RESUMEN
AIMS: The aim of this experimental in vivo pilot study was to evaluate the effect of the local delivery of pamidronate within a collagen membrane on the changes in the buccal soft and hard tissue dimensions at the time of immediate implant placement and whether this effect was influenced by the placement of bone substitutes. METHODS: In six beagle dogs, the distal roots of the third and fourth premolars were extracted, and immediate implants were placed. Treatment groups were randomly allocated to each socket: (i) covering the buccal bone with pamidronate-soaked collagen membrane (BP group), (ii) filling the gap defect with synthetic bone substitute (BS group), (iii) filling the gap defect with synthetic bone substitute and covering the buccal bone with pamidronate soaked collagen membrane (BP/BS group), (iv) no treatment (control group). Intraoral scanning was performed immediately after the surgery and at 20 weeks. Histomorphometric and micro-computed tomography (CT) outcomes were evaluated at 20 weeks. RESULTS: The micro CT analysis demonstrated that the BP group showed no apparent difference in vertical bone level with residual mesial root area, while control group showed significant buccal bone resorption at the implant site. The histomorphometric analysis demonstrated that the vertical bone level of buccal plate was significantly differed between the BP and control group (0.34 ± 0.93 and 1.27 ± 0.56 mm, respectively; p = .041). There was no statistically significant difference in the horizontal ridge width (HRW 1, 2, 3) among the groups. Also, the thickness, height and buccal contours of the soft tissue did not reveal significant changes among the groups. CONCLUSION: The local delivery of pamidronate to the outer surface of the buccal wall at the time of immediate implant placement effectively limits buccal bone resorption. The results from the present investigation should be interpreted with caution, as well as its clinical translatability. Further investigation is needed to understand the pamidronate binding and releasing kinetic, as well as the ideal carrier of this drug for its topical application.
RESUMEN
AIM: To investigate whether transmucosal healing is as effective as submerged healing in terms of buccal bone regeneration when guided bone regeneration (GBR) is performed simultaneously with implant placement. MATERIALS AND METHODS: In six dogs, buccal dehiscence defects were created in the edentulous mandibular ridge, sized 5 × 5 × 3 mm (length × height × depth). In each defect, a bone-level implant was placed, and four experimental groups were randomly assigned as follows: (i) transmucosal healing with GBR (T-GBR), (ii) transmucosal healing without GBR (T-control), (iii) submerged healing with GBR (S-GBR) and (iv) submerged healing without GBR (S-control). Data analyses were based on histological slides 5 months after implant placement. RESULTS: The T-GBR group showed significant differences compared to the control groups regarding defect height resolution, buccal bone thickness and mineralized tissue area (p < .05), but showed no significant differences when compared with the S-GBR group (p > .05). CONCLUSIONS: The mode of healing (transmucosal vs. submerged) does not influence bone regeneration at implant sites. The clinician may therefore choose the approach based on further clinical and patient-specific parameters.
Asunto(s)
Aumento de la Cresta Alveolar , Implantes Dentales , Animales , Perros , Regeneración Ósea , Implantación Dental Endoósea , Regeneración Tisular Guiada Periodontal , Cicatrización de HeridasRESUMEN
AIM: To test whether early implant placement into the extraction socket containing an uncalcified provisional matrix leads to successful osseointegration and stable marginal bone levels. MATERIALS AND METHODS: In six mongrel dogs, the mandibular molars were extracted. Three weeks later, early implant placement was performed according to three experimental protocols: (i) flapless implant placement with preservation of the provisional matrix; (ii) flap elevation, socket debridement and implant placement; and (iii) flap elevation, socket debridement, implant placement and guided bone regeneration (GBR). One untreated extraction socket served as a control group. Data analyses were based on histologic slides 3 months after implant placement. RESULTS: There were no differences in bone-to-implant contact between the three experimental groups (66.97%, 58.89% and 60.89%, respectively) (inter-group comparison p = .42). Marginal bone levels, first bone-to-implant contact as well as the thickness of the connective tissue did not reveal any significant differences between the groups (p = .85, .60 and .65, respectively). CONCLUSIONS: Flapless early implant placement into posterior extraction sockets was as effective as an open flap approach in conjunction with GBR. Mineralization of the socket seems to occur irrespective of the presence of dental implants or biomaterials.
