Tooth Extraction Socket Research Articles

The amount of macrophages and activated plasma cells on wound healing process affected by spirulina

Background: Spirulina which grows abundantly in tropical seas have been investigated to enhance immune system. The administration of spirulina in tooth extraction sockets was expected to optimise the function of immunocompetent cells. Therefore, wound healing process would be improved. Purpose: The aim of this study was to prove that administration of spirulina could influence immune system in tooth extraction sockets. Method: There were 28 Cavia cobayas used in this study and were put in group of four. Mandibular left incisive were extracted from each of them. The basis made from mixture of polyethylene glycol (PEG) 400 and PEG 4000 was administrated into each socket in control group (TG0). In addition, spirulina 12% was administrated into group TG1, spirulina 24% was administrated into group TG2, and spirulina 48% was administrated into group TG3. All of the Cavia cobaya were decapitated and the jaws were removed in day 5 after tooth extraction. The jaws were decalcified in EDTA solution, formed into paraffin block, processed for hematoxylin and eosin (H & E) and immunohistochemistry staining afterwards. Datas were analysed statistically using Anova method. Result: There was an augmentation in the number of macrophages and activated plasma cells after spirulina application. The administration of higher concentrations of Spirulina leads to greater amount of macrophages and activated plasma cells in each groups. Conclusion: In conclusion, spirulina is able to increase the amount of macrophages and activated plasma cells which play important role in healing process.

Hydroxyapatite combined with hyaluronic acid metronidazole gel increased the quantity of osteoblasts in the alveolar bone wistar rat

Background: Bone graft material have been used extensively in bone healing and periodontal treatment. Alloplast such as hydroxyapatite are frequently used to repair and reconstruct bone defects. By merely applying hydroxyapatite for the treatment of bone is not fully effective yet to produce new bone regeneration. Locally applied high molecular hyaluronic acid (HA) has been shown to stimulate differentiation and migration of mesenchymal cells. Recent studies on regenerative surgical procedures indicate that reduction of bacterial burden at the wound site may improve the clinical outcome of regenerative therapy. Metronidazole has the greatest bacteriostatic effect. A clinical application of HA metronidazole gels during the surgical therapy may reduce the bacterial contamination of surgical wound site. Purpose: The purpose of this study was to examine the effect of combination hydroxyapatite and HA metronidazole gel 1% on osteoblast cell number after wound healing process in the wistar rats incisor tooth extraction socket. Method: Twenty seven wistar rats were divided randomly into 3 groups. The first group consisted of wistar rats given hydroxyapatite were subjected to the mandibular incisor extraction socket. The second group were given hydroxyapatite combined with HA metronidazole gel 1%. The control group were filled with blood. Wistar rats were euthanized on day 14 and then preparation for histological examination was stained using hematoxylin-eosin and then the numbers of the osteoblasts were calculated. Result: The differences in each group were tested by one way Anova test ( α =0.05). The numbers of osteoblasts in each group had a significant difference (p<0.05): the highest numbers of osteoblasts were found in the group that was given hydroxyapatite combined with HA metronidazole, followed by the lower numbers of osteoblasts in the hydroxyapa ite group and the lowest numbers of osteoblasts were found in the control group. Conclusion: Adjunctive application of HA metronidazole to hydroxyapatite after tooth extraction increase the number of osteoblast in the treatment of bone defects on a wistar rat model.

High-Frequency, Low-Intensity Pulsed Ultrasound Enhances Alveolar Bone Healing of Extraction Sockets in Rats: A Pilot Study

Most studies of the beneficial effects of low-intensity pulsed ultrasound (LIPUS) on bone healing have used frequencies between 1.0 and 1.5 MHz. However, after consideration of ultrasound wave characteristics and depth of target tissue, higher-frequency LIPUS may have been more effective on superficially positioned alveolar bone. We investigated this hypothesis by applying LIPUS (frequency, 3.0 MHz; intensity, 30 mW/cm2) on shaved right cheeks over alveolar bones of tooth extraction sockets in rats for 10 min/d for 2 wk after tooth extraction; the control group (left cheek of the same rats) did not receive LIPUS treatment. Compared with the control group, the LIPUS group manifested more new bone growth inside the sockets on histomorphometric analysis (maximal difference = 2.5-fold on the seventh day after extraction) and higher expressions of osteogenesis-related mRNAs and proteins than the control group did. These findings indicate that 3.0-MHz LIPUS could enhance alveolar bone formation and calcification in rats.

