Comparative Assessment of Flap-Advancing Techniques in an Ex Vivo Cadaverous Porcine Model.

PURPOSE: Since flap advancement is a prerequisite for tension-free primary closure and successful regenerative procedures, the aim of this study was to test the efficacy of six surgical approaches for flap advancement in an ex vivo porcine model. MATERIALS AND METHODS: A total of 60 fresh mandibles from pigs were randomized into one of six groups: (1) trapezoidal full-thickness flap design with two vertical releasing incisions (control), (2) trapezoidal flap with linear periosteal scoring, (3) mucosal detachment technique, (4) mucosal detachment with horizontal extension, (5) mucosal detachment with horizontal and vertical extension, and (6) mucosal detachment with horizontal vertical and cutback extension. Coronal advancement of the flap was recorded as the primary variable; the surface area of exposed mucosa and the tear strength were recorded as secondary variables. RESULTS: Homogeneity existed among groups for preoperative keratinized tissue width and tissue thickness. Mucosal detachment with horizontal, vertical, and, cutback extensions achieved the highest amount of advancement. All remaining groups achieved a statistically higher advancement compared with the trapezoidal full-thickness flap (control). Pairwise comparison demonstrated statistical significance between any two groups (P < .001). A positive correlation was noted between exposed mucosa and flap advancement; the advancement increased 0.62 mm for each 10 mm2 of increase in the exposed mucosal surface. Strength at tear stress was the highest in the trapezoidal full-thickness flap (control) and mucosal detachment with horizontal-vertical-cutback incisions (P < .001). CONCLUSION: Coronal flap advancement was maximized in the mucosal detachment techniques and positively correlated with the area of exposed mucosa.

The Buccally Displaced Palatal (BDP) Flap to Increase Quantity and Thickness of Peri-implant Soft Tissue.

Common challenges encountered for atrophic maxilla rehabilitation are the inadequate width and height of attached keratinized mucosa (AKM) and shallow vestibular depth. This study presents a buccally displaced palatal (BDP) flap technique to increase the tissue thickness and AKM width at the second-stage surgery and reestablish the correct fornix depth. The peri-implant pocket depths, modified Plaque Index score, modified sulcus Bleeding Index score, and soft tissue recession were evaluated 6 and 12 months after prostheses loading. A total of 52 implants were placed and analyzed, and no implant failures were found. No significant changes in peri-implant parameters were observed between 6 and 12 months, and mean recession was less than 0.2 mm after 12 months. Though this change was statistically significant, it was clinically irrelevant. The results demonstrate that adequately healthy peri-implant soft tissues and substantial dimensional stability of vestibular soft tissues at the 1-year follow-up were achieved with the BDP flap technique. The BDP flap could represent a viable option for increasing the width and the height of AKM and establishing the correct maxillary fornix depth.

Classification Based on Extraction Socket Buccal Bone Morphology and Related Treatment Decision Tree.

BACKGROUND: Alveolar ridge preservation (ARP) can successfully reduce volumetric ridge changes. However, there is still no consensus on what technique is the most advantageous for each specific clinical scenario. Hence, the aim of the present paper was to provide a treatment decision tree to guide the choice of predictable ARP procedures based on extraction socket buccal bone morphology and integrity. MATERIAL AND METHODS: Three socket types (ST) are proposed and discussed based on buccal bone morphology (intact, dehiscence or fenestration). RESULTS: A decision tree for ARP was developed in order to merge ST classification with suitable treatment modalities. In the decision tree, the issue of when to allow unassisted healing or ARP was discussed. Described methods included bone grafting and collagen plug, and absorbable membrane or non-resorbable membrane, with or without flap elevation. CONCLUSION: A decision tree for ARP procedures was provided to guide clinicians towards the most conservative and predictable treatment approach based on remaining socket anatomical structures after extraction.

Mucosal Detachment Technique for Flap Advancement in a Thin Tissue Phenotype: Technique Illustration.

Passive-tension flap closure of primary wounds remains the most important factor for achieving predictable bone augmentation outcomes. So far, no specific surgical technique has been proposed for major flap advancement, specifically in the thin tissue phenotype (≤ 1.5 mm thick). This article illustrates a detailed description of the Mucosal Detachment Technique (MDT), which separates the mucosal tissue from the underneath periosteum and aims to achieve adequate flap flexibility to cover high-volume augmentation in the thin tissue phenotype. Separating the mucosa from the periosteum allows maintenance of vascularization and an even distribution of tension among the advanced flap. The MDT allows bone augmentation procedures in thin tissue phenotype flap. The flap advancement permits tension-free primary closure in all tissue phenotypes (both thin and thick), independent of the degree of volume augmentation.

