Radiographic bone level and soft tissue dimensional changes following explantation of implants affected by peri-implantitis: A retrospective exploratory evaluation.

BACKGROUND: While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation. AIM: To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation. MATERIAL AND METHODS: Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone. RESULTS: A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone. CONCLUSION: The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss.

Anatomical characteristics of the alveolar process and basal bone that have an effect on socket healing.

Following tooth extraction, a sequence of events takes place in order to close the wound and restore tissue homeostasis, a process called socket healing. The outcome of socket healing includes a marked reduction of the ridge dimensions. The amount of tissue loss that occurs during healing is influenced by several local and systemic factors. Thus, the aim of the present review was to describe the effect of anatomical characteristics of the alveolar process and basal bone on the socket healing outcome. The studies included showed that the quantity (number) and quality (composition) of socket walls exhibited a significant influence on the ridge diminution. A damaged socket (3 walls or less), as well as a thin buccal bone wall, which quickly resorbs negatively affected the healing outcome. Periodontally compromised sockets appeared to promote more extensive dimensional changes. Angulation between tooth and basal bone in addition to basal bone dimensions may also have altered the wound environment and influenced socket healing. The findings from the present review suggest that some anatomical characteristics of the alveolar process and basal bone have an effect on socket healing.

Healing of Alveolar Sockets Treated with Concentrated Growth Factors: A Split-Mouth Study.

Background: tooth extraction is a common procedure in oral surgery. The socket healing process involves hard and soft tissues and is characterized by intense remodeling, which may determine consistent dimension changes. Several autologous platelet concentrates (APCs) proved to be effective for enhancing alveolar socket healing after tooth extraction, accelerating socket closure and countering alveolar bone resorption. Concentrated growth factors (CGFs) are one of the most recently developed APCs, and their effect on the socket healing process still needs to be confirmed. Aim: The aim of the present split-mouth study was to evaluate the effectiveness of CGFs in enhancing the healing process in the postextraction alveolar socket and reducing postoperative pain. Methods: One hundred and fifty-four extractions were performed. One of the extraction sockets of each patient was treated with CGFs (test site), and the other socket was unfilled (control site). The main outcomes were: healing index, alveolar dimensions at the crestal level, socket closure, and pain perception. Descriptive statistics of the results were analyzed. Follow-up data were compared to baseline using paired tests. Results: The healing index on day 7 was significantly better (p < 0.001) in the test group (5.01 ± 1.30) as compared to the control group (6.65 ± 1.41). The mean visual analog scale for pain (VAS) was significantly higher for the control group when compared to the CGF group in the first 5 days postextraction. There was a trend toward greater socket closure in the CGF group, indicating faster healing, as compared to the control group at 7, 14, and 21 days. Conclusions: CGFs can represent a useful adjunctive tool, considering their mechanical and biological properties, for improving alveolar socket healing and reducing postoperative patient discomfort.

A comparison between anorganic bone and collagen-preserving bone xenografts for alveolar ridge preservation: systematic review and future perspectives.

After tooth extraction, dimensional changes affect the alveolar socket, leading to loss in alveolar bone height and width. Histological modifications also occur, with initial formation of a blood clot that is replaced with granulation tissue and subsequently with a provisional connective tissue matrix. Spontaneous healing ends with socket filling with woven bone, which is gradually replaced with lamellar bone and bone marrow. Adequate alveolar ridge dimensions and bone quality are required to assure optimal stability and osseointegration following dental implant placement. When a tooth is extracted, alveolar ridge preservation (ARP) procedures are an effective method to prevent collapse of the post-extraction socket. Heterologous bone is widely chosen by clinicians for ARP, and anorganic bone xenografts (ABXs) made bioinert by heat treatment represents the most used biomaterial in clinical applications. Collagen-preserving bone xenografts (CBXs) made of porcine or equine bone are fabricated by less invasive chemical or enzymatic treatments to remove xenogenic antigens, and these are also effective in preserving post-extraction sites. Clinical differences between anorganic bone substitutes and collagen-preserving materials are not well documented in the literature but understanding these differences could clarify how processing protocols influence biomaterial behavior in situ. This systematic review of the literature compares the dimensional changes and histological features of ABXs versus CBXs in ridge preservation procedures to promote awareness of different bone xenograft efficacies in stimulating the healing of post-extraction sockets.

