International Journal of Periodontics & Restorative Dentistry, 06/2011

The atrophic posterior mandible has unique challenges when implant placement is planned. The purpose of this case series was to evaluate the use of recombinant human bone morphogenetic protein 2/acelluar collagen sponge (rhBMP-2/ACS) and titanium mesh for augmentation of the atrophic posterior mandible prior to implant insertion. The case series included five patients with inadequate bone in the posterior mandible for implant placement. The residual ridges were augmented with rhBMP-2/ACS and a small amount of bone substitute. Titanium mesh was used to protect the graft sites. Dental implants were inserted after 6 months of healing. Healing of the grafted ridges was uneventful. Dental implants were placed in all grafted sites without the need for further bone augmentation. All 10 implants integrated well and were restored with single crowns. The use of rhBMP-2/ACS with titanium mesh was effective in this case series for augmentation of the atrophic posterior mandible prior to implant placement. This approach offers many advantages, including technical ease, no need for bone harvesting, decreased morbidity, and reduced surgical time.

The purpose of this randomized controlled clinical study was to compare the survival of a one-piece anodically oxidized surface implant when placed with a flapless or flap protocol. Bone loss measurements on radiographs and changes in clinical probing depths 1 year post-definitive restoration placement were recorded and compared. Fifty-two of 60 patients (implants) remained in the study at the 1-year follow-up. At the time of final evaluation, no implant was lost in either group. At the time of placement of the definitive restoration, there was a mean mesial and distal bone gain in both groups compared to bone levels present at the time of implant insertion. There were no significant changes in bone levels between placement of the definitive restoration and those recorded 12 months later, and no significant differences in bone levels between the flap or flapless group at 6 or 12 months were noted. No significant differences were seen either in pocket depth or change in pocket depth at 6 and 12 months in the flapless and flap groups. It was therefore concluded that one-piece anodically oxidized surface implants, 1 year post-definitive restoration insertion, had high survival rates (100%) and stable marginal bone and probing depth levels whether a flapless or flap protocol was used for implant insertion.

The aim of this study was to conduct a 1-year full esthetic evaluation of the treatment outcomes of gingival recession using the root coverage esthetic score (RES) system. One hundred patients with 195 single or multiple recessions were treated using different techniques. One year after surgery, the clinical outcomes were evaluated. Only 21 of 195 (11%) treated recessions obtained the maximum RES score (10), while 68 recessions (35%) showing complete root coverage obtained lower scores. Both single and multiple recessions treated with a coronally advanced flap with or without connective tissue grafting achieved similar RES scores. Free gingival grafts showed the lowest score.

The objective of this case series was to evaluate the clinical and histologic outcome of guided bone regeneration around simultaneously placed implants in sites with missing buccal bone walls. Eight weeks after tooth extraction, implants were inserted, and the sites were augmented in both the horizontal and vertical dimensions using a mineralized collagen bone substitute and a nonresorbable titanium-reinforced membrane. Six months later, small hard tissue biopsy specimens were harvested from the buccal bone walls at approximately mid-height of the original defect. The histologies revealed ongoing bone formation. Clinically, an adequate amount of hard and soft tissue volume had formed.

The coronally advanced flap has been documented as an effective surgical technique for the treatment of gingival recessions in cases of multiple adjacent recession defects, obtaining stable long-term results after 5 years of follow-up. The aim of the present study was to test the coronally advanced flap, in association with a connective tissue graft, in a case series of 10 patients presenting at least two gingival recessions on adjacent teeth in the posterior mandibular area. Periodontal parameters were recorded on teeth involved in the surgeries at baseline and 1 year. A total of 26 recessions were treated. No significant complication affected the surgeries, and no patient abandoned the study. Recession depth was reduced from 3.40 ± 0.83 mm at baseline to 0.28 ± 0.32 mm at the 1-year control, while differences in pocket depth were not significant. Keratinized tissue increased from 0.57 ± 0.46 mm to 3.05 ± 0.71 mm. Greater reductions in recession depth were observed in cases where the initial conditions were worse. A mean 91.2% ± 4.1% recession coverage was obtained. The coronally advanced flap in association with a connective tissue graft can be proposed as a valid therapeutic approach for multiple recession defects in mandibular posterior areas.