Influence of Vertical Soft Tissue Thickness on Crestal Bone Changes Around Implants with Platform Switching: A Comparative Clinical Study.

BACKGROUND: Numerous studies have shown the superiority of platform-switched implants in preserving crestal bone as compared with platform-matched implants. However, the influence of initial soft tissue thickness on development of crestal bone loss has not been addressed in previous studies; thus, further research is needed. PURPOSE: To evaluate crestal bone levels around platform-switched implants placed in thin and thick mucosal tissue. MATERIALS AND METHODS: Eighty patients (38 male and 42 female, mean age 44 ± 3.34 years) received 80 bone-level implants of 4.1 mm in diameter with platform switching (Institut Straumann AG, Basel, Switzerland). Tissue thickness was measured, and cases were distributed to Group 1, with thin soft tissue (2 mm or less, n = 40), and Group 2, with thick tissue (more than 2 mm, n = 40). Implants were placed with a one-stage approach and restored with screw-retained restorations. Radiographic examination was performed after implant placement, 2 months after healing, after restoration, and at 1-year follow-up post-reconstruction. Crestal bone loss was calculated. The Mann-Whitney U-test was applied, and significance was set to p ≤ .05. RESULTS: Implants in Group 1 (thin tissue) showed 0.79 mm of bone loss after 2 months. After 1-year follow-up, bone loss was 1.17 mm. Implants in Group 2 (thick tissue) showed bone loss of 0.17 mm after 2 months of implant placement and 0.21 mm after 1-year follow-up. The differences between groups were significant (p < .001) at both time points. CONCLUSIONS: It can be concluded that platform switching does not prevent crestal bone loss if, at the time of implant placement, mucosal tissue is thin. In thick soft tissue, use of platform-switched implants maintained crestal bone level with minimal remodeling.

Emergence profile design based on implant position in the esthetic zone.

One of the most challenging tasks in implant dentistry is to fulfill the esthetic expectations of patients. While implant positioning and adequate amounts of soft and hard tissues are essential for achieving an esthetic outcome, the emergence profile of an abutment/restoration also plays an important role in the definitive appearance of implant prostheses. Therefore, the purpose of this paper is to propose a clinical guideline for designing an abutment/prosthesis based on implant position. By customizing the emergence profile, the overlying soft tissues could be properly contoured and maintained, and pleasing implant prostheses could be achieved.

Impact of implantoplasty on strength of the implant-abutment complex.

PURPOSE: Implantoplasty, a procedure that is done to smooth contaminated implant surfaces, has been used in the treatment of peri-implantitis. It reduces the implant diameter, which might compromise the implant's strength. This in vitro study was designed to evaluate the effect of implantoplasty on implant strength. MATERIALS AND METHODS: Thirty-two tapered implants were used; half were 3.75 mm in diameter (narrow) and the other half were 4.7 mm in diameter (wide). All implants were connected to 20-degree angled abutments. The apical half of each implant was embedded in acrylic resin. Eight 3.75-mm- and eight 4.7-mm-diameter implants were randomly assigned to receive implantoplasty. The remaining implants did not receive implantoplasty (control group). Implantoplasty was performed with a series of diamond and polishing burs. The specimens were then loaded 30 degrees off-axis in a universal testing machine until fracture failure occurred. Bending and fracture strength values were recorded and analyzed statistically (α = .05). The fractured surfaces were evaluated under a scanning electron microscope. RESULTS: All narrow implants failed by fracture at the implant platform. The mean bending strength of narrow implants was statistically significantly reduced by implantoplasty (511.4 ± 55.9 N versus 613.9 ± 42.8 N). Implantoplasty did not affect the strength of wide implants; fracture failures occurred at the abutment screw. The fracture mode was ductile and the crack growth was oblique in direction, indicating complex stress distribution and concentration under loading. CONCLUSION: Within the limits of this study, implantoplasty appeared to weaken the strength of narrower implants. Therefore, this procedure should be performed with caution on narrower, freestanding implants that are subject to greater occlusal force (eg, posterior regions). Validation of these results is needed for different implant systems.

Periosteal pocket flap for horizontal bone regeneration: a case series.