Immediate Implant Vs Delayed Implant Placement- A Review of 100 Cases

Implant placement has been a renowned treatment for replacing and restoring missing teeth in recent past. Delayed implant placement signifies the placement of the implant in the healed extracted socket after a minimum of 5-6 months. In this recent world where everything is happening fast and time is something which everyone tries to utilise properly, the patients also want the treatment results immediately instead of waiting for long time. In 1989, it was Lazzara who introduced the technique of immediate implant placement by placing implants at the time of tooth extraction in the extracted tooth socket. In recent years several studies and advancements have been made regarding immediate implant placements. The greatest adavantages of immediate implant placements are they need minimum bone drilling, result in reduced crestal bone loss surrounding the implant and last but not least the patients need not wait for 4-6 months for the implants to be placed. In this article a small sample of 100 patients were treated with immediate implant placement and their results, advantages and disadvantages compared to delayed implant placement were recorded.

Effect of Diode Laser on Healing of Tooth Extraction Socket: An Experimental Study in Rabbits.

To evaluate the effect of low-level laser therapy on healing of extracted tooth socket of healthy rabbits. The sample of this study was 20 male rabbits of 2-2.5kg weight with age range of 8-12months. Right and left lower first premolar teeth were extracted. The extraction sockets of lower right first premolar were irradiated with 0.9W gallium-aluminum-arsenide (GaAlAs) diode laser for 5min, immediately after extraction and then every 72h for the next 12days. The extraction socket of left side were not exposed to laser and served as a control. The animals were sacrificed after 7, 14, 30 and 45days and the experimental and control sockets were removed from the harvested mandibles and prepared for haematoxylin and eosin staining and Masson's stain. The prepared slides were examined under light microscope for histological and histomorphometric examination. The histological examination showed that diode laser-treated sockets demonstrated early formed new bone with faster maturation of primary bone to secondary bone as compared to non-treated control sockets. Histomorphometric analysis revealed a statistically significant increase in the density and volume of trabecular bone in laser-treated sockets than control sockets. Diode laser application to tooth extraction socket has a positive effect on bone formation.

Novel bone substitute material in alveolar bone healing following tooth extraction: an experimental study in sheep.

Electrospun cotton wool-like nanocomposite (ECWN) is a novel synthetic bone substitute that incorporates amorphous calcium phosphate nanoparticles into a biodegradable synthetic copolymer poly(lactide-co-glycolide). The objectives of this study were to develop a tooth extraction socket model in sheep for bone graft research and to compare ECWN and bovine-derived xenograft (BX) in this model. Sixteen cross-bred female sheep were used. Bilateral mandibular premolars were extracted atraumatically. Second and third premolar sockets were filled (Latin-square allocation) with BX, ECWN or left unfilled. Resorbable collagen membranes were placed over BX and selected ECWN grafted sockets. Eight sheep per time period were sacrificed after 8 and 16weeks. Resin-embedded undemineralised sections were analysed for descriptive histology and histomorphometric analyses. At 8weeks, there were with no distinct differences in healing among the different sites. At 16weeks, osseous healing followed a fine trabecular pattern in ECWN sites. Non-grafted sites showed thick trabeculae separated by large areas of fibrovascular connective tissue. In BX grafted sites, xenograft particles were surrounded by newly formed bone or fibrovascular connective tissue. There were no statistically significant differences in bone formation across the four groups. However, ECWN sites had significantly less residual graft material than BX sites at 16weeks (P=0.048). This first description of a tooth extraction socket model in sheep supports the utility of this model for bone graft research. The results of this study suggested that the novel material ECWN did not impede bone ingrowth into sockets and showed evidence of material resorption.

