Impact of simultaneous placement of implant and block bone graft substitute: an in vivo peri-implant defect model

Background Insufficient bone volume around an implant is a common obstacle when dental implant treatment is considered. Limited vertical or horizontal bone dimensions may lead to exposed implant threads following placement or a gap between the bone and implant. This is often addressed by bone augmentation procedures prior to or at the time of implant placement. This study evaluated bone healing when a synthetic TiO2 block scaffold was placed in circumferential peri-implant defects with buccal fenestrations. Methods The mandibular premolars were extracted and the alveolar bone left to heal for 4 weeks prior to implant placement in six minipigs. Two cylindrical defects were created in each hemi-mandible and were subsequent to implant placement allocated to treatment with either TiO2 scaffold or sham in a split mouth design. After 12 weeks of healing time, the samples were harvested. Microcomputed tomography (MicroCT) was used to investigate defect fill and integrity of the block scaffold. Distances from implant to bone in vertical and horizontal directions, percentage of bone to implant contact and defect fill were analysed by histology. Results MicroCT analysis demonstrated no differences between the groups for defect fill. Three of twelve scaffolds were partly fractured. At the buccal sites, histomorphometric analysis demonstrated higher bone fraction, higher percentage bone to implant contact and shorter distance from implant top to bone 0.5 mm lateral to implant surface in sham group as compared to the TiO2 group. Conclusions This study demonstrated less bone formation with the use of TiO2 scaffold block in combination with implant placement in cylindrical defects with buccal bone fenestrations, as compared to sham sites.

AUTO-TRANSPLANTATION: AN INTERIM TREATMENT MODALITY (CURRENT UPDATES)

Paediatric dental patients demand special care and wider vision while treatment planning due to ongoing growth of jaw bones and existing permanent tooth buds within the bone. Tooth loss is very common even in younger age patients due to extensive tooth decay or as a result of traumatic dental injuries. Implants are in high demand to restore the lost tooth but use of implants is limited to adults or older age group. Thus auto-transplantation may be an intermediate or permanent treatment option to such cases due simple, less time consuming and cost effectiveness. Sidewise auto-transplantation maintains the bone dimensions to make it available further treatment on failure. Present review article include all the required facts about auto-transplantion.

Evaluation of osteogenic properties after application of hydroxyapatite-based shells of Portunus pelagicus

Background: After tooth extraction, the socket leaves a defect on the alveolar bone. The administration of shell crab-derived hydroxyapatite maintains bone dimensions that are important for achieving successful prosthodontic treatment. Purpose: The aim of the study was to determine the osteogenic properties, such as the number of osteoclasts, osteoblasts and osteocytes, after the application of hydroxyapatite-based shell crab in the post-extraction sockets of Wistar rats. Methods: There were two groups: the control group (K) and the treatment group (T). Wistar rats were randomly divided into control and treatment groups. After tooth extraction, hydroxyapatite gel derived from Portunus pelagicus shells was applied to the tooth sockets of Wistar rats. Observations and calculations of osteoclasts, osteoblasts and osteocytes were carried out on the 14th and 28th days under a light microscope with 400 times magnification. Statistical analysis was performed using one-way ANOVA. Results: There was a significant difference (p<0.05) between the K14 and P14 groups, K28 and P28 groups, K14 and K28 groups, and P14 and P28 groups. The results indicated that there were significant differences between groups of variables. Conclusion: The application of shell crab-derived hydroxyapatite (Portunus pelagicus) was able to decrease the number of osteoclasts and increase the number of osteoblasts and osteocytes.

Relationship between Maxillary Arch Shape and Maxillary Labial Bone Dimensions: A Pilot Study

OBJECTIVE: To determine whether there is any relationship between the thickness of the labial alveolar bone wall in the anterior portion of the maxilla and arch shape.MATERIALS AND METHODS: Thirty patients (age, 12–53 years) were selected from archived cone beam computed tomography (CBCT) cases. All maxillary front teeth were present in all the cases. The distance between the cementoenamel junction (CEJ) and the facial bone crest and the thickness of the labial alveolar bone wall at distances of 1, 3, and 5 mm apical to the facial bone crest were measured.RESULTS: The distance between the CEJ and the facial bone crest ranged from 2.24 mm and 3.08 mm. No significant differences were found between the thickness of the bone wall at 1, 3, and 5 mm apical to the crest. A significant difference was found between the U-shaped arch on one side and the V-shaped and square-shaped arches on the other side. The U-shaped arch and labial bone wall thickness were correlated at the 1-mm distance (F = (8, 276) = 3.24, p = 0.002). U-shaped and V-shaped arches were common in women, whereas square-shaped arches were common in men (χ2 = 105.5, p = 0.000).CONCLUSION: Our study is the first to associate arch shape and labial alveolar bone wall thickness.CLINICAL RELEVANCE: The association between the U-shaped arch and bone wall thickness may constitute a new indicator for the tendency of the labial alveolar bone to resorb after extraction and placement of endo-osseous implants.

Implant-to-root dimensions projected by panoramic radiographs inthe maxillary canine-premolar region: implications for dental implant treatment

Backgound This study aimed to compare panoramic radiography (PAN) and cone beam computed tomography (CBCT) determinations of implant-to-root dimensions (IRD) in anterior and posterior maxillary regions, and to help determine in which instances increased radiation exposure from CBCT scans may be justified. Methods IRD measured by PAN (PAN-D) from implant-to-root sites (central incisor, lateral incisor, canine, first premolar, and second premolar) was collected from 418 implant sites in 110 adults. The CBCT technique was used as the reference method for the estimation of IRD. The PAN analysis equations were developed using stepwise multiple regression analysis and the Bland–Altman approach was applied to assess the agreement between PAN and CBCT methods. Results The odds ratio that an implant at the canine-to-first premolar (9.7:1) (P = 0.000) or at the first premolar-to-second premolar region (4.5:1) (P = 0.000) belongs to the underestimation group was strong and highly significant. The root mean square error (RMSE) and pure error (PE) were highest for the canine-to-first premolar (RMSE = 0.886 mm, PE = 0.45 mm) and the first premolar-to-second premolar region (4.5:1) (RMSE = 0.944 mm, PE = 0.38 mm). Conclusions This study provides evidence of site-specific underestimations of available horizontal bone dimensions for implants when assessed by PAN. These data suggest that the canines and first and second premolars may have to be excluded when assessing root angulations via PAN.