A novel bone scraper for intraoral harvesting: a device for filling small bone defects

Autologous Cranioplasty Using a Dental SafeScraper Device

SUMMARY

Conventional methods to reconstruct cortical bone defects introduced by pediatric cranial vault remodeling (CVR) procedures have shortcomings. Use of bone burr shavings as graft material leads to variable ossification, and harvesting split-thickness cortical grafts is time-intensive and often not possible in thin infant calvaria. Since 2013, the authors' team has used the SafeScraper, originally developed as a dental instrument, to harvest cortical and cancellous bone grafts during CVR. The authors assessed the effectiveness of this technique by analyzing postoperative ossification using computed tomography scans of 52 patients, comparing cohorts treated with the SafeScraper versus those who received conventional methods of cranioplasty during fronto-orbital advancement. The SafeScraper cohort had a greater reduction in total surface area of all defects (-83.1% ± 14.9 versus -68.9% ± 29.8; P = 0.034), demonstrating a greater and more consistent degree of cranial defect ossification compared with conventional methods of cranioplasty, suggesting potential adaptability of this tool. This is the first study that describes the technique and efficacy of the SafeScraper in reducing cranial defects in CVR.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

A new semi-orthotopic bone defect model for cell and biomaterial testing in regenerative medicine

In recent decades, an increasing number of tissue engineered bone grafts have been developed. However, expensive and laborious screenings in vivo are necessary to assess the safety and efficacy of their formulations. Rodents are the first choice for initial in vivo screens but their size limits the dimensions and number of the bone grafts that can be tested in orthotopic locations. Here, we report the development of a refined murine subcutaneous model for semi-orthotopic bone formation that allows the testing of up to four grafts per mouse one order of magnitude greater in volume than currently possible in mice. Crucially, these defects are also "critical size" and unable to heal within the timeframe of the study without intervention. The model is based on four bovine bone implants, ring-shaped, where the bone healing potential of distinct grafts can be evaluated in vivo. In this study we demonstrate that promotion and prevention of ossification can be assessed in our model. For this, we used a semi-automatic algorithm for longitudinal micro-CT image registration followed by histological analyses. Taken together, our data supports that this model is suitable as a platform for the real-time screening of bone formation, and provides the possibility to study bone resorption, osseointegration and vascularisation.

Early bone formation in mini-lateral window sinus floor elevation with simultaneous implant placement: An in vivo experimental study

OBJECTIVE

To investigate the early bone formation in beagles with mini-lateral window sinus floor elevation and simultaneous implant placement.

MATERIAL AND METHODS

Six beagles were selected for the split-mouth design procedures. In each animal, one maxillary recess received a 5 mm-diameter mini-round lateral osteotomy (test group), and the contralateral maxillary recess received a large rectangular osteotomy (10 mm long and 8 mm wide), (control group). Simultaneous implant installation was executed on bilateral maxillary recesses. Tetracycline and calcein dyes were administered on the 14th, 13th days and the 4th, 3rd days prior to sacrifice, respectively. After 8 weeks of healing, the beagles were euthanized for fluorescent labeling and histomorphometric analyses.

RESULTS

In both groups, new bone formation initiated from the circumferential native bone of the maxillary recesses and extended toward the central sub-recess cavities. The maxillary recesses with the mini-window procedures exhibited superior mineral apposition rate, bone formation rate, and the percentage of new bone area to those of the group exposed to large osteotomy procedure (p < .05). While there was no significant difference in the value of bone-to-implant contact, the mini-window group displayed a tendency for an increase in this aspect (p > .05). Bone formation rate and new bone amount were not statistically correlated with bone-to-implant contact (p > .05).

CONCLUSION

The hypothesis that mini-lateral window sinus floor elevation with simultaneous implant placement would improve early new bone formation in augmented sinus compared with large lateral window procedure is accepted.

