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Purpose: Implants placed in fresh extraction sites and healed sites were restored simultaneously by cross-arch provisional fixed prostheses. Clinical and radiographic parameters were recorded for up to 36 months. Materials and Methods: Treatment with a full-arch implant prosthesis, either screw-retained or cemented, was assigned to 54 patients. A total of 676 implants were placed in either immediate extraction sites (n = 367) or in healed alveoli (n = 309), followed by placement of a one-piece provisional prosthesis. The definitive restoration was placed 3 to 6 months after implant placement. Clinical parameters were recorded and digital radiographs obtained at 6, 18, and 36 months. The chi-square test, t test, and analysis of variance with repeated measures were used for statistical analysis of the outcomes. Results: Osseointegration failed in 21 (3.1%) implants; 13 of these (62%) had been placed immediately after extraction. All occurred within 2 months of the surgical healing phase. Short (8-mm) and narrow (3.3-mm) implant configurations were significantly (P < .05) associated with failure. At 6, 18, and 36 months, average crestal bone resorption was 0.18 mm, 0.55 mm, and 0.79 mm for implants placed in fresh extraction sites and 0.31 mm, 0.78 mm, and 1.1 mm for implants placed in healed alveoli, respectively. These differences were statistically significant (P < .05 between sites at all examined periods). Crestal bone resorption also correlated to sites with simultaneous bone augmentation and implant placement. Conclusions: Implants placed and restored immediately in a cross-arch mode, whether in extraction sites or in healed alveoli, can be clinically successful and maintainable. Int J Oral Maxillofac Implants 2010;25:329-335. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to histomorphometrically evaluate the synthetic peptide analog P-15 bound to anorganic bovine mineral (PepgenjP15) in critical-size defects in the rat calvaria. Materials and Methods: A 5-mm-diameter critical-size defect was prepared in 48 rat skulls and divided into 4 equal groups: PepgenjP15 particles covered by a membrane, PepgenjP15 particles uncovered, nongrafted membrane-protected sites, and nongrafted uncovered control sites. At 12 weeks, histomorphometric measurements were made of the percentage area of newly formed bone and residual particles, the length of internal and external bone bridging, and linearly, the regenerated marginal and central total tissue augmentation height. Results: Nongrafted, membrane-protected sites gained 60.6% of newly formed bone, followed by 50.6% and 44.2% (P < .05 versus membrane only) at the grafted covered and uncovered sites, respectively. All experimental sites contained significantly (P < .005) more bone than did control sites (19.9%). In both types of grafted sites, the percentage area of PepgenjP15 particles was similar. Mean internal and external length of bone bridging at nongrafted membrane-protected sites (76.7% and 71.2%, respectively) was significantly greater (P < .005) than that of the grafted covered (43.95% and 51.8%, respectively), grafted uncovered ', (28.7% and 23.9%, respectively), and control (28% and 25.5%, respectively) groups, except for internal t; bone bridging in the grafted covered sites. Regenerated marginal and central augmentation heights (0.92 mm and 1.02 mm, respectively) were greatest in the grafted covered group, followed by the nongrafted membrane-protected (0.88 mm and 0.51 mm, respectively), and grafted uncovered (0.89 mm and 0.12 mm, respectively) groups, all of which were significantly greater (P < .001) than the control group (0.63 mm and 0.04 mm, respectively). Conclusion: While anorganic bovine mineral/cell-binding peptide contributes in volume, membrane application significantly increases the amount of bone regeneration. [ABSTRACT FROM AUTHOR]

PURPOSE: The aim of this study was to evaluate the capability of a configured titanium mesh (CTM) to serve as a mechanical and biologic device for restoring a vertically defected/resorbed alveolar ridge. MATERIALS AND METHODS: The study comprised 10 severely resorbed sites in 10 patients. Pre- and post-operative ridge measurements were taken with reference to the neighboring teeth and supporting screw head base of the CTM. Bovine bone mineral served as the augmentation filler material. The metal mesh was removed after 9 months. Subsequently, root-form, screw-type implants were placed. During the implant placement phase, cylindric bone samples were retrieved from the augmented area for histopathologic and histochemical examination. RESULTS: Upon soft tissue reflection and before augmentation, defect height, as recorded by a periodontal probe along the main threads exposed on the support screw, was between 5 and 8 mm (average 6.4 mm; SD +/- 1.17). At 9 months after augmentation, during the implant placement phase, the defect height was between 0 and 2 mm (average 1.2 mm; SD +/- 0.63). Differences were statistically significant (P < .001). Bone height gain was between 4 and 6 mm (average 5.2 mm, SD +/- 0.79), which gave an average bone fill of 81.2% (SD +/- 7.98). Polarizing microscopic examination of sections stained with Picrosirius red showed a gradual increase in new lamellar bone from coronal to apical cuts, reaching the highest area percentage in the deep apical zone. DISCUSSION: At 9 months postaugmentation using the CTM surgical technique, the quality and quantity of the newly established hard tissue appeared to be different in the coronal versus apical areas of the restored alveolar ridge. CONCLUSION: Although at 9 months postoperatively, the augmented alveolar ridge had different bone content, clinicohistochemical results demonstrated that this surgical technique could be a successful and predictable procedure for rebuilding a resorbed/defected ridge to accommodate endosseous implants. [ABSTRACT FROM AUTHOR]

Recent developments in osseous regenerative techniques have increased the demand for bone-substitute grafting materials. Porous deproteinized bovine bone mineral (PBBM), a biocompatible xenograft, has been used in different osseous deficiencies prior to or in conjunction with the placement of titanium implants. The different PBBM applications in fresh extraction sites, anatomic defects, and subantral floor elevation techniques are described. The use of an occlusive barrier membrane to regenerate bone via guided tissue regeneration principles was determined for each patient by clinical parameters. PBBM was well amalgamated and incorporated with the augmented hard tissue, but the transition between preexisting bone and the newly regenerated bone-like tissue was distinguishable by clinical examination even after 12 months. Grafted material was also identified using follow-up radiographs. In the presented cases, PBBM showed clinically satisfactory results as a biocompatible filler in bone augmentation procedures. [ABSTRACT FROM AUTHOR]

