Effect of Recombinant Human Platelet-Derived Growth Factor on Healing of Chronic Periapical Tissue Pathosis Following Apical Surgery in a Canine Model: A Histomorphometric and Microcomputed Tomography Analysis.

This canine in vivo study assessed the effect of recombinant human platelet-derived growth factor (rhPDGF) on the healing of periapical tissues following apical surgery. From a total of 96 premolar teeth, 64 teeth from six beagle dogs (2 years old) were classified as experimental and were randomly assigned to four experimental groups (16 teeth per group). After having the pulp extirpated, leaving teeth open to the oral cavity for 1 week, and sealing with an immediate restorative material for 8 weeks, nonsurgical endodontic treatment was performed. A split-mouth design was used, and intra-animal randomization of treatment sides was applied to the groups as follows: apical curettage + 1.5-mm root-end resection (Group 1); apicoectomy + mineral trioxide aggregate (MTA) root-end filling (Group 2); apicoectomy + MTA root-end filling + rhPDGF (Group 3); and apical curettage + rhPDGF (Group 4). The animals were sacrificed 24 months after apical surgery, and histologic and µCT analyses were performed for bone volume loss (BVL). Group 1 showed partial resolution of the periapical lesions without signs of tissue regeneration (BVL: 49.09 ± 10.97 mm3). Group 2 had minimal bone regeneration and showed cementum reformation in 9 teeth, with no direct attachment to the MTA (BVL: 35.34 ± 10.97 mm3). Group 3 showed regeneration of all damaged apical tissues without direct contact between the cementum and MTA (BLV: 4.51 ± 1.55 mm3). Group 4 showed regeneration of PDL, bone, and cementum and attachment of functional cementum fibers (BVL: 2.82 ± 2.3 mm3). The difference in BVL was statistically significant only for Groups 1 and 2 (P < .05). rhPDGF may help regenerate apical tissue structures following apical surgery.

Buccal Bone Remodeling Around Immediate Implants in STZ-Induced Diabetic Dogs: A Histologic and Microcomputed Tomographic Analysis.

Buccal bone remodeling around immediate implants placed in animals with streptozotocin (STZ)-induced diabetes has not been investigated. The present histologic and microcomputed tomography (µCT) in vivo experiment assessed the buccal bone remodeling around immediate implants, extraction socket healing, and bone-to-implant contact (BIC) in dogs with and without STZ-induced diabetes. Three male beagle dogs with STZ-induced diabetes and three healthy dogs (controls) were included. Fasting blood glucose levels were measured using a glucometer. Under general anesthesia, all animals underwent atraumatic tooth extraction of bilateral maxillary and mandibular second premolar teeth using Piezosurgery and immediate implant placement in the distal root socket. Primary closure was achieved for all implants and adjacent socket sites. After 11 months, all animals were sacrificed, and buccal bone thickness (BBT), marginal bone loss (MBL), BIC, and mesial extraction socket bone volume were assessed in control and diabetic animals using histologic and µCT examination. High-resolution µCT analyses were performed to identify the percentage of osteocytes and blood vessels in bone specimens harvested from a mesial extraction socket in each group. BBT and BIC were significantly higher in control dogs (P < .05), and diabetic dogs demonstrated significantly more MBL than control dogs (P < .05). Compared to healthy subjects, the sockets of induced diabetic dogs lost over 50% of bone horizontally and vertically. Control group had more significant osteocytes (38.85%) and blood vessels (37.87%), whereas the same values for STZ-induced diabetic dogs were 27.92% and 27.76%, respectively. Buccal bone loss and MBL were significantly higher around immediate implants placed in dogs with STZ-induced diabetes and were associated with multiple implant buccal thread exposure. A large percentage of socket space in diabetic dogs healed with nonosseous structure following tooth extraction.

Evaluation of Recombinant Human Platelet-Derived Growth Factor or Enamel Matrix Derivative Plus Calcium Hydroxide for Pulp Capping: A Randomized Controlled Human Clinical Trial.

