Transplantation of neural differentiated human mesenchymal stem cells into the cochlea of an auditory-neuropathy guinea pig model.

The aim of this study was to determine the effects of transplanted neural differentiated human mesenchymal stem cells (hMSCs) in a guinea pig model of auditory neuropathy. In this study, hMSCs were pretreated with a neural-induction protocol and transplanted into the scala tympani of the guinea pig cochlea 7 days after ouabain injury. A control model was made by injection of Hanks balanced salt solution alone into the scala tympani of the guinea pig cochlea 7 days after ouabain injury. We established the auditory neuropathy guinea pig model using 1 mM ouabain application to the round window niche. After application of ouabain to the round window niche, degeneration of most spiral ganglion neurons (SGNs) without the loss of hair cells within the organ of Corti and increasing the auditory brain responses (ABR) threshold were found. After transplantation of neural differentiated hMSCs, the number of SGNs was increased, and some of the SGNs expressed immunoreactivity with human nuclear antibody under confocal laser scanning microscopy. ABR results showed mild hearing recovery after transplantation. Based on an auditory neuropathy animal model, these findings suggest that it may be possible to replace degenerated SGNs by grafting stem cells into the scala tympani.

The biocompatibility and mineralization potential of mineral trioxide aggregate containing calcium fluoride-An in vitro study.

BACKGROUND/PURPOSE: MTA is used to induce hard tissue regeneration in various procedures. This study evaluated the biocompatibility and mineralization potential of mineral trioxide aggregate (MTA) containing calcium fluoride (CaF2). To verify if the change of components affected physical properties, the setting time, solubility, and surface roughness were measured. MATERIALS AND METHODS: Human dental pulp cells (HDPCs) were treated with powder and set MTA containing CaF2 (0, 1, 5, and 10 wt %). The proliferation of HDPCs was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The mineralization potential of HDPCs was investigated with the relative gene expression of alkaline phosphatase (ALP), collagen type I (ColI), osteocalcin (OCN), and runt-related transcription factor 2 (Runx2) using real-time reverse transcription polymerase chain reaction (RT-PCR). For investigating the physical properties, setting time and solubility were tested. Surface profiles of material were analyzed by a non-contact surface profiler and a scanning electron microscope (SEM). RESULTS: MTA-5% CaF2 mixtures increased the proliferation and the mineralization-related gene expression of HDPCs to a greater degree than pure MTA. The addition of CaF2 to MTA delayed the setting, but the difference was only significant in the MTA-10% CaF2. Solubility and surface roughness was not altered. CONCLUSION: The addition of more than 5% CaF2 can be considered to increase the regeneration potential of pulp cells without adverse effects on physical property.

Functional neural differentiation of human adipose tissue-derived stem cells using bFGF and forskolin.

BACKGROUND: Adult mesenchymal stem cells (MSCs) derived from adipose tissue have the capacity to differentiate into mesenchymal as well as endodermal and ectodermal cell lineage in vitro. We characterized the multipotent ability of human adipose tissue-derived stem cells (hADSCs) as MSCs and investigated the neural differentiation potential of these cells. RESULTS: Human ADSCs from earlobe fat maintained self-renewing capacity and differentiated into adipocytes, osteoblasts, or chondrocytes under specific culture conditions. Following neural induction with bFGF and forskolin, hADSCs were differentiated into various types of neural cells including neurons and glia in vitro. In neural differentiated-hADSCs (NI-hADSCs), the immunoreactivities for neural stem cell marker (nestin), neuronal markers (Tuj1, MAP2, NFL, NFM, NFH, NSE, and NeuN), astrocyte marker (GFAP), and oligodendrocyte marker (CNPase) were significantly increased than in the primary hADSCs. RT-PCR analysis demonstrated that the mRNA levels encoding for ABCG2, nestin, Tuj1, MAP2, NFL, NFM, NSE, GAP43, SNAP25, GFAP, and CNPase were also highly increased in NI-hADSCs. Moreover, NI-hADSCs acquired neuron-like functions characterized by the display of voltage-dependent tetrodotoxin (TTX)-sensitive sodium currents, outward potassium currents, and prominent negative resting membrane potentials under whole-cell patch clamp recordings. Further examination by RT-PCR showed that NI-hADSCs expressed high level of ionic channel genes for sodium (SCN5A), potassium (MaxiK, Kv4.2, and EAG2), and calcium channels (CACNA1C and CACNA1G), which were expressed constitutively in the primary hADSCs. In addition, we demonstrated that Kv4.3 and Eag1, potassium channel genes, and NE-Na, a TTX-sensitive sodium channel gene, were highly induced following neural differentiation. CONCLUSIONS: These combined results indicate that hADSCs have the same self-renewing capacity and multipotency as stem cells, and can be differentiated into functional neurons using bFGF and forskolin.