Asunto(s)
Oseointegración , Alveolo Dental , Animales , Perros , Oseointegración/fisiología , Alveolo Dental/cirugía , Extracción Dental , Colgajos Quirúrgicos/cirugía , Regeneración Tisular Guiada Periodontal/métodos , Implantación Dental Endoósea/métodos , Implantes Dentales , Mandíbula/cirugía , Desbridamiento , Tejido Conectivo , Diente Molar , Carga Inmediata del Implante Dental/métodosRESUMEN
OBJECTIVE: To investigate the early impact of plaque accumulation in a buccal dehiscence defect on peri-implant marginal bone resorption. MATERIALS AND METHODS: In six male Mongrel dogs, four dental implants were placed in the posterior maxilla on both sides (two implants per side). Based on the group allocation, each implant was randomly assigned to one of the following four groups to decide whether buccal dehiscence defect was prepared and whether silk ligation was applied at 8 weeks post-implant placement for peri-implantitis induction: UC (no defect without ligation); UD (defect without ligation); LC (no defect with ligation); and LD (defect with ligation) groups. Eight weeks after disease induction, the outcomes from radiographic and histologic analyses were statistically analyzed (p < .05). RESULTS: Based on radiographs, the exposed area of implant threads was smallest in group UC (p < .0083). Based on histology, both the distances from the implant platform to the first bone-to-implant contact point and to the bone crest were significantly longer in the LD group (p < .0083). In the UD group, some spontaneous bone fill occurred from the base of the defect at 8 weeks after implant placement. The apical extension of inflammatory cell infiltrate was significantly more prominent in the LD and LC groups compared to the UC group (p < .0083). CONCLUSION: Plaque accumulated on the exposed implant surface had a negative impact on maintaining the peri-implant marginal bone level, especially when there was a dehiscence defect around the implant.
RESUMEN
OBJECTIVE: To compare fully guided flapless implant surgery using a light-cured surgical guide (FG group) with partially guided open flap surgery (PG group) in the posterior maxilla when performing simultaneous sinus floor elevation in terms of the accuracy, time requirements, and patient/clinician-reported outcomes (PROMs and CROMs). MATERIALS AND METHODS: In this study, 56 tissue-level implants were placed with crestal sinus floor elevation in 56 patients at single-tooth sites, with 28 implants allocated to the PG group and 28 to the FG group. The deviations of the placed implants from the virtually planned positions were measured at the implant platform and apex and for the angular deviation. The presurgical preparation time and the duration of surgery were measured. PROMs and CROMs were made by administering questionnaires at multiple time points. RESULTS: Horizontal deviations at the platform and apex and the angular deviation were significantly smaller in the FG group than the PG group (p < .05). Presurgical preparation and surgery times were significantly shorter in the FG group (p < .001). Patient satisfaction and willingness to receive repeat treatment were significantly better in the FG group than in the PG group (p < .005 and .025, respectively). Clinicians were more satisfied in the FG group than the PG group (p < .05). CONCLUSION: When placing an implant with sinus floor elevation, the flapless approach using a fully guided surgical system can be more accurate, faster, and increase the satisfaction of both the clinician and patient compared to the partially guided surgery.
