International Journal of Periodontics & Restorative Dentistry, 06/2014

This case series presents the use of a resorbable "dome device" made of a slow, long-lasting resorbable suturing material to support the barrier creating and maintaining a secluded space to promote bone regeneration. Acellular dermal matrix or cross-linked resorbable collagen membrane, as barriers, combined with mineralized freeze-dried bone allograft, with simultaneous implant placement, were utilized in reconstructing non-space-making defects. Eight implants in six healthy patients were treated with a combination of these resorbable regenerative materials. Only one of seven was treated with a nonsubmerged approach. All sites remained completely covered and no implant exposure occurred during healing. At the 9- to 24-month reentry surgeries, the clinical bone density was equivalent to that of the native bone and the mean number of final exposed threads was 0.5. The mean buccal bone thickness achieved was 3.12 mm, with a mean total coverage of exposed threads in approximately 87.5% of the cases.

The aim of this study was to assess the threshold value for the perception of color changes of human gingiva. Standardized presentations of five cases in the esthetic zone were made with the gingiva and teeth separated. The color parameters L, a, and b (CIELab) of the gingival layers were adjusted to induce darker and lighter colors. In the presentations, the right side (maxillary right anterior) was unchanged, while the left side (maxillary left anterior) of the pictures was modified. Ten dentists, 10 dental technicians, and 10 lay people evaluated the color difference of the pictures. The mean ΔE threshold values ranged between 1.6 ± 1.1 (dental technicians) and 3.4 ± 1.9 (lay people). The overall ΔE amounted to 3.1 ± 1.5.

Traditional esthetic guidelines and denture-tooth selection protocols suggest a correlation between a patient's face and anterior tooth shapes. This study examined the correlation between face shape, maxilla shape, and maxillary anterior tooth form with fully automated algorithms. Three-dimensional digital datasets of the faces and maxillae were obtained from 117 people. Correlation was analyzed using canonical correlation analysis, ridge regression, and the Hausdorff-distance. A weak but not statistically significant correlation between face and tooth shape could be identified. However, a good prediction of tooth shape from the facial data was not possible. The described approach revealed a weak correlation between face shape and tooth shape, but the outcome was not accurate enough for clinical use.

Dental implant surface technology has evolved from a relatively smooth machined implant surface for osseointegration to more roughened osteoconductive surfaces. Recent studies suggest that peri-implant soft tissue inflammation with progressive bone loss (ie, peri-implantitis) is becoming a prevalent condition. One possibility that could explain such a finding is that more bacterial plaque forms on the roughened implant and abutment surfaces, which may result in the peri-implant inflammation in the soft tissues. This study compared 36 tissue-level implants with a machined transmucosal collar to 36 implants with a relatively roughened (SLActive) transmucosal surface in the dog. The implants were evaluated histologically and histomorphometrically after 3 and 12 months of loading. The results demonstrated that the connective tissue contact was similar between the two implant types but that the junctional epithelium and biologic width dimensions were greater around the implants with the machined collars. Interestingly, the amount of inflammation was similar between the two implant types. Slightly more bone formation and more mature collagen formation occurred around the implants with the roughened collars compared to the implants with machined collars. These results suggested that even if more plaque biofilm forms on the implants with the roughened SLActive surface compared to the machined surface, there is no biologic consequence related to the amount of inflammation or bone loss. In fact, the roughened surface promoted bone formation (was more osteoconductive) and more mature soft collagenous connective tissue.

Smoking is one of the strongest predictors of attachment and bone loss. Smokers demonstrate reduced inflammatory clinical signs, which could be due to local vasoconstriction and increased gingival epithelial thickness. The byproducts originating from tobacco oxidation modify the clinical characteristics and progression of periodontal disease. The aim of this study was to investigate the relationship between the thickness of marginal gingival oral epithelium, sulcular bleeding, and vascular caliber and density of the microvessels in smokers and nonsmokers with and without periodontitis and to better understand the role of smoking in relation to periodontal disease. One hundred twenty individuals were enrolled in this study and divided into four groups comprising 30 participants each. The clinical measurements carried out included probing depth, clinical attachment loss, and bleeding index, along with gingival biopsy specimens, which were subjected to immunohistochemical and histomorphometric analysis. Correlation of the clinical and histologic features revealed that smokers presented with fewer inflammatory signs, had fewer vascular elements in the subepithelial connective tissue layer, and showed a resultant increase in epithelial thickness irrespective of the presence of periodontitis. There was a mean increase of epithelial thickness of 181.3 μm (suprapapillary epithelial thickness [SET]) to 380.2 μm (maximal epithelial thickness [MET]) in smokers with periodontitis as compared to 157.4 μm (SET) to 325.3 μm (MET) in nonsmokers with periodontitis. The mean microvascular density in smokers with periodontitis was 325.4 per mm2, which was found to be statistically significantly less than that of nonsmokers with periodontitis, who had a mean value of 412.13 per mm2. The vessel caliber also was reduced in smokers, with a mean value ranging from 4.7 to 6.1 μm compared with a mean of 6.2 to 9.2 μm in nonsmokers, irrespective of the presence of periodontitis. Statistically significant differences were found in vascular density and thickness of gingival epithelium between smokers and nonsmokers with and without periodontitis. These differences may impact the progression of periodontal disease.

A mixture of mineralized allograft cortical and cancellous chips was used to augment the maxillary sinuses of 10 patients. Eleven sinus augmentation procedures were performed, and 19 bone cores were obtained at reentry after 6 to 7 months. Computed tomography at 6 months postaugmentation demonstrated bone formation in all sites. Light microscopic and histomorphometric evaluation confirmed bone formation at the treatment site that would receive osseointegrated implants to replace the missing maxillary posterior teeth. These encouraging results support the use of a mixture of mineralized allograft cortical and cancellous chips for sinus augmentation.