Spontaneous early exposure of submerged implants during the osseointegration healing phase may be a harmful factor that results in early crestal bone loss around the implants. The objective of this study was to assess the effect of spontaneous early exposure on crestal bone loss around submerged implants, with special attention given to the relationship between the degree of exposure and the amount of peri-implant bone loss. Crestal bone level relative to the shoulder of the implant was measured at the time of placement and at the time of exposure 4 to 5 months later. During the period between stage I and stage II surgery, implant sites were observed, and each implant site in which spontaneous early exposure was detected was recorded. Perforations were classified according to the degree of implant exposure from Class 0 (no perforation) to Class IV (complete exposure). Measurements from 206 implants in 64 patients produced 85 groups valid for statistical comparison; each of these contained at least 2 lesions of different types. There was a statistically significant difference between bone loss associated with intact mucosa (Class 0) and Class I, Class II, and Class III lesions, and between Class I and II lesions. There were no significant differences between Class I and III and between Class II and III. In Class II and III lesions, there was more bone loss associated with the buccal aspect of the implants. Of the 115 perforated sites, 10 were associated with bone loss exceeding 2 mm, 2 presented 3 to 4 mm bone loss, 1 showed more than 4 mm, and 1 displayed more than 5 mm. In view of the clinical implications that spontaneous early exposure may have on the success of osseointegration, prematurely partially exposed implants should be exposed as soon as possible after the perforation is observed. [ABSTRACT FROM AUTHOR]

Objective: The ESCAPE multicentre survey was designed to (a) compare the agreement of three relevant aesthetic scoring systems among different centres, and (b) evaluate the reproducibility of each question of the questionnaires. Materials and Methods: EFP centres (n = 14) were involved in an e‐survey. Forty‐two participants (28 teachers, 14 postgraduate students) were asked to score the one‐year aesthetic outcomes of photographs using the Before–After Scoring System (BASS), the Pink Esthetic Score (PES) and the Root coverage Esthetic Score (RES). Mean values of kappa statistics performed on each question were provided to resume global agreement of each method. Results: Between teachers, a difference of kappa ≥ 0.41 (p = .01) was found for BASS (75%) and PES (57%). Similarly, RES (84%) and PES (57%) were different (p < .001). No difference was found between BASS (75%) and RES (84%). No difference was found between students, whatever the scoring system. Questions of each scoring system showed differences in their reproducibility. Conclusions: The outcomes of this study indicate that BASS and RES scoring systems are reproducible tools to evaluate aesthetic after root coverage therapies between different centres. Among the various variables, lack of scar, degree of root coverage, colour match and gingival margin that follows the CEJ show the best reliability. [ABSTRACT FROM AUTHOR]

Aim: To compare the effect of timing of implant placement and guided bone regeneration (GBR) procedure on osseointegration and newly formed bone at 8 and 16 months. Material and Methods: In seven dogs, four different sites were bilaterally established: (1) an implant placed in a 6-month healed (6m-GBR) bovine bone mineral (BBM) grafted site; (2) a simultaneously placed implant with the grafted BBM (Si-GBR) followed by a membrane coverage; (3) an implant placed in a membraneprotected non-grafted defect; and (4) an implant placement in a naturally healed site (Cont). Histomorphometry was obtained at 8 and 16 months post-implant placement. Bone-implant contact (BIC), crestal bone resorption (CBR), vertical intra-bony (VIB) defect, bone (BAF) and particle (PAF) area fractions, and osteoconductivity (CON) levels were measured. Results: In all sites, BIC ranged between 62% and 79% with no significant differences. PAF ranged from 17% to 27%, with no effect of time. At 8 and 16 months, BAF was significantly smaller at the Si-GBR site when compared with all other sites, CON was significantly greater at the 6m-GBR site, and CBR and VIB were significantly smaller at the 6m-GBR when compared with the Si-GBR sites. Conclusions: The simultaneous and delayed techniques both showed a similar osseointegration level over time. However, the staged approach showed enhanced newly formed bone, higher osteoconduction around the grafted mineral, less CBR, and smaller vertical bone defect over time compared with the combined approach. [ABSTRACT FROM AUTHOR]

Purpose: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction., Materials and Methods: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned., Results: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement., Conclusion: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

This article defines immunophenotypes of stromal inflammatory and endothelial cells and fibroblasts 3 months after augmentation of the peri-implant soft tissue using a porcine cross-linked collagen matrix (VCMX). Peri-implant soft tissue samples were obtained from 12 patients at the lining mucosa (LM)-masticatory mucosa (MM) junction before (1) and 3 months after (2) augmentation. Immu- nohistochemical stains were performed to identify inflammatory cells (T [CD3] and B [CD20] lym- phocytes, plasma cells [CD138]), macrophages (CD68-proinflammatory, CD163-anti-inflammatory/ reparative), endothelial cells (CD31, CD34), and fibroblasts (CD90, TE-7). Differences in the mean positively stained cells pre- and postaugmentation were analyzed by Wilcoxon signed-rank test. CD31&#43; endothelial cells showed increased mean numbers in MM2 compared to MM1 (P &#61; .025) and in LM2 compared to LM1 (P &#61; .047). CD163&#43; anti-inflammatory macrophages showed higher mean numbers in MM2 than in MM1 (P &#61; .021) and in LM2 than in LM1 (P &#61; .012). All other cell phenotypes showed nonsignificant changes between pre- and postaugmentation. This molecular study provides novel insight on the frequency of stromal cell phenotypes in the wound healing process at 3 months postaugmentation with VCMX, with anti-inflammatory CD163&#43; macrophages being predominant. This should be further investigated to help find novel therapeutic approaches to modulate and promote the VCMX-related healing process.

Bone augmentation has become a routine procedure to enhance and/or repair a deficient or resorbed alveolar ridge for predictable and successful implant placement. The split expansion ridge i.e., the alveolar ridge splitting (ARS) procedure, is one of the less invasive procedures, and is characterized by minor morbidity. This would allow to widen narrow ridges in order to allow implant reconstruction in a sufficient bone volume. Its efficacy and long-term stability rely upon clinical opinions and long-term retrospective studies, while prospective comparative studies and randomized controlled trials are rare. This critical review presents the development of this technique, describes the surgical procedure, and provides technical notes and modifications. The learning curve and in-depth knowledge of the oral anatomy, as well as the recognition of incidence and management of complications are of utmost importance in the clinical application of the ARS procedure., (© 2023 The Authors. Periodontology 2000 published by John Wiley & Sons Ltd.)

Sinus augmentation has become an integrated surgical phase in posterior maxillary implant prosthesis reconstruction. Since the residual alveolar bony height usually requires additional volume particularly at this anatomical region, sinus floor augmentation is advocated routinely. Over the years, Implant success rate is proved to be comparable to the one in the pristine bone, which is well documented in the literature. Anatomical aspects as well as surgeon skills are at most importance to achieve predictable outcome. In this narrative review, the different osteotomy techniques, the indications toward 1 or 2-stage approaches, the control of the Schneiderian membrane integrity as well as the management of intra- and post-operative complications are thoroughly discussed according the current data. In light of the excellent long-term implant success rate concurrent with the application of contemporary advanced techniques of the sinus augmentation via the lateral wall osteotomy approach, reduce invasiveness and less complication occurrences are well documented. A well-codified patient selection involving the rhinologist as an integral medical team would be significantly beneficial toward early diagnosis. In-depth knowledge of the anatomy, execution of a well standardized surgical technique, and understanding the complication etiology and their management are prerequisites for reducing patient morbidity to minimal discomfort and predictable successful outcome., (© 2022 The Authors. Periodontology 2000 published by John Wiley & Sons Ltd.)

