Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models.

The mechanical property, microhardness, is evaluated in dental enamel, dentin, and bone in oral disease models, including dental fluorosis and periodontitis. Micro-CT (µCT) provides 3D imaging information (volume and mineral density) and scanning electron microscopy (SEM) produces microstructure images (enamel prism and bone lacuna-canalicular). Complementarily to structural analysis by µCT and SEM, microhardness is one of the informative parameters to evaluate how structural changes alter mechanical properties. Despite being a useful parameter, studies on microhardness of alveolar bone in oral diseases are limited. To date, divergent microhardness measurement methods have been reported. Since microhardness values vary depending on the sample preparation (polishing and flat surface) and indentation sites, diverse protocols can cause discrepancies among studies. Standardization of the microhardness protocol is essential for consistent and accurate evaluation in oral disease models. In the present study, we demonstrate a standardized protocol for microhardness analysis in tooth and alveolar bone. Specimens used are as follows: for the dental fluorosis model, incisors were collected from mice treated with/without fluoride-containing water for 6 weeks; for ligature-induced periodontal bone resorption (L-PBR) model, alveolar bones with periodontal bone resorption were collected from mice ligated on the maxillary 2nd molar. At 2 weeks after the ligation, the maxilla was collected. Vickers hardness was analyzed in these specimens according to the standardized protocol. The protocol provides detailed materials and methods for resin embedding, serial polishing, and indentation sites for incisors and alveolar. To the best of our knowledge, this is the first standardized microhardness protocol to evaluate the mechanical properties of tooth and alveolar bone in rodent oral disease models.

The mylohyoid line is highly variable but does not affect the microarchitecture of the edentulous alveolar bone - an anatomical micro-CT study.

OBJECTIVES: To evaluate in the absence of teeth the variability of the mylohyoid line (ML), the microarchitecture of the adjacent bone, and whether the variable prominence/width of the ML is associated with the quality of the adjacent bone. METHODS: µCT scans of 28 human mandibles from anatomical specimens were analyzed. The following parameters were assessed in four edentulous areas (first and second premolar (PM), first, second, and third molar (M1/2/3)): ML width, cortical thickness (CtTh), average cortical- (Avg.Ct.BV/TV), and trabecular bone volume fraction (Avg.Tb.BV/TV). RESULTS: The ML width increased from the PM towards the M2 region, which also showed the highest variance (range: 0.4-10.2 mm). The CtTh showed a decrease in the M3 region, while Avg.Ct.BV/TV and Avg.Tb.BV/TV hardly differed among the regions. In the multivariable model on the effect of the various parameters on the ML width, only gender and tooth region were significant. Specifically, male specimens were associated with a wider ML width compared to female specimens and the M2 region was associated with a wider ML width compared to the other tooth regions. CONCLUSION: The ML width was not associated with the cortical and trabecular bone quality in the adjacent bone, while gender and tooth region had a significant effect. Specifically, the ML width was lower in female, but peaked in the M2 region with a median width of 3-4 mm. CLINICAL RELEVANCE: From a clinical point of view, it was confirmed that the ML is in general a highly variable structure, especially in the M2 region, but the ML width does not allow any conclusions on the bone quality. Altogether, this underlines the need for an individual and accurate diagnostic prior to any surgical intervention.

Alveolar bone retention following treatment of dilacerated labial inversely impacted maxillary central incisors-a retrospective study.

The root of late-dental-age labial inversely impacted maxillary central incisors (LIIMCIs) typically develops to severe dilacerated morphology. Therefore, reliable posttreatment periodontal estimates of orthodontic treatment prognosis would be critical to the treatment value of impacted incisors. This study aims to analyze further changes in dimensions of the alveolar bone following the closed-eruption treatment of late-dental-age dilacerated LIIMCIs. Cone beam computed tomography (CBCT) scanning data of 16 patients with unilateral dilacerated late-dental-age LIIMCIs were collected, including the pretreatment (T1) and at the 2.23 ± 0.78 years follow-up stage (T2) respectively. Patients underwent closed-eruption treatments to bring the impacted incisor into the dental arch. Dolphin imaging software was used to measure alveolar bone height labially, palatally, and proximally to the site at T1 and T2, as well as alveolar bone thicknesses at 0, 2, 4, 6 and 8 mm below the initial measurement plane (IMP). The alveolar bone heights on the impacted and contralateral sides increased from T1 to T2 (p < 0.05). Alveolar bone growth on both sides had no significant difference. In T2, the mean values of labial and distal alveolar heights on the contralateral sides were greater than on the impacted sides (p < 0.05). The mean values of total alveolar bone thicknesses on the impacted sides in T1 were significantly smaller than those on the contralateral sides in IMP-0, 2, 4, 6, 8 (p < 0.05). The total thicknesses on the impacted sides in T2 increased and were significantly greater than on the contralateral sides (p < 0.05), except for the thickness in IMP-0. The closed-eruption treatment of dilacerated late-dental-age LIIMCIs results in no significant changes to alveolar bone height, except on the labial and distal sides, with increased alveolar bone thickness, suggesting that this approach may be viable first choice therapy for non-extraction orthodontic cases.

