Trabecular bone remodelling following lateral window maxillary sinus augmentation with allograft versus xenograft: a retrospective one-year comparative fractal dimension analysis.
Allografts produced higher early-phase FD values, while both materials achieved comparable radiographic trabecular complexity by the 6-month and 1-year follow-up periods, which suggest convergent radiographic remodelling over time.
Abstract
Background
Maxillary sinus augmentation is widely performed to enable implant placement in the atrophic posterior maxilla, and the radiographic remodelling patterns of different graft materials remain a topic of clinical interest. This retrospective study compared trabecular bone remodelling following lateral window maxillary sinus augmentation with allograft versus xenograft materials using FD analysis of panoramic radiographs over a one-year follow-up.
Methods
One hundred patients (50 allograft, 50 xenograft) treated between 2015 and 2023 were included. Panoramic radiographs obtained immediately postoperatively and at 3 months, 6 months, and 1 year were analyzed using ImageJ software according to the White and Rudolph box-counting method. Intragroup temporal changes were evaluated with the Friedman test and Bonferroni-corrected Wilcoxon signed-rank tests; intergroup comparisons were performed using the Mann-Whitney U test or independent samples t-test according to data distribution. Interobserver reliability was assessed using the intraclass correlation coefficient (ICC).
Results
Age and sex distributions were comparable between groups (p = 0.250 and p = 0.288, respectively). FD values changed significantly over time in both the allograft (p = 0.021) and xenograft (p < 0.001) groups. In the allograft group, only the 3-month versus 6-month comparison reached significance (p = 0.001), whereas in the xenograft group all pairwise comparisons except 6 months versus 1 year were significant. Intergroup comparisons revealed significantly higher FD values in the allograft group immediately postoperatively (p = 0.010) and at 3 months (p < 0.001), but no differences were detected at 6 months (p = 0.107) or 1 year (p = 0.751). Interobserver reliability was good across most measurements (ICC 0.794-0.856), with moderate reliability for the 6-month xenograft measurement (ICC = 0.744).
Conclusions
Allografts produced higher early-phase FD values, while both materials achieved comparable radiographic trabecular complexity by the 6-month and 1-year follow-up periods. These findings suggest convergent radiographic remodelling over time. Further histomorphometric and clinical studies are needed to confirm these FD-derived findings.
TRIAL REGISTRATION
Not applicable.
The Bone Ring Technique (BRT) is a newer viable option for restoring complex defects around dental implants with three-dimensional bone augmentation with significant height and width augmentation of buccal bone.
Priyadharshini Annamalai Senthur Pandian, Aniz Amanullah, Lakshmiganthan Mahalingam et al.· Journal of Clinical and Diag...· 0 citations
Within the limitations of this study, intentionally exposing the xenogeneic collagen matrix seal yielded comparable outcomes in non-contained and contained sockets, which may reflect the material's ability to reduce the adverse effects of socket-wall resorption.
Xinyi Zhou, Yuping Hong, Yang Yang et al.· Journal of Periodontal & Imp...· 0 citations
BACKGROUND
This study aimed to describe changes in marginal bone levels (MBL) and peri-implant trabecular radiomorphometric patterns during the osseointegration period in posterior mandibular implants healed with either healing abutments or cover screws.
METHODS
This retrospective radiographic cohort study included 53 posterior mandibular implants in 36 patients, classified into the healing abutment group (n = 22) and the cover screw group (n = 31), based on the immediate postoperative panoramic radiographs. Digital panoramic radiographs obtained before implant placement (T0), immediately after implant placement (T1), and after a 3-month osseointegration period (T2) were analyzed. Marginal bone level (MBL) changes and radiomorphometric indices, including fractal dimension (FD), lacunarity, bone area fraction (BAF), and mean gray value (MGV), were calculated.
RESULTS
MBL values decreased significantly from T1 to T2 in both groups (p < 0.05). No statistically significant between-group difference in MBL change was detected at either the mesial or distal surface (p > 0.05). In the overall cohort, mean lacunarity decreased, whereas mean FD, BAF, and MGV increased. Group-based analyses showed significant longitudinal changes in all radiomorphometric parameters in the cover screw group, while only FD changed significantly in the healing abutment group (p < 0.05). For the overall mean radiomorphometric values, no statistically significant between-group differences were detected at T2 (p > 0.05).
CONCLUSIONS
Posterior mandibular implants showed MBL reductions and radiomorphometric changes during the 3-month osseointegration period. MBL changes did not differ significantly between groups, while radiomorphometric trajectories differed descriptively. These findings provide descriptive radiographic information on early peri-implant bone changes and should be interpreted within the limitations of the retrospective cohort design.