Topical combined application of dexamethasone, vitamin C, and β-sodium glycerophosphate for healing the extraction socket in rabbits

An osteogenic inducer (OI) consisting of dexamethasone, vitamin C, and β-sodium glycerophosphate has the capacity to induce bone formation in vitro. The aim of this study was to assess the efficacy of the application of this OI on extraction socket healing. The bilateral first mandibular premolars were extracted from 75 New Zealand rabbits. Gelatin sponges carrying OI were implanted into the sockets. Sockets undergoing implantation of gelatin sponges alone were also evaluated, as well as non-implantation sockets. Specimens from each group were evaluated radiographically, histologically, and histomorphometrically using haematoxylin–eosin staining. Results showed earlier new bone formation and higher bone quality and quantity in the OI group compared to the other groups, and the differences were significant at 2, 4, 8, and 12 weeks postoperative. The OI significantly reduced the absorption of alveolar bone in terms of height; however, changes in the width were not significantly different between the three groups (P>0.05). The OI was shown to have a positive effect on healing of the tooth extraction sockets, was inexpensive, and was convenient to use during the operational procedure; therefore this could represent a promising implant material for human clinical application.

The decrease of fibroblasts and fibroblast growth factor-2 expressions as a result of X-ray irradiation on the tooth extraction socket in Rattus novergicus

Background: Wound healing involves cellular, molecular, physiological, and biochemical processes as responses to tissue damage. For instance, when a failure during tooth extraction occurs, radiographic examination, X-rays, is required. X-rays as an enforcer diagnosis can damage DNA chain, resulting in cell death and inhibition of wound healing process. Purpose: This research aims to analyze fibroblasts cell number and fibroblast growth factor-2 (FGF-2) expressions during wound healing process after tooth extraction as a result of X-ray irradiation. Methods: There were three research groups, each consisting of ten rats. Incisor tooth extraction was performed on the left lower jaw, and then X-ray examination was conducted at certain irradiation doses, namely 0 mSv, 0.08 mSv, and 0.16 mSv. Those animals were sacrificed on day 3, and on day 7 after the extraction, histopathology and immunohistochemistry examinations were conducted to determine fibroblast cell number and FGF-2 expressions. Data obtained were then analyzed by oneway ANOVA and Tukey HSD tests. Results: The number of fibroblasts decreased significantly in the group with the irradiation dose of 0.16 mSv applied on day 7 after the extraction (p <0.05). Similarly, the number of FGF-2 expressions decreased significantly in the group with the irradiation dose of 0.16 mSv applied on days 3 and 7 after the extraction (p <0.05). Conclusion: X-ray irradiation at a dose of 0.16 mSv can inhibit the healing process of tooth extraction wound due to the decreasing of fibroblasts cell number and FGF-2 expressions.

I–3 Effect of Low-Intensity Pulsed Ultrasound (LIPUS) in Rats With Healing Socket

Objective: Low-intensity pulsed ultrasound (LIPUS) has been widely used as a potent therapeutic tool to accelerate fracture healing. In the oral environment, however, the effect of LIPUS on wound fracture healing after implant placement and dental operation has not been well explored. This study aimed to characterize the local as well as humoral effect of LIPUS treatment of tooth extraction sockets in aged rats. Methods: Right maxillary first molars were removed from retired female breeder rats in control and LIPUS groups. LIPUS was applied extrabuccally to the socket for 20 minutes every 24 hours for 2 weeks starting 1 day after the extraction. The blood flow rate was measured by laser-Doppler flowmetry at the extraction socket, the dorsum of the tail base, and the dorsum of foot prior to and 2 hours after the 20-minute LIPUS treatment on 3, 7, 11 and 14 days after the tooth extraction. Results and Discussion: On and after post-extraction day 7, the baseline flow rate in the socket of the LIPUS group rats was significantly higher than that of the control group. Increased peripheral blood vessels are confirmed with histochemical staining of the undecalcified sections prepared from the experimental and control sockets. The flow rate in the socket of the LIPUS group rats transiently dropped after the exposure and returned to the basal level in about 2 hours. LIPUS exposure also affected the blood flow rate transiently but positively at remote sites such as foot. Angiogenic effect, which may involve systemic propagation of reactive molecule(s), was suggested.

