International Journal of Periodontics & Restorative Dentistry, 03/2014

This study evaluates whether alveolar ridge preservation and new bone formation is possible through extraction site management using autogenous hard and soft tissue grafts, in cases of buccal alveolar bone defects. Fifty-eight extraction sockets were consecutively completely filled with autogenous bone chips after tooth extraction in 49 patients from 2004 to 2006. At least half of the buccal alveolar wall was absent after tooth extraction in all cases. A free gingival-connective tissue graft from the palate sealed the grafted extraction site. Approximately 10 to 12 (mean, 10.9) weeks after socket augmentation, implants were inserted. A histomorphometric analysis was performed on trephine bone cores removed from the grafted sockets in seven consecutive cases. Standardized volumetric measurements of the buccal alveolar contour were evaluated before tooth extraction, 1 year, and 5 years after prosthetic incorporation. Implants could be inserted into 47 (81.0%) treated extraction sockets without additional grafting procedures. In 11 patients (19.0%), implant placement was combined with local grafting techniques. Bone grafts were mature and well revascularized 10 to 12 (mean, 10.9) weeks after socket augmentation. The mean amount of vital bone was 52.0% ± 8.6%. Standardized volumetric measurements showed that 83.3% of the reference points representing the outer alveolar contour did not change significantly from baseline to 1 year after prosthetic incorporation and from baseline to 5 years after prosthetic incorporation. None of the reference points showed a statistically significant change in volume from 1 to 5 years after prosthetic incorporation. Extraction site management using autogenous hard and soft tissue grafts enables new bone formation in cases of buccal alveolar bone defects, offers a long-term alveolar ridge preserving technique, and reduces total implant treatment time.

Anatomical characteristics, such as shallow vestibular depth, high frenum attachments, and thin labial bone tend to make treatment of mandibular gingival recession defects particularly challenging. Even though a number of recent systematic reviews have identified the connective tissue graft (CTG) in combination with coronally advanced flaps (CAF) as the most consistently effective treatment procedure for Miller Class I and II defects, they did not separate maxillary vs mandibular outcomes, reporting instead aggregate results. In this prospective consecutive case series, recombinant human platelet-derived growth factor-BB (rhPDGF-BB) was combined with CTGs for the treatment of Miller Class I or II mandibular gingival recession defects in 11 healthy patients. Changes for both mean recession depth and width from baseline to week 24 were statistically significant, with mean recession depth decreasing from 3.4 ± 0.5 mm to 0.8 ± 0.8 mm and mean recession width decreasing from 3.1 ± 0.7 mm to 1.7 ± 1.3 mm. As a result of the improvement in recession depth, the mean percent root coverage seen in this mandibular prospective consecutive case series at 6 months was 79.6%. Despite treatment results that were comparable to historical norms, the outcomes, especially percent root coverage at 24 weeks, were somewhat less favorable, emphasizing the anatomical challenges of mandibular recession defects.

The dental literature has reported vertical soft tissue changes that can occur with immediate implant placement, bone grafting, and provisional restoration ranging from a gain or loss of 1.0 mm. However, little is known of the effects of facial-palatal collapse of the ridge due to these clinical procedures. Based upon treatment modalities rendered, an ensuing contour change can occur with significant negative esthetic consequences. The results of a retrospective clinical cohort study evaluating the change in horizontal ridge dimension associated with implant placement in anterior postextraction sockets are presented for four treatment groups: (1) group no BGPR = no bone graft and no provisional restoration; (2) group PR = no bone graft, provisional restoration; (3) group BG = bone graft, no provisional restoration; and (4) group BGPR = bone graft, provisional restoration. Bone grafting at the time of implant placement into the gap in combination with a contoured healing abutment or a provisional restoration resulted in the smallest amount of ridge contour change. Therefore, it is recommended to place a bone graft and contoured healing abutment or provisional restoration at the time of flapless postextraction socket implant placement.