Fate of sudden deafness occurring in the only hearing ear: outcomes and timing to consider cochlear implantation.

The present study was undertaken to learn the outcome of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) in their only hearing ear. Timing to conduct a cochlear implantation was also determined in those who did not recover the hearing. The study group comprised 25 patients who confronted ISSNHL in their only hearing ear. A total of 192 patients, who had ISSNHL in one ear and had normal contralateral ear, served as the control. Demographically there were no significant differences between the groups. The recovery rate was similar between the groups: 64.0% in the experimental and 62.5% in the control group. The duration until the recovery of ISSNHL in the only hearing ear was 5-90 days (average 17.6 days). In the experimental group, 8 patients did not recover from ISSNHL, and underwent cochlear implantation in 6 with satisfactory results. These results suggest that the same treatment is applicable for patients with ISSNHL regardless of whether their contralateral ear is deaf or normal. For those who do not recover from ISSNHL in their only hearing ear, culminating in bilateral deafness, we may consider further definitive treatment including cochlear implantation as early as 3 months after initiating the treatment of ISSNHL.

Calcium silicate-based root canal sealers: a literature review.

Epoxy resin-based sealers are currently widely used, and several studies have considered AH Plus to be the gold-standard sealer. However, it still has limitations, including possible mutagenicity, cytotoxicity, inflammatory response, and hydrophobicity. Drawing upon the advantages of mineral trioxide aggregate, calcium silicate-based sealers were introduced with high levels of biocompatibility and hydrophilicity. Because of the hydrophilic environment in root canals, water resorption and solubility of root canal sealers are important factors contributing to their stability. Sealers displaying lower microleakage and stronger push-out bond strength are also needed to endure the dynamic tooth environment. Although the physical properties of calcium silicate-based sealers meet International Organization for Standardization recommendations, and they have consistently reported to be biocompatible, they have not overcome conventional resin-based sealers in actual practice. Therefore, further studies aiming to improve the physical properties of calcium silicate-based sealers are needed.

Huge cholesterol granuloma of the middle ear extending to middle cranial fossa.

Cholesterol granuloma (CG) may erode into the middle ear, the mastoid bone and the petrous apex. However, aggressive erosion into the cranial cavity is extremely rare. Here we report a case of huge CG extending to the middle cranial fossa. Temporal bone computerized tomography showed a soft tissue mass which destroyed the bony plate of the posterior and middle cranial fossa. On magnetic resonance imaging, the mass revealed a high signal on both T1 and T2-weighted images. The mass compressed the middle cranial fossa without invasion into the brain. The CG was removed by extended cortical mastoidectomy. The postoperative course was uneventful and there were no neurological complications.

A primary large cholesterol cyst of the mastoid presenting with dysgeusia.

The occurrence of postoperative secondary cholesterol cysts in the mastoid has been previously reported, however the occurrence of a primary large cholesterol cyst in the mastoid with bony destruction of the facial nerve has rarely been reported. The case report of a 17-year-old female patient with a primary large cholesterol cyst with dysgeusia is presented. Computed tomography and magnetic resonance imaging findings for the lesion distinguish a cholesterol granuloma, cholesteatoma and vascular tumor. The patient underwent a canal wall down mastoidectomy with mastoid obliteration. A dehiscent portion of the mastoid segment of the facial nerve was visible within the cavity; the gross finding of the facial nerve was edematous in appearance. Five years later, there has been no recurrence of disease.

Antibacterial effect of octylcyanoacrylate against ciprofloxacin-resistant Pseudomonas aeruginosa isolates from patients with chronic suppurative otitis media.