Fully automatic AI segmentation of oral surgery-related tissues based on cone beam computed tomography images.

Accurate segmentation of oral surgery-related tissues from cone beam computed tomography (CBCT) images can significantly accelerate treatment planning and improve surgical accuracy. In this paper, we propose a fully automated tissue segmentation system for dental implant surgery. Specifically, we propose an image preprocessing method based on data distribution histograms, which can adaptively process CBCT images with different parameters. Based on this, we use the bone segmentation network to obtain the segmentation results of alveolar bone, teeth, and maxillary sinus. We use the tooth and mandibular regions as the ROI regions of tooth segmentation and mandibular nerve tube segmentation to achieve the corresponding tasks. The tooth segmentation results can obtain the order information of the dentition. The corresponding experimental results show that our method can achieve higher segmentation accuracy and efficiency compared to existing methods. Its average Dice scores on the tooth, alveolar bone, maxillary sinus, and mandibular canal segmentation tasks were 96.5%, 95.4%, 93.6%, and 94.8%, respectively. These results demonstrate that it can accelerate the development of digital dentistry.

Radiographic evaluation of the distance between the restoration margin and the alveolar bone crest in dental implant patients: A retrospective study.

OBJECTIVES: The recently introduced Implant Disease Risk Assessment (IDRA) identifies a restoration margin-alveolar bone crest (RM-AC) distance of less than 1.5 mm as a key risk factor for peri­implant disease among eight major risk factors. This study evaluated the impact of the RM-AC distance on marginal bone loss (MBL) through radiographic analysis. METHODS: This retrospective cross-sectional study included 77 partially edentulous patients (39 females and 38 males, aged 22 to 76 years) with 202 platform-switched conical connection implants, cement-retained, implant-supported fixed restorations, and bone-level implants placed between 2016 and 2021. Dental implants were followed for least 6 to 36 months at follow up functional loading. Study participants were categorized into Group A (RM-AC distance ≤ 1.5 mm, n = 69) and Group B (RM-AC distance > 1.5 mm, n = 133). Twelve patients in Group B and five patients in Group A had no history of periodontal disease. The MBL was measured radiographically from the most coronal point of the implant shoulder to the alveolar bone, and the RM-AC distance was measured from the restoration margin to the alveolar crest. Multinomial logistic regression analysis was used for statistical evaluation. RESULTS: The incidence of MBL in Group A was statistically significant and 3.42 times higher than that in Group B. The rate of MBL in periodontitis Stage 4 was found to be 26.31 times higher than that in periodontitis Stage 2. The incidence of MBL was 6.097 and 5.02 times higher with increasing implant diameter and length, respectively. CONCLUSION: This study conclusively demonstrates that RM-AC distance ≤ 1.5 significantly increases the risk of MBL, particularly in patients with a history of periodontal disease. CLINICAL SIGNIFICANCE: This study highlights the critical role of maintaining an RM-AC distance greater than 1.5 mm in the prevention of MBL, particularly in patients with a history of periodontal disease. Since implant diameter and length have a significant impact on the risk of MBL, it emphasizes that implant demographics should also be carefully evaluated.

A radiographic and histological study to compare red (650 nm) versus near infrared (810 nm) diode lasers photobiomodulation for alveolar socket preservation.