Surface roughness is important for implant osseointegration. It has mostly been assessed by amplitude and height descriptors. Fractal analysis is derived from fractal geometry and is used to describe the organization of objects found in nature, quantifying their shape complexity with a value. Fractal dimension (Df ) is an index of the space-filling properties of an object and can be used as a parameter that describes the organization of surface roughness. The greater the Df value, the more chaotic the surface topography. The aim of this study was to assess the Df of implants with three different surface topographies to evaluate whether a novel method to measure roughness of implant surface topography could be developed. Forty-five disk-shaped samples (10 × 2 mm) with three different surface topographies were analyzed by scanning electron microscopy: group A, machined surface; group B, sandblasted and acid-etched surface; and group C, sandblasted, acid-etched, and neutralized surface. Images at 20,000× and 50,000× magnification were processed for quantitative analysis of Df using the box-counting method. Df values were correlated to the image magnification. At 20,000× magnification, Df for groups A, B, and C was 1.81, 1.67, and 1.59, respectively. At 50,000× magnification, Df was lower for all examined groups; more specifically, Df was 1.77, 1.59, and 1.42 for groups A, B, and C, respectively. Statistically significant differences were found between groups A and C at both magnifications. Df is used widely and successfully as a measurement to characterize anatomical structures and physiologic and pathologic processes. Df not only provides an index of roughness size values, but also a measure of roughness spatial organization; therefore, it could be a promising method to differentiate between rough surfaces capable of supporting osseointegration.

The aim of this study was to compare modified Widman flap surgery (MW) to coronally advanced flap surgery combined with carbon dioxide laser root conditioning (CAF + CO2) from baseline to 15 years of follow-up. Each of 25 patients participating in this study were treated using a split-mouth design: In one quadrant, the teeth received MW surgery (control), and on the other side, after a full-thickness flap was raised, a CO2 laser was used and the fullthickness flap was repositioned coronally and sutured (CAF + CO2, test). Plaque Index, Gingival Index, probing depth, and clinical attachment level were monitored from baseline to 15 years. For probing depths >= 7 mm, CAF + CO2 sites provided greater pocket reduction (P .01), and data on clinical attachment level showed a significant difference between control and test sites at 5 to 6 mm (P .001) and >= 7 mm (P .001). This study showed that CAF + CO2 therapy resulted in significantly higher improvements than MW surgery.

An array of therapeutic options are available for treatment of gingival recession defects, though many of these are better suited for treatment of isolated defects. Some of the limitations of current techniques include the need for harvesting of autogenous donor tissues and their associated morbidity, as well as scar formation at the recipient site resulting from surface incisions. Moreover, muscle pull during healing often leads to incomplete root coverage or relapse of the recession. The current case reports introduce a novel, minimally invasive approach applicable for both isolated recession defects as well as multiple contiguous defects in the maxillary anterior region. Access to the surgical site is obtained by means of an approach referred to as vestibular incision subperiosteal tunnel access (VISTA). This entails making an access incision in the maxillary anterior frenum, followed by elevation of a subperiosteal tunnel. VISTA allows for both access as well as an opportunity to coronally reposition the gingival margins of all involved teeth. In this approach, recombinant human platelet-derived growth factor BB saturated onto a matrix of beta-tricalcium phosphate is introduced using VISTA over root dehiscences to enhance periodontal healing. A novel method of stabilization of the gingival margins is also introduced, referred to as coronally anchored suturing, designed to maintain the coronal positioning during healing. The current report describes the technique and two clinical case documentations for treatment of Miller Class I and II defects, demonstrating stable, long-term outcomes. Although VISTA has been applied in other regions, its application is most advantageous in the esthetic zone.

Replacement of lost teeth using oral implants is an accepted treatment modality with well-documented high long-term success rates. Conventional screw- or threaded cylinder-type implants have been used almost exclusively. Their incongruence with the extraction socket necessitates the use of a barrier membrane or bone augmentation to prevent down-growth of connective tissue or epithelium between the implant and socket. Although some minor changes in implant design have been made, the neck and abutment connection areas have not changed much in the past 30 years. Custom-made root analog implants have been employed clinically in rare instances; however, they yielded failure rates of up to 96% at 1 year of follow-up. So far, ovoid implants are the closest in design regarding resemblance to the natural tooth anatomy. Root analog zirconia implants with macroretentions were developed and produced for immediate single-stage replacement of missing or hopeless teeth. This article discusses the treatment and 3-year follow-up of a patient with such an implant for replacement of a maxillary molar.