BACKGROUND: There has been a steady increase in the number of cases of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) otorrhea; this is a growing medical concern. For otological surgery in children, octylcyanoacrylate can be an alternative method of closure for surgical incisions. Recent in vitro studies have shown that octylcyanoacrylate is effective as an antimicrobical barrier. To date, there have been only rare reports on the antibacterial effect of octylcyanoacrylate against CRPA. The purpose of this study is to determine the antimicrobial effects of octyl-cyanoacrylate against the CRPA that was isolated from patients with chronic suppurative otitis media. PATIENTS AND METHODS: Clinical CRPA (n=20) bacteria and ciprofloxacin-sensitive PA (CSPA) (n=20) were obtained from patients. The susceptibilities to various antibiotics were determined by disk diffusion method. RESULT: Both CSPA and CRPA were resistant to octylcyanoacrylate. CONCLUSION: Results demonstrated that octylcyanoacrylate has no antibacterial activity against CSPA and CRPA.

Congenital cholesteatoma associated with blue eardrum.

The classic presentation of congenital cholesteatoma is a pearl behind the anterior-superior quadrant of an intact tympanic membrane. Idiopathic hemotympanum is characterized by a dark blue eardrum, the most prominent feature of which is the presence of cholesterol granulomas. Blue eardrum is associated with eustachian tube dysfunction. Despite the well-established relationship between eustachian tube dysfunction and the development of pediatric cholesteatoma, little has been written concerning the appropriate timing of tympanostomy tube placement. To date, there are no reports of congenital cholesteatoma associated with blue eardrum. A recent case of advanced congenital cholesteatoma (stage IV) associated with blue eardrum was treated using preoperative tympanostomy tube insertion. Tympanostomy tubes were helpful in preventing recurrence of the cholesteatoma after surgery. The case is presented along with a review of the literature.

The use of piperacillin-tazobactam coated tympanostomy tubes against ciprofloxacin-resistant Pseudomonas biofilm formation: an in vitro study.

BACKGROUND AND OBJECTIVE: Bacterial biofilm formation has been implicated in the high rate of persistent otorrhea after tympanostomy tube insertion. It has been suggested that the tube material may be an important factor in the development of otorrhea. Recently we reported the presence of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) biofilms on infected tympanostomy tubes following the use of intractable post-tympanostomy tubes and the onset of otorrhea. In this study, we have evaluated the resistance of piperacillin-tazobactam coated with chitosan on a tympanostomy tube to prevent CRPA biofilm formation in vitro. MATERIALS AND METHODS: Three sets each of piperacillin-tazobactam coated silicone tubes (n=5), commercial silver-oxide coated silicone tubes (Activent, Silic) (n=5) and control uncoated tympanostomy tubes (Paparella type 1) (n=5) were processed for evaluation. The piperacillin-tazobactam coated tympanostomy tubes were compared with the silver-oxide coated tubes and the uncoated control tubes for resistance to CRPA biofilm formation after in vitro incubation. RESULTS: Scanning electron microscopy showed that the surface of the silver-oxide coated tube (Activent) formed a thick biofilm with crusts as well as an uncoated tube. In contrast, the surface of a piperacillin-tazobactam coated tympanostomy tube showed virtually no CRPA biofilm formation. CONCLUSION: The piperacillin-tazobactam coated tympanostomy tube showed resistance to CRPA biofilm formation. The piperacillin-tazobactam coating may be useful to reduce CRPA biofilm formation; however, further in vivo studies are necessary.

Pulp-dentin regeneration: current approaches and challenges.

Regenerative endodontic procedures for immature permanent teeth with apical periodontitis confer biological advantages such as tooth homeostasis, enhanced immune defense system, and a functional pulp-dentin complex, in addition to clinical advantages such as the facilitation of root development. Currently, this procedure is recognized as a paradigm shift from restoration using materials to regenerate pulp-dentin tissues. Many studies have been conducted with regard to stem/progenitor cells, scaffolds, and biomolecules, associated with pulp tissue engineering. However, preclinical and clinical studies have evidently revealed several drawbacks in the current clinical approach to revascularization that may lead to unfavorable outcomes. Therefore, our review examines the challenges encountered under clinical conditions and summarizes current research findings in an attempt to provide direction for transition from basic research to clinical practice.

Effects of combined BCG and DHEA treatment in preventing the development of asthma.