Previous findings indicated that the laser photobiomodulation is more effective than the control or placebo in preserving the alveolar socket. This study aimed to compare two different lasers regarding their effectiveness in aiding alveolar socket preservation. Twenty extraction sockets were selected then divided into two equal groups. Group A was exposed to 650 nm Diode laser, and Group B to 810 nm Diode laser following the same protocol and parameters after a standard alveolar socket preservation procedure with collagen plug. Radiographic analysis with cone beam computed tomography was done to compare the alveolar bone surface area immediately after extraction and three months post-operatively, while bone samples collected before implant drilling were histologically examined for newly formed bone evaluation and histomorphometric analysis in terms of percentage of new bone surface area, percentage of unmineralized bone and finally, immunohistochemical analysis of Osteocalcin reaction surface area as well as optical density. Radiographically, infrared (810 nm) Diode effect on alveolar bone surface area has significantly exceeded the red laser, while histologically, red (650 nm) Diode has demonstrated statistical significance regarding all parameters; newly formed bone surface area percentage, unmineralized bone area percentage and finally Osteocalcin bone marker reaction surface area percentage and optical density. Under the specified conditions and laser parameters, photobiomodulation using the 810 nm Diode got the upper hand radiographically, yet histologically, the red 650 nm Diode managed to dominate all histological parameters when both employed as an adjunct to alveolar socket preservation procedures.

Evaluation of Bone Growth around Autotransplanted Teeth Using Cone-Beam Computed Tomographic Images.

INTRODUCTION: The aim of this observational study was to evaluate bone growth at the recipient site of autotransplanted teeth using cone-beam computed tomography (CBCT) images and to compare it to the control tooth. METHODS: Bone growth was measured on CBCT images obtained from the anterior region of the maxilla, which received a single transplant of immature premolars due to early loss of the central incisor. The results were compared to the bone growth of contralateral central incisor that served as control. The sample consisted of 13 autotransplanted teeth and 13 control teeth. It was determined the thickness of the buccal bone of the marginal ridge, the thickness of the palatal bone of the marginal ridge, the height of the maxillary bone, and the thickness of the maxillary bone at its mid-height. The measurements were analyzed statistically, adopting a significance level of 5%. RESULTS: The mean interval between the dental autotransplantation surgery and the CBCT scan was 16.2 years. The mean thickness of the buccal bone of the marginal ridge, thickness of the palatal bone of the marginal ridge, height of the maxillary bone, and thickness of the maxillary bone at its mid-height were, respectively, 0.85, 0.94, 19.6, and 8.85 mm for autotransplanted teeth and 0.79, 1.09, 18.88, and 8.5 mm for control teeth. There were no significant differences in the bone measurements between autotransplanted and control teeth (P > .05). CONCLUSIONS: The growth of maxillary bone in the region that received the autotransplanted tooth was proportional to that of maxillary bone that supports the contralateral tooth. Thus, autogenous transplantation is efficient in maintaining the bone architecture at the recipient site.

The repeatability of periodontal imaging with intraoral ultrasound scanning.

OBJECTIVE: Ultrasound is a non-invasive and low-cost diagnostic tool widely used in medicine. Recent studies have demonstrated that ultrasound imaging might have the potential to be used intraorally to assess the periodontium by comparing it to current imaging methods. This study aims to characterize the repeatability of intraoral periodontal ultrasound imaging. MATERIALS AND METHODS: Two hundred and twenty-three teeth were scanned from fourteen volunteers participating in this study. One operator conducted all the scans in each tooth thrice with a 20 MHz intraoral ultrasound. The repeatability of three measurements, alveolar bone crest to the cementoenamel junction (ABC-CEJ), gingival thickness (GT), and alveolar bone thickness (ABT), was calculated with intercorrelation coefficient (ICC). Measurements were also compared with mean absolute deviation (MAD), repeatability coefficient (RC), and descriptive statistics. RESULTS: ICC scores for intra-rater repeatability were 0.917(0.897,0.933), 0.849(0.816,0.878), and 0.790(0.746,0.898), MAD results were 0.610 mm (± 0.508), 0.224 (± 0.200), and 0.067 (± 0.060), and RC results were 0.648, 0.327, and 0.121 for ABC-CEJ, GT, and ABT measurements, respectively. CONCLUSION: Results of the present study pointed towards good or excellent repeatability of ultrasound as a measurement tool for periodontal structures. CLINICAL RELEVANCE: Clinicians could benefit from the introduction of a novel chairside diagnostic tool. Ultrasound is a non-invasive imaging assessment tool for the periodontium with promising results in the literature. Further validation, establishment of scanning protocols, and commercialization are still needed before ultrasound imaging is available for clinicians.

Factors affecting local alveolar bone thickness in unilateral maxillary canine-lateral incisor transposition.