The aim of the present study was to generate an international and multidisciplinary consensus on the clinical management of implant protrusion into the maxillary sinuses and nasal fossae. A total of 31 experts participated, 23 of whom were experts in implantology (periodontologists, maxillofacial surgeons and implantologists), 6 were otolaryngologists and 2 were radiologists. All the participants were informed of the current scientific knowledge on the topic based on a systematic search of the literature. A list of statements was created and divided into three surveys: one for all participants, one for implant providers and radiologists and one for otolaryngologists and radiologists. A consensus was reached on 15 out of 17 statements. According to the participants, osseointegrated implants protruding radiographically into the maxillary sinus or nasal fossae require as much monitoring and maintenance as implants fully covered by bone. In the event of symptoms of sinusitis, collaboration between implant providers and otolaryngologists is required. Implant removal should be considered only after pharmacological and surgical management of sinusitis have failed.

The objective of this study was to assess volumetric and linear changes of buccal mucosal thickness at implant sites following soft tissue augmentation with a volume-stable collagen matrix (VCMX). Soft tissue augmentation using a VCMX was performed in 12 patients at the time of implant placement. Hydrocolloid impressions were taken prior to surgery and at 1 and 6 months postsurgery. Stone cast models were scanned, and stereolithography (STL) files from the three time points were uploaded to an image-analysis software. At all time points, linear and volumetric measurements of the contour changes up to 3 mm apical to the mucosal margin were performed and were analyzed statistically. At 1 mm apical to the mucosal margin, the change in soft tissue thickness between presurgery (T1) and 1 month (T2) amounted to 0.21 ± 1.22 mm, and the change between T1 and 6 months (T3) was 0.08 ± 1.47 mm. At 3 mm apical to the mucosal margin, the change in soft tissue thickness was 1.92 ± 1.70 mm between T1 and T2 and 0.31 ± 1.26 mm between T1 and T3. Contour (volumetric) changes revealed an increase of 0.58 ± 0.73 mm between T1 and T2 and an overall gain of 0.55 ± 0.73 mm between T1 and T3. Soft tissue augmentation with VCMX increased the ridge profile. The increase in ridge width was greater at 3 mm below the ridge crest than at 1 mm below the ridge crest. Remodeling processes during healing showed a decrease in the ridge contour between 1 and 6 months.

Purpose: To evaluate the efficacy of autogenous particulate dentin as a bone substitute to maintain dimensional volume in human socket preservation procedures., Materials and Methods: Particulate dentin was used in socket site preservation procedures. The extracted natural tooth was ground to particles 250 to 1,200 μm in size to fill the socket site. At 6 months, during the implant placement stage, hard tissue biopsy specimens were harvested by a 2.5-mm cylindrical trephine bur for the histologic analysis. Histomorphometry was carried out with ImageJ software to calculate direct bone to grafted dentin particles contact, newly formed bone, and particulate dentin area fractions., Results: Fifteen patients went through the socket preservation procedure using particulate dentin as the grafted bone substitute. De novo bone formation filled the entire grafted area. Newly formed bone was observed throughout the entire grafted area, particularly around the grafted dentin particles. The majority of particles were surrounded by direct contact with newly formed osseous tissue enriched by osteocytes. Newly formed bone ankylosed to particulate dentin and became a solid matrix preserving the ridge dimension. Histomorphometric measurements showed that the new bone formation area fraction was on average 38.4% ± 16.5%, while the residual particulate dentin showed an average of 29.9% ± 14.4%, and 31.7% ± 14.2% was captured by the connective tissue component. Particulate dentin was in direct contact with newly formed bone at an average rate of 69.1% ± 22.8%., Conclusion: Particulate dentin showed complete biocompatibility and high osteoconduction. Thus, it can be used as an appropriate grafting biomaterial to maintain socket site volume dimensionally for subsequent implant placement procedures.

Aim: This study aims to examine the composition of lining and masticatory mucosa at the pre- and post-soft tissue augmentation procedures with a volume-stable cross-linking collagen matrix (VCMX) in humans., Materials and Methods: In 12 patients, single implant sites were augmented with a VCMX. Biopsies were obtained including masticatory (MM) and lining (LM) mucosa before augmentation and at 12 weeks post-augmentation procedures. Rete pegs density (RPD), length (RPL), and blood vessel density (BVD) were histomorphometrically analyzed at both time points. Picrosirius red staining under polarized light microscopy was used to evaluate collagen fiber organization. The effects of time and tissue type were evaluated by ANOVA with repeated measures., Results: Both MM and LM areas demonstrated an increase in mean RPL following augmentation, 382.6 µm ± 95.1 vs. 290.5 µm ± 79.3 and 335.6 µm ± 94.2 vs. 292.9 µm ± 77.0, respectively (p < .05). There was a significant difference in the numbers of RP per 1 mm length (RPD) between the MM (9.2 ± 1.7) and LM (6.1 ± 2.8) mucosa but not between the pre- and post-VCMX augmentation time points. The mean BVD in the LM was greater than in the MM (5.5 ± 2.4 and 6.3 ± 2.4 vs. 3.4 ± 3.3 and 3.7 ± 1.8, respectively, p < .05) but not between time points. The collagen fiber arrangements pre- and post-augmentation were not significantly different., Conclusion: Augmentation with VCMX did not alter the composition of lining and masticatory mucosa at implant sites., Clinical Relevance: A thick soft tissue phenotype around the implant neck is an important factor to maintain peri-implant health. A non-autogenous cross-linking collagen matrix is proposed as an alternate graft substitute in soft tissue augmentation procedures in order to improve implant soft tissue phenotype., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To monitor and compare the nonsubmerged (single-stage, SS) and submerged (two-stage, TS) implant placement techniques up to the final prosthesis delivery. Marginal bone level and marginal bone loss rate of both surgical techniques were compared., Method and Materials: Marginal bone level was measured, using an image processing program (ImageJ), from periapical radiographs at the times of placement (T0), exposure (Te), initial loading (T1), and at the final prosthetic delivery (T2), with a total time span of a mean of 13.2 ± 3.3 months. By timing normalization, marginal bone level and marginal bone loss rate (mm/month), following SS and TS implant placement techniques and other local and systemic parameters were analyzed. Asymmetric analyses using Mann-Whitney test followed by the correlation Pearson analyses were applied. A P value < .05 defined statistical significance., Results: In total, 268 implants (42 patients) were monitored. Marginal bone loss rate was 0.15 ± 0.13 mm and 0.13 ± 0.11 mm, between T0 and T2, for the SS and TS techniques, respectively. Marginal bone level and marginal bone loss rate were higher among smokers for both techniques at various time points. Bruxers had higher marginal bone loss rate than nonbruxers between T0 and T1, and T0 and T2. Marginal bone loss rate around implants that were placed at the posterior maxilla was higher than those at the posterior mandible between T1 and T2. Interproximal implant distance correlated negatively with marginal bone loss rate between T0 and T2 (P < .05)., Conclusions: The results suggest that both techniques achieved similar clinical outcome. Smoking, bruxism, anatomical location, and interproximal implant distance apparently affect the marginal bone level and marginal bone loss rate of both implant placement approaches. The implant placement surgical mode, combined with various systemic and/or anatomical factors could play a significant role in maintaining marginal osseous level around the implant neck.