Implants Survival Rate in Regenerated Sites with Innovative Graft Biomaterials: 1 Year Follow-Up.

In thirteen different dental clinics in Singapore, Spain, Czech Republic and Italy, 504 patients were selected, and 483 dental implants were placed in maxillary sites after alveolar socket preservation (ASP) procedures with an autologous demineralized tooth extracted as graft material from an innovative Tooth Transformer device was obtained. All procedures used were reported in n°638 Ethical Committee surgical protocol of University of Chieti and approved. After 4 months, at dental implant placing, bone biopsies were performed to evaluate the histologic outcomes, and 12 months after implant loading, global implant survival rate, failure percentage and peri-implant bone loss were detected. After ASP, only 27 post-operative complications were observed and after 4 months, bone biopsy histomorphometric analysis showed a high percentage of bone volume (BV) 43.58 (±12.09), and vital new bone (NB) 32.38 (±17.15) with an absence of inflammation or necrosis areas. Twelve months after loading, only 10 dental implants failed (2.3%), with a 98.2% overall implant survival rate, nine cases showed mucositis (1.8%) and eight showed peri-implantitis (1.6%). At mesial sites, 0.43 mm (±0.83) of bone loss around the implants was detected and 0.23 mm (±0.38) at the distal sites with an average value of 0.37 mm (±0.68) (p > 0.568). Several studies with a longer follow-up will be necessary to confirm the preliminary data observed. However, clinical results seem to suggest that the post-extraction socket preservation procedure using innovative demineralized autologous tooth-derived biomaterial may be a predictable procedure to produce new vital bone able to support dental implant rehabilitation of maxilla edentulous sites.

Microbiological and FE-SEM Assessment of d-PTFE Membrane Exposed to Oral Environment after Alveolar Socket Preservation Managed with Granular nc-HA.

AIM: The aim of this study was to analyze, by the aid of microbiological analysis and the field emission scanning electron microscopical (FE-SEM) analysis, the role of high-density polytetrafluoroethylene (d-PTFE) membranes in avoiding the microbial colonization of a nanocrystalline hydroxyapatite (nc-HA) bone graft and the involvement of this colonization in the healing process. MATERIALS AND METHODS: Six patients underwent extraction of unrecoverable teeth, and a socket preservation technique was carried out with nc-HA synthetic bone graft and then covered with a d-PTFE membrane. After 28 days from surgery, FE-SEM analysis and BioTimer assay technique to assess the microbiological count of streptococci species were carried out. Data were collected and analyzed by the Student's t test (confidence interval: 95%). RESULTS: The mean amount of bacteria measured on the upper side of the membrane was 6.52 ± 0.50 CFU, while on the lower side, it was 6.59 ± 0.40 CFU. Significant differences were not found between the two sides of the membrane or between the different sectors (p > 0.05). The FE-SEM analysis revealed structured biofilms on both sides of the membrane: species of cocci, bacilli, and fusobacteria were recognizable in occasional settled vegetations. CONCLUSION: Since the amount of bacteria found was low, the improved impermeability of the d-PTFE membrane permitted the healing process to proceed uneventful and without signs of infection or inflammation. CLINICAL RELEVANCE: The infection of the graft site could lead to a failure of the socket preservation technique which could delay or compromise the rehabilitation following procedures. The use of d-PTFE can improve the bone regeneration thanks to its antimicrobial properties.

Photobiomodulation as an adjunctive therapy for alveolar socket preservation: a preliminary study in humans.