This in vivo study assessed calcium hydroxide's effect as a matrix carrier for recombinant human platelet-derived growth factor (rhPDGF) and enamel matrix protein (EMD) on pulp tissue healing following pulp capping. Intact premolar sites (n = 18) were included. Coronal access and pulpotomy were performed, and each tooth was exposed to the oral cavity for 1 hour before pulp capping was performed. Teeth were randomly assigned to one of the following pulp-capping groups (n = 6 each): Group 1 (CaOH2 only); Group 2 (CaOH2+EMD); and Group 3 (CaOH2+rhPDGF). Coronal access cavities were then sealed. Immediate preoperative, postoperative, and 4-month follow-up radiographs were taken. At 4 months, teeth were extracted atraumatically and histomorphometric and micro-CT analyses were performed. Group 1 showed formation of thin, uneven, highly porous dentin-like structure with tunnel defects (average thickness: 0.18 to 0.19 mm). Lack of continuity of the newly formed tissue and interrupted communication tunnels were seen between the pulpal space and pulp-capping material. Group 2 showed formation of highly dense, nonporous, even-thickness dentin-like structure obliterating multiple areas of the pulp space (average thickness: 0.9 to 0.94 mm). Abundant odontoblast lacunae were present in the pulp and structure. Group 3 showed formation of an inconsistent, uneven dentin-like structure that appeared highly porous (average thickness: 1.04 to 1.05 mm). It was without tunneling, and abundant odontoblastic lacunae were present. No statistically significant differences were found between Groups 2 and 3, but both were richer in newly formed dentin-like structure with more thickness than Group 1 (P < .05). Addition of EMD to CaOH2 can result in multiple root canal calcifications, mostly in the coronal and apical thirds of the canals. The calcified tissue does not appear to resemble secondary dentin in form, shape, amount, or density. Addition of rhPDGF to CaOH2 may not cause root canal calcifications. The newly formed structure differs from secondary dentin in degree of mineralization, porosity, and density.

Regeneration of Secondary Dentin Using Recombinant Human Platelet-Derived Growth Factor and MTA for Pulp Capping: A Randomized Controlled Human Clinical Trial.

This in vivo study assessed the effect of mineral trioxide aggregate (MTA) as a matrix carrier for recombinant human platelet-derived growth factor (rhPDGF) and enamel matrix protein (EMP) on pulp tissue healing following pulp capping. Eighteen intact human premolars scheduled for extraction were included. Coronal access and pulpotomy were performed, and each tooth was left exposed to the oral cavity for 1 hour before pulp capping was performed. Teeth were randomly assigned to one of the following pulp-capping groups (n = 6 each): Group 1 (MTA only); Group 2 (MTA+EMP); or Group 3 (MTA+rhPDGF). Coronal access cavities were then sealed. Immediate preoperative, postoperative, and 4-month follow-up radiographs were taken. At 4 months, the teeth were extracted atraumatically, and histomorphometric and micro-computed tomography (µCT) analyses were performed. Group 1 showed a thin, uneven, irregular dentin-like structure. Its average thickness was 0.3 ± 0.084 mm measured histologically and 0.29 ± 0.091 mm measured by µCT. Group 2 showed of a nonporous, even-thickness dentin-like structure with multiple root-canal obliterations. Highly dense, atubular dentin-like structures associated with presence of odontoblastic lacunae were seen. The structure's average thickness was 0.87 ± 0.09 mm (histologically) and 0.81 ± 0.17 mm (µCT). Group 3 showed a thick and complete 3D continuous seal of newly formed dentin-like structure covering the pulpal space. It resembled secondary dentin in form, porosity, and tubular structural organization, and its average thickness was 0.94 ± 0.02 mm (histologically) and 0.91 ± 0.09 mm (µCT). Groups 2 and 3 showed higher amounts of newly formed dentin-like structure, that was also thicker, than Group 1 (P < .05). No statistically significant differences in structure thickness were found between Groups 2 and 3. The nature of the structure can differ if rhPDGF or EMP is added to MTA for pulp-capping purposes. Combination of rhPDGF and MTA resulted in a newly formed structure resembling secondary dentin, whereas a combination of EMP and MTA produced a nonporous, highly dense dentinal-like structure associated with significant root-canal obliterations.

Efficacy of the enamel matrix derivative to induce cementogenesis in vital and endodontically treated teeth with osseous dehiscence defects.

This experiment assessed the efficacy of the enamel matrix derivative (EMD) to regenerate cementum in vital and endodontically treated teeth with osseous dehiscence defects. Five adult female beagle dogs were used. Thirty maxillary teeth (bilateral maxillary canines and second and fourth premolars) were randomly divided into two experimental groups (groups A and B, containing 12 teeth each) and one control group (group C). Endodontic treatment was only performed on teeth in group A compared with teeth in groups B and C. Buccal osseous dehiscence defects were surgically created in teeth from all groups. Teeth in the experimental group were treated with the EMD, whereas the controls were not. After 5 months, the animals were sacrificed and block sections of the teeth in experimental and control groups were processed for histological analysis. Newly regenerated cementum was observed in all teeth in groups A and B. No cementum regeneration was observed in group C. There was a significant difference in cementum generation between the experimental and control groups (P < 0.001). EMD therapy induces cementogenesis in vital and endodontically treated teeth with osseous dehiscence defects.

