference model that served as control, and data were analyzed using independent test (α = 0.05). RESULTS: The results showed that the accuracy of the implant impressions did not show any significant difference between the tilted and straight implants except in y-coordinate (P = 0.012). CONCLUSION: Within the limitations of this study, the accuracy of the implant impressions did not differ for different implant angulations in All-on-Four treatment plan.

The effect of Er,Cr:YSGG laser irradiation on the push-out bond strength of RealSeal self-etch sealer.

OBJECTIVE: The aim of this study was to evaluate the effect of an erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on the push-out bond strength of RealSeal Self-Etch (SE) sealer. BACKGROUND DATA: Various methods are used for smear layer removal in endodontics, such as the application of Er,Cr:YSGG lasers. This laser system may influence the bond strength of resin-based sealers. METHODS: Sixty single-rooted extracted teeth were selected. After root canal preparation, samples were divided into two experimental groups and one positive control group (n=20 per group). In group 1, the smear layer was removed by irrigation with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). In group 2, the smear layer was removed using a 2.78 µm Er,Cr:YSGG laser with radial firing tips (RFT3) (parameters: 1.5 W, 140 µs, 20 Hz, and 15% water to 15% air ratio), moving at 2 mm/sec in an apico-coronal direction. Group 3 served as a positive control group. Five specimens from each group were selected for scanning electron microscope (SEM) observation. The remaining 45 roots were obturated with RealSeal SE/Resilon and subjected to push-out tests. Data were analyzed using one way analysis of variance (ANOVA) and Tamhane's test. RESULTS: The results showed no significant difference between push-out bond strength of root canal fillings in the EDTA+NaOCl group and the 1.5 W laser group (p>0.05). The positive control group showed the lowest push-out bond strength. CONCLUSIONS: The results of the present study indicate that the application of an Er,Cr:YSGG laser with radial firing tips did not adversely affect the push-out bond strength of RealSeal SE sealer to dentin.

The effect of implant connection length on the dimensional impression accuracy of inclined implants.

PURPOSE: Accurate recording of implant locations is essential for precise passively fitting prostheses with proper support. This in vitro study evaluated the accuracy of impressions made of parallel and nonparallel implants with different lengths of impression coping connections. MATERIALS AND METHODS: A reference model containing four internal-connection implant analogs (two at 0 degrees and two at 30 degrees in relation to the perpendicular line) was fabricated. Thirty medium-consistency silicon impressions of this model were made using the open-tray impression technique. Three groups of 10 specimens each were made with different impression coping connection lengths (2, 1.5, or 1 mm). Impressions were poured with type IV stone. The positional accuracy of the implant replica heads in the x-, y-, and z-axes was evaluated using a coordinate measuring machine, and measurements were compared with the obtained dimensions from the reference model. Data were analyzed with two-way analysis of variance (α = .05). RESULTS: There was no significant difference in impression accuracy, regardless of the lengths of the impression connections. Additionally, there was no significant difference between the impression accuracy of inclined and straight implants, except in the y-axis (P = .006). CONCLUSIONS: Within the limitations of this study, the accuracy of implant impressions did not differ for different lengths of transfer coping connections of inclined and straight implants.

Periradicular surgery of human permanent teeth with calcium-enriched mixture cement.

INTRODUCTION: Root-end preparation and restoration with an endodontic material are required when nonsurgical endodontic retreatment has failed or is impossible. The present clinical study reports the treatment outcomes of periradicular surgery using calcium-enriched mixture (CEM) cement. MATERIALS AND METHODS: A prospective outcome study of periradicular surgery using CEM was conducted on 14 permanent teeth with persistent apical periodontitis. Using a standardized surgical protocol, 2-3 mm of the root apex was resected; approximately 3 mm deep root-end cavities were ultrasonically prepared and filled with CEM cement. All patients were available for recall. RESULTS: Clinical and radiographic examination revealed complete healing of periradicular lesions, i.e. regeneration of periodontal ligament and lamina dura in 13 teeth (93% success) during a mean time of 18 months; moreover, the teeth were functional and asymptomatic. CONCLUSION: Favorable treatment outcomes in this prospective clinical study suggested that CEM cement may be a suitable root-end filling biomaterial.

