International Journal of Periodontics & Restorative Dentistry, 03/2019

The purpose of this animal study was to determine which ratio of hydroxyapatite (HA) and tricalcium phosphate (TCP) is the most appropriate in the composition of alloplastic biphasic block grafts, in terms of bone density and bone formation, for the regeneration of alveolar defects. Different concentrations of HA/TCP were used for the alloplastic block grafts: 100/0 (HA100 group), 79/21 (HA75 group), and 57/43 (HA50 group); the control treatment filled the defect with a collagen plug. All control and test sites were covered with a resorbable collagen membrane. Sacrifices were performed at 4, 12, and 24 weeks after grafting. Microcomputed tomography and histologic and histomorphometric analyses were performed to determine bone density and the characteristics of the regenerated bone as well as the percentages of newly formed bone (NB), residual material (RM), and connective tissue (CT). Bone density increased significantly over time (P .001), with stabilization between 12 and 24 weeks (P = 1.000). No differences in density were observed between the different test blocks (P = .813). The percentage of NB increases over time, independent of the concentration (P .001). At 12 weeks, the control group exhibited more NB than the HA100 group (P .001). At 24 weeks, the HA50 group exhibited more NB than the HA100 (P .001) and control (P = .066) groups. At 24 weeks, the HA100 and HA75 groups showed high RM percentages. The HA50 group exhibited an increased tendency of less RM percentage compared with the HA100 and HA75 groups. Although slight differences were found, the HA50 group's HA/TCP ratio seems the appropriate concentration when taking into account the bone density and percentage of NB and RM at 12 and 24 weeks of healing.

The purpose of this case series was to evaluate the survival rate and the incidence of complications of implants inserted and immediately loaded in sites where an impacted tooth was present in the anterior maxillary or mandibular arches (incisor to premolar). The implants were immediately inserted, drilling through the impacted teeth. Site preparation started in the crestal bone and continued into the impacted tooth's enamel and dentin. Seven patients were treated and 11 implants were inserted, 3 in the mandibular arch and 8 in the maxillary arch. All implants healed uneventfully without any adverse clinical or radiographic signs or symptoms, resulting in a success rate of 100%. Once loaded, the implants were in function and monitored for 5 to 7 years. Although more studies and a larger sample size are needed to validate this unconventional procedure, it may be considered as a possible clinical option to overcome invasive procedures and surgical complications related to the extraction of impacted teeth.

The purpose of this case series was to evaluate peri-implant tissues in 10 patients at 1 year after placement of a tapered 3.0-mm laser-microtextured dental implant (Laser-Lok, BioHorizons) using a two-stage approach. Clinical and radiographic measurements were assessed. Keratinized tissue at the facial surfaces of each implant had a slight increase of 0.73 mm (95% confidence interval [CI], P = .058), and marginal bone levels had significant increase of 1.85 mm (95% CI, P = .005) at 1 year compared to baseline. These data suggest that 3.0-mm laser-microtextured implants demonstrate stable or improved soft and hard tissue parameters at 1 year postloading.

This case series aimed to clinically and histologically evaluate porcine-derived membrane used for vertical thickening of thin soft tissues. Twenty porcinederived collagen membranes and bone-level implants were placed in 20 patients. After 2 months, thickened soft tissues were measured and biopsy samples were harvested. All xenografts healed successfully. The average thickness of thin soft tissue before vertical thickening was 1.65 ± 0.36 mm, while tissue thickness increased to 3.45 ± 0.52 mm after the procedure (P .001); the mean thickness increase was 1.8 ± 0.13 mm. Histologic analysis showed complete integration of the graft and no differences (P = .4578) in vascularization between the host (39.74 ± 17.15 vessels/mm2) and graft (30.43 ± 11.26 vessels/mm2). It can be concluded that porcine-derived membrane can be used for vertical soft tissue thickening with substantial gain in tissue height.