Both BCG and dehydroepiandrosterone (DHEA) induce Th1 immune responses and suppress Th2 allergic reactions. To investigate whether the combination of BCG and DHEA has an additive effect on asthma prevention, BALB/c mice (n = 10 per group) were given an intraperitoneal injection of BCG at the beginning of sensitization, and fed mice chow containing DHEA throughout the study. In female mice, the combined administration of 2 x 10(4) CFUs BCG and 0.01% DHEA effectively suppressed the ovalbumin-induced increase in airway sensitivity to methacholine (56.5 vs. 8.2 mg/mL, p < 0.01), while BCG (13.9 mg/mL) or DHEA (17.9 mg/mL) alone did not. However, the addition of high dose (0.1%) DHEA decreased the efficacy of high dose (2 x 10(5) CFUs) BCG in suppressing the airway responsiveness and eosinophilia. In male mice, the treatments with BCG and/or DHEA were less effective, and the interferon-gamma/interleukin-4 ratio in the splenocyte supernatant was significantly higher and the ovalbumin-specific IgE concentration in the serum was significantly lower as compared to female mice. In conclusion, the combination of low doses of BCG and DHEA had an additive effect in suppressing the development of airway hypersensitivity. Androgens in males and DHEA overdose might reduce the efficacy of BCG.

Congenital cholesteatoma extending into the internal auditory canal and cochlea: a case report.

We report here on a case of congenital cholesteatoma that extended into the internal auditory meatus and cochlea. A 17-year-old boy underwent surgery for a very large cholesteatoma, which was discovered behind an intact tympanic membrane. Pure tone audiometry revealed an unresponsive ear. High resolution temporal bone computed tomography showed perilabyrinthine extension with its absence in the vestibular area, and destruction of the bony cochlea at the basal turn, the tegmen and the posterior cranial fossa. Magnetic resonance imaging revealed no intracranial extension. Surgical exploration of the middle ear and the mastoid cavity revealed that both the vestibule and the basal turn of the cochlea were filled with a noninfected cholesteatoma. The cholesteatoma extended into the internal auditory meatus through translabyrinthine destruction; it extended into the basal turn of the cochlea through the infralabyrinthine route. The bony segment of the facial nerve canal demonstrated near total dehiscence. The cholesteatoma was removed by the transotic approach. Congenital cholesteatoma is characterized by no specific history. Therefore, early detection of this malady can be challenging, but it is important to prevent such complications as were observed in this reported case.

Antibacterial effect of octylcyanoacrylate against methicillin-resistant Staphylococcus aureus isolates from patients with chronic suppurative otitis media.

UNLABELLED: There has been a steady increase in the number of cases of methicillin-resistant Staphylococcus aureus (MRSA) otorrhea; this is a growing medical concern. For otological surgery in children, octylcyanoacrylate can be an alternative method of closure for surgical incisions. Recent in vitro studies have shown that octylcyanoacrylate is effective as an antimicrobical barrier. To date, there have been only rare reports on the antibacterial effect of octylcyanoacrylate against MRSA. The purpose of this study is to determine the antimicrobial effects of octylcyanoacrylate against the MRSA that was isolated from patients with chronic suppurative otitis media. MATERIALS AND METHODS: Clinical MRSA (n=20) bacteria and methicillin-sensitive SA (MSSA) (n=20) were obtained from patients. The susceptibilities to various antibiotics were determined by disk diffusion method. RESULTS: MSSA was sensitive to octylcyanoacrylate. The antibacterial activity of octylcyanoacrylate was weak against MRSA. CONCLUSION: Our results demonstrated that octylcyanoacrylate has slight antibacterial activity against MRSA.

The effect of Interceed for reducing adhesion as a middle ear packing agent: an experimental study.

BACKGROUND AND OBJECTIVE: Interceed (oxidized regenerated cellulose) has been used to prevent postoperative abdominal adhesion. However, the efficacy and safety of using Interceed in middle ear surgery have not been thoroughly studied. MATERIALS AND METHODS: The animals were divided into two groups: the Interceed group and the Gelfoam (Gelatin sponge) group. In every group, the study was performed on five guinea pigs (ten ears). Under the aseptic condition, the middle ear mucosa was abraded using a pick through a myringotomy incision. Interceed and Gelfoam were then packed into the guinea pigs' middle ear cavities. The auditory brainstem responses (ABRs) were assessed preoperatively and at 3 weeks after the operation with the animals under general anesthesia. Histopathologic study was performed 3 weeks after the operation. RESULTS: The ABR results on postoperative week 3 showed no statistically significant difference for myringotomy and postpacking. The fibrosis, middle ear mucosa thickening and adhesion formation appeared to be less in the Interceed group compared with the Gelfoam group. Any foreign body reaction was not observed in the Interceed group. CONCLUSION: Our results show that Interceed is nonototoxic and biocompatible with the guinea pig's middle ear cavity. Therefore, these results suggest that Interceed could be used safely in the middle ear as a middle ear packing agent during otosurgery.