INTRODUCTION: This study aimed to use 3-dimensional data to investigate the factors affecting local alveolar bone thickness in unilateral maxillary canine-lateral incisor transposition. METHODS: Pretreatment cone-beam computed tomography data of 34 patients with unilateral maxillary canine-lateral transposition were imported into Dolphin Imaging software (version 11.8; Dolphin Imaging and Management Solutions, Chatsworth, Calif) for 3-dimensional reconstruction. The age, gender, and type of transposition at the beginning of treatment were recorded. The thickness and height of the transposed canine, the labiopalatal and distomedial distance from the transposed canine to the apex of the lateral incisor, the inclination of the transposed lateral incisor, the apical height of the lateral incisor, and the alveolar bone thickness in the apical plane were measured. Multiple linear regression analyses were applied to investigate the factors affecting alveolar bone thickness in the apical plane of the transposed lateral incisor. Two sample t test were applied to assess the difference of alveolar bone thickness in patients of different ages. RESULTS: The 10 boys and 24 girls had a mean age of 12.26 ± 2.34 years. In all 34 participants, the apical alveolar bone thickness of transposed lateral incisors was significantly higher than that of the unaffected side (P <0.05). Based on multiple regression analyses, factors associated with a wider alveolar bone thickness were as follows: age (ß = -0.237; P = 0.008), the labiopalatal distance from the transposed canine to the apex of the lateral incisor (ß = 0.675; P <0.001), and the inclination of the transposed lateral incisor (ß = 0.048; P = 0.032). Patients aged <11 years had significantly thicker alveolar bone than that of patients aged >11 years (P <0.05). CONCLUSIONS: Patients with younger age, greater lateral incisor inclination, and greater labiopalatal distance between canine and lateral incisor had more alveolar bone thickness. Early treatment permits tooth movement within the thicker alveolar bone.

Alveolar morphometry in young adults with and without agenesis of the upper lateral incisor: A retrospective study.

INTRODUCTION: We aimed to compare alveolar morphometry in young adults with agenesis of the upper lateral incisor versus the side without agenesis and versus matched controls. MATERIAL AND METHODS: In this observational retrospective study, cone beam computed tomography scans were obtained of 36 upper hemiarches from young adults aged 15 to 30 years. The hemiarches were distributed into three groups: group 1: 12 upper hemiarches presenting agenesis of the upper lateral incisor; group 2: 12 upper hemiarches from the opposite side without agenesis of the upper lateral incisor (control group 1); and group 3: 12 upper hemiarches without agenesis of the upper lateral incisor matched for age and sex with respect to the affected group (control group 2). A trained and calibrated investigator performed all the alveolar measurements at two different times, including sagittal, coronal and axial slices of each hemiarch. Paired Student's t-tests, Chi-square and repeated measures ANOVA with Bonferroni correction were used, (P<0.05). RESULTS: Apical mesial evaluation of group 1 (4.22±1.19mm) was significantly lower (P<0.001) than that of groups 2 (6.72±1.17mm) and 3 (7.58±1.67mm). Apical distal evaluation also showed differences (P<0.001) among the three groups, with the dimension being smaller in group 1 with agenesis (4.53±1.14mm), followed by group 2 without agenesis (6.23±1.55mm) and the healthy control group 3 (7.73±1.71mm). CONCLUSIONS: Lateral incisor agenesis significantly reduces the alveolar dimensions of the affected area. In cases of unilateral agenesis, the unaffected side also shows sequelae, with decreased dimensions compared to cases without agenesis. This condition should be taken into account when making therapeutic decisions regarding rehabilitation with implants or canine replacement.

Comprehensive analysis of the maxillary esthetic zone for immediate implant placement using cone beam computed tomography: A study of 352 maxillary images.