Several techniques have been proposed to maintain full papillary form and preserve soft tissue during periodontal surgical access. However, very little evidence of long-term results is available. The aim of the present paper is to report the 15- to 20-year follow-up outcomes of a case series study of papillae preservation flap surgery in esthetic areas. Twenty-two patients (10 women, 12 men; mean age: 41.3 years) with moderate to advanced generalized periodontitis were included in this study carried out in a private office from 1994 to 1996. In each patient, nonsurgical therapy with scaling and root planing was performed. Following this initial phase of therapy and the periodontal re-evalutaion, a papillae preservation flap surgery was performed in the anterior maxillary area in each subject. Full-mouth Plaque Index (FMPI), Gingival Index (GI), full-mouth Bleeding Score (FMBS), probing depth (PD), bleeding on probing (BOP), clinical attachment level (CAL), gingival recession (GR), and papilla height (PH) were assessed at the baseline and at each year of the follow-up. GI and BOP decreased with a statistical difference after surgery (P .05) and remained low over the entire observation period. At the end of the follow-up period, PD and CAL decreased significantly (P .05) compared to baseline (PD from 7.18 ± 0.91 mm to 2.98 ± 0.49 mm; CAL from 8.06 ± 1.2 mm to 4.01 ± 0.28 mm). Gingival recession and papilla height did not change significantly after surgery compared to baseline (GR from 0.88 ± 0.42 mm to 0.92 ± 0.36 mm; PH from 5.6 ± 1.1 mm to 4.2 ± 0.8 mm) and remained stable over the 15 to 20 years of the study (GR = 1.12 ± 0.36 mm; PH = 4.9 ± 0.9 mm) (P > .05). Results of the present long-term study show that the papillae preservation flap procedure may be applied successfully to the treatment of periodontal pockets in the maxillary anterior region.

This study evaluated implant outcome in patients with Down syndrome (DSPs) and provides clinical guidelines to maximize treatment outcome. A total of 57 implants were placed in eight DSPs. During follow-up, implant survival was recorded and crestal bone level was evaluated when possible. After a mean follow-up time of 5 years, six patients with 45 implants were evaluated and an implant survival rate of 84.4% was recorded. A mean crestal bone loss of 1.7 mm (SD 0.9) was measured in three patients around 20 implants. Down syndrome is not a contraindication to dental implant placement, but multiple complicating factors yield reduced implant survival.

This study aimed to histologically investigate the bone tissue response to zirconia implants functionalized with a biomimetic calcium phosphate (CaP) coating incorporated with bone morphogenetic protein-2 (BMP-2). Zirconia implants coated with biomimetic CaP were prepared with and without BMP-2. Untreated zirconia implants served as a control. These three groups of implants were placed randomly in the mandibles of six beagle dogs (n = 6). Three months later, samples were harvested for histomorphometric analysis. The present study showed that the application of a biomimetic CaP coating incorporated with BMP-2 enhanced the peri-implant osteogenesis for zirconia implants.

This study evaluated the impact of soft tissue grafts to reduce marginal periimplant recession (MPR) after 1 year of follow-up. A total of 24 patients with one single failing maxillary incisor presenting facial bone dehiscence and receiving an immediate implant, bone graft, and provisional were randomly divided into three groups (n = 8 in each group): control (CTL), collagen matrix (CM), and connective tissue graft (CTG). Clinical, photographic, and tomographic analyses were performed to evaluate tissue alterations. The use of a CTG avoided MPR (P .05) and provided better contour of the alveolar ridge (P .01) and greater thickness (P .05) of the soft tissue at the implant facial aspect.