Objective: The aim was to evaluate the efficacy of periodontal regenerative therapy using enamel matrix derivatives (EMDs) in aggressive periodontitis patients, and to determine the contribution of maintenance via periodic supportive periodontal treatment. Method and materials: In total, 28 patients were evaluated, comprising 74 intrabony sites. In 50 sites EMD gel was applied, and in 24 sites EMD was combined with deproteinized bovine xenograft. Patients were assigned to a supportive periodontal treatment program; 18 patients fulfilled the program, defined as the well-maintained (WM) group; 10 did not comply, defined as the nonmaintained (NM) group. Probing depth (PD), clinical attachment level (CAL), and radiographic bone level (BL) were recorded. Data were compared presurgically (T0), 6 months postsurgery (T1), and 3 to 10 years posttreatment (T2). Results: Both surgical modalities achieved similar PD reduction, CAL gain, and BL gain, maintained over time. T1 to T2 showed a mean gain/loss of 0.21 ± 0.5 mm and 0.04 ± 1.1 mm, and -0.65 ± 3.0 mm and -0.73 ± 3.0 mm for PD and CAL, respectively, at the WM/NM groups, respectively. BL gain was 21.6% and 11.5% for the WM/NM groups, respectively (P < .05). The courses of the PD, CAL, and BL differed between the WM and NM groups during the observation periods (P < .05). Conclusion: Periodontal regeneration via EMD with/without the combination of deproteinized bovine xenograft can be maintained in aggressive periodontitis cases. It appears that periodic supportive periodontal treatment is a determinant factor in achieving this task.

Background: The efficacy of human freeze-dried bone (h-FDB) as particulate vs block forms as a proper onlay augmented bone graft material to accommodate implants is undetermined., Purpose: To evaluate osseointegration and new bone formation at implants placed in FDB blocks (BL group) and those at the adjunction of particulate FDB (PR group)., Materials and Methods: Twelve pairs of h-FDB blocks were stabilized bilaterally to the calvaria of 12 rabbits. Twenty-four SLA implants were placed at the remodeled grafted blocks, 4 months later. A circumferential gap was created around one implant in each pair and packed with particulate h-FDB. Section biopsies were obtained at 2-month post implant placement (6 months post-block grafting). Bone-to-implant contact (BIC) and bone-area fraction (BAF) were histomorphometrically calculated., Results: The mean BIC was 34.4% and 33.5% for the BL and PR groups, respectively. The mean BAF was 23.9% and 26.4% for the corresponding groups, respectively. Osseointegration and newly formed bone were evident mostly between the threaded portions of the implants in proximity to the host rabbit calvaria compared to its cervical neck., Conclusion: The particulate and the cancellous block h-FDB forms yielded similar BIC and BAF outcome. Full revascularization/revitalization is questioned., (© 2019 Wiley Periodicals, Inc.)

Background and Aims: To review the regenerative technologies used in bone regeneration: bone grafts, barrier membranes, bioactive factors and cell therapies., Material and Methods: Four background review publications served to elaborate this consensus report., Results and Conclusions: Biomaterials used as bone grafts must meet specific requirements: biocompatibility, porosity, osteoconductivity, osteoinductivity, surface properties, biodegradability, mechanical properties, angiogenicity, handling and manufacturing processes. Currently used biomaterials have demonstrated advantages and limitations based on the fulfilment of these requirements. Similarly, membranes for guided bone regeneration (GBR) must fulfil specific properties and potential biological mechanisms to improve their clinical applicability. Pre-clinical and clinical studies have evaluated the added effect of bone morphogenetic proteins (mainly BMP-2) and autologous platelet concentrates (APCs) when used as bioactive agents to enhance bone regeneration. Three main approaches using cell therapies to enhance bone regeneration have been evaluated: (a) "minimally manipulated" whole tissue fractions; (b) ex vivo expanded "uncommitted" stem/progenitor cells; and (c) ex vivo expanded "committed" bone-/periosteum-derived cells. Based on the evidence from clinical trials, transplantation of cells, most commonly whole bone marrow aspirates (BMA) or bone marrow aspirate concentrations (BMAC), in combination with biomaterial scaffolds has demonstrated an additional effect in sinus augmentation and horizontal ridge augmentation, and comparable bone regeneration to autogenous bone in alveolar cleft repair., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The purpose of this study is to evaluate and compare, retrospectively, the outcome of two different periodontal regeneration procedures in patients suffering from aggressive periodontitis (AgP). Twenty-eight patients were diagnosed with AgP, suffering from several intra-bony defects (IBD); that were treated by one of two periodontal regeneration techniques randomly assigned to each patient: a. guided tissue regeneration (GTR) or b. an application of extracted enamel matrix derivatives (EMD) combined with demineralized bone xenograft particles (DBX). Probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession were recorded. Pre-treatment and follow-up (up to 10 years from the surgery) recordings were analyzed statistically within and between groups. A significant reduction was shown at time on PPD and CAL values, however, not between subject groups. CAL values decreased in all sites. At the EMD group (44 sites), CAL gain was 1.92 mm (±1.68) from pre-treatment to follow-up (p < 0.001) and at the GTR group (12 sites) CAL gain of 2.27 (±1.82) mm. In conclusion, 1⁻10 years observations have shown that surgical treatment of AgP patients by either GTR or by application of EMD/DBX results in similar successful clinical results., Competing Interests: The authors declare no conflict of interest

Objectives: The aim of this study is to evaluate the effect of operators experience and skill on treatment results of initial non-surgical periodontal therapy., Materials and Methods: Initial periodontal treatment was carried out by either second-year periodontal residents (PR) or last year dental students (DS). From the treatment records of patients in each group, plaque and bleeding indices, and pocket depth (PD) at baseline and at re-evaluation were collected retrospectively on each tooth at six locations. Data were separated according to tooth type, area, and probing depth categories, sub-grouped to 1-3, 4-5, and ≥ 6 mm., Results: Fifty and 49 records of DS and PR patients, accordingly, were analyzed. Initial periodontal treatment improved patient compliance in both groups and reduced signs of inflammation with significantly superior results in the PR group. Significant change in percentage of pockets was recorded in each category. The increase in percentage of sites with PD 1-3 mm and decrease in percentage of PD ≥ 6 mm pockets was significantly (p ≤ 0.001) superior in patients treated by PR. Percentage of 4-5 mm pockets was significantly reduced in both groups (p ≤ 0.01), with a significantly greater reduction in the mandibular molar and anterior teeth in the PR group., Conclusions: Experience and skill significantly affect the outcome of non-surgical periodontal therapy, with more positive improvement in patient compliance and clinical parameters when performed by a more qualified operator., Clinical Relevance: Improvement of operator skills may decrease the number of residual pockets and increase patient compliance following non-surgical periodontal treatment.