RESUMEN
OBJECTIVE: To evaluate the effect of a self-retaining block-type bone substitute (srBB) on the dimensional stability of the horizontal ridge width at the coronal level in a buccal dehiscence model. MATERIALS AND METHODS: Four box-shaped bone defects with a buccal dehiscence were surgically prepared in the partially edentulous mandible (n = 6). Experimental biomaterials were randomly assigned to each site: (1) Control group: no treatment, (2) particle-type bone substitute (PBS) group, (3) collagenated soft block bone substitute (csBB) group, and (4) self-retaining synthetic block bone (srBB) group. In all grafted groups, a collagen membrane covered the biomaterials. At 16 weeks, clinical, histological, and radiographic analyses were performed. RESULTS: Three of the six blocks in the srBB group became exposed and fell out during the first week after surgery. Therefore, the remaining three specimens were renamed RsrBB group. The RsrBB group showed an increase horizontal ridge compared to the pristine bone width at 2-4 mm below the CEJ, while the other groups showed resorption (augmented width at 2 mm below: 4.2, 42.4, 36.2, and 110.1% in the control, PBS, csBB, and RsrBB groups, respectively). The mineralized bone area was largest in the RsrBB group (4.74, 3.44, 5.67, and 7.77 mm2 in the control, PBS, csBB, and RsrBB groups, respectively.). CONCLUSIONS: The srBB group demonstrated the highest volume stability at the coronal level. These findings would potentially suggest that self-retaining block bone substitute might be a good candidate for alveolar ridge preservation.
Asunto(s)
Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Sustitutos de Huesos , Humanos , Pérdida de Hueso Alveolar/cirugía , Aumento de la Cresta Alveolar/métodos , Sustitutos de Huesos/uso terapéutico , Colágeno , Extracción Dental , Alveolo Dental/cirugíaRESUMEN
OBJECTIVES: To evaluate clinical, clinician- and patient-reported outcomes (PROs) of two adjacent single posterior implants immediately loaded with definitive single crowns up to 1 year. Ten patients in need of two adjacent posterior single implants were included. All implants were placed applying a fully digital workflow. Definitive screw-retained single zirconia crowns were delivered within 72 h after implant placement. Clinical parameters, patient- and clinician-reported outcomes were assessed up to 1 year of follow-up. CLINICAL CONSIDERATIONS: Clinical outcomes remained stable, with no implant failures or technical and biological complications throughout the observation period. Patient satisfaction was very high at baseline (crown delivery) and remained consistently high at 6 and 12 months of follow-up. Crown insertion 3 days after implant placement was rated as an easy procedure by clinicians. CONCLUSIONS: Two adjacent single implants with immediate definitive restorations (<72 h) in the posterior region appear to be a viable and easy treatment option to shorten the overall treatment time and potentially enhancing patient satisfaction. However, randomized controlled trials are needed to confirm the advantages of this treatment protocol over a delayed loading approach. CLINICAL SIGNIFICANCE: In selected cases, immediate implant loading with definitive restorations in the posterior region appears a valuable and straightforward option to shorten the overall treatment time.
Asunto(s)
Coronas , Implantes Dentales de Diente Único , Carga Inmediata del Implante Dental , Satisfacción del Paciente , Humanos , Carga Inmediata del Implante Dental/métodos , Femenino , Persona de Mediana Edad , Masculino , Adulto , Prótesis Dental de Soporte Implantado , Prueba de Estudio ConceptualRESUMEN
STATEMENT OF PROBLEM: Interest is growing in immediately loading definitive implant-supported prostheses. However, it appears that implant protocols are evolving faster than their scientific validation. PURPOSE: The purpose of this scoping review was to identify the current trends, feasibility, and clinical outcomes of a specific clinical loading scenario (type A), where a single definitive implant-retained restoration is delivered within 3 days. The focus question was "In partially edentulous patients requiring an implant-retained prosthesis (population), is immediate loading with a definitive restoration (concept) a viable treatment option (context)?" MATERIAL AND METHODS: An electronic search was conducted in the PubMed, CENTRAL, Scopus, Embase, and Web of Science databases. Two authors independently reviewed the studies, screened titles and abstracts, and performed full-text analysis. Cross-reference checks within the bibliography of included studies, relevant reviews, and guideline were conducted. Bibliometric information and study details were extracted. RESULTS: The search identified 2568 titles after removing duplicates. Four studies involving 91 participant and 100 implant-retained restorations were included in this scoping review. The selected articles were a randomized controlled trial (RCT), a prospective clinical study, and the remaining 2 were case series. The follow-up periods investigated ranged from 6 to 26 months. All studies evaluated marginal bone loss as a primary outcome, and only 1 implant failure was reported. Patient-reported outcome measures were favorable, and no major biological or technical complications were reported in any study. CONCLUSIONS: Immediate loading with a definitive restoration within 3 days appears to be a suitable approach in specific clinical situations.