Bone remodeling results in loss of alveolar bone height and thickness. Photobiomodulation (PBM) based on photochemical stimulation by low-intensity lasers emerges as an adjunctive therapy for alveolar socket preservation. Our study aimed to evaluate the effects of PBM therapy on alveolar bone repair. Twenty healthy patients in need of bilateral extraction of lower molars were enrolled in this split-mouth randomized and blind clinical trial. The extraction sites were randomly selected to receive either the PBM therapy with a CW GaAIAs diode laser (808 nm; 0.028 mm2; 0.1 W; 3.6 W/cm2; 89 J/cm2; 2.5 J/point) or no treatment (Control). Bone biopsies were harvested 45 days after the dental extraction and evaluated using micro-computerized tomography (µCT), morphometric, and histological analysis. Data were compared using the paired t test, and the level of significance was set at 5%. Bone surface (p = 0.029), bone surface/total volume (p = 0.028), trabecular number (p = 0.025), and connectivity density (p = 0.029) were higher at the PBM group compared with Control. The histological observations confirmed the µCT findings. PBM samples exhibited higher number of organized and connected bone trabeculae along with higher density of blood vessels than Control. Control samples displayed a dense and highly cellular connective tissue at the central area accompanied by the presence of immature bone trabeculae at the periphery. Our results indicated that the PBM therapy improved the newly bone trabeculae formation and their connectivity which increased bone surface, indicating the positive effect of the laser on alveolar human socket repair.

Extracellular matrix composition during bone regeneration in the human dental alveolar socket.

Within the dental alveolar socket, the sequence of events following tooth extraction involves deposition of a provisional connective tissue matrix that is later replaced by woven bone and eventually by lamellar bone. Bone regeneration within the dental alveolar socket is unique since the space occupied by the root(s) of a tooth does not originally contain any bone. However, extracellular matrix composition of the healing alveolar socket has not previously been investigated. Here, alveolar bone biopsies representing early (7-46 months, < 4y) and late (48-60 months; 4-5y) healing periods were investigated using Raman spectroscopy, X-ray micro-computed tomography and backscattered electron scanning electron microscopy. Partially or completely edentulous individuals and those with a smoking habit were not excluded. Between < 4y and 4-5y, mineral crystallinity and bone mineral density increase, phenylalanine, proline/hydroxyproline, and bone surface-to-volume ratio decrease, while the carbonate-to-phosphate ratio, the mineral-to-matrix ratio, and the collagen crosslink ratio remain relatively unchanged. Observed exclusively at 4-5y, hypermineralised osteocyte lacunae contain spherical and rhomboidal mineral nodules. Spearman correlation analysis reveals several significant, high (ρ = 0.7-0.9; p ≤ 0.01) and moderate (ρ = 0.5-0.7; p ≤ 0.01) correlations. Mineral crystallinity and proline/hydroxyproline, the carbonate-to-phosphate ratio and phenylalanine, mineral crystallinity and bone surface-to-volume ratio, the carbonate-to-phosphate ratio and bone surface-to-volume ratio, proline/hydroxyproline and bone mineral density, and bone mineral density and bone surface-to-volume ratio are negatively correlated. Mineral crystallinity and bone mineral density, and proline/hydroxyproline and bone surface-to-volume ratio are positively correlated. Although bone regeneration in the dental alveolar socket follows typical bone healing patterns, the compositional and microstructural patterns reveal mature bone at <4y with indications of better mechanical competence at 4-5y.

Hard and soft tissue changes in the rehabilitation of the anterior maxilla with triangular shape neck implants: a retrospective clinical study with a one-year follow up.

Aim of this retrospective study was to evaluate the one-year clinical and radiographic outcomes of implants with a triangular shaped neck inserted immediately after tooth extraction in esthetic zones. Patients in which immediate postextraction implants were placed and restored in the anterior maxilla, who underwent a Cone Beam Computed Tomograpy (CBCT) at baseline and after 12-16 months were included. The socket was preserved using deproteinized bovine bone to fill the buccal gap, and a resorbable collagen membrane. One-year implant survival and prosthesis success were evaluated. Hard and soft tissue stability was assessed by measuring various parameters on CBCT images. Clinical evaluation was also performed and Pink Esthetic Score (PES) assessed. Data from baseline and one-year follow-up were statistically compared using paired tests and a significance threshold of p=0.05. Twenty patients (13 males, 7 females, mean age 50.42±11.35 years) were included. Each contributed with one implant. No implant was lost. A significant improvement in PES was detected. Excellent hard and soft tissue preservation was observed after one year of function. Immediate placement of implants with a triangular shaped neck after tooth extraction, can be a suitable solution even for areas with a high aesthetic demand, such as the anterior maxilla.

Bone Regeneration of Hydroxyapatite with Granular Form or Porous Scaffold in Canine Alveolar Sockets.