Clinical and histological reaction of periodontal tissues to subgingival resin composite restorations

OBJECTIVES

To compare the clinical and histological response of supracrestal periodontal tissues to subgingival composite restorations versus natural root surfaces MATERIAL AND METHODS: In 29 subjects with a single tooth requiring subgingival restorations, a deep margin elevation (DME) procedure with composite resin was applied. Full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), and focal probing depth (PD) were measured at baseline, before DME, and after 3 months. The distance between the coronal marked (CM) point to the apical margin of the composite reconstruction (AMR), at baseline, and to the tip of the periodontal probe inserted to reach the bottom of the sulcus (APP), 3 months later, was measured. An all-around secondary flap, harvested to ensure the subsequent single-crown prosthetic rehabilitation was histologically processed. The histological inflammation degree was evaluated in areas of gingival tissues adjacent to the composite (group B) and adjacent to the natural surface of each single tooth (group A).

RESULTS

Significant FMPS, FMBS, and PD decreases were observed (p < 0.05). CM-AMR and CM-APP were significantly different (p < 0.05), suggesting an attachment gain after 3-months. The inflammation level of gingival tissue was similar in groups A and B (p > 0.05).

CONCLUSIONS

For the first time, this topic was clinically and histologically studied in humans. Subgingival restorations resulted compatible with gingival health, with levels similar to that of untreated root surfaces.

CLINICAL RELEVANCE

Deep margin elevation procedure produces favorable clinical and histological outcomes allowing a routine utilization in reconstructive dentistry.

New bone formation after transcrestal sinus floor elevation was influenced by sinus cavity dimensions: A prospective histologic and histomorphometric study

OBJECTIVE

The aim of this multicenter prospective study was to analyze clinically and histologically the influence of sinus cavity dimensions on new bone formation after transcrestal sinus floor elevation (tSFE).

MATERIAL AND METHODS

Patients needing maxillary sinus augmentation (residual crest height <5 mm) were treated with tSFE using xenogeneic granules. Six months later, bone-core biopsies were retrieved for histological analysis in implant insertion sites. Bucco-palatal sinus width (SW) and contact between graft and bone walls (WGC) were evaluated on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were quantified by means of forward multiple linear regression analysis.

RESULTS

Fifty consecutive patients were enrolled and underwent tSFE procedures, and forty-four were included in the final analysis. Mean percentage of newly formed bone (NFB) at 6 months was 21.2 ± 16.9%. Multivariate analysis showed a strong negative correlation between SW and NFB (R²  = .793) and a strong positive correlation between WGC and NFB (R²  = .781). Furthermore, when SW was stratified into three groups (<12 mm, 12 to 15 mm, and >15 mm), NFB percentages (36%, 13% and 3%, respectively) resulted significantly different.

CONCLUSIONS

This study represented the first confirmation based on histomorphometric data that NFB after tSFE was strongly influenced by sinus width and occurred consistently only in narrow sinus cavities (SW <12 mm, measured between buccal and palatal walls at 10-mm level, comprising the residual alveolar crest).

Bony spicules trapped in peri-implant soft tissue: a common unrecognized finding

According to the study, there were unexpected tiny bone spicules being inspected in peri‐implant soft tissue. These displaced autogenous bone chips were probably presented when preparing implant sites. The displaced bone spicules seemed not induced significant inflammatory reactions; on contrary, defects of specimens and dissolving bone spicules pictures were demonstrated.

A prospective randomized controlled trial of the two-window technique without membrane versus the solo-window technique with membrane over the osteotomy window for maxillary sinus augmentation

BACKGROUND

Maturation of the grafted volume after lateral sinus elevation is crucial for the long-term survival of dental implants.

PURPOSE

To compare endo-sinus histomorphometric bone formation between the solo- and two-window maxillary sinus augmentation techniques with or without membrane coverage for the rehabilitation of multiple missing posterior teeth.

MATERIALS AND METHODS

Patients with severely atrophic posterior maxillae were randomized to receive lateral sinus floor elevation via the solo-window technique with membrane coverage (Control Group) or the two-window technique without coverage (Test Group). Six months after surgery, bone core specimens harvested from the lateral aspect were histomorphometrically analyzed.