RESUMEN
INTRODUCTION: Microbiome from a "healthy cohort" is used as a reference for comparison to cases and intervention. However, the studies with cohort-based clinical research have not sufficiently accounted for the multistability in oral microbial community. The screening is limited to phenotypic features with marked variations in microbial genomic markers. Herein, we aimed to assess the stability of the oral microbiome across time from an intervention-free "healthy" cohort. METHODS: We obtained 33 supragingival samples of 11 healthy participants from the biobank. For each participant, we processed one sample as baseline (T0) and two samples spaced at 1-month (T1) and 3-month (T2) intervals for 16S ribosomal RNA gene sequencing analysis. RESULTS: We observed that taxonomic profiling had a similar pattern of dominant genera, namely, Rothia, Prevotella, and Hemophilus, at all time points. Shannon diversity revealed a significant increase from T0 (p < .05). Bray Curtis dissimilarity was significant (R = -.02, p < .01) within the cohort at each time point. Community stability had negative correlation to synchrony (r = -.739; p = .009) and variance (r = -.605; p = .048) of the species. Clustering revealed marked differences in the grouping patterns between the three time points. For all time points, the clusters presented a substantially dissimilar set of differentially abundant taxonomic and functional biomarkers. CONCLUSION: Our observations indicate towards the presence of multistable states within the oral microbiome in an intervention-free healthy cohort. For a conclusive and meaningful long-term reference, dental clinical research should account for multistability in the personalized therapy approach to improve the identification and classification of reliable markers.
Asunto(s)
Microbiota , Micrococcaceae , Humanos , ARN Ribosómico 16S/genética , Microbiota/genética , Estudios de Cohortes , Biomarcadores , Micrococcaceae/genéticaRESUMEN
AIM: It has been proposed that platelet-rich fibrin (PRF) can be used to support bone regeneration during alveolar ridge augmentation. The aim of this study was to determine whether an approach utilizing PRF provides similar performance to the established guided bone regeneration (GBR) procedure. MATERIALS AND METHODS: Two-wall defects were surgically created in beagle dogs and treated in three experimental groups: (i) a sticky bone (SB) substitute prepared using liquid PRF and deproteinized porcine bone mineral (DPBM); (ii) SB covered with solid PRF compressed into a membrane; and (iii) GBR performed using DPBM covered by a collagen membrane. Quantitative reverse-transcription polymerase chain reaction was applied to the specimen after 1 week of healing, and microcomputed tomography (micro-CT) and histological outcomes were analysed after 8 weeks of healing. RESULTS: Compared with GBR, PRF resulted in a moderate increase in the expression levels of osteoblast and osteoclast markers, osteocalcin, and calcitonin receptor. Moreover, PRF modestly increased angiogenesis and the inflammation markers vascular endothelial growth factor (VEGF) and IL-6. Micro-CT and histological analyses confirmed the expected increased alveolar ridge area, with no significant differences between the three groups. Consistently, graft consolidation, as indicated by new bone formation at the defect site, did not differ significantly between groups. CONCLUSIONS: The present results demonstrate that PRF-based approaches perform comparably to the established GBR procedure in terms of the consolidation of DPBM in two-wall alveolar defects.
Asunto(s)
Sustitutos de Huesos , Fibrina Rica en Plaquetas , Perros , Porcinos , Animales , Microtomografía por Rayos X , Factor A de Crecimiento Endotelial Vascular , Regeneración ÓseaRESUMEN
AIM: To compare the peri-implant soft-tissue dimensional changes following guided bone regeneration between particulate (particle group) and collagenated soft-block-type (block group) biphasic calcium phosphate (BCP). MATERIALS AND METHODS: This study investigated 35 subjects: 18 in the particle group and 17 in the block group. Cone-beam computed tomography obtained at 6 months post surgery and optical impressions taken periodically (before surgery, 6 months post surgery, and 1 year post surgery) were superimposed. The ridge contour changes over time and the peri-implant mucosal thicknesses were measured diagonally and horizontally, and analysed statistically. RESULTS: The increases in diagonal (1.12 ± 0.78 mm) and horizontal (2.79 ± 1.90 mm) ridge contour of the block group were significantly higher than those in the particle group during the first 6 months (p < .05); however, the contour hardly changed thereafter (diagonal: 0.07 ± 0.75 mm; horizontal: -0.34 ± 1.26 mm), resulting in the 1-year contour changes similar between the two groups. Regardless of the type of BCP, the ridge contour increased significantly over 1 year when the dehiscence defect had a contained configuration (p < .05). CONCLUSIONS: The increase in soft-tissue dimensions for 1 year was similar between the two groups. The mucosal contour increase was larger when the surgery was conducted in a more contained defect, and this was not influenced by the type of BCP.