3D-printed β-TCP biomaterials demonstrated favourable clinical and radiographic outcomes for alveolar ridge regeneration supporting single implant rehabilitation and may provide a predictable alternative for localized alveolar ridge regeneration supporting single implant rehabilitation.
Carlo Mangano, Henriette Lerner, A. Aksu et al.· E -journal of dentistry· 0 citations
Background: Limited residual bone height in the posterior maxilla often necessitates sinus floor elevation before implant placement. Piezosurgery-assisted crestal sinus floor elevation offers a minimally invasive approach with reduced membrane-related complications. Concentrated growth factor (CGF) has been proposed to enhance bone regeneration; however, the additional benefit of combining CGF with allograft remains unclear. This randomized clinical trial compared radiographic, clinical, and biochemical outcomes following crestal sinus floor elevation using CGF with or without demineralized freeze-dried bone allograft (DFDBA).
Methods: Twenty posterior maxillary implant sites requiring indirect sinus floor elevation were randomly allocated into two groups (n=10 each): group A, piezosurgery-assisted crestal sinus elevation with CGF + DFDBA; and group B, CGF alone. Simultaneous implant placement was performed in all sites. Vertical bone height (VBH) and bucco-palatal width (BPW) were assessed using cone-beam computed tomography at baseline and 6 months. Implant stability quotient (ISQ) was measured at baseline and 3 months. Osteopontin (OPN) levels in peri-implant crevicular fluid were evaluated at 15, 45, and 90 days using enzyme-linked immunosorbent assay.
Results: Both groups demonstrated significant increases in vertical bone height and implant stability over time (p<0.05). Group A showed significantly greater vertical bone gain at 6 months compared with group B (p<0.05). Bucco-palatal width remained relatively stable in both groups, although a significant reduction was observed in group B. OPN levels increased progressively in both groups during healing and were significantly higher in group A at all-time intervals (p<0.05).
Conclusions: Piezosurgery-assisted crestal sinus floor elevation using CGF, with or without allograft, resulted in favorable clinical and radiographic outcomes. The addition of DFDBA to CGF yielded greater vertical bone gain and higher OPN levels, suggesting enhanced regenerative activity during early healing.
Tanya Attre, S. Malhotra, R. Chowdhry et al.· International Journal of Cli...· 0 citations
Accurate assessment of alveolar bone morphology is essential for implant treatment planning in the anterior maxilla, where anatomical characteristics may influence surgical procedures and aesthetic outcomes. This study aimed to evaluate alveolar crest height and width, buccal bone thickness, buccal undercut depth, and root position around healthy maxillary anterior teeth using cone-beam computed tomography (CBCT), while investigating the influence of age, gender, and tooth type on these parameters.
CBCT images of 1,668 maxillary anterior teeth from 278 periodontally healthy individuals aged 20–79 years were retrospectively evaluated. Alveolar crest height and width, buccal bone thickness, buccal undercut depth, and the root-crest angle were measured using a standardized CBCT protocol. Data were analyzed using robust mixed ANOVA with Holm-adjusted post hoc comparisons. Intraobserver and interobserver reliability were assessed using intraclass correlation coefficients (ICC).
Age group and tooth type significantly affected all evaluated parameters (all
p
< 0.001). The greatest alveolar crest height and root-crest angle were observed in the 70–79-year age group, whereas the alveolar crest width was greatest in the 20–29-year age group. Buccal bone thickness and buccal undercut depth peaked in the 50–59-year age group. Canines exhibited the greatest alveolar crest width and root-crest angle. Conversely, lateral incisors displayed the thickest buccal bone, the deepest buccal undercut, and the narrowest alveolar crest width. Males generally presented with greater alveolar crest width than females, whereas buccal bone thickness was significantly greater in males only for lateral incisors and canines. No significant interaction effects were identified between age group and tooth type or between gender groups and measurement point. Intraobserver agreement ranged from 0.709 to 0.991, and all interobserver ICC values exceeded 0.90.
Morphological characteristics of the anterior maxilla vary significantly by age, gender, and tooth type. The lateral incisor region demonstrates the least favorable anatomy due to its thin buccal bone and pronounced buccal undercut, highlighting the necessity of a comprehensive CBCT evaluation for individualized implant treatment planning to minimize potential surgical complications.
This study was retrospectively registered on August 18, 2025, at ClinicalTrials. gov. Registration number: NCT07133503.
Duygu Taskin, E. Dursun, E. M. Canger· BMC Oral Health· 0 citations