Connective tissue-cementum regeneration: a new histologic regeneration following the use of enamel matrix derivative in dehiscence-type defects. A dog model.

The goal of this investigation was to evaluate histologically and histometrically the healing process in dehiscence-type defects treated by enamel matrix derivative (EMD). Five adult female beagle dogs were used. Buccal osseous dehiscences were surgically created on the maxillary canines and the second and fourth premolars. Thirty defect sites were randomly assigned to treatment and control groups (15 defect sites for each group). The treatment group received EMD application, while the control groups received no EMD. After 4 months of healing, the dogs were sacrificed and tissue blocks were prepared. Histometric parameters were employed to evaluate the type of periodontal tissues that formed in the defects. All created dehiscence defects in the test sites treated by EMD had formed functional connective tissue fibers inserted into regenerated cellular cementum. The mean amount of apicocoronal regenerated cementum was 3.74 +/- 0.43 mm in EMD- treated sites, whereas the control sites had not formed cementum in the created dehiscence defects (P < .000). Statistically significant differences were found between treatment and control sites. Within the limits of this study, it can be concluded that EMD alone effectively promoted new cementum and functionally oriented connective tissue formation.

MTA preparations from different origins may vary in their antimicrobial activity.

OBJECTIVE: The antimicrobial effects of 4 mineral trioxide aggregate (MTA) preparations, 2 white-colored (WMTA-1, WMTA-2) and 2 gray-colored (GMTA-1, GMTA-2), against C. albicans and E. faecalis were assessed in vitro. METHODOLOGY: Minimal inhibitory concentration (MIC) for each preparation was determined using the tube dilution test and Sabouraud agar media for C. albicans and brain heart infusion media for E. faecalis. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 24-, 48-, and 72-hour time periods. Samples of 0.1 mL from each of the experimental and control tubes were subcultured on agar or brain heart infusion plates to confirm visible signs of bacterial or fungal growth. RESULTS: MIC of MTA against the 2 microorganisms tested varied among the 4 preparations tested. WMTA-1 and WMTA-2 inhibited C. albicans growth at concentrations of 3.125 mg/10 mL and 25 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). WMTA-1 and WMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 50 mg/10 mL, respectively, and statistically significant differences were found between WMTA-1 and WMTA-2 (P < .001). GMTA-1 and GMTA-2 inhibited E. faecalis growth at concentrations of 12.5 mg/10 mL and 3.125 mg/10 mL, respectively, and statistically significant differences were found between GMTA-1 and GMTA-2 (P < .001). Both GMTA-1 and GMTA-2 inhibited C. albicans growth at a concentration of 3.125 mg/10 mL and no statistical differences were found between the preparations. Subculture of the broth tubes in agar or brain heart infusion plates confirmed the turbidity test result. CONCLUSION: The origin of MTA as well as the type of preparation may affect its antimicrobial characteristics. Clinicians should be aware of variations that may exist among such MTA preparations.

Successful treatment of a radicular groove by intentional replantation and Emdogain therapy: four years follow-up.

Radicular groove is an anatomical malformation that often causes severe periodontal defects. Treatments of such an anomaly present a clinical challenge to the operator. Presented is a case of successful treatment of radicular groove associated with a maxillary lateral incisor of a 15-year-old girl. A combination of endodontics, intentional replantation, and Emdogain therapy was used. At 4-year follow-up, the patient was comfortable and complete resolution of the periapical pathology was evident.

Antibacterial effect of two mineral trioxide aggregate (MTA) preparations against Enterococcus faecalis and Streptococcus sanguis in vitro.

The antibacterial effects of gray-colored MTA (GMTA) and white-colored MTA (WMTA) against Enterococcus faecalis and Streptococcus sanguis were assessed in vitro using the tube dilution test. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 0, 1, 24, 48, and 72-hour time periods. A direct correlation was found between GMTA and WMTA concentrations and their antibacterial effect. Tubes containing GMTA in concentrations of 50, 25, and 12.5 mg/ml did not show E. faecalis growth at any of the time periods tested whereas tubes containing WMTA showed E. faecalis growth at all concentrations and time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations of 50, 25 and 12.5 mg/ml and tubes containing similar concentrations of WMTA (p < 0.001). Tubes containing GMTA in concentrations of 50, 25, 12.5, 6.25, and 3.12 mg/ml and tubes containing WMTA in concentrations of 50, 25, and 12.5 mg/ml did not show S. sanguis growth at any of the time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations 6.25 and 3.12 mg/ml and tubes containing similar concentrations of WMTA (p < 0.001). It appears that the susceptibility of E. faecalis and S. sanguis to MTA differed and that GMTA requires lower concentrations than WMTA to exert the same antibacterial effect against each of the microorganisms tested.