STATEMENT OF PROBLEM: Previous studies have examined the maxillary esthetic zone for immediate implant placement, but these studies had small sample sizes and did not investigate multiple parameters. PURPOSE: The purpose of this cross-sectional study was to use cone beam computed tomography (CBCT) to evaluate the sagittal root position (SRP), alveolar bone concavity, labial bone perforation (LBP), and tooth-ridge angle in the maxillary anterior teeth region. MATERIAL AND METHODS: A total of 352 CBCT images of patients (180 men and 172 women) who visited the dental hospital between 2018 and 2023 were analyzed. The sample included 2112 anterior maxillary teeth. SRP, alveolar bone concavity, tooth ridge angle, and LBP were assessed using virtual implant simulation. The data were analyzed by using chi-squared and kappa tests to analyze distributions and agreement, respectively, dependent and independent t-tests to assess sex and tooth-specific differences, and the Spearman correlation test to explore potential correlations (α<.05). RESULTS: The CBCT images revealed that the majority of SRP were in Class I (85.4%), with smaller percentages in Class II (12.5%) and Class IV (2.3%); Class III was the least common (1%). The canine exhibited the most significant alveolar bone concavity angle average (149.14 ±6.35 degrees), followed by the lateral incisor (142.32 ±8.7 degrees). The canines had the highest occurrence of LBP (63.1%) (P<.01). Women had a higher frequency of labial bone perforation and deeper alveolar bone concavities than men (P<.01). CONCLUSIONS: The findings of this study indicate that careful assessment and planning are necessary for immediate implant placement in the maxillary anterior region. The significant occurrence of LBP highlights the importance of thorough planning and evaluation to avoid surgical mishaps and complications which may necessitate bone grafting and result in added costs and time. Special attention should be given to women and the canine area.

Evaluation of maxillary alveolar ridge formation and ridge continuity after secondary alveolar bone grafting using cancellous and cortico-cancellous bone graft in unilateral cleft alveolus using cone beam computed tomographic scan - a randomized controlled trial.

PURPOSE: The aim of present study was to compare and evaluate the maxillary alveolar ridge formation and ridge continuity using cancellous and corticocanellous bone graft harvested from anterior iliac crest for complete secondary unilateral cleft alveolus defects. MATERIAL AND METHOD: All patients were randomized into two groups for secondary alveolar bone grafting. Group I (n = 10) patients treated with cancellous particulate bone graft and group II (n = 10) patients treated with cortico-cancellous block graft. Maxillary alveolar ridge bone formation was assessed with the help of cone beam computed tomography (CBCT) scan using Planmeca Romexis Viewer 5.0 software. Maxillary alveolar ridge continuity was assessed with axial section of CBCT scan and clinical occlusal photograph. Preoperative CBCT scan and occlusal photographs were compared with post-op 6-month CBCT scan and occlusal photographs. RESULT: The mean preoperative volume of cleft defect in group I was 4.2576 cm3 whereas in group II it was 4.2268 cm3. The mean postoperative bone bridge formation after 6 months in group I was 4.055 cm3 whereas in group II it was 3.8103 cm3. Preoperative and 6-month postoperative axial sections of CBCT scans were compared and 100% maxillary alveolar ridge continuity was achieved in both groups. The preoperative and postoperative occlusal photographs of both the groups were compared and showed accurate bone and well aligned maxillary alveolar ridge formation in all patients. CONCLUSION: The present study concluded that maxillary alveolar ridge formation rate is less in cortico-cancellous iliac crest block graft compared to cancellous iliac crest particulate graft, but is equally good as cancellous bone graft. CLINICAL TRIAL REGISTRATION NO: (REF/2020/09/031605)/ CTRI/ 2020/09/028001.

Age estimation from alveolar bone loss, re-evaluation of Ruquet's method.

There are many dental age estimation methods, but all the methods do not correspond, especially for aging methods for adults and mature individuals, to the reality of the forensic field, which favors simple, effective, and easy-to-use methods. Ruquet (2015) developed a method based on alveolar bone loss that predicts age for individuals between 25 and 60 years old and is even more accurate for those 25-40 years old. This study re-evaluated Ruquet's alveolar bone loss method using three-dimensional imaging of individuals whose age and sex were known, without taking into account their medical conditions. Digital measurements, from the cemento-enamel junction (CEJ) to the alveolar bone crest (ABC), were performed on the mesial and distal surfaces of teeth on 243 patients, independent of the tridimensional imaging test. With these measurements, two alveolar bone loss averages (ABL) were calculated, one with all the teeth present on the arches and another with only Ramfjörd's teeth. Bone loss showed a significant correlation with age (p < 0.001). The age estimation with all teeth and with only Ramfjörd's teeth showed a statistically significant difference, and age estimation was more accurate when all teeth were used. The assessment of alveolar resorption appears to be an interesting tool for age estimation in adult individuals. However, the method still lacks precision, and the mean absolute errors (MAEs) obtained by age group were all greater than 5 years, except for the age group 35-39 years old, for the age estimation with all teeth. Further studies should explore this existing correlation between alveolar bone loss and age and refine this method to make it more accurate.