Guided bone regeneration has been shown to be a successful technique to increase the ridge width for dental implant placement. However, in cases of severe or localized horizontal bone deficiencies, achieving sufficient soft tissue mobilization to ensure primary wound closure over the augmented area can be difficult. This article describes a buccal periosteal pocket flap proposed to overcome these challenges. The flap design results in a periosteal pocket, which allows filling of bone-grafting material while facilitating primary tension-free soft tissue closure by splitting of the mucosa. The flap gives stability to the augmented volume within the pocket. Ridge widths of five patients consecutively treated with this technique were recorded before and 24 weeks after augmentation. Results from these cases showed a mean 389% ± 301% gain in bone width (range, 50% to 1,420%) when the periosteal pocket flap design was used. Data obtained from this study suggest that the periosteal pocket flap design could be a predictable alternative flap approach for correction of severe or localized horizontal bone deficiencies.

Effect of guided tissue regeneration on newly formed bone and cementum in periapical tissue healing after endodontic surgery: an in vivo study in the cat.

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.

Clinical and histologic evaluation of a granular bovine bone biomaterial used as an adjunct to GTR with a bioresorbable bovine pericardium collagen membrane in the treatment of intrabony defects.

BACKGROUND: The aim of the present study is to evaluate the clinical and histologic healing of deep intrabony defects treated with guided tissue regeneration (GTR) with a collagen membrane from bovine pericardium and implantation of granular bovine bone biomaterial. METHODS: Thirty patients with one deep, combined 1- and 2-wall intrabony defect exhibiting a probing depth ≥6 mm and an associated intrabony defect ≥3 mm were treated with GTR with a bioresorbable collagen membrane from bovine pericardium and adjunct implantation of a granular bovine bone biomaterial. The clinical results were evaluated 1 and 3 years after surgery. In addition, five teeth fulfilling the inclusion criteria but scheduled for extraction because of advanced periodontitis or restorative considerations were treated similarly and then extracted along with a portion of their surrounding periodontal tissues for histologic evaluation 6 months after surgery. RESULTS: Healing was uneventful in all patients. Significant clinical improvements were observed at 1 and 3 years postoperatively (P <0.01; probing depth averaged 4.4 ± 1.6 and 4.7 ± 1.4 mm and clinical attachment level gain was 3.9 ± 1.4 and 3.5 ± 1.3 mm, respectively). The histologic evaluation revealed formation of new cellular cementum and new periodontal ligament in four of the five cases. In general, the xenograft particles seemed to be mostly embedded in connective tissue without any evidence of new bone formation. CONCLUSION: GTR treatment of intrabony defects with the collagen membrane from bovine pericardium and adjunct implantation of the new bovine bone biomaterial may result in significant clinical improvements that can be maintained over a period of 3 years, and regeneration of cementum and periodontal ligament, but without bone formation.

Systematic approach for the propagation of postgraduate dental implant education in developing countries.

PURPOSE: To analyze the outcome of the formative feedback and summative assessment in 2 different groups of dentists after a postgraduate dental implant course. This course was conducted with the hope of developing a systematic approach to implant dentistry training. METHODS: A 6-day mini-residency postgraduate dental implant course which was approved for 75 credit hours by the international congress of oral implantologists and approved for fellowship after a satisfactory grade at the end of course examination was conducted at the Faculty of Dentistry of the University of Ibadan in West Africa. This course was organized by the Caribbean affiliate of the International Congress of Oral Implantologists utilizing the syllabus which has been instrumental in training Caribbean Dentist since 2004. The postgraduate course in implantology was delivered to 2 groups of participants: group I comprising mainly of faculty staff from the major dental schools in Nigeria with previous postgraduate qualifications and group II were general dental practitioners in private practice in Nigeria.The outcome of the assessment by the 2 different groups was compared with the outcome of implant postgraduate courses in dentistry that are presently documented in Medline/Pubmed. RESULTS: There was no significant difference in the reason for attending the course when the 2 groups are compared (P value ranged from 0.82 to 0.93). Both groups expressed good and similar response to the overall quality of the presentation (P value = 0.19), comprehensiveness of topics covered (P value = 0.34), organization of presentation (P value = 0.34). The multiple choice question assessment at the end of the course was very difficult for both groups and the performance was below average for both groups. CONCLUSIONS: The 6-days mini-residency course combined with the 1-month distance learning component was adequate for the sustainability stage and this lead to certification of 72% of the delegates via the examination route.