Investigation of a Novel PLGA/CaP Scaffold in the Healing of Tooth Extraction Sockets to Alveolar Bone Preservation in Humans.

It is expected that 40% to 60% of initial alveolar bone volume will be lost up to 6 months after tooth extraction. OsteoScaf(TM) (TRT, Toronto, ON, Canada) (poly (DL-lactide-co-glycololide/calcium phosphate [PLGA/CaP] scaffold) is a novel bone substitute material and represents a promising alternative for maintaining alveolar bone integrity in this clinical scenario. Here it was hypothesized that OsteoScaf would reduce alveolar bone lost after tooth extraction in patient, acting as a clot-retention device. A total of 10 patients (32 sockets) were included in the study, of which 16 sockets were grafted with OsteoScaf and 16 were used as control (coagulum alone). Cone beam computed tomography (CBCT) was performed both immediately following extraction and also at 120 days postoperatively, at which time biopsy samples were also harvested for histological analyses. Quantitative analysis of CBCT showed less bone resorption in the OsteoScaf groups, being 10.5% to 14.4% less bone lost in the center of the socket, 15.4% in the buccal region, and 12.6% in the palatal. Qualitative histological analysis showed new bone tissue in direct apposition to the scaffold - demonstrating its osteoconductive nature. OsteoScaf diminished the expected bone lost during the postextraction remodeling of the alveolar bone ridge at 120 days postextraction.

Evaluation of the zone of keratinized tissue using exposed acellular dermal matrix over tooth extraction sites: a randomized controlled clinical trial.

The presence of an adequate zone of keratinized tissue has been associated with implant health. This study evaluated the zone of keratinized tissue using exposed acellular dermal matrix (ADM) over extraction sites. Fifteen sites received ADM, and fifteen control sites received no biomaterial. All sites were sutured with no attempt to achieve primary closure. Initial measurements of buccal and lingual keratinized tissue were taken from the mucogingival line (MGL) to the most coronal gingival margins. Final measurements were taken from the buccal MGL to the lingual MGL 90 days after surgery. Gingival biopsies were taken before implant placement. Test and control groups exhibited a mean value of 4.40 ± 1.45 mm and 1.40 ± 1.40 mm, respectively. The newly formed tissue revealed similar histological aspect of normal keratinized tissue. Exposed ADM used over tooth extraction sockets can predictably be used to increase the zone of keratinized tissue.

Survival of Implants in Immediate Extraction Sockets of Anterior Teeth: Early Clinical Results.

The aims and objectives of this study were placement of implants in freshly extracted sockets of anterior teeth and to evaluate the implant stability, peri-implant radiolucency and gingival inflammation around implant over a short period of 30 months. A total of 12 patients (8 male and 4 female), ranging in the age from 20 to 50 years, from March 2007 to June 2007, were evaluated for immediate implant placement into 22 fresh extraction sockets. Only maxillary and mandibular anterior teeth/roots (central incisors, lateral incisors and canines) were considered for replacement with implants. One piece implant with integrated abutment and integrated surface, non-submerged, threaded and tapered at apical 5 mm, sand-blasted and acid etched surfaced implants (HI-TEC TRX-OP Implants of Life Care Company) were used. The mobility was not present in any of the implants at all the follow up visits. There were 2 implants at 6 month, 1 implant at 12 month, 1 implant at 18 month visits, showing peri-implant radiolucency at some sites at bone to implant contact site. Severe gingival inflammation was not observed in any of the implant site. At every follow-up visit, every implant met the criteria of success and none was found to be failed over a 30 months duration i.e. 100% success rate was achieved by implants in immediate extraction socket. The success rate of implant survival in this study was found 100%. These implants have fulfilled all the criteria of implant success and based on the defined criteria, the success rate of implants placed in immediate extraction sockets of anterior teeth compared favorably with the conventional implants. The early results of the present study showed that high survival rates with the implants in immediate extraction sockets can be achieved.