RESULTS

Ten patients in each group underwent 21 maxillary sinus augmentations. Histomorphometric analysis revealed mean newly formed bone values of 26.08 ± 16.23% and 27.14 ± 18.11%, mean connective tissue values of 59.34 ± 12.42% and 50.03 ± 17.13%, and mean residual graft material values of 14.6 ± 14.56% and 22.78 ± 10.83% in the Test and Control Groups, respectively, with no significant differences.

CONCLUSIONS

The two-window technique obtained comparative maturation of the grafted volume even without membrane coverage, and is a viable alternative for the rehabilitation of severely atrophic posterior maxillae with multiple missing posterior teeth.

Comparison of the effect of three autogenous bone harvesting methods on cell viability in rabbits

Background. This study was designed to compare the viability of autogenous bone grafts, harvested using different methods, in order to determine the best harvesting technique with respect to more viable cells.

Methods. In this animal experimental study, three harvesting methods, including manual instrument (chisel), rotary device and piezosurgery, were used for harvesting bone grafts from the lateral body of the mandible on the left and right sides of 10 rabbits. In each group, 20 bone samples were collected and their viability was assessed using MTS kit. Statistical analyses, including ANOVA and post hoc Tukey tests, were used for evaluating significant differences between the groups.

Results. One-way ANOVA showed significant differences between all the groups (P=0.000). Data analysis using post hoc Tukey tests indicated that manual instrument and piezosurgery had no significant differences with regard to cell viability (P=0.749) and the cell viability in both groups was higher than that with the use of a rotary instrument (P=0.000).

Conclusion. Autogenous bone grafts harvested with a manual instrument and piezosurgery had more viable cells in comparison to the bone chips harvested with a rotary device.

Maxillary Sinus Grafting With Biphasic Bone Ceramic or Autogenous Bone: Clinical, Histologic, and Histomorphometric Results From a Randomized Controlled Clinical Trial

PURPOSE

The present, randomized, controlled clinical trial compared the histologic and histomorphometric results from maxillary sinus augmentation with either biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% β-tricalcium phosphate) or autogenous bone (AB) as bone-grafting materials.

MATERIAL AND METHODS

Ten patients received bilateral sinus elevation surgery with intraoral AB chips (control group) on one side and BCP (test group) on the contralateral side. After a healing period of 6 to 8 months, implant sites were created and trephine cores were harvested for histological and histomorphometric analysis of the grafted areas.

RESULTS

The histological examination of biopsies showed BCP particles interconnected by bridges of a vital newly formed bone. Histomorphometry demonstrated that the amount of newly formed bone in the control group (36.8%) was significantly greater than that in the BCP (28.2%) group (P = 0.0032). BCP and AB cores revealed an average of residual graft particles of 32.9% and 4.8%, respectively. The average percentage of soft tissue components was 38.9% in the BCP cores and 58.4% in the AB cores.

CONCLUSIONS

Based on our findings, the amount of vital bone formation was significantly higher for AB than that for BCP. However, BCP seemed to be a biocompatible and osteoconductive material that can be used with success as a bone substitute in maxillary sinus procedures.

Two-stage crestal sinus elevation by sequential drills in less than 4 mm of residual ridge height: a clinical and histologic case report

PURPOSE

The aim of this work, the first human histologic case report of this technique, was a clinical and histologic evaluation of implant placed in a severely atrophic maxilla using a 2-stage crestal sinus elevation.

CASE PRESENTATION

A 52-year-old woman required rehabilitation of an atrophic maxilla with a fixed implant-supported prosthesis. At the first surgery, a crestal sinus lift was performed using beta-tricalcium phosphate (β-TCP), as radiographic tracer, and mineralized human bone allograft (MHBA) as grafting material. After 6 months, a bone core biopsy was taken, and 2 implants were placed in the augmented sites. Four months later, implants were exposed, and 2 splinted gold-porcelain crowns were delivered. Histology highlighted basal bone disappearance, replaced by a wide composite network (∼50% vol/vol) of MHBA granules connected by newly formed bone, and osteoblastic activities.

