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- 3D printing (2)
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- dental implants (2)
- dentoalveolar surgery (2)
- oral and maxillofacial surgery (2)
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- Medizin (8)
Background: To assess the influence of ridge preservation procedures on the healing of extraction sockets under antiresorptive therapy.
Material and Methods: A total of 10 Dutch Belted rabbits were randomly allocated to either the intravenous administration of amino‐bisphosphonate (zoledronic acid) (Za) (n = 5) or a negative control group (no Za [nZa]) (n = 5). At 6 months, the mandibular and maxillary molars were extracted and the four experimental sites randomly allocated to the following subgroups: (a) socket grafting using a collagen‐coated natural bone mineral (BOC) + primary wound closure, (b) coronectomy (CO), or (c) spontaneous healing + primary wound closure (SP). Za medication was continued for another 4 months. Histomorphometrical analyses considered, for example, crestal hard tissue closure of the extraction site (C) and mineralized tissue (MT) formation.
Results: Za‐SP was associated with an incomplete median C (31.76% vs 100% in nZa‐SP) and signs of bone arrosion along the confines of the socket. BOC had no major effects on increases in C and MT values in the Za group. CO commonly resulted in an encapsulation and partial replacement resorption of residual roots by MT without any histological signs of osteonecrosis.
Conclusions: (a) Za‐SP was commonly associated with a compromised socket healing and signs of osteonecrosis, (b) BOC had no major effect on socket healing in the Za group, and (c) CO at noninfected teeth might be a feasible measure for the prevention of a Za‐related osteonecrosis of the jaw.
Objective: To assess the influence of biphasic calcium phosphate materials with different surface topographies on bone formation and osseointegration of titanium implants in standardized alveolar ridge defects.
Materials and methods: Standardized alveolar ridge defects (6 × 6 mm) were created in the mandible of 8 minipigs and filled with three biphasic calcium phosphate materials (BCP1–3, 90% tricalcium phosphate/10% hydroxyapatite) with different surface properties (micro- and macroporosities) as well as a bovine-derived natural bone mineral (NBM) as a control. At 12 weeks, implants were placed into the augmented defects. After further 8 weeks of healing, dissected blocks were processed for histological analysis (e.g., mineralized (MT), residual bone graft material (BS), bone-to-implant contact (BIC)).
Results: All four biomaterials showed well-integrated graft particles and new bone formation within the defect area. MT values were comparable in all groups. BS values were highest in the NBM group (21.25 ± 13.52%) and markedly reduced in the different BCP groups, reaching statistical significance at BCP1-treated sites (9.2 ± 3.28%). All test and control groups investigated revealed comparable and statistically not significant different BIC values, ranging from 73.38 ± 20.5% (BCP2) to 84.11 ± 7.84% (BCP1), respectively.
Conclusion* All bone graft materials facilitated new bone formation and osseointegration after 12 + 8 weeks of healing.
Objectives: To assess the short‐term clinical outcomes of lateral augmentation of deficient extraction sockets and two‐stage implant placement using autogenous tooth roots (TR).
Material and methods: A total of n = 13 patients (13 implants) were available for the analysis. At the time of tooth extraction, each subject had received lateral augmentation using the respective non‐retainable but non‐infected tooth root where the thickness of the buccal bone was <0.5 mm or where a buccal dehiscence‐type defect was present. Titanium implants were placed after a submerged healing period of 6 months and loaded after 20 ± 2 weeks (V8). Clinical parameters (e.g., bleeding on probing—BOP, probing pocket depth—PD, mucosal recession—MR, clinical attachment level—CAL) were recorded at V8 and after 26 ± 4 weeks (V9) of implant loading.
Results: At V9, all patients investigated revealed non‐significant changes in mean BOP (−19.23 ± 35.32%), PD (0.24 ± 0.49 mm), MR (0.0 ± 0.0 mm) and CAL (0.24 ± 0.49 mm) values, respectively. There was no significant correlation between the initial gain in ridge width and changes in BOP and PD values.
Conclusions: The surgical procedure was associated with stable peri‐implant tissues on the short‐term.
Background: The present study aimed to assess the three‐dimensional changes following soft tissue augmentation using free gingival grafts (FGG) at implant sites over a 3‐month follow‐up period.
Methods: This study included 12 patients exhibiting deficient keratinized tissue (KT) width (i.e., <2 mm) at the vestibular aspect of 19 implants who underwent soft tissue augmentation using FGG at second stage surgery following implant placement. Twelve implants were considered for the statistical analysis (n = 12). The region of interest (ROI) was intraorally scanned before surgery (S0), immediately post‐surgery (S1), 30 (S2) and 90 (S3) days after augmentation. Digital scanned files were used for quantification of FGG surface area (SA) and converted to standard tessellation language (STL) format for superimposition and evaluation of thickness changes between the corresponding time points. FGG shrinkage (%) in terms of SA and thickness was calculated between the assessed time points.
Results: Mean FGG SA amounted to 91 (95% CI: 63 to 119), 76.2 (95% CI: 45 to 106), and 61.3 (95% CI: 41 to 81) mm2 at S1, S2, and S3, respectively. Mean FGG SA shrinkage rate was 16.3% (95% CI: 3 to 29) from S1 to S2 and 33% (95% CI: 19 to 46) from S1 to S3. Mean thickness gain from baseline (S0) to S1, S2, and S3 was 1.31 (95% CI: 1.2 to 1.4), 0.82 (95% CI: 0.5 to 1.12), and 0.37 (0.21 to 0.5) mm, respectively. FGG thickness shrinkage was of 38% (95% CI: 17.6 to 58) from S1 to S2 and 71.8% (95% CI: 60 to 84) from S1 to S3. Dimensional changes from S1 to S3 were statistically significant, P <0.017. Soft tissue healing was uneventful in all patients.