Purpose: To assess the extent of osseointegration with rough-surface implants and new bone formation (NBF) within human freeze-dried bone blocks (h-FDB) grafted over rabbit calvaria., Materials and Methods: A total of 18 rectangular h-FDB blocks were stabilized bilaterally to the calvaria of nine New Zealand rabbits by two mini titanium screws each. A total of 18 rough-surface implants (5.0 × 6.0-mm) were placed, 9 simultaneously (immediate placement [IP]) on one side and 9 at 3 months after block grafting (delayed placement [DP]) on the contralateral side. At 12 weeks after the second surgical procedure, block biopsies were harvested and processed for histologic analysis. Morphometric measurements consisted of bone-to-implant contact (BIC) and the extent of NBF from the calvarial surface and outward into the block. A paired t test was applied for statistical analysis., Results: All h-FDB blocks were integrated, and the implants showed clinical stability. Histologically, the BIC was primarily between the apical end of the implants and the host rabbit calvaria. Bone growth between the implant threads was minimal and inconsistent among all animals. Morphometric measurements showed that the mean BIC of the IP and DP implants with the blocks was 10.50% ± 5.99% and 23.06% ± 9.58%, respectively (P < .001). NBF was observed primarily in the cancellous compartment of the block adjacent to the recipient calvarial bed. The extent of NBF into the block around the IP and DP implants was 9.95% ± 8.41% and 12.90% ± 11.07%, respectively (P = 0.2)., Conclusion: In this model, a significantly lower BIC was demonstrated when implants were placed simultaneously with h-FDB block grafting compared to those placed in a two-stage mode. However, both techniques showed limited osseointegration.

Objectives: To retrospectively evaluate and compare two regenerative periodontal procedures in young individuals with aggressive periodontitis (AgP)., Methods: Thirty-two patients aged 14-25 years (mean ± SD 19.3 ± 5.7) were diagnosed as having AgP with multiple intra-bony defects (IBDs) and treated by one of two regenerative modalities of periodontal therapy: guided tissue regeneration (GTR) using deproteinized bone xenograft (DBX) particles and a resorbable membrane (the GTR group), or an application of enamel matrix derivatives (EMD) combined with DBX (the EMD/DBX group). Periodic monitoring of treated sites included recording of probing depth (PD), clinical attachment level (CAL) and gingival recession. Pre-treatment and 1-year post-operative findings were statistically analysed within and between groups., Results: The PD and CAL values decreased significantly with time, but not those between study groups. The mean pre-treatment and 1-year post-treatment PDs of the IBDs of the GTR group (n = 16; sites = 67) were 8.93 ± 1.14 mm and 3.58 ± 0.50 mm, respectively, and the mean CALs were 9.03 ± 1.03 mm and 4.16 ± 0.53 mm respectively. The mean PDs of the EMD/DBX group (n = 16; sites = 73) were 8.77 ± 1.04 mm and 3.61 ± 0.36 mm, respectively, and the mean CALS were 8.79 ± 1.04 mm and 3.77 ± 0.22 mm respectively (p < 0.001 for all)., Conclusion: Surgical treatment of AgP patients by either GTR or by application of EMD/DBX yielded similarly successful clinical results at 1-year post-treatment., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: Evaluate the antibacterial properties of three commercial collagen membranes for guided bone regeneration (GBR)., Method and Materials: BioGide®, OsseoGuard®, and CopiOs® membranes were tested for antibacterial properties against Streptococcus sanguinis, Staphylococcus aureus, and Staphylococcus epidermidis using a direct contact test (DCT). Samples of each membrane, sized 5 × 2 mm, were fixed to the side wall of 6 wells in a 96-well microtiter plate. Bacterial suspension was placed on each sample. The plate was incubated at 37°C for 1 hour to allow suspension fluid evaporation. Fresh medium was added to each well and the plate was mixed. Non-contaminated membrane samples served as negative control. Bacterial growth was monitored spectrophotometrically at 650 nm for 24 hours. ANOVA and Tukey's comparison tests were used for the statistical analysis., Results: The presence of the membrane samples did not disrupt bacterial growth. However, the presence of OsseoGuard membrane accelerated bacterial growth rate of S sanguinis and S epidermidis as compared to the other two membranes and control samples (P < .001), and of S aureus as compared to the control alone (P < .001)., Conclusions: The tested collagen membranes have no antibacterial properties. However, OsseoGuard presents a significant bacterial growth enhancement effect with possible significant clinical implications on the success of regenerative procedures around teeth and implants.

Purpose: The purpose of this study is to evaluate implants placed at different times of bone augmentation., Materials and Methods: Four implants were placed in seven dogs: one at a 6-month bovine mineral grafted site (6-month Bio-Oss® grafted site [6mBio]), one at a grafted membrane-protected simultaneously augmented (Fresh Bio-Oss® grafted site [FrBio]) site, one at a clotted (nongrafted clotted membrane-protected site [Clot]) membrane-protected site, and one at a pristine (nongrafted uncovered site [Cont]) site. Implants were exposed after 6 months. The same protocol was repeated on the contralateral side, at a delay of 8 months. Peri-implant care was performed throughout the hygienic phase (2 and 10 months, respectively) every 48 to 72 hours. Probing depth and bleeding on probing were recorded. Implant stability was determined by a Periotest® (Medizintechnik Gulden, Modautal, Germany). Statistical analysis was conducted using analysis of variance with repeated measures., Results: Average probing depth at the simultaneously grafted sites was 2.21 mm and 2.03 mm at 8 and 16 months, respectively. At the 6-month grafted sites, it was 1.96 mm and 1.57 mm. At the Clot sites, it was 2.68 mm and 2.07 mm, and 2.21 mm and 1.82 mm at the Cont sites, respectively. The average bleeding on probing was 0.50 and 0.42 at the FrBio sites, and 0.35 and 0.07 at the 6mBio sites during the respective periods. At the Clot sites, it was 0.50 and 0.28, and at the Cont sites, 0.43 and 0.21, respectively. Probing depth significantly reduced over the time at 6mBio, Clot, and Cont sites (p < .03). Average implant stability score at the FrBio sites was -0.24 and -0.27, and -0.50 and -0.46 at the 6mBio sites, at 8 and 16 months, respectively. At the Clot sites, it was -0.35 and -0.46. Cont sites averaged -0.37 at both periods. Implant stability was significantly higher (p < .005) comparing 6mBio over FrBio, 6mBio over Cont, and Clot over FrBio sites., Conclusions: Immediate and delayed augmentations are safe modes. Probing depth and bleeding indices gradually improved along time. Implant stability was higher at the delayed mode., (© 2011 Wiley Periodicals, Inc.)