Comprehensive view of the posterior mandibular ridge morphology.

The anatomy of the posterior mandibular ridge and the anatomical structures present in this region are important in the planning and execution of dental treatments. The aim of this study was to examine all forms of alveolar ridge in detail to provide a comprehensive description of the posterior mandibular ridge. This study included 1865 cross-sectional sections of cone beam computed tomography scans obtained from 511 Iranian patients with a mean age of 48.14 years (280 female, 231 male). The alveolar ridge was described based on the ridge shape, including the existence and location of convexity and concavity. The morphology of the posterior mandibular ridge was categorized into 14 types: straight, pen shape, oblique, D type, B type, kidney, hourglass, sickle, golf club, toucan beak, tear, cudgel, basal, and saddle. Among the alveolar ridge types, the straight type in the premolar region and toucan beak type in the molar region were most frequent in the female, male, dentulous, and edentulous ridges. This study found significant differences in alveolar ridge morphology according to sex, dental status, and region of the ridge (all P < 0.001). In conclusion, the morphology of the alveolar ridge varies significantly between the sexes and between dentulous and edentulous locations.

Effects of boric acid on alveolar sockets filling after dental extraction in rats.

PURPOSE: After extraction, dental alveolus filling aims to reduce bone loss and maintain the alveolus volume during patient rehabilitation. Boric acid (BA) is a boron-derived compound with osteogenic properties and an interesting candidate for alveoli filling. This study aims to investigate the osteogenic capacity of the local application of BA in dental socket preservation. METHODS: Thirty-two male Wistar rats were submitted to upper right incisor extraction and randomly divided into four groups (n = 8): control group (no intervention), BA (8 mg/kg) socket filling, bone graft (Cerabone®, Botiss, Germany), and BA + bone graft socket filling. Animals were euthanized 28 days after dental extraction. MicroCT and histological analysis were performed to evaluate the newly formed bone on the dental alveolus. RESULTS: MicroCT analysis demonstrated that bone volume fraction (BV/TV), bone surface (BS), bone surface/bone volume ratio (BS/BV), bone surface density (BS/TV), trabecular thickness (Tb.Th), total bone porosity (Po-tot), and total volume of pore space (Po.V(tot)) from BA and BA + bone graft rats were significantly different from the control group. Histological evaluation displayed a delayed bone repair in BA rats, with the presence of connective tissue and inflammatory infiltrate. However, the BA + bone graft group demonstrated histological aspects like the bone graft animals, with less organized osteoblasts, suggesting inferior bone repair. CONCLUSION: Osteogenic capacity did not depend on the BA local application after 28 days of dental extraction. The presence of inflammation in the BA group can represent toxicity induced by the substance dosage used.

Horizontal ridge augmentation with particulate cortico-cancellous freeze-dried bone allograft alone or combined with injectable-platelet rich fibrin in a randomized clinical trial.

OBJECTIVES: The objective of this study is to assess the effectiveness of horizontal ridge augmentation using FDBA in combination with injectable-platelet rich fibrin (i-PRF) versus FDBA alone. To fulfill this aim, the radiographic and histomorphometric outcomes are compared. METHOD: The study involved 41 patients who had horizontal alveolar ridge defects categorized as either B (2.5-7 mm) or C (0-2.5 mm). The control group received FDBA alone (n = 20), while the test group received FDBA in combination with i-PRF (n = 21). The horizontal dimensions of the alveolar ridge were measured at 0, 2, 4, and 6 mm from the bone crest using CBCT before and 6 months after alveolar ridge augmentation. In the second-stage surgery, 24 biopsies were taken from the augmented bone - 13 from the control group and 11 from the test group, and were examined histologically and histomorphometrically. The data were analyzed using Pearson correlation coefficient, chi-square, paired-t, and two-sample t tests. RESULTS: There was no significant difference (p > 0.05) in the increase of mean ridge width between the test group and the control group after 6 months at distances of 0, 2, 4, and 6 mm from the crest, with differences of -0.28, 0.12, 0.52, and 1.04 mm, respectively. However, the amount of newly formed bone and material residues was significantly higher in the FDBA + i-PRF group compared to the FDBA alone group (45.01% and 13.06% vs 54.03% and 8.48%, respectively). There was no significant difference in the amount of soft tissue between the two groups (41.02% and 37.5%, p > 0.05). CONCLUSION: The study found that there was no statistically significant difference in the increase of horizontal ridge width between the FDBA + i-PRF group and the FDBA group. However, the histomorphometric analysis revealed that the FDBA + i-PRF group had a higher proportion of newly formed bone, less connective tissue, and fewer residual particles. This suggests a superior quality of bone formation compared to the FDBA group.