Gingival fibroblasts (GFs) play a considerable role in the maintenance of the gingival apparatus as well as in connective tissue repair. Mobility of a periodontal wound or soft tissue graft can impair connective tissue healing from the GFs. Enamel matrix derivative (EMD) is an enamel matrix protein used clinically for periodontal regeneration of intrabony defects and furcations, as well as treatment of gingival margin recessions. The goal of this project was to compare the effects of varying concentrations of EMD, with and without cyclic mechanical strain, on cellular wound fill of human GFs using an in vitro defect healing model. GFs were seeded and cultured in six-well flexible-bottomed plates. A 3-mm wound was created in the central portion of each confluent well. Three wells were treated with each EMD concentration of 0 µg/mL (control), 30 µg/mL, 60 µg/mL, or 120 µg/mL. The plates were placed in an incubator containing a strain unit to subject test plates to cyclic strain. An identical set of control plates were not flexed. Cells were examined on days 4, 8, 12, and 16. Microphotographs were taken and wound fill measurements made using image analysis software. The percent wound fill was calculated. All nonflexed plates, regardless of EMD concentration, reached > 90% defect fill at similar rates by day 16. However, in the flexed plates, EMD had a significant negative effect on defect fill. The defect fill was 55.7% for 0 µg/mL EMD, 48.2% for 30 µg/mL EMD, 36.7% for 60 µg/mL EMD, and 34.1% for 120 µg/mL EMD on day 16 for the flexed GFs. EMD, in concentrations as high as 120 µg/mL, did not significantly affect the amount of defect fill with nonflexed GFs. However, when the GFs were flexed, the addition of EMD had a significant negative effect on defect fill in a dose-dependent manner.

This study evaluated buccal bone maintenance after implantation with a surgical flap approach immediately following tooth extraction in a dog model. Mandibular premolars of six dogs were extracted, and threaded implants of 4-mm diameter and 8-mm length with as-machined and dual acid-etched surfaces were placed through balanced procedures in the distal root extraction sockets with a fullthickness flap design. Submerged healing was allowed for 4 weeks, and following euthanization, bone-to-implant contact and buccal and lingual bone loss were evaluated. None of the parameters evaluated were indicative of an effect of implant surface in hindering bone loss around immediately placed implants.

Surgical and nonsurgical techniques have been proposed to regenerate interdental papillae. The results are influenced by the morphology of the interdental space, which is the housing for the papilla. The concept of the interdental papillary "house" has been established not only to allow diagnosis of the causes of papillary loss, but also to manage and predict reconstruction of the interdental gingival tissue. The adjacent teeth in contact, involving the proximal contact, contour and shape of the teeth, course of the cementoenamel junction, interdental distance, and underlying bone crest, determine the outline of the house. Since the components are combined, an understanding of each allows adequate treatment planning involving interdisciplinary procedures. This new concept serves as a guide and teaching aid for the practitioner.

Periodontium-derived stem cells (pdSCs) can be cultured as dentospheres and differentiated into various cells of the neuronal lineage such as glial cells, thereby demonstrating their stem cell state. This study investigated whether pdSCs could be differentiated into the osteogenic lineage and, if so, whether these cells are able to regenerate periodontal tissue in vivo in an athymic rat model. Human adult pdSCs were isolated during minimally invasive periodontal surgery and expanded in vitro. To induce osteogenic differentiation, expanded pdSCs were cultured for 3 weeks in osteogenic differentiation media. Staining for alkaline phosphatase expression was positive, suggesting osteogenic differentiation. For in vivo studies, pdSCs were delivered onto suitable collagen sponges and implanted into periodontal defects on the right buccal cortex of the mandible in 16 immunodeficient nude rats. Histologic analysis of samples from the test side revealed reformation of periodontal ligament-like tissue, collagen fibers, and elements of bone, but no functional periodontal tissue regeneration. The data show that human adult pdSCs are capable of regenerating elements of bone and collagen fibers in an in vivo animal model.

Although every effort is made to place dental implants in a proper position, the restorative dentist does not always succeed. Historically, treatment options for poorly placed implants included removing the implant or leaving it "sleeping." Recent modifications of an existing technique, the segmental osteotomy, may offer hope in these situations by rendering many of these "hopeless" implants salvageable. This paper presents lessons learned from a series of cases in which segmental osteotomies were performed to improve the esthetic outcome of implant malpositioning. Two clinical cases (one successful, one failed) utilizing segmental osteotomy to surgically correct malposed implants are presented with a review of the literature associated with the technique. With adherence to proper case selection and detailed surgical protocol, segmental osteotomy is a viable treatment option to correct misaligned dental implants.

This study aimed to elucidate the changes in subgingival microflora before the extraction of severely periodontally involved teeth and 1 year after immediate implant placement and provisionalization without flap elevation. Clinical parameters were recorded for 20 maxillary anterior teeth from 10 individuals before and after implant treatment. The clinically observed improvement in the soft tissues was found to be compatible with a less pathogenic flora. Concentrations of periodontopathogens in the periodontal sites were heavily reduced when transformed into peri-implant sites, whereas the relevant counts of the beneficial microorganisms were increased.