1.Early implant placement in sites with ridge preservation or spontaneous healing: histologic, profilometric, and CBCT analyses of an exploratory RCT
Stefan P. BIENZ ; Edwin RUALES-CARRERA ; Wan-Zhen LEE ; Christoph H. F.Christoph H. F. HÄMMERLE ; Ronald E. JUNG ; Daniel S. THOMATHOMA
Journal of Periodontal & Implant Science 2024;54(2):108-121
Purpose:
The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion.
Methods:
Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/ CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis.Patients were followed up after the final crown insertion and again at 1 year post-procedure.
Results:
Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by −2.11 mm for the DBBM-C/CM group, −1.62 mm for the DBBM-C group, and −1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by −0.27 mm for the DBBM-C/CM group, −2.73 mm for the DBBM-C group, and −1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were −0.19 mm in the DBBM-C/CM group, −0.09 mm in the DBBM-C group, and −0.29 mm in the SH group.
Conclusions
Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.
2.Early implant placement in sites with ridge preservation or spontaneous healing: histologic, profilometric, and CBCT analyses of an exploratory RCT
Stefan P. BIENZ ; Edwin RUALES-CARRERA ; Wan-Zhen LEE ; Christoph H. F.Christoph H. F. HÄMMERLE ; Ronald E. JUNG ; Daniel S. THOMATHOMA
Journal of Periodontal & Implant Science 2024;54(2):108-121
Purpose:
The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion.
Methods:
Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/ CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis.Patients were followed up after the final crown insertion and again at 1 year post-procedure.
Results:
Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by −2.11 mm for the DBBM-C/CM group, −1.62 mm for the DBBM-C group, and −1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by −0.27 mm for the DBBM-C/CM group, −2.73 mm for the DBBM-C group, and −1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were −0.19 mm in the DBBM-C/CM group, −0.09 mm in the DBBM-C group, and −0.29 mm in the SH group.
Conclusions
Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.
3.Early implant placement in sites with ridge preservation or spontaneous healing: histologic, profilometric, and CBCT analyses of an exploratory RCT
Stefan P. BIENZ ; Edwin RUALES-CARRERA ; Wan-Zhen LEE ; Christoph H. F.Christoph H. F. HÄMMERLE ; Ronald E. JUNG ; Daniel S. THOMATHOMA
Journal of Periodontal & Implant Science 2024;54(2):108-121
Purpose:
The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion.
Methods:
Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/ CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis.Patients were followed up after the final crown insertion and again at 1 year post-procedure.
Results:
Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by −2.11 mm for the DBBM-C/CM group, −1.62 mm for the DBBM-C group, and −1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by −0.27 mm for the DBBM-C/CM group, −2.73 mm for the DBBM-C group, and −1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were −0.19 mm in the DBBM-C/CM group, −0.09 mm in the DBBM-C group, and −0.29 mm in the SH group.
Conclusions
Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.
4.Local tissue effects of various barrier membranes in a rat subcutaneous model
Nadja NAENNI ; Hyun-Chang LIM ; Franz-Josef STRAUSS ; Ronald E. JUNG ; Christoph H. F. HÄMMERLE ; Daniel S. THOMA
Journal of Periodontal & Implant Science 2020;50(5):327-339
Purpose:
The purpose of this study was to examine the local tissue reactions associated with 3 different poly(lactic-co-glycolic acid) (PLGA) prototype membranes and to compare them to the reactions associated with commercially available resorbable membranes in rats.
Methods:
Seven different membranes—3 synthetic PLGA prototypes (T1, T2, and T3) and 4 commercially available membranes (a PLGA membrane, a poly[lactic acid] membrane, a native collagen membrane, and a cross-linked collagen membrane)—were randomly inserted into 6 unconnected subcutaneous pouches in the backs of 42 rats. The animals were sacrificed at 4, 13, and 26 weeks. Descriptive histologic and histomorphometric assessments were performed to evaluate membrane degradation, visibility, tissue integration, tissue ingrowth, neovascularization, encapsulation, and inflammation. Means and standard deviations were calculated.
Results:
The histological analysis revealed complete integration and tissue ingrowth of PLGA prototype T1 at 26 weeks. In contrast, the T2 and T3 prototypes displayed slight to moderate integration and tissue ingrowth regardless of time point. The degradation patterns of the 3 synthetic prototypes were similar at 4 and 13 weeks, but differed at 26 weeks. T1 showed marked degradation at 26 weeks, whereas T2 and T3 displayed moderate degradation.Inflammatory cells were present in all 3 prototype membranes at all time points, and these membranes did not meaningfully differ from commercially available membranes with regard to the extent of inflammatory cell infiltration.
Conclusions
The 3 PLGA prototypes, particularly T1, induced favorable tissue integration, exhibited a similar degradation rate to native collagen membranes, and elicited a similar inflammatory response to commercially available non–cross-linked resorbable membranes.The intensity of inflammation associated with degradable dental membranes appears to relate to their degradation kinetics, irrespective of their material composition.