Aesthetic flap design for correction of buccal fenestration defects.

Flapless immediate implant surgery has been proposed as a means of reducing the surgical trauma to soft tissue and maintaining natural gingival anatomy. The aesthetic outcome in such cases may, however, be jeopardized when localized horizontal and vertical deficiencies occur. In order to correct such deficiencies, a novel flap design was developed that protected the soft tissue that had the most significant impact on the patient's appearance. This aesthetic buccal flap (ABF) was created coronally so that the supraosseous soft tissue remained undisturbed and allowed the use of guided bone regeneration techniques to correct apical dehiscences. The likelihood of obtaining an optimal aesthetic result was, therefore, enhanced.

A bovine-bone mineral block for the treatment of severe ridge deficiencies in the anterior region: a clinical case report.

A bovine-bone mineral block was used to treat a severe horizontal and vertical anterior ridge deficiency. Such a block can be shaped to conform to the defect, and it avoids the need for harvesting autogenous bone or fixation of the block with screws. After a 6-month integration period, an implant was placed. Six months later the implant was restored with a single crown. The case has been followed for 3 years. Slow bone resorption has been observed at the interface between the block and the surrounding bone, but the interproximal bone peaks, important for soft tissue support and esthetics, have been maintained over time. The 3-year follow-up results suggest that bovine-bone mineral blocks may be a suitable bone-replacement material for augmentation of extensive alveolar ridge defects in the anterior region.

Implant success, survival, and failure: the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference.

The primary function of a dental implant is to act as an abutment for a prosthetic device, similar to a natural tooth root and crown. Any success criteria, therefore, must include first and foremost support of a functional prosthesis. In addition, although clinical criteria for prosthetic success are beyond the scope of this article, patient satisfaction with the esthetic appearance of the implant restoration is necessary in clinical practice. The restoring dentist designs and fabricates a prosthesis similar to one supported by a tooth, and as such often evaluates and treats the dental implant similarly to a natural tooth. Yet, fundamental differences in the support system between these entities should be recognized. The purpose of this article is to use a few indices developed for natural teeth as an index that is specific for endosteal root-form implants. This article is also intended to update and upgrade what is purported to be implant success, implant survival, and implant failure. The Health Scale presented in this article was developed and accepted by the International Congress of Oral Implantologists Consensus Conference for Implant Success in Pisa, Italy, October 2007.

[Vertical augmentation of the mandible using cortico-spongious xenoblocks. A histomorphometrical study in dogs]. / Vertikale Unterkiefer- augmentation mit kortikospongiösen Xenoblöcken. Eine histomorphometrische Tierstudie.

The aim of the present study was to histologically evaluate vertical ridge augmentation of the mandible using partially deproteinized cortico-spongious xenogenous blocks (XB) in dogs. Standardized acute-typed vertical lower jaw defects were surgically created in edentulous ridges of six foxhounds. Two similar bone blocks of 6 mm height were randomly inserted on each mandibular side and fixed with both a titanium implant and an osteosynthetic screw. Three groups were tested: i) XB (CS-Block bovin, Tutogen Medical) alone, ii) XB covered with a native xenogenous collagen membrane (XB+M) (Tutodent Membran, Tutogen Medical), and iii) autogenous blocks (AB), harvested during defect preparation from the ipsi- and contralateral side. After three months of submerged healing, the miniscrews were removed and replaced by secondary dental implants. In general, histological analysis revealed that augmentation of XB, used alone or in combination with a collagen membrane, did not lead to significant supracrestal bone apposition, resulting in means of 14 +/- 9% for XB and 25 +/- 9% for XB+M of basal ossification of the blocks. AB revealed significantly higher ossification rates of 46 +/- 16%. BIC rates were significantly higher for AB (70 +/- 15%) than for XB (26 +/- 15%) and XB+M (32 +/- 12%) (P < 0.05, Mann Whitney U-Test, respectively). Within the limits of the present study it was concluded that XB alone or in combination with a collagen membrane doesn't seem to be useful for vertical ridge augmentation procedures of the mandible.

Use of the natural tooth for soft tissue development: a case series.