Comparison of antifungal activity of white-colored and gray-colored mineral trioxide aggregate (MTA) at similar concentrations against Candida albicans.

The killing effect of similar concentrations of white-colored MTA and gray-colored MTA against Candida albicans was assessed in vitro using the tube dilution test. A direct correlation was found between MTA concentration and its killing effect on C. albicans. At time period zero, both white-colored and gray-colored MTA samples showed Candida growth regardless of the concentration. Tubes containing gray-colored MTA in concentrations of 50, 25, 12.5, 6.25, and 3.125 mg/ml and tubes containing white-colored MTA in concentrations of 50 and 25 mg/ml did not show C. albicans growth at any of the other time periods tested. Tubes containing white-colored MTA in concentrations of 12.5 mg/ml or less showed Candida growth at all the time periods tested. Statistically, a significant difference was found between tubes containing either 50 mg/ml or 25 mg/ml and tubes containing lower concentrations of white-colored MTA (p < 0.001). A significant difference was also found between tubes containing gray-colored MTA in concentrations of 12.5 mg/ml or less and tubes containing similar concentrations of white-colored MTA (p < 0.001). It appears that both gray-colored and white-colored MTA in concentrations of 50 mg/ml and 25 mg/ml are effective in killing C. albicans for periods of up to 1 wk. Lower concentrations of gray-colored MTA may still be effective while lower concentrations of white-colored MTA may not.

Effect of white-colored mineral trioxide aggregate in different concentrations on Candida albicans in vitro.

The antifungal action of different concentrations of white-colored mineral trioxide aggregate (MTA) against Candida albicans was assessed in vitro. Fresh mix of MTA was prepared at concentrations varying from 0.78 mg/ml to 50 mg/ml by dilution with 10 ml molten agar at 45 degrees C. The MTA-agar compound was thoroughly mixed and the uniform mix was then poured into sterile Petri dishes and allowed to set. A total of 348 agar plates were prepared and divided into experimental groups of 11 plates each and control groups of 5 plates each. Plates of agar without MTA served as positive control and plates without C. albicans served as negative control. Fresh inoculate of C. albicans was prepared by growing an overnight culture from a stock culture. Aliquots of C. albicans were then taken from the stock culture and plated on the agar compound of the experimental and positive control groups. All plates were incubated at 37 degrees C for 1, 24, 48, and 72-h periods. At each time period, the presence of C. albicans colonies was assessed and recorded. A direct correlation was found between MTA concentration and its inhibition effect on C. albicans growth. Plates containing MTA in concentration of 50 mg/ml showed significantly better killing action against C. albicans in all of the time periods tested (p < 0.001). Plates containing MTA in concentration of 25 mg/ml showed antifungal activity only at 1 and 24-h time periods. Plates containing lower concentrations of MTA did not show any antifungal activity. It appears that under the conditions of this study, white-colored MTA in concentration of 50 mg/ml is effective in killing C. albicans for periods of up to 3 days. Lower MTA concentrations may not be effective.

Human saliva penetration of root canals obturated with two types of mineral trioxide aggregate cements.

The sealing ability of orthograde mineral trioxide aggregate (MTA) root canal filling against human saliva was assessed in vitro. Leakage of gray-colored MTA, white-colored MTA and vertically condensed gutta-percha and sealer were compared. Forty-three extracted single-rooted human teeth were serially instrumented to a file size 40/0.06 at the apex and obturated with either gray-colored MTA (group A), white-colored MTA (group B), or gutta-percha and Kerr Canal Sealer EWT (group C). The teeth were then mounted in a model to test for saliva leakage. After 42 days, one root in group A (9.1%), four roots in group B (36.4%), and nine roots in group C (81.8%) showed saliva leakage. Statistically, a significant difference was found between group A and group C (p < 0.001). No statistical difference was found between group A and group B. Out of the root samples that leaked, the one sample in group A leaked after 36 days. Of the four samples in group B, one sample leaked after 32 days, one sample after 33 days, and two samples after 39 days. All nine samples in group C had leaked after 19 days. It appears that under the conditions of this study both MTA preparations may be more resistant to human saliva leakage than vertically condensed gutta-percha and sealer.

Successful treatment of a radicular groove by intentional replantation and Emdogain therapy.

Radicular groove is an anatomical malformation often predisposing to a severe periodontal defect. Treatment of such an anomaly presents a clinical challenge to the operator. Presented is a case of successful treatment of a radicular groove associated with a maxillary lateral incisor in a 15-year-old girl. A combination of endodontic, intentional replantation and Emdogain therapy was used. At 1-year follow-up, the patient was comfortable and active healing was evident.