The purpose of this study was to compare extraction sites augmented with bovine bone mineral (BBM) with and without resorbable membrane coverage. BBM particles were grafted in fresh human extraction sockets of 23 patients; in 12 of these patients, a guided tissue regeneration (GTR) membrane was applied. After 9 months of histomorphometric evaluation, cylindric hard tissue specimens were obtained. Percent bone area fractions (BAFs) of the crestal, middle, and apical sections from each specimen were calculated using the point-counting technique. Changes in values were compared. In sites augmented with BBM, the mean BAF ranged from 22.8% (coronal) to 36.3% (apical) compared to sites augmented with BBM and collagen membrane (35.2% [coronal] to 47% [apical]). Comparison between the different depths and the two groups showed a distinct increase in BAF from coronal to apical regions (P < .001). This pattern was observed in both groups (P < .001) and was significantly higher in the group augmented with BBM and collagen membrane (P < .05). In the immediate postextraction phase, BBM as a grafted biomaterial preserved the socket volume and enabled newly formed bone for future implant site preparation. The amount of the osseous fraction increased with GTR membrane.

Introduction: The purpose of this study was to evaluate the influence of anorganic bovine bone as a grafted biomaterial on newly formed bone and cementum in periapical regions after surgical endodontic treatment in cats., Methods: After inducing apical periodontitis in 9 cats, root canal and surgical endodontic treatment were performed on 72 roots of first and second maxillary premolars. Bone defects were treated with biomaterial particles + a membrane, biomaterial only, a membrane only, or left unfilled (control). Histomorphometry on nondecalcified sections were performed at 3 and 6 months after surgery. Analysis of variance with repeated measures was used within 2 and 3 subject factors to analyze newly formed bone, cementum, biomaterial conduction, and resorption., Results: At each time period, bone formation was greater at the grafted membrane-protected sites than in the grafted-unprotected sites. At 6 months, the bone area fraction at membrane nongrafted sites was greater than in the grafted-protected sites. The new cementum was significantly greater at 6 months than at 3 months and greater at the grafted membrane-protected sites over the unprotected ones at 6 months. Statistically, the grafted biomaterial, the membrane, and the time contributed significantly to the amount of new bone (P<.05) with no significant interaction. Biomaterial osteoconduction was significantly affected by the time. All 3 variables showed a significant interaction on new cementum., Conclusions: There was significantly more bone formation after surgical endodontic treatment when membrane and bone grafts were used as compared with bone grafts only or unfilled control sites. However, it appears that the key factor to the enhanced tissue regeneration is the membrane and not the grafted biomaterial., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

A dual mucogingival treatment is presented in which severely traumatized maxillary central incisors sustained lateral and extrusive luxation injuries in a roadside accident. Injuries resulted in complete loss of the overlying radicular labial cortical plate followed by a gingival soft tissue cleft, which created a Grade II Miller recession defect in relation to the labial aspect of the maxillary central incisors. A multidisciplinary treatment approach was used, including emergency care, endodontic therapy, and sequential dual periodontal soft tissue rehabilitation. Subepithelial connective tissue grafting was carried out using two techniques, which proved successful in achieving complete coverage of the defect sites. This two-stage surgical approach enabled achievement of ample vascularization for soft tissue grafting and enhanced its predictability for optimal outcome. At the 3-year follow-up, clinical and radiographic examination showed a maintainable functional and esthetic status.

Purpose: The objective of this study was to compare the clinical and histologic peri-implant parameters of a nano-calcium phosphate (CaP)-coated dual acid-etched (DAE) implant (n = 7) to those of an uncoated DAE implant (n = 7)., Materials and Methods: The study included seven dogs who received implants bilaterally in edentulous mandibular areas; in the right side, procedures were performed 8 months after procedures in the left mandible. Clinical parameters were measured prior to euthanasia (8 months after the second set of implants was placed), followed by histologic nondecalcified processing for morphometric evaluation. Bone-implant contact (BIC), crestal bone resorption (CBR), intrabony defect (IBD), and bone area fraction (BAF) were measured. Analysis of variance with repeated measures and a two-tailed Pearson correlation test were applied., Results: Probing depth, Bleeding Index, and keratinized mucosal height were stable in both groups; there was a significant improvement in probing depths with time (P = .014). Morphometric measurements showed BIC from 75% to 89% in both groups at 8 and 16 months. The nano-CaP-coated group (n-CaP) showed a significant increase in BIC over time when compared to the DAE group (P = .02). Crestal bone level was maintained in both groups with average resorption of 1.4 to 1.5 mm at the n-CaP implants and 1.1 to 1.2 mm at the DAE implants at 8 and 16 months, respectively. Mean IBD values were 0.88 to 1.18 mm at the n-CaP implants and 0.65 to 0.66 mm at the DAE implants at the respective periods., Conclusions: Within the limitations of this study, both the DAE and the n-CaP-surface implants showed successful osseointegration and functional soft and hard tissue adaptation. Except for the significant increase in BIC around the n-CaP implants over time, both showed similar clinical and histologic findings.

The fresh extraction socket site in the immediate post-extraction phase possesses unique characteristic wound healing cascade. Marked horizontal and vertical resorption of the edentulous ridge occurred shortly following tooth extraction. In periodontally involved teeth, when partial/full socket wall destruction is evident, the ingrowth of connective tissue into the extraction site is unavoidable leading to a deficient ridge. The use of bone substitute materials aiming to preserve the alveolar ridge by stabilizing the blood clot, thus maintaining the volume of the site and at the same time serves as an osteoconductive scaffold which facilitates continual bone formation. immediate Implant placement, is also a reliable, predictable, and successful procedure. Comparative studies regarding immediate implant placement vs. delayed placement (healed sites) reported similar high survival rate for both procedures. The addition of nonfunctional immediate provisionalization (clearance of all contacts in centric occlusion and during eccentric movements to avoid full functional loading of the implant during healing) achieving an instant aesthetic solution, has been shown to have predictable results. However, a meticulous surgical protocol should be followed. In recent years, an immediate functional loading of cross-arch splinted implants proved to be a reliable and successful approach. Moreover evidence-based data comparing immediate, early and delayed loading failed to show significant difference between those treatment modalities. Apparently, primary stability of implants is an important factor in achieving predictable success. It seems that the addition of controlled loading did not impair those results. A systematic review of the current literature related to this procedure showed a survival rate of over 95% in 34 prospective/retrospective studies. Since clinical parameters were proved to be equal whether implants were placed immediate post-extraction or delayed in a healed alveolar ridge, it appears that cross-arch immediate loading of implants placed in extraction and/or healed edentulous ridges is a predictable procedure with long term stability of the results.