The achievement of optimal esthetics around anterior dental implants has been a major challenge for many clinicians. The key to an esthetically pleasing appearance lies in the clinician's ability to properly manage the soft tissue profile around dental implants. Hence, the purpose of this case report is to describe a new technique that uses the patient's own natural tooth for the provisional implant restoration to develop soft tissue architecture that is almost identical to the patient's original immediately after tooth extraction. Ten consecutively treated patients were included in this series. Clinical measurements included soft tissue height, papilla appearance, and probing pocket depths. Other parameters such as radiographic bone levels and quality-of-life ratings were also recorded. Results from this study showed that all patients achieved a normal or Class 1 papilla appearance similar to the original appearance of the natural tooth. All patients were very happy with the treatment outcome. This newly suggested approach for restoring an anterior implant can be valuable and esthetically pleasing.

Treatment sequencing for the multiunit restoration: hard and soft tissue considerations.

Although the predictability of treating full or partial edentulism with dental implants has long been established, the choice of whether to use a fixed or removable prosthesis to restore such implants remains a complex one. Attention to such factors as the amount of vertical and horizontal bone loss that has occurred, the quality and quantity of the soft tissue, and the patient's restorative history can simplify treatment planning.

Piezosurgery: basics and possibilities.

Useful in a variety of oral surgery procedures, piezosurgery has therapeutic features that include a micrometric cut (precise and secure action to limit tissue damage, especially to osteocytes), a selective cut (affecting mineralized tissues, but not surrounding soft tissues), and a clear surgical site (the result of the cavitation effect created by an irrigation/cooling solution and oscillating tip). Because the instrument's tip vibrates at different ultrasonic frequencies, since hard and soft tissues are cut at different frequencies, a "selective cut" enables the clinician to cut hard tissues while sparing fine anatomical structures (e.g., schneiderian membrane, nerve tissue). An oscillating tip drives the cooling-irrigation fluid, making it possible to obtain effective cooling as well as higher visibility (via cavitation effect) compared to conventional surgical instruments (rotating burs and oscillating saws), even in deep spaces. As a result, implantology surgical techniques such as bone harvesting (chips and blocks), crestal bone splitting, and sinus floor elevation can be performed with greater ease and safety.

Pericardium membrane and xenograft particulate grafting materials for horizontal alveolar ridge defects.

PURPOSE: The purpose of this study was to evaluate the clinical feasibility of using a native collagen physical resorbable barrier made of bovine pericardium to augment localized alveolar ridge defects for the subsequent placement of dental implants. MATERIALS & METHODS: There were 8 systemically healthy patients with 19 implant sites (aged 35 to 68 years), with inadequate dental alveolar ridge widths, selected for study. All patients completed initial therapy, which included scaling, root planning, and oral hygiene instruction. All ridge defects were augmented with bovine xenograft and a collagen pericardium membrane. Horizontal (width) hard tissue measurements were taken the day of ridge augmentation surgery, or implant placement and augmentation (baseline), and at the 6-month (reentry or uncovering) surgery. RESULTS: The change in ridge width varied from a loss of 0.2 mm to a gain of 7.8 mm, measured clinically with a mean value of 3.0368 and a median of 2.8 mm from baseline. CONCLUSIONS: The results suggested that pericardium collagen membrane may be a suitable component for augmentation of localized alveolar ridge defects in conjunction with different xenografts.

Esthetic buccal flap for correction of buccal fenestration defects during flapless immediate implant surgery.

BACKGROUND: Clinically, it is a tremendous challenge to create natural gingival esthetics after immediate or delayed implant placement. Hence, flapless immediate implant surgery has been proposed to overcome the shortfalls of these techniques. Nonetheless, one of the major limitations for this technique is its inability to correct localized horizontal/vertical deficiency, dehiscence, or fenestration without jeopardizing esthetic outcomes. Therefore, the aim of this paper was to present a new flap design, the esthetic buccal flap (EBF), aimed at overcoming this potential problem while maintaining the optimal esthetic appearance. METHODS: Five consecutively EBF-treated patients with simultaneous implant placement were included in this pilot case study. Clinical measurements were taken at the time of prosthesis insertion and 6 and 12 months after surgery. These included soft tissue height, papillae appearance, scar appearance, and mid-buccal probing depth. RESULTS: Data obtained from this pilot case study showed that soft tissue height was preserved, and papillae appearance remained the same as at presurgery. No scar tissue was reported in any cases. Mid-buccal probing depths remained consistent throughout the study. CONCLUSION: The results indicate that EBF, together with simultaneously guided bone augmentation, allows clinicians to correct apical buccal fenestration defects while maintaining the supraosseous soft tissue during flapless immediate implant surgery.