This study was undertaken to assess bone regeneration using hydroxyapatite (HA). The primary focus was comparison of bone regeneration between granular HA (gHA) forms and porous HA (pHA) scaffold. The extracted canine alveolar sockets were divided with three groups: control, gHA and pHA. Osteogenic effect in the gHA and pHA groups showed bone-specific surface and bone mineral density to be significantly higher than that of the control group (p<0.01). Bone volume fraction, bone mineral density, and amount of connective tissue related to disturbing osseointegration of the gHA group was higher than in the pHA group. Quantity of new bone formation of the pHA group was higher than that of the gHA group. This study demonstrated that gHA and pHA are potentially good bone substitutes for alveolar socket healing. For new bone formation during 8 weeks' post-implantation, HA with porous scaffold was superior to the granular form of HA.

Alveolar socket preservation technique: Effect of biomaterial on bone regenerative pattern.

BACKGROUND: There is a lack of evidence in the literature on the correlation between histomorphometric findings and gene/protein expression markers for bone metabolism. AIM: Evaluation of the histological features, changes in protein expression and gene activation for specific markers of bone metabolism following application of the alveolar ridge preservation technique with magnesium-enriched hydroxyapatite (MgHA). MATERIALS AND METHODS: For each patient (n=15), bone samples were harvested after tooth extraction and processed for immunohistochemical and gene expression analysis (T0). Then, all alveolar sockets were grafted with MgHA. After 4 months (T1), bone samples were harvested for histomorphometrical, immunohistochemical and gene expression analysis. Gene expression and protein expression were evaluated for: RANK, RANKL, OPG, IL-6, TNF-α. RESULTS: For all markers, gene expression increased, but not significantly, from T0 to T1. The mean RANKL/OPG ratio was 1.88±1.24. Protein expression increased significantly (p<0.05) for TNF-α, IL-6, RANK and RANKL. Histomorphometrical features at T1 were not significantly related to protein expression at T0. CONCLUSIONS: After ridge preservation with MgHA, markers for bone catabolism were activated. No significant correlation was found between histomorphometrical features of the regenerated tissue and protein expression at baseline.

Various autogenous fresh demineralized tooth forms for alveolar socket preservation in anterior tooth extraction sites: a series of 4 cases.

The aim of this study was to evaluate the clinical relevance of autogenous fresh demineralized tooth (Auto-FDT) prepared at chairside immediately after extraction for socket preservation. Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. Extraction sockets were filled with these materials and dental implants were installed immediately or after a delay. A panoramic radiograph and a conebeam CT were taken. In two cases, tissue samples were taken for histologic examination. Vertical and horizontal maintenance of alveolar sockets showed some variance depending on the Auto-FDT and barrier membrane types used. Radiographs showed good bony healing. Histologic sections showed that it guided good new bone formation and resorption pattern of the Auto-FDT. This case series shows that Auto-FDT prepared at chairside could be a good material for the preservation of extraction sockets. This study will suggest the possibility of recycling autogenous tooth after immediate extraction.

Effect of autologous platelet concentrates for alveolar socket preservation: a systematic review.

The current literature was reviewed to evaluate the effect of autologous plasma concentrates on the preservation of extraction sockets. A comprehensive literature search was performed from October 2013 to February 2014 in the MEDLINE/PubMed and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Four studies, published between the years 2010 and 2013, met the eligibility criteria and were included in the review. There were 102 extractions (55 tests, 47 controls) in 82 patients. There was considerable heterogeneity between studies with regard to the design, follow-up time, surgical techniques, and method of preparation of plasma concentrates, and therefore the data could not be analyzed quantitatively. The use of plasma concentrates seems to accelerate healing and soft tissue epithelialization in extraction sockets and reduce postoperative pain and discomfort. However, there is no evidence to date to confirm that plasma concentrates improve hard tissue regeneration.

Buccal bone deficiency in fresh extraction sockets: a prospective single cohort study.