The aim of this study was a retrospective assessment of the up to 8-year clinical outcomes of zirconia ceramic single-retainer resin-bonded fixed dental prostheses (RBFDPs). Fifteen subjects (9 women, 6 men) with 15 anterior zirconia ceramic RBFDPs were included. The RBFDPs replaced 5 maxillary central incisors, 7 maxillary lateral incisors, and 3 mandibular lateral incisors. The patients willing to participate were recalled and the survival of the RBFDPs was assessed. The technical outcome was evaluated with modified United States Public Health Service criteria. Fracture and/or chipping of the restoration, occlusal wear, marginal adaptation, marginal discoloration, shape, surface texture, and esthetic integration were recorded. Biologic parameters were assessed, including vitality, probing pocket depth, gingival recession, plaque control record, bleeding on probing, and periodontal mobility. Data were descriptively analyzed using a paired t test (P < .05). Fifteen subjects with 15 RBFDPs were examined after a mean follow-up period of 53.3 months (SD, 23 months). No catastrophic failures occurred. The 4-year survival rate was 100%. Two early debondings occurred with successful recementation. No chipping of the veneering ceramic occurred. No differences in biologic outcomes between test and control teeth were found. The zirconia ceramic RBFDPs exhibited excellent clinical results in anterior regions and had a positive effect on the esthetic outcomes of the pontic regions.

In the mandibular anterior area, gingival recession can be associated with a minimal amount or lack of attached gingiva, a shallow vestibule, and high frenum insertion. These anatomical features may preclude the use of traditional root coverage procedures. This case series describes a a bilaminar technique with flap incision in the fornix for the treatment of adjacent gingival recession defects in patients with a shallow vestibule. It achieved high predictability in complete root coverage without decreasing the vestibular depth. At 24 months, the treatment resulted in 90.6% ± 16.8% root coverage, and 11 of the 15 treated teeth (73.3%) were completely covered.

This article describes alveolar ridge reconstruction in the esthetic zone using autogenous bone blocks harvested from the chin, taking into account the way the bone block is harvested, stabilized, and contoured in the recipient site. The 38 procedures were divided into two groups: group 1, using piezoelectric surgery, and group 2, using rotary instruments. The piezoelectric surgery technique made it possible to introduce surgical modifications. An observation of bone regeneration and follow-up clinical observations 5 to 7 years after the procedure revealed that the piezoelectric surgery technique provides better and more predictable clinical results for bone regeneration.

The purpose of this study was to assess osseous parameters and stability of maxillary anterior teeth following crown lengthening surgery. Thirty-six patients requiring facial crown lengthening of 277 maxillary anterior and first premolar teeth were included. Presurgical and intraoperative clinical measurements were recorded at baseline and 1, 3, and 6 months postsurgery at midfacial, mesiofacial, and distofacial line angles. The data presented here suggest that when crown lengthening anterior maxillary teeth, the distance between the desired gingival margin and alveolar crest is usually insufficient to allow for biologic width. In addition, there is significant tissue rebound that may stabilize by 6 months. Tissue rebound appears related to flap position relative to the alveolar crest at suturing. These findings suggest that clinicians should establish proper anterior crown length with osseous resection.

The guided tissue regeneration (GTR) procedure has been demonstrated to successfully correct gingival recession (GR) defects. The aim of this study was to assess the feasibility of using the combination of a coronally advanced flap (CAF) with an extracellular membrane (ECM) to correct GR. GR defects were induced in the maxillary posterior region in five baboons. A 3-month healing period followed before the ECM was placed over the defect and covered with a CAF. Probing depth (PD), recession depth (RD), recession width (RW), and keratinized tissue width (KTW) were measured at baseline and 3 months postoperatively. Block biopsies of the treated areas were submitted for histologic review after a healing period of 3 months. There were no significant differences between the test (ECM + CAF) and control (CAF) groups in terms of changes in PD, RD, RW, and KTW after 3 months of treatment. However, significant differences have been noted for preoperation and postsurgery RD and RW values for both the control and test groups. Histomorphometric results showed minimal alveolar bone and connective tissue replacing the ECM membrane. CAF (either with or without the use of an ECM) is effective for the treatment of GR defects.