The effect of anti-adhesive packing agents in the middle ear of guinea pig.

BACKGROUND & OBJECTIVE: The presence of adhesions after middle ear surgery is not uncommon. Fibrosis can cause conductive hearing loss and it contributes to retraction of the tympanic membrane in the post-surgery patient. The purpose of this study was to evaluate the anti-adhesive effect of Seprafilm and MeroGel in the abraded mucosa of a guinea pig's middle ear. MATERIALS AND METHODS: Fifteen pathogen-free adult male albino guinea pigs weighing 250-300g each were used. Under an aseptic condition, the middle ear mucosa was abraded using a pick through a myringotomy incision. Seprafilm, MeroGel and Gelfoam, respectively, were then packed into guinea pigs' middle ear cavities. Auditory brainstem responses (ABRs) were assessed preoperatively and 3 weeks after operation. RESULTS: The ABR results at postoperative week 3 showed no statistically significant difference for the myringotomy and postpacking, except for the MeroGel packing. However, there was no significant threshold on the 6 weeks' postoperative ABR. The Gelfoam group demonstrated extensive fibrosis and adhesion within the bulla cavity. The Seprafilm and MeroGel groups showed no adhesion in the middle ear cleft after abrasion of the mucosa. CONCLUSION: From these results, we suggest the use of Seprafilm and MeroGel to improve the results of otosurgery.

Evaluating the ototoxicity of topical piperacillin-tazobactam.

BACKGROUND AND OBJECTIVE: With the increased use of ototopical ciprofloxacin solution, newly evolved bacterial fluoroquinolone resistance has also become more of a problem. The emergence of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) has created a new therapeutic challenge in otology. We evaluated the ototoxicity of topical fortified piperacillin-tazobactam solution by performing experiments in young male albino guinea pigs (weight, 250-300 g each). MATERIALS AND METHODS: Antimicrobial assay by direct contact test using scanning electron microscope was performed. Twenty guinea pigs (250-300 g) were treated with fortified piperacillin-tazobactam solution. In experimental group 1 (n=10), a gelfoam ball impregnated with 120 microl of fortified piperacillin-tazobactam was implanted on the round window membrane by a posterior approach. In experimental group 2 (n=10), 20 microl of fortified piperacillin-tazobactam was injected into the middle ear cavity via silicone tube with a small hole placed in the superior aspect of the bulla by drilling. The drug application through the tube was performed for 7 consecutive days. In control group (n=5), a gelfoam ball impregnated with 120 microl of gentamicin solution (80 mg/2 ml) was implanted on the round window membrane. RESULTS: The fortified piperacillin-tazobactam 20 microl treated CRPAs showed destruction of their cell membrane in antimicrobial assay by direct contact test. No significant difference in the mean auditory brainstem response (ABR) thresholds before and after drug administration was found for the experimental group. However, significant elevation of the mean ABR thresholds was found for the control group. In experimental group, scanning electron microscopy showed almost normal sterociliary arrangements and surface structure on the inner and outer hair cells. However, significant destruction of outer hair cells was identified in control group. CONCLUSION: This present study's data suggests that fortified piperacillin-tazobactam solution can be effectively used for topically treating CRPA otorrhea in those patients who suffer with chronic suppurative otitis media.