OBJECTIVE: The purpose of this prospective single cohort study was to evaluate the use of xenograft and collagen membranes in treating full or partial buccal bone defects of fresh extraction sockets in the esthetic zone. MATERIALS AND METHODS: Thirty-three patients requiring tooth extraction in the anterior maxillary area and showing a complete or partial buccal bone plate deficiency (more than 2 mm) were consecutively enrolled and treated. Corticocancellous porcine bone and platelet-rich fibrin (PRF) with a collagen membrane were used to graft the extraction sockets, and the membranes were left exposed to the oral cavity with a secondary soft tissue healing. The outcome variables were as follows: width of keratinized mucosa, facial soft tissue levels, clinical bone changes (measured with a clinical splint), implant and prosthesis failures, and peri-implant marginal bone changes. RESULTS: All treated sites allowed the placement of implants; the width of keratinized mucosa at the mid-facial aspect showed an increase of 2.3 mm 5 months after the grafting procedure, and its value was 3.2 ± 0.6 mm at 1-year follow-up. The mean values of the facial soft tissue level indicated an increase over time. The bone level showed an improvement of 0.8 ± 0.1 mm and 0.7 ± 0.1 mm at mesial and distal sites, respectively, when compared to the baseline measurements. Finally, in the palatal area, no bone changes were observed. No implant failed during the entire observation period. CONCLUSIONS: Findings from this study showed that xenograft and PRF, used for ridge preservation of the extraction sockets with buccal bone plate dehiscence in the esthetic zone, can be considered effective in repairing bone defects before implant placement. The secondary soft tissue healing over the grafted sockets did not compromise bone formation; moreover, the soft tissue level and the width of keratinized gingiva showed a significant improvement over time.

Bone tissue modelling and remodelling following guided bone regeneration in combination with biphasic calcium phosphate materials presenting different microporosity.

OBJECTIVES: The aim of this study was to investigate bone regeneration following application of a novel biphasic calcium phosphate (BCP I) composed of microstructured granules of 90% ß-tricalcium phosphate (ß-TCP)/10% hydroxyapatite (HA) compared to BCP non-microstructured biphasic calcium phosphate with a composite of 60% hydroxyapatite/40% ß-TCP (BCP II) and a deproteinized bovine bone mineral (DBBM) at surgically created defects in the mandible of minipigs in a combined approach with guided bone regeneration (GBR). MATERIAL AND METHODS: Sixteen minipigs were used for the study. Lower premolars P2, P3, P4 and first molar M1 were extracted. Following 3 months of healing, two defects with a width and depth of 7 mm were created bilaterally in the mandible. The different grafting materials were randomly placed in the created defects and covered by means of a collagen membrane. After 3 and 8 weeks, biopsies were sampled. All specimens were evaluated with descriptive histology and histomorphometric evaluations complemented by micro-CT scan analysis. RESULTS: All three biomaterials presented with higher bone volume at 8 weeks compared to 3 weeks (P < 0.0442). BCP I and DBBM demonstrated a significant higher amount of bone formation compared to BCP II at 8 weeks (P < 0.0328). BCP I also demonstrated a significant higher percentage of remaining graft volume compared to the other test groups both at 3 and 8 weeks (P < 0.0001 to P < 0.0003). Congruently, defects containing BCP I showed a significant higher amount of mineralized tissue compared to the other groups. CONCLUSIONS: All the three test materials performed well with regard to bone formation at 8 weeks. BCP I showed significant higher amounts of newly formed bone despite a higher remaining graft volume compared to the other groups. With regard to the regenerative outcome, all the three materials can be recommended for clinical use.

Various autogenous fresh demineralized tooth forms for alveolar socket preservation in anterior tooth extraction sites: a series of 4 cases / 대한악안면성형재건외과학회지

The aim of this study was to evaluate the clinical relevance of autogenous fresh demineralized tooth (Auto-FDT) prepared at chairside immediately after extraction for socket preservation. Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. Extraction sockets were filled with these materials and dental implants were installed immediately or after a delay. A panoramic radiograph and a conebeam CT were taken. In two cases, tissue samples were taken for histologic examination. Vertical and horizontal maintenance of alveolar sockets showed some variance depending on the Auto-FDT and barrier membrane types used. Radiographs showed good bony healing. Histologic sections showed that it guided good new bone formation and resorption pattern of the Auto-FDT. This case series shows that Auto-FDT prepared at chairside could be a good material for the preservation of extraction sockets. This study will suggest the possibility of recycling autogenous tooth after immediate extraction.

Biphasic alloplastic graft used to preserve the dimension of the edentulous ridge: an experimental study in the dog.