Asunto(s)
Aumento de la Cresta Alveolar , Sustitutos de Huesos , Implantes Dentales , Humanos , Implantación Dental Endoósea/métodos , Sustitutos de Huesos/uso terapéutico , Regeneración Tisular Guiada Periodontal/métodos , Regeneración Ósea , Minerales/uso terapéutico , Aumento de la Cresta Alveolar/métodosRESUMEN
Polycaprolactone has exhibited expediency as a biomaterial for bone regenerative procedures preclinically. The present report of the two clinical cases in the posterior maxilla is the first to describe clinical application of a customized 3D printed polycaprolactone mesh for alveolar ridge augmentation. Two patients needing extensive ridge augmentation procedures for dental implant therapy were selected. Polycaprolactone meshes were virtually designed, 3D printed and applied in combination with a xenogeneic bone substitute. Cone-beam computed tomography was taken pre-operatively, immediately after the surgery, and 1.5 to 2 years after the delivery of implant prostheses. The serial cone-beam computed tomography images were superimposed to measure the augmented height and width at 1 mm increments from the implant platform to 3 mm apically. After 2 years, the mean [maximum, minimum] bone gain was 6.05 [8.64, 2.85] mm vertically and 7.77 [10.03, 6.18] mm horizontally at 1 mm below the implant platform. From immediately postoperative to 2 years, there was 14 % reduction of augmented ridged height and 24 % reduction of augmented width at 1 mm below the platform. All implants placed in augmented sites were successfully maintained until 2 years. The customized Polycaprolactone mesh might be a viable material for ridge augmentation in the atrophic posterior maxilla. This needs to be confirmed through randomized controlled clinical trials in future studies.
RESUMEN
AIM: To assess the effect of Schneiderian membrane (SM) perforation on bone formation by applying a particulate deproteinized bovine bone mineral (PBBM). MATERIALS AND METHODS: Bilateral sinus augmentation was performed in eight rabbits. The same amount of PBBM was placed at a sinus where the SM was intentionally perforated for the perforation group (standardized to 3 mm diameter) and the other sinus with an intact SM that served as the intact group. At 12 weeks, all animals were euthanized for radiographic and histomorphometric analyses. RESULTS: The area of the newly formed bone in the perforation group was significantly less than that in the intact group (18.7% and 25.5%, respectively, p = .028). The newly formed bone in the area close to the perforated SM was significantly less than that in the intact group (18.7% and 26.1%, respectively, p < .05). However, there was no significant difference in the total augmented area (p = .234) and the total augmented volume (p = .382) between the two groups. CONCLUSION: SM perforation had an adverse effect on new bone formation, predominantly close to the area of membrane perforation. However, no significant difference was found in the total augmented volume between the SM perforation and the intact groups.