Background: The crestal core elevation (CCE) technique is reportedly a less invasive procedure than the lateral window elevation technique. We retrospectively evaluated long-term outcomes of CCE procedures over an 11-year time period., Methods: Core preparations were made after extractions of 57 upper molars in 45 patients. Extraction sites were drilled with a calibrated trephine bur to an estimated distance of 1 mm from the sinus membrane. The trephined interradicular bone and underlying sinus membrane were imploded into the sinus. The surgical crater and residual extraction socket were filled with deproteinized bovine bone mineral or freeze-dried bone allograft, stabilized, and protected with an absorbable collagen membrane and fully covered with coronally positioned flaps. Implants were placed 4 months later. Success was defined if ≥9 mm available bone height was available. Where the available bone height varied between 7 and 9 mm, implant placement was complemented using the bone-added osteotome sinus floor elevation technique; those sites were defined as a "partial success.", Results: The CCE technique was successful in 31 (68.9%) out of 45 sites, and partially successful in six (13.3%) out of 45 sites. Eight sites failed (17.8%). Surgical failures were caused by core detachment resulting in large tears of the sinus membrane. Implants placed in successful sites presented a 100% survival rate during the study duration., Conclusions: CCE implemented simultaneously with molar extractions provided therapeutic benefits and clinical limitations. The subsequent implant placement using CCE revealed an excellent survival rate in the study population evaluated.

Objectives: to assess the correlation between maxillary sinus inferior mucosal thickening and sinus outflow obstruction., Material and Methods: the study included 280 computerized tomography (CT) scans (560 maxillary sinuses). CT aimed to assess sinusitis; trauma to the face and intubated patients were excluded. Mucosal thickening was graded as < 5 mm (1), < 10 mm (2), < 15 mm (3), < 20 mm (4) and > 20 mm (5), and classified by appearance as normal, rounded, circumferential, irregular, or complete. Maxillary sinus outflow was classified as patent or obstructed., Results: mucosal thickening was found in 36.1% of the maxillary sinuses, graded as 31.2% (1), 34.2% (2), 12.9% (3), 5.4% (4) and 16.3% (5), and classified as rounded (11.8%), irregular (10.4%), circumferential (8.8%) and complete (5.2%). Sinus outflow was obstructed in 15% of the scans. Mucosal thickening of < 5 mm (11.1%), < 10 mm (36.2%) and > 10 mm (74.3%) was associated with sinus obstruction (P<0.0001). Rounded (6.1%), circumferential (55.2%), irregular (38.8%) and complete (100%) mucosal appearances were associated with sinus obstruction (P<0.001). When statistically combined, a substantial risk for sinus obstruction was observed with irregular mucosal appearance of > 5 mm (56.5% for grade 2 up to 82.6% for grades 3-5) and circumferential appearance (21.4% for grade 1 up to 100% for grades 3-5). A low risk for obstruction was found with the rounded appearance (mean 6.1%)., Conclusions: irregular (> 5 mm), circumferential and complete mucosal appearance are associated with an increased risk for sinus outflow obstruction and an ENT consultation is recommended. A rounded mucosal appearance of any grade is associated with a low risk for sinus obstruction. Routine CT scans, including the maxillary sinus ostium, are recommended.

Teeth replacement in the esthetic zone is a considerable challenge. Dental implants are usually the preferred treatment alternative for tooth replacement. The present review discusses several clinical issues concerning implant placement in the esthetic area. It is still unclear whether raising a flap at the time of implant placement enhances alveolar crest remodeling. However, a flapless surgical procedure could avoid changes in the free gingival margin and maintain the the attached gingiva width. A submarginal approach not involving the free gingival margin can be applied to treat bone defects with the GBR technique. Implants should be placed as palatal as possible while maintaining optimal restoration emergence profile and the horizontal bone defect filled with a non resorbable material such as bovine bone mineral. Thick periodontal biotype and coronally positioned free gingival margin usually lead to better results. Immediate implant placement in presence of a periapical lesion may be performed, however, sites should be thoroughly debrided prior to implant placement.

Objectives: The evaluate the clinical outcome of bone augmentation with the use of particulate mineralized freeze-dried bone allograft (FDBA) with or without the addition of autogeneous bone chips, applied in a bi-layered (BL) technique, covered by a resorbable cross-linked collagen membrane., Material and Methods: Fifty patients presenting with a vertical and/or lateral ridge deficiency of at least 3 mm were included: Group FDBA, N=27 patients, particulate FDBA was the only graft; and Group BL, N=23 patients, a BL bone grafting procedure where autogenous bone chips were the inner layer and FDBA the outer. Bone graft was covered with a ribose cross-linked collagen barrier membrane. Ridge dimensions were clinically or radiographically (computerized tomography scan) measured at the time of the bone augmentation procedure and at implant placement or uncovering and the maximum linear vertical or horizontal calcified tissue gain was calculated. Statistical analysis consisted of linear regression analysis, with maximum bone gain being the dependent variable., Results: In the FDBA group, mean vertical bone gain was 3.47 mm (SD 1.25) and the horizontal, 5 mm (SD 1.28), while in the BL values were 3.5 mm (SD 1.2) and 3.6 mm (SD 1.72), respectively. Addition of autogenous bone does not appear to statistically significantly enhance the results. Spontaneous membrane exposure occurred in 24% of the cases and was the only variant that significantly influenced results (P<0.001)., Conclusions: Large vertical and/or horizontal ridge deficiencies may be treated with FDBA and ribose cross-linked collagen barrier membranes with good clinical outcome. No added effect of the application of a layer of autogenous bone in these bone augmentation procedures could be demonstrated. Spontaneous membrane exposure was the only parameter to affect the degree of new calcified tissue formation., (© 2010 John Wiley & Sons A/S.)