BACKGROUND: Loss of teeth results in marked qualitative and quantitative alterations of the alveolar process at the edentulous site. It was observed that a graft comprised of bovine bone mineral placed in the fresh extraction socket delayed tissue modeling, but preserved the dimension of the ridge at edentulous sites. OBJECTIVE: To analyze the influence of a biphasic synthetic graft on tissue modeling and remodeling during healing of extraction wounds. MATERIAL AND METHODS: Five beagle dogs were used. Two premolars in the maxilla and two in the mandible were included. Full thickness flaps were elevated and the distal roots were removed. An alloplastic graft (BPCAP; α-TCP core coated with nanocrystalline biomimetic hydroxyapatite) embedded in porcine collagen was placed to fill the fresh extraction socket of the premolar sites. Flaps were replaced to cover the entrance of the extraction sockets during early healing. The extraction and grafting procedures were scheduled to allow for the study of 1, 2, and 3 months socket healing. The biopsies from the maxillary sites were decalcified, embedded in paraffin, and stained to allow the study of various aspects of hard tissue formation. The biopsies from the mandibular sites were processed for ground sectioning and used to evaluate alterations of ridge dimensions after 3 months of socket healing. RESULTS AND CONCLUSION: It was documented that the biphasic alloplastic graft did not undergo marked resorption during tissue modeling and remodeling, but allowed large amounts of bone to form within the post-extraction site. Grafting the experimental sites with this biomaterial furthermore counteracted ridge resorption that otherwise occurs following tooth extraction.

Behaviour of soft tissues healing around single bone-level-implants placed immediately after tooth extraction A 1 year prospective cohort study.

AIM: The aim of this study was to verify if the three-dimensional implant position in fresh alveolar socket may influence the maintenance of stable gingival margins around single premolar restorations with immediate implant placement. METHODS: After 16 weeks of healing, implants were loaded with single crowns. Documentation consisted in peri-apical radiographs taken: before treatment; at the time of implant placement; at the time of prosthetic rehabilitation and 12 months after the start of prosthetic function. Parameters assessed were: the presence/absence of inter-proximal papilla; the inter-implant-tooth distance (ITD); the distance from the base of the crown contact-point to the inter-dental bone crest (CPB); and the buccal-gingival tissue modifications. ITD, CPB values and the modification of buccal-gingival tissue were determined using an image processing software. RESULTS: Twenty-one healthy patients with thick gingival biotype, with a total of 21 maxillary premolars scheduled for extractions were enrolled. Following extraction, implants were immediately positioned. A 100% of implant survival rate was observed after 12 months of function. The presence of the mesial papilla was significantly correlated with the mean mesial CPB value (P = 0.0519 by means of two-tailed Mann-Whitney U-test). No significant correlation was found between the mesial papilla presence and the mean mesial ITD score (P = 0.7722 by means of two-tailed Mann-Whitney U-test). Furthermore, the presence of the distal papilla was not significantly correlated with the mean distal ITD and CPB values: scores of 0.7195 and 0.8225 were calculated respectively. CONCLUSION: In the premolar area, the relationship between the presence of a complete inter-proximal papilla and ITD parameter was not significant (P > 0.05). The relationship between the presence of a complete inter-proximal papilla and CPB parameter still remain unclear. Nevertheless, a more large sample size is required to confirm this trend. Moreover, it was observed that the buccal-gingival tissue withdrew in the range 0-1 mm after 1 year of prosthetic function.

Tissue changes of extraction sockets in humans: a comparison of spontaneous healing vs. ridge preservation with secondary soft tissue healing.