Asunto(s)
Elevación del Piso del Seno Maxilar , Animales , Bovinos , Seno Maxilar/diagnóstico por imagen , Seno Maxilar/cirugía , Mucosa Nasal , Osteogénesis , ConejosRESUMEN
AIM: To test whether soft-type block bone substitute used for guided bone regeneration (GBR) of peri-implant defects leads to a different dimension of the augmented hard tissue than particulate bone substitute. MATERIALS AND METHODS: In 40 patients, 40 two-piece dental implants were placed >2 months after tooth extraction. Following random allocation, 20 peri-implant bone dehiscences were grafted with a soft-type block made of synthetic biphasic calcium phosphate (BCP) + collagen and 20 bone dehiscences with particulate BCP. All the sites were covered with a collagen membrane stabilized with titanium pins. Immediately after wound closure and after 6 months, the horizontal dimension (HD) of the augmented hard tissue was measured at the level of implant shoulder using cone beam computed tomography. During re-entry at 6 months, the defect fill was clinically assessed. RESULTS: At 6 months, the median HD measured 1.15 mm (mean: 1.31 mm) in the soft-block group and 0.93 mm (mean: 1.05 mm) in the particulate group (p = .6). At 6 months, 7.1% of contained defects and 61.9% of non-contained defects showed an incomplete vertical defect fill. CONCLUSIONS: Soft-type block of BCP + collagen used for GBR of peri-implant defects did not differ from particulate BCP regarding the dimension of the augmented hard tissue after 6 months of healing.
Asunto(s)
Aumento de la Cresta Alveolar , Sustitutos de Huesos , Implantes Dentales , Aumento de la Cresta Alveolar/métodos , Regeneración Ósea , Sustitutos de Huesos/uso terapéutico , Colágeno/uso terapéutico , Implantación Dental Endoósea/métodos , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Membranas Artificiales , Minerales/uso terapéuticoRESUMEN
AIM: The aim of this study was to identify the additional effects of collagen membrane (CM) and of synthetic bone substitute (BS) on lateral bone augmentation of chronic peri-implant defect with titanium mesh (TM). MATERIALS AND METHODS: Atrophic alveolar ridge was induced in six canine mandibles, and 5 peri-implant defects were achieved in each hemi-mandible. Bone augmentation was attempted using the following randomly allocated modalities: (1) Control: no treatment, (2) TM only group: blood clot covered by TM, (3) TM+BS group: BS covered by TM, (4) TM+CM group: blood clot covered by TM and CM, and (5) TM+BS+CM group: BS covered by TM and CM. After 16 weeks of submerged healing, micro-CT and histomorphometric analyses were performed. RESULTS: TM exposure occurred in one case in the TM only group, one case in the TM+CM group, and two cases in the TM+BS+CM group. Histologically, pseudo-periosteum was observed along the inner and outer surfaces of TM, and the directions of the collagen fiber within the pseudo-periosteum differed according to the additional use of CM. In general, the TM only group rendered higher values in vertical defect fill and dimension of the augmented hard tissue in comparison with the other treatment groups. CONCLUSIONS: Due to the small sample size, this pilot study remains inconclusive. Within the limitations of the study, the use of CM and/or BS did not appear to have an additional benefit on lateral bone augmentation of peri-implant defect with TM.
Asunto(s)
Aumento de la Cresta Alveolar , Sustitutos de Huesos , Implantes Dentales , Aumento de la Cresta Alveolar/métodos , Regeneración Ósea , Sustitutos de Huesos/farmacología , Colágeno , Implantación Dental Endoósea/métodos , Regeneración Tisular Guiada Periodontal/métodos , Proyectos Piloto , Mallas Quirúrgicas , TitanioRESUMEN
AIM: To assess the changes in peri-implant soft tissue levels after the surgical treatment of peri-implantitis. METHODS: Randomized controlled trials, controlled clinical trials, cohort studies and case series, evaluating the changes in the position of the mucosal margin before and after surgical treatment of peri-implantitis, were searched. Secondary outcomes were changes in keratinized mucosa (KM), radiographic bone levels, probing depths (PD), plaque indices, bleeding on probing and patient perception. Meta-analyses were performed to determine weighted mean differences (WMD) or effects (WME). RESULTS: Twenty-six articles, reporting 20 investigations, were included. Reconstructive approaches yielded significantly less increase in mucosal recession, when compared to access flaps (n = 3, WMD = -1.35 mm, 95% confidence interval [CI] [-2.62; -0.07], p = .038). When comparing among reconstructive surgical interventions similar outcomes were observed irrespective of the use of a barrier membrane (n = 3, WMD = -0.01 mm, 95% CI [-0.15; 0.13], p = .917). When considering the effects over time, limited mucosal recession was observed after reconstructive procedures (n = 23, WME = 0.389 mm, 95% CI [0.204; 0.574]), p = .001), while increased recession was reported with either resective or access flap surgery (n = 6, WME = 1.21 mm, 95% CI [0.70; 1.72], p = <.001; and n = 3, WME = 0.95 mm, 95% CI [0.20; 2.10], p = .106; respectively). When resective and reconstructive approaches were combined the highest values on peri-implant recession were reported (n = 2, WME = 1.97 mm, 95% CI [0.81; 3.14], p < .001). Reconstructive surgical interventions were associated with greater radiographic bone level gains, while similar values were reported for PD reduction when comparing reconstructive, access and resective procedures. CONCLUSIONS: Resective surgical procedures were associated with significant post-surgical recession while minimal recession was observed in regenerative interventions.