Gingival recession is a component of periodontal disease that leads to exposure of the root surface, root hypersensitivity, and esthetic concerns. Treatment of these cases is typically performed with autologous grafts harvested from the palate. However, this is associated with a second surgical site that increases surgical time and patient morbidity. A potential alternative is the use of cryopreserved umbilicalcord allografts, which are known to contain anti-inflammatory properties and have been used clinically by numerous medical specialties. In this observational series, three patients with gingival recession (average gingival margin [GM]: 3.16 ± 1.13 mm) showing Miller Class I to III gingival recession were treated with cryopreserved umbilical-cord allografts. Ten days after the root coverage procedure, all patients reported no pain or discomfort, and only normal, mild swelling was observed. After 3 months, the gingival tissue was completely healed and matched the color and texture of the patient's surrounding tissue. At 1 year after surgery, patients exhibited 100% root coverage at 33 of 38 treated sites (average GM: 0.18 ± 0.51 mm), as well as an increase in band of attached gingiva. The encouraging safety and effectiveness of this report warrant further investigation of using cryopreserved umbilical cord allografts for periodontal root coverage.

A total of six patients treated from 2010 to 2014, having a knife-edge ridge (Cawood-Howell Class IV resorbed ridges) and requiring an implant-prosthetic rehabilitation, were selected. Tomographic measurement of the edentulous ridges was performed before grafting and after implant placement. At 6 months postgraft, a total of 41 implants had been inserted, 17 in the posterior region, 12 in the central region, and 12 in the anterior region. No surgical or healing complications were recorded, and the prostheses were loaded 6 to 9 months after implant placement. The tomographic measurements demonstrated an increased area in all the sites where bone augmentation had been performed, corresponding to 11.1% in the anterior region, 94.7% in the central region, and 760.2% in the posterior region. Histology was performed in 2 patients, one at 1 year and the other at 5 years postgrafting, and demonstrated the presence of mature lamellar bone tissue and newly formed bone without morphologic signs of necrosis or inflammation and a reduction of 50% to 30% of the grafted material. Although this study included a small number of clinical cases, it demonstrated how management of the atrophic maxillary ridge, with the goal of implant placement, may be handled using a technique that requires a single anorganic bovine bone-derived mineral treatment combined with a plasma rich in growth factors and resorbable collagen membrane.

Thirty-eight patients (aged 25 to 74) requesting extraction-socket and sinus augmentation procedures (27 and 11 patients, respectively) prior to implant placement volunteered to participate in this case series protocol. Surgical sites were grafted with either biphasic calcium phosphate (BCP) + collagen (for extractionsocket augmentation) or BCP with a collagen barrier membrane (for maxillary sinus augmentation). All patients completed the 1-year postloading follow-up, which consisted of clinical and radiographic evaluations. No implants were lost, and both healthy soft tissue support and good radiographic evidence of supporting bone were found around implants. The result of this short-term evaluation of implants placed in areas grafted with alloplasts seemed to be favorable and promising.

Chronic periodontitis progression may go through phases of remission and exacerbation. The possibility of periodontal pathogens translocating from infected periodontal sites to peri-implant sites has been reported. Additionally, a history of periodontal disease seems to be a risk factor for peri-implantitis. The present case reports a flare-up of chronic periodontitis concomitant with an episode of peri-implant infection on a documented stable implant site. Periodontal infection was managed nonsurgically by scaling root planing and antibiotic treatment. Peri-implant infection was treated by open-flap debridement and implant surface decontamination. A remarkable regeneration on the peri-implant defect occurred steadily over a 3-year period, leading to a full regeneration of the site relying exclusively on the individual healing resources.

The aim of these case reports was to introduce a simplified novel connective tissue graft (CTG) harvesting technique, the ring method, which could be used in the maxillary tuberosity area in particular. A special CTG harvesting punch was fabricated to obtain a ring-shaped CTG that had a uniform thickness. The ring graft was then used for peri-implant soft tissue augmentation with successful clinical outcomes. The ring method is a technically insensitive and minimally invasive surgical procedure that provides a certain amount of CTG for various periodontal plastic surgical interventions.