Oral health status in preschool asthmatic children in Iran.

Asthma is a chronic inflammatory disorder of the airways, which is diagnosed by periodic symptoms of inflammation, bronchial spasm, and increased mucosal secretions. It has higher incidence among the preschool children. There are many contradictory reports based on the effect of asthma on oral health, however it has been hypothesized that asthma could lead to poor oral health. The objective of the present study was to investigate oral health indices in 44 preschool children of three to six years old with mild to moderate asthma and 46 matched healthy children in Tehran Children's Respiratory Center. Dental plaque, gingival inflammation, mouth breathing, and dental caries were evaluated by one trained examiner according to World Health Organization [WHO] criteria. Culture and colony counting of streptococcus mutans and lactobacillus species were carried out in saliva specimens of the patients. The effects of different factors on the colony counts were statistically analyzed using linear regression analysis. The level of mother's education and preexisting asthma disease in children had significant effect on the colony counts of streptococcus species whereas no factor was found to influence the number of lactobacillus counts significantly. The results indicated no significant differences between the children with asthma and those without asthma regarding (decayed, missing, filled, teeth) dmft index (mean of 3.34 in asthmatic children and 3.0 in the control group). Therefore, it can be deduced that the presence of asthma disease did not increase the probability of tooth decay.

Finite element reconstruction of a mandibular first molar.

INTRODUCTION: Mandibular first molar is the most important tooth with complicated morphology. In finite element (FE) studies, investigators usually prefer to model anterior teeth with a simple and single straight root; it makes the results deviate from the actual case. The most complicated and time-consuming step in FE studies is modeling of the desired tooth, thus this study was performed to establish a finite element method (FEM) of reconstructing a mandibular first molar with the greatest precision. MATERIALS AND METHODS: An extracted mandibular first molar was digitized, and then radiographed from different aspects to achieve its outer and inner morphology. The solid model of tooth and root canals were constructed according to this data as well as the anatomy of mandibular first molar described in the literature. RESULT: A three-dimensional model of mandibular first molar was created, giving special consideration to shape and root canal system dimensions. CONCLUSION: This model may constitute a basis for investigating the effect of different clinical situations on mandibular first molars in vitro, especially on its root canal system. The method described here seems feasible and reasonably precise foundation for investigations.

Bone age estimation by cervical vertebral dimensions in lateral cephalometry.

OBJECTIVES: A critical issue in contemporary orthodontics is bone age estimation. The most reliable method for skeletal age evaluation is hand-wrist radiography; but it requires further radiation. There is an increasing attention for evaluating cervical vertebrae to reduce the radiation to the patients. The aim of this study was to estimate bone age by measuring 3rd and 4th cervical vertebrae (C3, C4) dimensions. MATERIALS AND METHODS: We conducted a correlational study on 91 Iranian individuals aged 8-18 years. After taking lateral cephalometry and hand-wrist radiographs, C3 and C4 were measured using Vixwin 2000 software. Hand-wrist bone age, determined on Greulich Atlas, was the reference test. Stepwise multiple linear regression model demonstrated the correlation between the two measurements. RESULTS: Anterior height of the fourth cervical vertebrae (AH4) had the strongest simple correlation with hand-wrist bone age (r=0.831, P<0.001) and was the only variable that remained in stepwise multivariate regression model. The regression model was: Bone age=0.989×AH4+3.308. Adjusted R2 was 0.686 (p<0.001). CONCLUSIONS: Lateral cephalometric radiographs are useful for bone age estimation, and might be an alternative for hand-wrist radiography, with the advantage of radiation reduction.

Correlation between dental and cervical vertebral maturation in Iranian females.