CONCLUSION

This case report demonstrates the possibility of executing a staged transcrestal sinus lift in atrophic situations. MHBA evidenced usefulness in maintaining bone volume. Histologic analyses confirmed the sound outcome of the graft augmentation. Additional studies would be beneficial to confirm or refute the reliability of this technique.

A prospective study on the morbidity resulting from calvarial bone harvesting for intraoral reconstruction

Calvarial bone grafts are used for reconstruction of the maxilla or mandible to enable implant placement. The aim of this study was to assess the morbidity resulting from the use of calvarial bone grafts to reconstruct the maxilla and mandible. Thirty-six consecutive patients were included in this prospective study (14 men and 22 women; mean age 59 ± 8.2 years). Perioperative and postoperative complications related to harvesting of the calvarial bone were scored, as well as the occurrence of intraoral complications (average follow-up 25 ± 12 months). Perioperative exposure of the dura occurred in four patients and the graft broke during harvesting in five patients. With a change in the technique, these complications no longer occurred. Postoperative pain levels at the calvarial donor site were low (visual analogue scale (VAS) 1.9 ± 2.0 on day 1) and of short duration (5.2 ± 4.7 days to becoming pain-free). In all cases sufficient bone could be harvested to enable the placement of implants. The exposure of the dura and the intraoral complications were of no clinical consequence. Therefore, calvarial bone grafts appear to be promising for use in pre-implant intraoral reconstructions.

Gene expression and morphometric parameters of human bone biopsies after maxillary sinus floor elevation with autologous bone combined with Bio-Oss® or BoneCeramic®

OBJECTIVES

Although the clinical success of Bio-Oss(®) and BoneCeramic(®) has been corroborated by histologic and histomorphometric findings, the biological events that occur during healing after maxillary sinus floor elevation (MSFE) are unknown. Here, we evaluated biopsies of grafted bone with a mixture of autologous bone and Bio-Oss(®) or BoneCeramic(®) after two different healing time periods to understand the molecular process underlying bone formation after MSFE.

MATERIAL AND METHODS

Seven patients, following a bilateral split-mouth design model and needing a MSFE to allow implant placement, were recruited for this study. Right or left sinuses were grafted with autologous maxillary bone combined either with Bio-Oss(®) or BoneCeramic(®) , respectively. Twenty biopsies were taken at the time of implant insertion after 4-5 months or 6-8 months of MSFE, and analyzed by micro-computed tomography (microCT) and gene-expression analysis.

RESULTS

MicroCT analysis revealed no differences in the morphometric parameters or BMD either after 4-5 months or 6-8 months of MSFE between Bio-Oss(®) and BoneCeramic(®) . At molecular level, a higher expression of bone forming gene Runx2 was observed after 4-5 months of MSFE in the Bio-Oss(®) compared with the BoneCeramic(®) group.

CONCLUSIONS

Our results indicate that differences found at the molecular level between Bio-Oss(®) and BoneCeramic(®) are not translated to important differences in the 3D microstructure and BMD of the grafted bone.

Impact of bone graft harvesting techniques on bone formation and graft resorption: a histomorphometric study in the mandibles of minipigs

BACKGROUND

Harvesting techniques can affect cellular parameters of autogenous bone grafts in vitro. Whether these differences translate to in vivo bone formation, however, remains unknown.

OBJECTIVE

The purpose of this study was to assess the impact of different harvesting techniques on bone formation and graft resorption in vivo.

MATERIAL AND METHODS

Four harvesting techniques were used: (i) corticocancellous blocks particulated by a bone mill; (ii) bone scraper; (iii) piezosurgery; and (iv) bone slurry collected from a filter device upon drilling. The grafts were placed into bone defects in the mandibles of 12 minipigs. The animals were sacrificed after 1, 2, 4 and 8 weeks of healing. Histology and histomorphometrical analyses were performed to assess bone formation and graft resorption. An explorative statistical analysis was performed.