It has been shown that implant designs and different vertical positions have an influence on crestal bone. The purpose of this study was to use finite element (FE) analysis to biomechanically investigate the influence of the stress/strain distribution in a maxillary anterior 3.0-mm-diameter implant in relation to its apicocoronal level after oblique loading. Two different FE models, depending on implant position relative to bone crest, were applied. It can be concluded that placing the implant-abutment interface supracrestally provides decreased levels of stress and strain in the surrounding bone. However, placing the implant 0.5 mm supracrestally is also acceptable according to this analysis.

The purpose of this study was to identify the factors that create differences in opinion between dental professionals when treatment planning for a patient whose problem is limited to one or more maxillary incisors. A series of computer-generated scenarios was created in which anterior teeth were compromised for various reasons. The cases were used to survey a diverse group of practitioners regarding whether to treat or extract a tooth under the given circumstances. The results indicated that numerous patient-associated factors had statistically significant effects on the decision-making process. These included the patient's age, root length, root morphology, periodontal status, history of prior endodontic treatment, presence of posts, and size of periapical radiolucencies. The data also showed that a clinician's educational background had a dramatic impact on his or her treatment recommendation.

The socket or ridge preservation approach known as the "ice cream cone" technique was used in type 2 sockets in this retrospective analysis of 11 extraction sites. A type 2 extraction socket is defined as having the presence of facial soft tissue with a partial or complete dehiscence of the buccal bone plate. All teeth were extracted atraumatically without flap elevation. A resorbable collagen membrane was contoured into an ice cream cone- shape, placed into the socket defect, and grafted with human freeze-dried bone allograft. Buccolingual dimensional changes were measured manually with a digital caliper sensitive to 0.01 mm on pre- and posttreatment casts using an acrylic template and a three-dimensional (3D) digital scanner, as well as radiographically with pre- and post-cone beam computed tomography (CBCT) scans. All implants were placed 6 months after socket preservation and achieved primary stability with a minimum torque value of 35 Ncm with a mean buccal-lingual dimensional loss of 1.32 mm. The dimensional change of the ridge from pre- to postextraction reflective of the healed grafted site ranged from a loss of 0.46 to 2.25 mm with a mean of 1.28 mm (CBCT), 0.31 to 2.71 mm with a mean of 1.36 mm (digital calipers), and 0.21 to 2.80 mm with a mean of 1.32 mm (3D digital scanner). All 11 implants were immobile and clinically osseointegrated. The so-called ice cream cone technique allows for the reconstruction of a buccal plate dehiscence to enable the placement of an implant; however, the ridge dimension was diminished by 1.32 mm compared with the width of the extraction socket prior to tooth removal.

The aim of this study was to evaluate the use of bonded partial restorations compared with full-coverage porcelain-fused-to-metal (PFM) crowns as a viable treatment option for endodontically treated posterior teeth. Forty-five recently extracted maxillary first premolars were collected, endodontically treated, and mounted in acrylic blocks. The specimens were randomly divided into three groups and prepared to receive their respective restorations. The teeth in group 1 received full-coverage porcelain-fused-to-metal crowns. The teeth in group 2 received bonded partial restorations made from pressed ceramics (lithium disilicate) involving a functional cusp (palatal). Finally, group 3 received bonded partial restorations made from pressed ceramics involving the buccal cusp and keeping a functional cusp (palatal) intact. All group 1 restorations were cemented using glass ionomer cement. Restorations in groups 2 and 3 were bonded using a dual-cured resin cement. All specimens were subjected to an aging process and tested for shear bond strength using a universal loading machine. The mean force applied in Newtons to cause failure for group I was 674.90 ± 94.16 N, for group 2, 463.46 ± 61.11 N, and for group 3, 849.33 ± 68.92 N. P values obtained using one-way analysis of variance showed a highly significant difference between groups 2 and 3 (P = .001), groups 1 and 2 (P = .001), and groups 1 and 3 (P = .001). The fracture modes observed in all groups involved restorations and tooth fracture. This in vitro study suggests that endodontically treated posterior teeth with intact functional cusps can be restored with bonded partial porcelain restorations. However, if the loss of tooth structure involves the functional cusp, full-coverage PFM crowns are the treatment of choice.