Histological evaluation of local application of collagen I and /or vascular endothelial growth factor(An experimental study in rats)

Background: The study was designed to evaluate the effect of local application of exogenous VEGF/collagen I separately and as a combination in socket healing. Sixty male Albino Wistar rats were subjected for a surgical tooth extraction of upper 1st molar of both sides (right side was considered as experimental site, while left be the control one, treated with 1µL of normal saline). The rats were scarified at 3, 7, 14, 28 days post extraction. Socket healing was histologically examined with immunohistochemistochemical localization of ALP&FGF2. Materials and Method: Sixty male Albino Wistar rats were subjected for a surgical tooth extraction of upper 1stmolar of both sides (right side was considered as experimental site, while left be the control one). The animals were divided into following groups according to the applicable of biomaterials. A. Control group the tooth socket treated with 1μL of normal saline B. Experimental group includes • Group I contains (20) rats, the tooth socket treated with 1μL of VEGF • Group II contains (20) rats the tooth socket treated with 1μL of collagen type I • Group III contains (20) rats, the tooth socket treated with 1μL of a combination of VEGF and collagen I. Results: At 28 days all groups show re-epithelization but in different thickness, and with newly bone apposition and with different maturity. For positive cells expressed ALP, VEGF group records a high mean values at 3, 14, 28 days periods and with high differences in comparison to other groups while control group reports a high mean value at 7 days . For positive cells expressed FGF2. Control group illustrates a high record for the mean of positive cells expressed FGF2 at 3,7days periods and with high differences in comparison to other groups, while combination group reports a high mean value at 14 days . Conclusion: Results, high lighted on the effect of local application of VEGF in extracted tooth socket that facilitate epithelization, while combination of (collagen and VEGF) shows a high mineralization zone.

Medical management of a case of central giant cell granuloma masquerading as a periapical pathosis

Lesions of non-endodontic origin may mimic periapical pathosis. Errors in one or more of the clinical reasoning steps of diagnosis of such lesions may ultimately lead to misdiagnosis and ensuing complications. Central giant cell granuloma (CGCG) is one such lesion of non-endodontic origin which can present as periapical pathosis. Here, we present a case of CGCG in a 33-year-old female patient who visited our department with a complaint of growth from the extraction sockets of upper front teeth, which were extracted 1 month back after a misdiagnosis as periapical pathosis. Suspecting a non-endodontic lesion, radiographic examination and incisional biopsy were performed and a final diagnosis of CGCG was made. Biweekly intra-lesional steroids were given for 6 weeks and patient was followed up for 6 months.

Clinical and Radiographical Assessment of Topical Application of Collagen Fibrils on Tooth socket Healing

Aims: To evaluate the effect of collagen fibers that placed immediately in alveolar bone socket after tooth extraction on homeostasis, quality and quantity of bone formation and their complications.Materials and Methods: The study group consists of 10 patients who attend to Oral and Maxillofacial Department in Dentistry College of Mosul University. The patients complained from chronic periapical lesions in badly carious two teeth in the same jaw (upper or lower jaw) that indicated for teeth extraction. Every patient underwent teeth extraction after receive local anesthesia with vasoconstriction, immediately after teeth extraction we put highly concentrated collagen material PARASORB® Dental Cones: 1 collagen cone contains 22.4 mg native equine collagen fibrils (RESORBA Wundversorgung GmbH & Co. KG, Germany) in one tooth socket (study site) and leave the other tooth socket to fill with blood clot (control group),Follow up the patients clinically and radiographically were done immediately after placement the material followed by different interval depending on the using test until six weeks. Results: The clinical assessment showed there is high significant difference (p-value ≤ 0.01) in the haemostatic condition between the study and control sites while there is no significant difference (p-value >0.05) in infection involvement of both study and control sites. The radiographical assessment of bone formation showed significant difference in bone density between study sites and control sites after two weeks (p-value ≤0.05), and high significant difference at fourth and sixth weeks (p-value ≤0.001). Conclusions: The collagen fibril play important role in control of hemorrhage following tooth extraction, prevent infection at the surgical site, promote granulation tissue formation and wound healing, reduce alveolar ridge resorption after tooth extraction (socket preservation) and enhance bone formation.