Asunto(s)
Implantes Dentales , Periimplantitis , Procedimientos de Cirugía Plástica , Índice de Placa Dental , Humanos , Periimplantitis/diagnóstico por imagen , Periimplantitis/cirugía , Colgajos QuirúrgicosRESUMEN
AIM: To investigate the immunohistochemical characteristics of a highly porous synthetic bone substitute and a cross-linked collagen membrane for guided bone regeneration. METHODS: Three experimental groups were randomly allocated at chronic peri-implant dehiscence defect in 8 beagle dogs: (i) biphasic calcium phosphate covered by a cross-linked collagen membrane (test group), (ii) deproteinized bovine bone mineral covered by a natural collagen membrane (positive control) and (iii) no treatment (negative control). After 8 and 16 weeks of submerged healing, dissected tissue blocks were processed for immunohistochemical analysis. Seven antibodies were used to detect the remaining osteogenic and angiogenic potential, and quantitative immunohistochemical analysis was done by software. RESULTS: The antigen reactivity of alkaline phosphatase was significantly higher in the test group compared to the positive and negative controls, and it maintained till 16 weeks. The intensity of osteocalcin was significantly higher in the positive control at 8 weeks than the other groups, but significantly decreased at 16 weeks and no difference was found between the groups. A significant large number of TRAP-positive cells were observed in the test group mainly around the remaining particles at 16 weeks. The angiogenic potential was comparable between the groups showing no difference in the expression of transglutaminase II and vascular endothelial growth factor. CONCLUSION: Guided bone regeneration combining a highly porous biphasic calcium phosphate synthetic biomaterial with a crosslinked collagen membrane, resulted in extended osteogenic potential when compared to the combination of deproteinized bovine bone mineral and a native collagen membrane.
Asunto(s)
Sustitutos de Huesos , Implantes Dentales , Animales , Materiales Biocompatibles , Regeneración Ósea , Sustitutos de Huesos/farmacología , Bovinos , Perros , Regeneración Tisular Guiada Periodontal , Membranas Artificiales , Factor A de Crecimiento Endotelial VascularRESUMEN
OBJECTIVES: To assess the osseointegration of calcium-coated (CS) and chemically modified, sandblasted, large-grit, acid-etched (MS) dental implants with a lack of primary mechanical stability. MATERIALS AND METHODS: Eighteen implants in CS and MS groups each were loosely placed in the mandible of six mongrel dogs and allowed to heal for 2, 4 and 8 weeks. Implant stability quotient (ISQ) and implant stability test (IST) values recorded periodically and bone-to-implant contact (BIC) and the number of Haversian canals per 1 mm2 measured histologically were statistically analysed (p < .05). RESULTS: All CS and MS implants placed survived. Compared with immediately after installation, ISQ and IST values in both groups increased significantly to over 76 at 2 weeks (p < .0083) and remained stable thereafter. BIC was significantly greater at 8 weeks (61.3 ± 13.6% in CS group; 57.6 ± 5.9% in MS group) compared to 2 and 4 weeks in both groups (p < .017). There were no significant intergroup differences in ISQ, IST or BIC at different time points. Significantly more Haversian canals were observed in group CS (6.2 ± 1.0/mm2 ) compared with group MS at 4 weeks (3.7 ± 1.8 /mm2 ; p < .05), while intergroup difference was not significant at 8 weeks. CONCLUSION: Both CS and MS implants inserted without primary stability obtained osseointegration within 2 weeks, and lamellar bone adjacent to the implants was first observed at 8 weeks. The formation of primary osteons was more active at 4 weeks in group CS than in group MS.