The facial-coronal ridge crest alterations after single immediate implant placement and provisionalization with thin buccal plate phenotype in anterior maxilla: A radiographic case-series study.

AIM: To explore the features of and potential landmarks that predict crestal ridge remodeling after immediate implant placement and provisionalization (IIPP) with thin buccal plate phenotype in the anterior maxilla. MATERIALS AND METHODS: Patients requiring IIPP of single maxillary incisor with thin buccal bone plate (<1 mm) were recruited. Cone-beam computed tomography (CBCT), performed before and 6 months after the intervention, were three-dimensionally superimposed. A virtual line connecting the bony emergence points of adjacent teeth was drawn as a reference. The facial-coronal alveolar crest of the extraction socket and healed ridge were located in mesial, middle and distal cross-sectional planes, and linear ridge reductions were measured. The correlation between ridge reduction and local factors was analyzed. RESULTS: Fifty patients were included. From the extraction socket to healed ridge, the alveolar crest underwent linear bone reduction of 1.50 ± 0.50, 1.54 ± 0.66 and 1.65 ± 0.73 mm in the mesial, middle, and distal regions in an apical-palatal direction. The middle region had significantly higher horizontal (facial-palatal) but lower vertical (coronal-apical) bone reduction than the mesial and distal areas (P < 0.01). The facial-coronal ridge crest of the healed ridge located close to the reference line. Ridge reduction positively correlated with the distance between the initial facial-coronal crest of the extraction socket and the reference line (P < 0.01). CONCLUSIONS: Alveolar crest of the socket lost its curvature and tended to attain a flat profile after IIPP due to inconsistent ridge reduction in middle, mesial and distal areas. The reference line may be a potential landmark for predicting the ridge crest after remodeling.

A comparison of alveolar ridge mucosa thickness in completely edentulous patients.

PURPOSE: The purpose of this cross-sectional clinical study was to determine and compare alveolar ridge mucosa thickness at crestal, buccal, and lingual locations of the maxillary and mandibular arches in completely edentulous patients using a dedicated, ultrasonic gingival scanner. MATERIALS AND METHODS: Thirty-eight completely edentulous subjects were included in the study. In each subject, soft tissue thickness was measured at 28 sites of the edentulous ridge by a single calibrated examiner. Intra-observer reliability was calculated with Intraclass Correlation Coefficients by measuring 10 subjects twice, after 1 week. Measurements (mm) were taken at the buccal, lingual, and crestal aspects of the ridge with a dedicated ultrasonic scanner. Repeated measures ANOVA and paired t-tests were used to compare the mean buccal, lingual, and crestal soft tissue thicknesses at each site. The Generalized Estimating Equations model was used to study the effects of age, sex, and race. Confidence level was set to 95%. RESULTS: Mean tissue thickness ranged from 0.96  to 1.98 mm with a mean of 1.63 ± 0.25 mm. Intraclass Correlation Coefficients were > 0.97. No significant differences between buccal, crestal, and lingual sites were noted for the mandibular arch as well as at 4 sites on the maxillary arch (maxillary right second molar, maxillary right canine, maxillary left first premolar, maxillary left second molar). However, significant differences in soft tissue thickness were noted for all remaining maxillary sites. Race was found to be positively correlated with tissue thickness, with Black individuals showing a significantly greater thickness than White individuals at 4 sites (maxillary right first molar, maxillary left canine, mandibular right second premolar, mandibular right first molar). Age was found to be positively correlated with tissue thickness at 4 sites (maxillary left central incisor, maxillary left first molar, maxillary left second molar, mandibular left second premolar) and negatively correlated at 2 sites (mandibular right canine, mandibular right second molar). Female sex was positively (maxillary left second premolar, maxillary left second molar) and negatively (mandibular right canine) correlated, respectively, with tissue thickness at 3 sites. When data for anterior and posterior sites were respectively pooled, tissue thickness was significantly less at anterior sextant lingual and crestal sites, while no difference was seen for buccal sites. CONCLUSION: Statistically significant differences for alveolar ridge mucosa thickness were found at several sites in the maxilla and between anterior and posterior sextants for lingual and crestal sites in the maxillary and mandibular arches. Tissue thickness differences were also noted for race with Black individuals showing greater tissue thickness at some sites. Age and sex did not show a clear effect on tissue thickness. Recorded differences in tissue thickness were however small and appear of uncertain clinical significance.