Effects of caffeic acid phenethyl ester on palatal mucosal defects and tooth extraction sockets.

AimThe purpose of this study was to evaluate the effects of caffeic acid phenethyl ester (CAPE) on palatal mucosal defects and tooth extraction sockets in an experimental model.Materials and methodsForty-two male Sprague-Dawley rats with a mean age of 7 weeks and weighing 280–490 g were used in this study. The rats were randomly divided into two groups: group A (the control group, n=21) and group B (the experimental group, n=21). Under anesthesia with ketamine (8 mg/100 g, intraperitoneally), palatal mucosal defects were created and tooth extraction was performed in the rats in groups A and B. Group A received no treatment, whereas group B received CAPE. CAPE was injected daily (10 μmol/kg, intraperitoneally). The rats were killed on days 7, 14, and 30 after the procedures. Palatal mucosa healing and changes in bone tissue and fibrous tissue were evaluated histopathologically.ResultPairwise comparisons showed no statistically significant difference between days 7 and 14 in either group (P>0.05). At day 30, bone healing was significantly better in group B (CAPE) than in group A (control) (P<0.05). Fibrinogen levels at day 30 were significantly higher in group A (control) than in group B (CAPE) (P<0.05). Pairwise comparisons showed no statistically significant difference in palatal mucosa healing levels between days 7 and 14 in both groups (P>0.05).ConclusionIn conclusion, the findings of this study suggest that CAPE can significantly improve tooth socket healing.

Mesenchymal Stem/Progenitor Cell Isolation from Tooth Extraction Sockets

Bone marrow–derived mesenchymal stem/progenitor cells (BMSCs) are commonly used in regeneration therapy. The current primary source of BMSCs is the iliac crest; however, the procedure is associated with various burdens on the patient, including the risk of pain and infection. Hence, the possibility to collect BMSCs from other, more accessible, sources would be an attractive approach. It is well known that stem cells migrate from surrounding tissues and play important roles in wound healing. We thus hypothesized that stem/progenitor cells could be isolated from granulation tissue in the dental socket, and we subsequently collected granulation tissue from dog dental socket 3 d after tooth extraction. After enzyme digestion of the collected tissue, the cells forming colonies constituted the dental socket–derived stem/progenitor cells (dDSCs). Next, dDSCs were compared with dog BMSCs (dBMSCs) for phenotype characterization. A flow cytometric analysis showed that dDSCs were positive for CD44, CD90, and CD271 but negative for CD34 and CD45, similar to dBMSCs. dDSCs also exhibited osteogenic, adipogenic, and chondrogenic differentiation ability, similar to dBMSCs, with a higher capacity for colony formation, proliferation, and motility than dBMSCs. In addition, an in vivo ectopic bone formation assay showed that dDSCs and dBMSCs both induced hard tissue formation, although only dDSCs formed a fibrous tissue-like structure connected to the newly formed bone. Finally, we tested the ability of dDSCs to regenerate periodontal tissue in a one-wall defect model. The defects in the dDSC-transplanted group (β-TCP/PGA/dDSCs) were regenerated with cementum-like and periodontal ligament-like tissues and alveolar bone, whereas only bony tissue was observed in the control group (β-TCP/PGA). In conclusion, we identified and characterized a population of stem/progenitor cells in granulation tissue obtained from the dental socket that exhibited several characteristics similar to those of BMSCs. Dental sockets could therefore be a novel source for isolating stem/progenitor cells from bone.

The combination use of platelet-rich fibrin and treated dentin matrix for tooth root regeneration by cell homing.