Conclusions: The present three‐dimensional assessment suggests that FGG undergo significant dimensional changes in SA and thickness over a 3‐month healing period.
Aim: To assess volumetric tissue changes at peri‐implantitis sites following combined surgical therapy of peri‐implantitis over a 6‐month follow‐up period.
Materials and Methods: Twenty patients (n = 28 implants) diagnosed with peri‐implantitis underwent access flap surgery, implantoplasty at supracrestally or bucally exposed implant surfaces and augmentation at intra‐bony components using a natural bone mineral and application of a native collagen membrane during clinical routine treatments. The peri‐implant region of interest (ROI) was intra‐orally scanned pre‐operatively (S0), and after 1 (S1) and 6 (S2) months following surgical therapy. Digital files were converted to standard tessellation language (STL) format for superimposition and assessment of peri‐implant volumetric variations between time points. The change in thickness was assessed at a standardized ROI, subdivided into three equidistant sections (i.e. marginal, medial and apical). Peri‐implant soft tissue contour area (STCA) (mm2) and its corresponding contraction rates (%) were also assessed.
Results: Peri‐implant tissues revealed a mean thickness change (loss) of −0.11 and −0.28 mm at 1 and 6 months. S0 to S1 volumetric variations pointed to a thickness change of −0.46, 0.08 and 0.4 mm at marginal, medial and apical regions, respectively. S0 to S2 analysis exhibited corresponding thickness changes of −0.61, −0.25 and −0.09 mm, respectively. The thickness differences between the areas were statistically significant at both time periods. The mean peri‐implant STCA totalled to 189.2, 175 and 158.9 mm2 at S0, S1 and S2, showing a significant STCA contraction rate of 7.9% from S0 to S1 and of 18.5% from S0 to S2. Linear regression analysis revealed a significant association between the pre‐operative width of keratinized mucosa (KM) and STCA contraction rate.
Conclusions: The peri‐implant mucosa undergoes considerable volumetric changes after combined surgical therapy. However, tissue contraction appears to be influenced by the width of KM.
Background: Recent advances in 3D printing technology have enabled the emergence of new educational and clinical tools for medical professionals. This study provides an exemplary description of the fabrication of 3D‐printed individualised patient models and assesses their educational value compared to cadaveric models in oral and maxillofacial surgery.
Methods: A single‐stage, controlled cohort study was conducted within the context of a curricular course. A patient's CT scan was segmented into a stereolithographic model and then printed using a fused filament 3D printer. These individualised patient models were implemented and compared against cadaveric models in a curricular oral surgery hands‐on course. Students evaluated both models using a validated questionnaire. Additionally, a cost analysis for both models was carried out. P‐values were calculated using the Mann‐Whitney U test.
Results: Thirty‐eight fourth‐year dental students participated in the study. Overall, significant differences between the two models were found in the student assessment. Whilst the cadaveric models achieved better results in the haptic feedback of the soft tissue, the 3D‐printed individualised patient models were regarded significantly more realistic with regard to the anatomical correctness, the degree of freedom of movement and the operative simulation. At 3.46 € (compared to 6.51 €), the 3D‐printed patient individualised models were exceptionally cost‐efficient.
Conclusions: 3D‐printed patient individualised models presented a realistic alternative to cadaveric models in the undergraduate training of operational skills in oral and maxillofacial surgery. Whilst the 3D‐printed individualised patient models received positive feedback from students, some aspects of the model leave room for improvement.
Background and Objective: Macrophages’ cytokine expression and polarization play a substantial role in the host's “destructive” inflammatory response to periodontal and peri‐implant pathogens. This study aimed to evaluate cell viability, anti‐inflammatory activity, and macrophage polarization properties of different cranberry concentrates.
Methods: THP‐1 cells (monocytic line) were treated with phorbol myristic acid to induce macrophage differentiation. Human gingival fibroblasts (HFIB‐G cell line), osteosarcoma‐derived osteoblasts (SAOS‐2 cell line), and induced macrophages were treated with cranberry concentrates at 25, 50, and 100 µg/mL for 120 seconds, 1 hour and 24 hours. Untreated cells at the same time points served as controls. For anti‐inflammatory analysis, induced macrophages exposed to cranberry concentrates (A‐type PACs) were stimulated with lipopolysaccharides (LPS) derived from E coli for 24 hours. Cell viability, interleukin (IL)‐8, IL‐1 ß, IL‐6, and IL‐10 expression of LPS‐stimulated macrophages, and macrophage polarization markers were evaluated through determination of live‐cell protease activity, enzyme‐linked immunosorbent assay, and immunofluorescence staining semi‐quantification.
Results: Cranberry concentrates (A‐type PACs) did not reduce HGF, SAOS‐2, and macrophage viability after 24 hours of exposure. Pro‐inflammatory cytokine expression (ie IL‐8 and IL‐6) was downregulated in LPS‐stimulated macrophages by cranberry concentrates at 50 and 100 µg/mL. Anti‐inflammatory IL‐10 expression was significantly upregulated in LPS‐stimulated macrophages by cranberry concentrates at 100 µg/mL after 24 hours of exposure. M1 polarization significantly decreased when LPS‐stimulated macrophages were exposed to cranberry concentrates. High levels of positive M1 macrophages were present in all untreated control groups. M2 polarization significantly increased at all LPS‐stimulated macrophages exposed to cranberry concentrates for 1 and 24 hours.
Conclusion: Cranberry‐derived proanthocyanidins may have the potential to act as an anti‐inflammatory component in the therapy of periodontal and peri‐implant diseases.