Asunto(s)
Implantes Dentales , Animales , Calcio , Implantación Dental Endoósea , Diseño de Prótesis Dental , Perros , Mandíbula/cirugía , Oseointegración , Propiedades de Superficie , TitanioRESUMEN
OBJECTIVE: To assess the efficacy of three mechanical decontamination methods in four types of commercially available implants. MATERIAL AND METHODS: Ninety-six implants of four commercial brands with different designs (regarding thread depth and thread pitch) were soaked in a surrogate biofilm (ink) and air-dried. Circumferential standardized peri-implant defects with 6 mm in depth and 1.55 mm in width were custom-made with a 3D printer. Stained implants were inserted in the defects and instrumented with three different methods: a titanium brush (TNB), a metallic ultrasonic tip (IST) and an air abrasive (PF). Standardized photographs were taken vertically to the implant axis (flat view), and with angulations of 60° (upper view) and 120° (lower view) to the implant long axis. The percentage of residual stain (PRS) was calculated with the image analysis software. Scanning electron microscope evaluations were performed on the buccal aspect of the implants at the central level of the defect. RESULTS: The efficacy of PF was significantly inferior to the TNB and IST in all implant designs, while there were no significant differences between TNB and IST. IST showed significantly higher PRS in the implant with the highest thread pitch, while the TNB had the highest PRS in the implant with a marked reverse buttress-thread design. The micro-thread design had the lowest values of PRS for all decontamination methods. The apically facing threads represented the areas with highest PRS for all implant designs and decontamination methods. CONCLUSION: Thread geometry influenced the access of the decontamination devices and in turn its efficacy. Implants with lower thread pitch and thread depth values appeared to have less residual staining. CLINICAL RELEVANCE: Clinicians must be aware of the importance of thread geometry in the decontamination efficacy.
Asunto(s)
Implantes Dentales , Periimplantitis , Descontaminación , Humanos , Periimplantitis/prevención & control , Propiedades de Superficie , TitanioRESUMEN
OBJECTIVE: To compare the clinical, radiographic, and histological healing patterns between the immediate and delayed applications of bone morphogenetic protein-2 (BMP-2) in damaged extraction sockets in dogs. MATERIALS AND METHODS: The distal roots of the fourth premolars of the mandible were extracted bilaterally in five beagle dogs, and buccal bone defects (4 mm wide and 9 mm high) were surgically created. Collagenated biphasic calcium phosphate (CBCP) soaked for 10 min in 100 µL of BMP-2 solution was applied immediately to the defect site in the control group. In the test group, the BMP-2 solution of same dose was injected into the grafted site 2 weeks after grafting with a saline-soaked CBCP. The dogs were sacrificed 2 weeks later. Clinical, histological, and radiographic analyses were followed. RESULTS: Swelling and inflammatory reactions were predominantly observed in the control group at 2 weeks. The area of new bone formation was significantly larger in the control group compared with the test group (10.8 ± 7.0 mm2 [mean ± SD] and 6.3 ± 3.1 mm2, respectively; p = 0.043). No significant difference was found in ridge width at 2 mm, 4 mm and 6 mm below the lingual bone crest between the control (2.6 ± 1.0 mm, 3.2 ± 0.9 mm and 4.5 ± 0.5 mm, respectively) and test group (3.3 ± 1.0 mm, 3.7 ± 1.3 mm and 4.2 ± 1.0 mm; all p > 0.05). CONCLUSIONS: Delayed application of BMP-2 2 weeks after surgery did not show any advantage over immediate application of BMP-2 in terms of new bone formation. CLINICAL RELEVANCE: This study suggests that it might be better to apply BMP-2 immediately in alveolar ridge preservation, instead of delayed application, in order to enhance new bone formation.