Endogenous regeneration through cell homing provides an alternative approach for tissue regeneration, except cell transplantation, especially considering clinical translation. However, tooth root regeneration through cell homing remains a provocative approach in need of intensive study. Both platelet-rich fibrin (PRF) and treated dentin matrix (TDM) are warehouses of various growth factors, which can promote cell homing. We hypothesized that endogenous stem cells are able to sense biological cues from PRF membrane and TDM, and contribute to the regeneration of tooth root, including soft and hard periodontal tissues. Therefore, the biological effects of canine PRF and TDM on periodontal ligament stem cells (PDLSCs) and bone marrow mesenchymal stem cells (BMSCs) were evaluated respectively in vitro. Beagle dogs were used as orthotopic transplantation model. It was found that PRF significantly recruited and stimulated the proliferation of PDLSCs and BMSCs in vitro. Together, PRF and TDM induced cell differentiation by upregulating the mineralization-related gene expression of bone sialoprotein (BSP) and osteopotin (OPN) after 7 days coculture. In vivo, transplantation of autologous PRF and allogeneic TDM into fresh tooth extraction socket achieved successful root regeneration 3 months postsurgery, characterized by the regeneration of cementum and periodontal ligament (PDL)-like tissues with orientated fibers, indicative of functional restoration. The results suggest that tooth root connected to the alveolar bone by cementum-PDL complex can be regenerated through the implantation of PRF and TDM in a tooth socket microenvironment, probably by homing of BMSCs and PDLSCs. Furthermore, bioactive cues and inductive microenvironment are key factors for endogenous regeneration. This approach provides a tangible pathway toward clinical translation.

Healing of Bio-Oss® grafted marginal gaps at implants placed into fresh extraction sockets of incisor teeth in dogs: a study on the effect of submerged vs. non-submerged healing.

To evaluate the effect of submerged vs. non-submerged (NS) protocols in healing outcomes of grafted marginal defects of immediate implants. The second maxillary incisors were extracted bilaterally in six greyhound dogs. Bone level reduced diameter implants were installed into the extraction sockets leaving orofacial gaps of 2 mm wide. Defects were filled with Bio-Oss(®) and covered with Bio-Gide(®). On the one side, the flap was advanced to fully submerge the implant, and on the other, the flap was sutured to allow NS healing. After 3 months of healing, the dogs were sacrificed and block biopsies were obtained to perform histological and morphometric analysis. All implants were clinically healthy and well integrated into bone. In the majority of the specimens, the original bone in the coronal 2-3 mm of the buccal crest had completely resorbed and was replaced by a regenerated bone wall consisting of Bio-Oss(®) particles surrounded by newly formed bone. Horizontal and vertical resorption of the buccal bone resulted in ≥1 mm exposure of the implant surface in one-third of implants. Minor differences existed in some aspects of hard tissue healing between submerged and NS. There was very little difference in healing outcomes as well as modelling of the facial bone wall between the submerged and NS protocols in relation to immediate implant placement in this dog model.

The Effect of Cigarette Smoking on the Healing of Extraction Sockets

The aim of this study was to investigate immunohistochemically the influence of cigarette smoking on the socket healing after tooth extraction in rats. Eighty-four male rats were divided into 3 groups; 2 groups were considered as experimental and the other as control. The animals in test 1 were exposed to smoking regimen before the surgery and after the surgery, but the animals in test 2 were exposed to the smoking regimen only before surgery. All animals' maxillary right central incisors were extracted and killed at the 3rd, 7th, 15th, and 28th day. The samples taken on third day after tooth extraction were stained immunohistochemically with fibronectin antibody and the other with type I collagen antibody. On the third day after tooth extraction, samples in the control group were intense stained (3) (+++); in the test 1 they were slight positive (1) (+) and in the test 2 they were moderate positive (2) (+ +). As a result of scoring type I collagen antibody, there was no statistically significant difference between the groups at seventh day, but there were statistically significant differences between the groups at the 15th and 28th day (P = 0.000 and P = 0.001, respectively). Comparison of the paired intense scores of type I collagen antibody staining according to days within each groups were not statistically significant. As a result, we have found out that the healing process of the tooth extraction socket is negatively affected by cigarette smoke.