This study aimed to evaluate the effect of hydrofluoric (HF)-acid-etching time and the impact of a resin-cement layer on the biaxial flexural strength and structural reliability of a zirconia-reinforced lithium silicate (ZLS) glass ceramic. Disc-shaped specimens (n = 15) were divided according to: etching time (conditioning with 10% HF acid for 20, 40, and 60 seconds), and application of a resin-cement layer. Biaxial flexural, contact angle, and roughness analyses were performed. When the resin-cement layer was not present, flexural strength data increased with increasing etching times: 20 seconds = 250.8 MPa; 40 seconds = 278.4 MPa; 60 seconds = 342.9 MPa. Application of resin cement increased the strength values (20 seconds of acid etching on specimens with a resin-cement layer = 341.8 MPa). Different etching times did not affect the roughness of ZLS, and the contact-angle analysis presented lower values for 60 seconds of acid etching. The flexural strength of ZLS was only sensitive to surface changes when less exposure time was conducted. Longer etching times (40 and 60 seconds) should be considered for conditioning ZLS ceramic along with adhesive cementation.

Collagen matrices (CMs) could be used instead of connective tissue grafts (CTGs) for treatment of gingival recession (GR). The authors aimed to compare clinical outcomes after treatment of isolated GR affecting both maxillary canines of 10 patients (n = 10) with CM (OsteoBiol Derma) or CTG in conjunction with coronally advanced flap. After 12 months, CM and CTG showed complete correction in 7/10 and 10/10 of sites, respectfully, and percentage of root coverage was 85% ± 24% and 100%, respectively. For treatment of isolated GR, CM is a viable alternative to CTG.

This paper performed time and cost analyses and compared conventional vs computer-assisted implant planning and placement (CAIPP) protocols when placing single implants in partially edentulous patients. Partially edentulous patients were randomly allocated to one of three treatment groups: preoperative planning based on a conventional two-dimensional radiograph and free-hand implant placement (control [C], n = 26) or computer-assisted implant planning based on three-dimensional (3D) computer-tomography (test group 1 [T1], n = 24; test group 2 [T2], n = 23). A surgical guide was produced by stereolithography in T1 and by 3D printing in T2. In all patients, open-flap implant placement procedures were performed. Time and costs derived from each working step were recorded for each treatment protocol. Descriptive and analytic statistics were used to display the data and uncover differences between treatment groups. Overall office time was similar in all groups (C = 63.8 min; T1 = 77.2 min; T2 = 81.7 min). CAIPP and conventional protocols required similar times to perform the preoperative diagnosis, radiographic exam, and implant surgery. CAIPP protocols required longer surgical planning and template-production times. Overall economic costs were 31% (T1) to 20% (T2) higher for the CAIPP protocols due to the radiographic investigation and the surgical template production (C = Swiss francs [CHF] 1,567; T1 = CHF 2,268; T2 = CHF 1,946). In the present indication and methodologic set-up, computer-assisted protocols did not show an advantage over conventional protocols in terms of time or financial savings. The temporal and financial expenses should be put into perspective to potential benefits.

Keratinized tissue around implants is beneficial for soft tissue stability and esthetics. The aim of this investigation is to show the use of amnion/chorion membrane to increase the keratinized tissue. Fifteen patients were grafted with the allograft at the first or second stage of implant surgery. The mean values of keratinized tissue were 1.27 ± 0.46 mm, 2.00 ± 0.38 mm, 2.80 ± 0.78 mm, and 3.27 ± 0.80 mm at the initial evaluation and 7, 15, and 60 days postsurgery (prosthetic delivery was at day 60), respectively (P .001). Most increase occurred between 7 days up to the prosthetic delivery. Use of the amnion/chorion membrane seems to improve keratinized-tissue expansion.

This article aims to evaluate and compare the 10-year bone anchorage and protrusion of implants into the sinus using cone beam computerized tomography (CBCT) and periapical radiography. Implants (≤ 10 mm) were placed with osteotome sinus floor elevation (OSFE) without grafting in maxillae with bone height ≤ 8 mm. After 10 years, the CBCT analysis showed bone presence at the buccal and palatal implant sides and corroborated the results obtained using periapical radiographs. In the absence of any symptom or complication, the use of two-dimensional radiography is sufficient for routine long-term follow-up of implants after OSFE without grafting.