RESULTS

The amount of new bone increased, while the amount of residual bone decreased over time with all harvesting techniques. At all given time points, no significant advantage of any harvesting technique on bone formation was observed. The harvesting technique, however, affected bone formation and the amount of residual graft within the overall healing period. Friedman test revealed an impact of the harvesting technique on residual bone graft after 2 and 4 weeks. At the later time point, post hoc testing showed more newly formed bone in association with bone graft processed by bone mill than harvested by bone scraper and piezosurgery.

CONCLUSIONS

Transplantation of autogenous bone particles harvested with four techniques in the present model resulted in moderate differences in terms of bone formation and graft resorption.

Risk of bacterial contamination of bone harvesting devices used for autogenous bone graft in implant surgery

Background

Various instruments have been developed for collecting bone debris during intraoral autogenous bone graft procedures in implant surgery. The aim of this study was to quantitatively determine the degree of contamination in bone debris collected by different devices.

Methods

Twelve patients underwent autogenous bone collection using a bone chisel, bone scraper, trephine drill, and bone filter during bone augmentation surgery as a part of implant therapy, and the total bacterial count in bone debris collected by each was determined.

Results

Following anaerobic incubation, bacterial colony formation was found in all of the samples. The mean colony forming units (CFU)/g in samples collected by the trephine drill was found to be significantly lower than that of samples obtained with the other devices, while those values for samples collected by the bone scraper and bone filter was significantly higher as compared to the bone chisel and trephine drill.

Conclusion

The bacterial levels may still carry the infection risk. Thus prophylactic antibiotic therapy maybe indicated when using bone particles for intraoral augmentation procedures.

Is socket healing conditioned by buccal plate thickness? A clinical and histologic study 4 months after mineralized human bone allografting

OBJECTIVE

The aim of this study was to clinically and histologically analyze the healing of grafted sockets by mineralized human bone allograft (MHBA) and nongrafted sockets, correlating the results with buccal plate thickness.

MATERIAL AND METHODS

Thirty-one sockets were randomly split into control (CG) and treatment (MHBA grafted) (TG) groups and, subsequently, into four subgroups according to buccal plate thickness: a ≤ 1 mm and b > 1 mm. Ridge thickness, depth, and height were monitored. Four months after, at implant placement, a bone core biopsy for histologic and morphometric analyses was taken.

RESULTS

The differences of buccal height (TG-a -0.27 and CG-a -1.17 mm) and width (TG-a 0.55 and CG-a 2.67 mm, TG-b 0.12 and CG-b 1.17 mm) were statistically significant. The increase in bone amount CG-b (28.17%) compared with CG-a (16.98%) was statistically significant. Soft tissue amount of TG-b (54.21%) and TG-a (56.91%) was lower than that of CG-b (71.83%) and CG-a (83.01%), both being statistically significant (P = 0.002).

CONCLUSIONS

The results proved that thin buccal plates had a worse outcome on socket healing and that network formation by MBHA not only predisposes a successful implant insertion but also acts as size keeper.

Autogenous bone with or without hydroxyapatite bone substitute augmentation in rat calvarium within a plastic cap

OBJECTIVES

We evaluated the effect of autogenous bone (AB) and hydroxyapatite bone (HA) for the assessment of bone augmentation beyond the skeletal envelope in the rat calvarium.

STUDY DESIGN

The calvaria of 12 rats were exposed and 2 plastic caps were placed with AB and HA or AB alone in the calvarium. Images of bone augmentation within the plastic caps were taken using micro-CT (R_mCT). Histologic sections were cut along the same plane as those used for the R_mCT images at 12 weeks. Bone volume (BV) was calculated using BV-measuring software.

RESULTS

BV increased at both the experimental and control sites. The newly generated tissue did not significantly differ between the experimental and control sites; however, the mineralized tissue was significantly higher at control sites compared with experimental sites.

CONCLUSIONS

The results indicate that the combination of HA and AB was biocompatible and allowed osteoconduction.