Objective: The aim of this study was to evaluate histologically the bio-degradation of two layers of Bio-Gide((R)) (BG) membrane, as compared with that of a single layer., Material and Methods: Two circular calvarial bony defects, 5 mm in diameter, were made in 24 Wistar rats. BG membrane, labeled with biotin, was cut into 5-mm-diameter disks, and placed in defects either as a mono-layer membrane (MLM) or as a double-layer membrane (DLM). Rats were sacrificed after 4 or 9 weeks and histology was performed. Membranes were stained with horseradish peroxidase-conjugated streptavidin and aminoethyl carbazole as a substrate for detection of biotinylated collagen. The area of collagen and thickness of the residual membranes were measured by image analysis software. Statistical analysis was performed using the non-parametric Wilcoxon's signed-ranks test., Results: At 4-week collagen area per measurement window within the DLM sites (0.09+/-0.05 mm(2)) was significantly greater (P<0.01) than that in the MLM sites (0.047+/-0.034 mm(2)). At 9 weeks, the collagen area was also greater in the DLM sites (0.037+/-0.026 mm(2)) compared with that of the MLM sites (0.025+/-0.016 mm(2)); however, this difference did not reach statistical significance. The rate of membrane degradation, calculated as percent membrane lost compared with baseline, was similar for the DLM and MLM at both time points ( approximately 60% at 4 weeks and approximately 80% at 9 weeks). In addition, the residual DLM thickness at 4 weeks (475.5+/-73.77 mum) was significantly (P<0.01) greater than that of MLM (262.38+/-48.01 mum). At 9 weeks, membrane thickness was also greater in the DLM sites (318.22+/-70.45 mum) compared with that of the MLM sites (183.32+/-26.72 mum); however, this difference did not reach statistical significance. The reduction in thickness between 4 and 9 weeks was 30% for MLM and 33% for DLM., Discussion: The use of a double layer of BG membrane results in a barrier of increased collagen area and thickness, compared with application of a single layer.

Background: Early barrier membrane degradation may result in decreased bone formation in guided bone regeneration (GBR) procedures. The aim of this study was to evaluate the bio-degradation of cross-linked (CLM) and non-cross-linked (NCLM) collagen membranes experimentally exposed to the oral environment of study animals., Methods: In eight cats, 48 surgical procedures were performed, three along each side of the palate: 24 full-thickness soft tissue perforations were made and 24 full-thickness mini-flaps were raised. CLM or NCLM discs were placed either under the perforations and peripheral mucosa and left exposed (experimental) or covered by the flaps (controls). The four treatment modalities were equally distributed among the eight animals. Block sections were retrieved at 7 and 28 days post-operatively, providing histological specimens (6 each) at 7 and 28 days for each treatment modality., Results: Histological observation revealed that CLM and NCLM remained intact in the control sites during the 28 days. At 7 and 28 days, CLM appeared interrupted in three and two experimental sites, respectively, and were undetected in the remaining sites. NCLM were interrupted in two sites each at 7 and 28 days, and were undetected in the other sites. There was no statistical difference between control specimens and between CLM and NCLM of the different treatment modalities at 7 or 28 days., Conclusions: Both cross-linked and non-cross-linked membranes were resistant to tissue degradation and maintained continuity throughout the study. However, none of the membranes was resistant to degradation when exposed to the oral environment

Objective: The aim of this study was to examine the efficacy of a new biphasic hydroxyapatite/tricalcium phosphate (HA/TCP) bone substitute in combination with particulate autogenous bone in sinus floor augmentation procedures., Material and Methods: A simultaneous or a two-stage sinus augmentation and implant placement were conducted in 28 patients. A mixture of HA/TCP and autogenous bone chips in a 1 : 1 ratio was used as the grafting biomaterial. Cylindrical specimen bone retrieval was performed in all patients except one. Specimens were harvested either at 6 (n=14) or 9 (n=13) months post-augmentation. For histologic and histomorphometric evaluations, the non-decalcified tissue processing (Donath's technique) was performed., Results: Newly formed bone around the grafted particles was found in all samples. The encircling, highly cellular bone followed the outline of the grafted particles in direct contact. Both woven and lamellar types of bone were observed. Morphometrically, the total mean bone area fraction of all sections was 34.8+/-10.3%, increasing from 28.6+/-7.8% at 6 months to 41.6+/-8.3% at 9 months (P<0.001). Mean particle area fraction average was 25.5+/-11.6% and 23.5+/-9.3% at 6 and 9 months, respectively, with a total mean of 24.5+/-10.4%. The increase in bone area fraction was not significantly correlated to the decrease of the grafted particles area fraction., Conclusions: The biphasic HA/TCP showed biocompatible and osteoconductive properties. This alloplast as a composite with autogenous bone chips promotes newly formed bone, which increases in its fraction along an extended healing period.

Background: Collagen barrier membranes are commonly applied in periodontal and bone-regenerative procedures. Membranes differ in their resorption pattern following implantation, thus influencing clinical outcome. The purpose of this study was to quantitatively evaluate the biodegradation of three different commercially available collagen membranes., Methods: Collagen membranes were cut into 5-mm-diameter disks and labeled with aminohexanoyl-biotin-N-hydroxy-succinimide ester. One membrane disk of each type (non-cross-linked [NCL], glutaraldehyde cross-linked [GCL], and ribose cross-linked [RCL]) was implanted on the calvaria of 20 Wistar rats. Block sections were retrieved after 2 days (baseline, two animals), 14 days (10 animals), or 28 days (eight animals). Decalcified histologic sections were stained with streptavidin horseradish peroxidase. Residual membrane thickness and area were measured. Statistical analysis consisted of analysis of variance (ANOVA) with repeated measures., Results: Statistically significant differences in the amount of residual membrane material were recorded within each membrane (among different time points) and among different membranes at the same time points (P <0.001). At 28 days, the least amount of residual collagen area, expressed as the percentage of baseline, was observed in the NCL group (13.9% +/- 10.25%), followed by the GCL (24.7% +/- 35.11%) and RCL (91.3% +/- 10.35%) groups. Residual membrane thickness, expressed as the percentage of baseline thickness, presented a similar pattern (31% +/- 16.55%, 37% +/- 41.90%, and 94.1% +/- 12.22%, respectively). ANOVA with repeated measures showed a significant interaction between membranes and time (P <0.001)., Conclusions: The tested membranes differed in their degradation patterns and collagen contents. Membranes should be chosen for each clinical case according to the desired biodegradation characteristics.

Objective: This double-blind study clinically and histologically evaluated long-term barrier bio-durability of cross-linked and non-cross-linked collagen membranes (CLM and NCLM) in sites treated by guided bone regeneration procedures., Materials and Methods: In 52 patients, 52 bony defects were randomly assigned to treatment with either a CLM or a NCLM. Post-surgical spontaneous membrane exposures were recorded. Before implant placement, full-thickness standard soft tissue discs were retrieved wherever suitable for histologic examination., Results: Spontaneous membrane exposure was observed in 13 (50%) CLM sites and in six (23.1%) NCLM sites (P<0.05). Clinical healing at exposed sites lasted 2-4 weeks. CLM were histologically intact in all non-perforated sites, were interrupted in five perforated sites, and undetected in four. NCLMs were undetected in all 18 specimens examined. In three non-perforated CLM sites, bone apposition and ossification at or within the membrane was observed., Conclusions: CLMs were more resistant to tissue degradation than NCLMs, and maintained integrity during the study. Neither membrane was resistant to degradation when exposed to the oral environment. CLMs were associated with a higher incidence of tissue perforations. In non-perforated sites, CLM ossification at or within the membrane was occasionally observed.