Mastoid obliteration using a hyaluronic acid gel to deliver a mesenchymal stem cells-loaded demineralized bone matrix: an experimental study.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate whether a combination of expanded human mesenchymal stem cells (hMSCs) with hyaluronic acid gel in human demineralized bone matrix (hDBM) can promote osteogenesis in a mastoid obliteration procedure, with using the guinea pig as an animal model. MATERIALS AND METHODS: Fourteen male guinea pigs were used for the experiment. Bulla obliteration using 6-diamidino-2-phenylindole (DAPI)-labeled hMSCs (2x10(6)) loaded into hDBM with hyaluronic acid hydrogel was performed in the experimental group (n=7). The control group was obliterated using hDBM only (n=7). The histologic findings and microCT images were obtained from each bulla at 3 and 7 weeks postsurgery. RESULTS: The increased soft tissue intensity caused by chondrogenic differentiation around the implanted hMSCs-loaded hDBM was identified, as compared to the hMSCs-free hDBM group. All the hMSCs-loaded hDBM at 7 weeks post-implantation displayed greater amounts of bone filling the bulla space, as compared to the hMSCs-free hDBM implanted group. In the hMSCs-free hDBM group, microCT shows incomplete new bone formation, as compared to the hyaluronic acid gel-hMSCs treated group. CONCLUSION: The successful formation of bone using allogeneic hMSCs loaded onto hDBM and hyaluronic acid hydrogel to repair critically sized bulla defects in the guinea pig model was accompanied with the absence of any local response to the foreign cells. The use of hMSCs-loaded hDBM and hyaluronic acid hydrogel is appropriate for performing clinical mastoid obliteration.

Reformulated mineral trioxide aggregate components and the assessments for use as future dental regenerative cements.

Mineral trioxide aggregate, which comprises three major inorganic components, namely, tricalcium silicate (C3S), dicalcium silicate (C2S), and tricalcium aluminate (C3A), is promising regenerative cement for dentistry. While mineral trioxide aggregate has been successfully applied in retrograde filling, the exact role of each component in the mineral trioxide aggregate system is largely unexplored. In this study, we individually synthesized the three components, namely, C3S, C2A, and C3A, and then mixed them to achieve various compositions (a total of 14 compositions including those similar to mineral trioxide aggregate). All powders were fabricated to obtain high purity. The setting reaction of all cement compositions was within 40 min, which is shorter than for commercial mineral trioxide aggregate (~150 min). Over time, the pH of the composed cements initially showed an abrupt increase and then plateaued (pH 10-12), which is a typical behavior of mineral trioxide aggregate. The compression and tensile strength of the composed cements increased (2-4 times the initial values) with time for up to 21 days in an aqueous medium, the degree to which largely depended on the composition. The cell viability test with rat mesenchymal stem cells revealed no toxicity for any composition except C3A, which contained aluminum. To confirm the in vivo biological response, cement was retro-filled into an extracted rat tooth and the complex was re-implanted. Four weeks post-operation, histological assessments revealed that C3A caused significant tissue toxicity, while good tissue compatibility was observed with the other compositions. Taken together, these results reveal that of the three major constituents of mineral trioxide aggregate, C3A generated significant toxicity in vitro and in vivo, although it accelerated setting time. This study highlights the need for careful consideration with regard to the composition of mineral trioxide aggregate, and if possible (when other properties are satisfactory), the C3A component should be avoided, which can be achieved by the mixture of individual components.

Evaluation of bioactive glass for mastoid obliteration: a guinea pig model.

BACKGROUND: Mastoid obliteration seeks to replace an open mastoid cavity with material that will become viable and free of infection and cholesteatoma. The purpose of this study was to evaluate the efficacy of bioactive glass ceramic particles for mastoid obliteration using a guinea pig animal model. MATERIALS AND METHODS: Ten male guinea pigs (weighing 250-300 g) with normal eardrums and Preyer reflexes were used. Bulla obliteration using bioactive glass was performed on the left side in all guinea pigs. The implanted bioactive glass ceramic particles were examined clinically and radiologically by computed tomography (CT) and histologically. RESULTS: Clinically, there were no signs of inflammation, infection or implant exposure in all guinea pigs. The CT scans showed hyperintense areas that represented new bone formation. Histological evidence of new bone formation was observed in the implant specimens that included: active osteoblasts, osteocytes, chondrocytes and osteoid tissue. There was a definite bond between the implant and the bone interface at the areas of new bone formation. No inflammatory or foreign body reactions, caused by the bioactive glass ceramic particle implantation, were observed in the surrounding tissue. CONCLUSION: Our results suggest that bioactive glass ceramic particles are an ideal implant material. Further studies on bioactive glass ceramic particles should include a larger animal trial to lay the groundwork for human studies.