Injectable platelet rich fibrin versus hyaluronic acid with bovine derived xenograft for alveolar ridge preservation. A randomized controlled clinical trial with histomorphometric analysis.

BACKGROUND: Alveolar ridge preservation (ARP) is a technique that aims to maintain bone volume and minimize resorption after tooth extraction. OBJECTIVE: This study aimed to compare the effectiveness of injectable platelet-rich fibrin (I-PRF) versus hyaluronic acid (HA) in combination with xenografts for ARP. METHODS: This randomized controlled trial included 36 patients (20 females and 16 males) who required implant placement in the upper arch. The patients were randomly allocated to one of three groups (n = 12 each): I-PRF with xenografts, HA with xenografts, or xenografts alone. All patients underwent ARP, and the extraction sockets were sealed with a free gingival graft harvested from the palate, a total of 36 implants were inserted. Cone-beam CT scans were performed before and 4 months postoperatively to measure radiographic bone gain as the primary outcome. Clinical parameters, including soft tissue thickness and clinical bone width, were evaluated preoperatively, and at 4 months and 1 year postoperatively. Additionally, histological assessment of core bone biopsies was performed 4 months postoperatively using histomorphometric analysis to determine the percentages of newly formed bone, mature bone, and residual grafts. RESULTS: Regarding the radiographic bone gain 4 months postoperative the HA group exhibited the highest value (9.78 ± 0.87), which was significantly greater than the values observed in the I-PRF and control groups (8.60 ± 1.27 and 7.99 ± 0.89, respectively) (one-way ANOVA, p = 0.007). Crestal bone loss was significantly higher in the control group (-0.98 ± 0.18) than in the I-PRF group (-0.53 ± 0.11) and HA group (-0.33 ± 0.15) groups (one-way ANOVA, p < 0.001). In the histomorphometric analysis, the mean area fraction of newly formed bone trabeculae was significantly higher in the HA group (56.66 ± 7.35) than in the I-PRF group (28.74 ± 5.15) and the control group (24.05 ± 3.64) (repeated measures ANOVA, p < 0.001). Additionally, the mean area fraction of residual graft material was higher in the I-PRF group (6.76 ± 2.59), followed by the control group (2.71 ± 1.24), while the HA group had the lowest value (2.63 ± 1.27) (Repeated measures ANOVA, p < 0.001). CONCLUSION: The combination of HA with xenografts yielded better radiographic and histological outcomes in terms of new bone formation and degree of bone maturation than the I-PRF and control groups. Furthermore, I-PRF improved soft tissue thickness. Please note that clinical trial registration was not completed prior to participant recruitment and randomization. The registration link for this trial is https://clinicaltrials.gov/ct2/show/NCT05781529.

Three-dimensional analysis of the alveolar ridge profiles of maxillary central incisors in children for autotransplantation.

BACKGROUND: Sufficient alveolar housing is fundamental to ensure the favorable prognosis of autotransplanted teeth. However, little is known about the alveolar ridge profiles of the anterior maxilla in children. Therefore, this study aimed to investigate the alveolar ridge profiles of the anterior maxilla in growing children. METHODS: A total of 169 Korean children aged 10-13 years old were included in this retrospective study. Demographic data and cone-beam computed tomography scans of 244 maxillary central incisors were collected. For each tooth, the alveolar ridge thickness was determined at 1-, 3-, and 5-mm levels below the cemento-enamel junction. The alveolar process height and labial concavity were also evaluated. Statistical analyses were performed to evaluate differences according to age and sex. RESULTS: The alveolar ridge thickness did not differ according to age. The alveolar ridge thickness in males was significantly greater than that in females among those aged 10 and 11 years. The average alveolar process height was 17.43 ± 2.22 mm. The alveolar process height hardly changed with age from 10-13 years, whereas the alveolar process height of males was significantly greater compared with that of females among those aged 10 years. The labial concavity was approximately 150˚, with no significant differences between age and sex. CONCLUSIONS: Within the limits of this study, the anatomy of the alveolar ridge in the maxillary central incisors showed sufficient capacity as a recipient site for autotransplantation using mandibular premolars, especially in males. These findings serve as a valuable resource for facilitating autotransplantation in children.