BACKGROUND: Considerable variations in the development stage among patients of the same chronological age have led to introduce the concept of the developmental age based on the maturation of different organs such as cervical vertebrae or teeth. OBJECTIVES: The purpose of this study was to investigate the correlation between the stages of tooth calcification and the cervical vertebral maturation in Iranian females. PATIENTS AND METHODS: Four hundred females (age range, 8 to 14 years) participated in the study. To determine the dental maturational stage, calcification of the mandibular teeth except for third molars were rated according to the method suggested by Demirjian et al. To evaluate the stage of skeletal maturation, cervical vertebral morphologic changes were assessed on lateral cephalometric radiographs according to the method explained by Baccetti et al. Correlations between bone maturation and teeth calcification were showed by Spearman's correlation and Kendall's tau-b coefficients. The relevant associations were investigated by ordinal logistic regression models. RESULTS: Correlations between the two stages were observed in the first and second premolars, canine and central incisors. All these correlations were significant. The association between cervical vertebral maturation and tooth calcification was greatest in the lateral incisor (odds ratio (OR) = 11, 95% confidence interval (CI): 6.6-18.3). However, considering the 95% CI for OR, no significant difference was detected among the second molar, first molar and lateral incisor. CONCLUSION: The relationship between calcification of teeth and maturation of cervical bones was significant. Bone maturation can be predicted by using teeth calcification stages, especially in the second molar, first molar and lateral incisor.

MTA resorption and periradicular healing in an open-apex incisor: A case report.

This case report describes the periradicular healing and resorption of an unintentional extrusion of mineral trioxide aggregate (MTA) in an open-apex central incisor. A 22-year old female with a symptomatic open-apex right maxillary central incisor associated with a periradicular lesion was referred for evaluation and treatment. After chemomechanical debridement, the apical third of the root canal was filled with MTA to create an apical plug. Postoperative radiographs showed the extrusion of MTA into the periradicular lesion. The tooth was then restored with a post and crown. At the 2-year follow-up, the tooth was asymptomatic and radiographs revealed complete healing of the periradicular area. At the 7-year follow-up, complete resorption of the extruded MTA was evident. The results of this case study indicate that complete resorption of extruded MTA is possible in the long term; however, the extrusion of MTA in open-apex tooth should still be avoided.

Periradicular regeneration after endodontic surgery with calcium-enriched mixture cement in dogs.

INTRODUCTION: The aim of this in vivo study was to compare the response of periradicular tissues to mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement as root-end fillings and to analyze hard tissue healing after periradicular surgery. METHODS: Intentional periradicular lesions were induced in 32 premolar teeth in 4 beagle dogs. The root canals were prepared, dried, and obturated with laterally condensed gutta-percha with sealer, and the coronal access cavities were filled with amalgam. After surgical exposure of the apices, 2-3 mm of the apical root was resected, and root-end cavities were ultrasonically prepared. The root-end cavities were randomly filled with MTA or CEM cement. After 2 months, the animals were killed; tissue blocks were removed and prepared for histologic examination. Hard tissue healing including cementum and new bone formation in addition to concentration and extent of inflammation were evaluated. RESULTS: Eight samples were excluded. The major finding was the cementum deposition adjacent to MTA in 11 of 12 samples and CEM cement in 10 of 12 samples. With one-way analysis of variance, no significant difference was observed between the periradicular tissue response to tested materials. CONCLUSIONS: CEM cement and MTA were associated with regenerative periapical tissue response when used as root-end filling biomaterials.

Permanent molar pulpotomy with a new endodontic cement: A case series.

The aim of this case series was to determine the clinical and radiographic success rate of pulpotomy, with new endodontic cement (NEC), in human mature permanent molar teeth. Twelve molars with established irreversible pulpitis were selected from patients 14 - 62 years old. The selection criteria included carious pulp exposure with a positive history of lingering pain. After isolation, caries removal, and pulp exposure, pulpotomy with NEC was performed and a permanent restoration was immediately placed. At the first recall (+1 day) no patients reported postoperative pain. One wisdom tooth had been extracted after two months because of failure in coronal restoration. Eleven patients were available for the second recall, with a mean time of 15.8 months. Clinical and radiographic examination revealed that all teeth were functional and free of signs and symptoms. Histological examination of the extracted teeth revealed complete dentin bridge formation and a normal pulp. Although the results favored the use of NEC, more studies with larger samples and a longer recall period were suggested, to justify the use of this novel material for treatment of irreversible pulpitis in human permanent molar teeth.