Safe harvesting of outer table parietal bone grafts using an oscillating saw and a bone scraper: a refinement of technique for harvesting cortical and "cancellous"-like calvarial bone

Calvarial bone is a readily available source of bone for preimplantation augmentation procedures of the alveolar process. However, the calvaria consist mostly of cortical bone, and cancellous bone of the diploic space is scarce. A bone scraper (Safescraper Twist; META, Reggio Emilia, Italy) was used to create a beveled trough around the calvarial outer table graft to facilitate its removal with an oscillating saw. Using the scraper, copious amounts (>10 mL) of "cancellous"-like bone could be collected. This new application of the Safescraper Twist obviated milling down additional cortical pieces.

Sinus graft with safescraper: 5-year results

PURPOSE

In the procedure of sinus floor elevation, autogenous bone, allogenic grafts, and several other bone substitutes are used. However, autogenous bone is still considered the gold standard. Donor sites for autogenous bone are generally the iliac crest, oral cavity, calvarium bone, and tibia. In this work the experience with the use of a Safescraper device for harvesting of autogenous bone is reported and a decision-making algorithm for grafting in sinus floor elevation procedures is proposed.

MATERIALS AND METHODS

Forty sinus augmentation procedures were performed in 34 patients. All sinuses were filled with a mixture of autogenous bone and bovine hydroxyapatite. A Safescraper device was used to harvest autologous bone from the maxillary area. Platelet-rich plasma was used to sustain bone placement. Sixty-five dental implants were placed at 4 months with a flapless procedure. A clinical and radiological 5-year retrospective case series of a cohort is reported.

RESULTS

In all cases new bone formation was confirmed radiologically and implant placement was performed successfully. Analysis of samples obtained by biopsy with histology and microcomputed tomography showed the presence of mature bone. Healing problems were observed in only 1 case.

CONCLUSIONS

Sinus augmentation with bone grafts obtained from oral cavity with a bone scraper device has the advantage of providing autogenous bone without the need for an extra surgical approach. This procedure yields satisfactory results in bone formation, implant survival, and patient satisfaction. When combined with a flapless approach for implant placement, a decrease in the morbidity of the entire process is achieved.

[Technical note:simple tools in preimplant surgery]

Osteotomes, the bone scraper, and the bone trap are simple tools used for preprosthetic surgery. They are not very invasive, present little risks, and they can be used in private surgical practice with local anaesthesia. The osteotome preserves, dilates, and condenses the alveolar bone instead of eliminating it like drilling does. It does not require any motor or irrigation. It increases the width and the height of the alveolar crest. It allows the localized expansion of narrow or misshapen alveolar crest when its width ranges between 3 and 4.5mm. It also allows performing a localized sinus lift, when the sinus floor height ranges between 4 and 8mm. The bone scraper is used to retrieve cortical chips of parietal bone for sinus lift. The bone trap is connected to the suction tube. It is used to collect bone powder after milling or bone drilling. These simple tools should be available for all maxillofacial surgeons in specific indications.

Differentiation potential of adult human mesenchymal stem cells

Human mesenchymal stem cells (HMSCs) which are isolated from bone marrow stroma, peripheral blood, dermis, muscle and adipose tissue have the advantage of potential autologous transplantation ability. They can be differentiated into chondrogenic, osteogenic, adipogenic and myogenic lineages. Problems of stem cells from bone marrow are low cell numbers, low isolated volumes, pain, and to some extent ethical concerns. The isolation of mesenchymal stem cells from human adipose tissue was recently identified as an alternative source, since these cells are easy to obtain in big cell numbers. Adipose tissue is derived from embryonic mesoderm and contains a heterogeneous stromal cell population. To achieve lineage-specific differentiation of these cells they have to be cultured in media supplemented with appropriate factors. Inductions of the cells into multiple mesenchymal lineages resulted in the expression of several lineage-specific genes, proteins and specific metabolic activity. In conclusion, the potential benefit of the multi-germline capacity of HMSCs seems to be a promising approach for allogenic cell therapy and human tissue engineering.