The aim of this study was to histologically assess alveolar bone remodeling around immediate implants placed in single and multiple contiguous extraction sites. Ten dogs were divided into three groups (with six sites per group) on the basis of premolar teeth extraction: group 1 = one tooth extracted, group 2 = two contiguous teeth extracted, and group 3 = more than two contiguous teeth extracted. Immediate implants were placed in each group. Histologic assessment of arches showed no evidence of vertical bone loss (VBL) around implants in group 1 compared with groups 2 (P < .001) and 3 (P < .001). Buccal and lingual bone thicknesses and bone-to-implant contact (BIC) were higher around implants in group 1 compared with groups 2 (P < .001) and 3 (P < .05). Buccal and lingual bone thicknesses, BIC, and VBL are compromised around implants in multiple contiguous extraction sites compared with those in a single extraction site.

The goal of this study was to evaluate the ability of the modified apically repositioned flap (MARF) technique to increase keratinized tissue at the donor site and to analyze if this procedure would enhance the indication for and predictability of the laterally positioned flap (LPF) without any consequences to the donor area. Thirty isolated defects with recession and/or lack of attached gingiva were treated in 30 healthy patients. All donor areas adjacent to these defects lacked ideal gingival conditions both in height and width. The MARF technique was used to increase these areas 8 weeks before the LPF was performed. Clinical evaluation was done at the donor and receptor areas after 18 months. The results showed that the donor area increased from 2.78 to 5.01 mm at 8 weeks and remained at 3.28 mm after the use of the LPF. The marginal tissue recession and probing depth remained clinically unchanged. In the receptor area, the recession decreased from 1.86 to 0.57 mm, and the keratinized and attached tissue increased from 0.71 to 3.57 mm and from 0.05 to 2.49 mm, respectively. The use of the MARF technique to enhance keratinized tissue at the donor area proved to be an efficient and predicable technique that also augmented LPF use without any consequences to the donor site.

This study reports on the histologic characteristics of the early phases of implant osseointegration, focusing on osteopontin concentrations in the coronal area of implants placed with marginal defects and in control sites without defect preparation. In the mandibular right area of 12 dogs, two recipient sites were prepared and the margins were widened to obtain a gap of 0.5 mm at one site (small defect) and 1.25 mm at another site (large defect). Implants were placed and allowed a fully submerged healing. The procedure was subsequently performed in the left side in such a way as to obtain healing times of 5, 10, 20, and 30 days. Paraffin sections were stained with osteopontin antibodies and analyzed. At control implants, scarcely organized collagen fibers were observed in the space between the pristine bone and implant and were quickly replaced by mineralized tissue. In the small and large defects, the collagen fibers were organized in a layer that ran parallel to the implant at day 10 and became denser and thicker with time. Osteopontin was evenly distributed in the peri-implant tissue at control implants, while it was mainly located in the collagen bundle section around the implants placed in the defects.

The aim of this clinical case series was to evaluate buccal bone thickness using cone beam computed tomography and to demonstrate optimal clinical outcomes for implants placed into extraction sockets in the anterior maxilla with a thin biotype, by placing a graft of mineralized and demineralized human bone allograft into the buccal gap. The preliminary outcomes showed good preservation of soft and hard tissue architecture after 1 year in function. In particular, in eight patients, this allograft mixture appeared to minimize the amount of buccal contour change in the extraction site ridge with a thin buccal plate.