INTRODUCTION: As a consequence of extraction, the height of the buccal wall tends to decrease and results in the disappearance of bundle bone. To modify bone remodelling after extraction, various ridge preservation techniques have been proposed. The present research was drawn up with the following considerations in mind: to evaluate and to compare changes of hard and soft tissues in post-extraction sockets which received a ridge preservation procedure, with post-extraction sockets which had healed naturally. MATERIALS AND METHODS: Each patient was randomly allocated to a test or control group using a specific software package. After extraction, the sockets were carefully inspected and any granulation tissue was removed. The control sites received silk sutures to stabilize the clot without any grafting material. The test sites were grafted with corticocancellous porcine bone and a collagen membrane. All experimental sites had the membranes left exposed to the oral cavity with a secondary wound healing. The thickness of the buccal alveolar bone, if present, was carefully measured at the time of tooth extraction using a calliper at 1 mm from the edge of the wall. The following clinical parameters were evaluated at baseline and after 4 months at implant placement: vertical bone changes, horizontal bone changes and width of keratinized gingiva. The length, diameter and need for additional bone augmentation were assessed for both groups at the time of implant insertion. RESULTS: The control group showed vertical bone resorption of 1 ± 0.7 mm, 2.1 ± 0.6 mm, 1 ± 0.8 mm and 2 ± 0.73 mm at the mesial, vestibular, distal and lingual sites respectively. Moreover, changes in horizontal dimension showed an average resorption of 3.6 ± 0.72 mm. The test sites showed a horizontal bone remodelling of 0.3 ± 0.76 mm, 1.1 ± 0.96 mm, 0.3 ± 0.85 mm, 0.9 ± 0.98 mm at the mesial, vestibular, distal and lingual sites respectively. The horizontal bone resorption at the test sites was 1.6 ± 0.55 mm. The keratinized gingiva showed a coronal shift of 0.7 mm in the control group when compared to 1.1 mm in the test group. In addition, 42% of sites in the control group required an additional bone augmentation at implant placement, when compared to 7% in the test sites. CONCLUSIONS: This study clearly points out that an alveolar ridge preservation technique performed with collagenated porcine bone and a resorbable membrane--according to the procedure reported in this study--was able to limit the contour changes after tooth extraction. Finally, the test sites showed a better preservation of facial keratinized tissue when compared to control sites; grafted sites allowed the placement of longer and wider implants when compared to implants inserted in non-grafted sites.

O aspirado de medula óssea melhora a regeneração no alvéolo de extração e os resultados com o uso de blocos ósseos frescos congelados homógenos. Um estudo clínico randomizado com tomografia computadorizada feixe cônico e histomorfométrico / Autologous bone marrow aspirate improves alveolar socket regeneration and bone augmentation outcomes with fresh-frozen cortico-cancellous bone blocks. A randomized, clinical CBCT and histomorphometric study

O objetivo deste artigo foi comparar as técnicas cirúrgicas convencionais com as mesmas técnicas associadas ao uso de medula óssea autógena. Para tal, 21 pacientes foram submetidos à cirurgia de regeneração óssea, as quais foram subdivididas em dois tipos de procedimentos (Procedimento 1 e Procedimento 2). No Procedimento 1, os pacientes tiveram dez dentes extraídos da forma menos traumática possível. Seis pacientes tiveram seus alvéolos preenchidos com medula óssea autóloga, e nos outros cinco pacientes nada foi enxertado. No Procedimento 2, foi realizada a enxertia em bloco com osso córtico medular homógeno fresco congelado. Cinco pacientes tiveram os enxertos impregnados com medula óssea autóloga, e os outros cinco pacientes tiveram os blocos ósseos fixados, sem associação alguma. Após um período de seis meses de cicatrização, implantes dentários foram instalados e uma biópsia foi realizada, o que proporcionou confecção de lâminas histológicas. Os pacientes também foram acompanhados pelos exames de tomografia computadorizada feixe cônico. A associação da medula óssea autóloga, tanto no Procedimento 1 como no Procedimento 2, resultou na obtenção de um maior volume ósseo, sendo que no Procedimento 2 notou-se uma melhor qualidade óssea.

The aim of this study was to compare surgical techniques for bone regeneration with the use of autologous marrow bone aspirate. For this, 21 patients were divided in two separate procedures. On the first procedure, ten teeth were atraumatically extacted: six fresh sockets receive autologous bone marrow and five sockets were filled with blood clot. On the second procedure, a cortico-cancellous, fresh-frozen, homogenous bone block was used for bone augmentation in five patients, while the other five received the same therapy but added to bone marrow aspirate. After a six-month healing period, dental implants were placed and a biopsy performed for histomorphometric analysis. Also, CBCT analyses were performed. The use of bone marrow aspirate resulted in better bone volume for both aspects, being that better bone qualities were observed in the second procedure.