The purpose of this study was to evaluate the long-term clinical outcomes around implants placed in sites previously augmented with demineralized bovine bone mineral with 10% collagen (Bio-Oss Collagen, Geistlich). In this prospective study, 36 consecutive, healthy patients, in need of a single-tooth extraction (incisors, canines, and premolars) and implant replacement, were included. After tooth extraction, Bio-Oss Collagen was inserted in the socket and covered either with a double layer of collagen membrane (test) or with a few drops of a flowable polylactide polymer (control). Following a healing period of 4 to 6 months, a single nonsubmerged implant surgery was performed. After cementation of a single ceramic crown, patients were asked to follow an individualized supportive periodontal therapy program. Clinical and radiographic data were obtained after prosthesis delivery (baseline) and at the 10-year follow-up visit. At the 10‑year examination, two patients were lost to follow-up. All implants demonstrated healthy peri-implant soft tissues as documented by standard parameters (full-mouth plaque score, full-mouth bleeding score, local bleeding on probing) in both groups. Mean soft tissue recession (REC) was 0.39 ± 0.54 mm for the test group and 0.50 ± 0.33 mm for the control, with no significant difference between the two groups. The results of this prospective study confirmed the long-term stability of the peri-implant marginal soft tissues supported by regenerated bone by means of the described technique using Bio-Oss Collagen. If the patient is properly followed throughout time, the risk for mucosal recession is low, with 1 mm of mean REC after 10 years.

Dentists contemplating sinus augmentation frequently take a cone beam computed tomography (CBCT) scan as part of the work-up. Maxillary sinus pathology is common, and such dentists will be faced with pathologic sinus findings. Not all sinus pathology needs to be treated. The purpose of this article is twofold: to describe the most common sinus findings as seen on a CBCT scan and a way to recognize them, as well as to provide an algorithm for decision making on when further evaluation of the sinus is necessary.

This case series evaluated the use of a collagen matrix with a coronally advanced flap procedure for the treatment of multiple recession defects. Fifteen patients with a total of 80 recession defects were included. Root coverage was 85% ± 13% at 6 months and 81% ± 22% at 12 months. Complete root coverage was achieved in 60% of the sites after 6 months and in 56% after 12 months. The percentage of sites with thick gingival morphotype increased significantly. The results indicated that the collagen matrix may be a useful alternative to the connective tissue graft in the treatment of multiple recession defects.

Fifty patients underwent single-tooth replacement in the maxillary and mandibular incisor area using two-piece 3.0-mm-diameter implants. Clinical and radiographic measurements of soft and hard tissue levels and esthetic parameters (pink esthetic score/white esthetic score [PES/WES]) were assessed at 3 years. No implant failed (success rate: 100%), and facial soft tissues and marginal bone levels remained stable throughout the study period. The mean total PES/WES was high (14.1 ± 1.75), and only one implant demonstrated an unfavorable esthetic outcome (PES/WES = 10). The use of 3.0-mm-diameter implants appears to be a viable treatment procedure in the medium term for single-tooth anterior restorations with limited dimensions.

The aim of this study was to assess the impact of replacing conventional mandibular complete dentures with implant-supported fixed complete dentures (ISFDs) on the oral health-related quality of life (OHQOL) of edentulous patients and on the associated kinesiographic parameters. The patients had their complete dentures replaced by ISFDs and were assessed after 1, 2, 3, 6, and 12 months. An improvement of general OHQOL was observed 2 months after treatment with ISFDs. Kinesiographic recordings revealed significant mandibular vertical and horizontal opening increases and a greater vertical intrusion of the maxillary complete dentures during clenching after the treatment with ISFD.

The need to increase the predictability of periodontal regeneration has encouraged clinicians and researchers to employ cell-stimulating proteins in combination with osteoconductive scaffolds, based on the principles of tissue engineering. The purpose of this clinical and radiographic study was to compare the regenerative potential of the combination of β-tricalcium phosphate (β-TCP) and recombinant human platelet-derived growth factor BB (rhPDGF-BB) in the grafting of intraosseous defects with the established technique of bone grafting with β-TCP alone. A total of 30 sites from 15 patients with infrabony defects in two different quadrants were selected, and the sites were randomly divided into test sites (rhPDGF + β-TCP) and control sites (β-TCP alone) using a split-mouth design. Clinical parameters, including probing pocket depth, clinical attachment level, and gingival recession, were recorded at baseline, 6 months, and 9 months. Radiographic evaluation was carried out to evaluate defect fill, change in alveolar crest height, and percentage of defect fill at baseline, 6 months, and 9 months. Both the experimental groups showed statistically significant reduction in probing pocket depth and gain in clinical attachment level. On intergroup comparison, sites treated with rhPDGF + β-TCP demonstrated a significantly greater pocket depth reduction (P .05) and greater gain in clinical attachment level (P .01). Mean percentage defect fill was significantly greater in test sites as compared with control sites at 6 and 9 months (P .01). rhPDGF + β-TCP-treated sites demonstrated a significant gain in mean alveolar crest height at 6 and 9 months (P .05), while β-TCP-treated sites demonstrated crestal resorption. Both groups demonstrated potential in enhancing periodontal regeneration; however, on comparison between the two groups, the results obtained by rhPDGF + β-TCP were significantly better with respect to both clinical and radiographic parameters.

This study investigated whether the use of a dual-layer polytetrafluoroethylene (PTFE)/porcine-derived bioresorbable pericardium membrane enhances the osseointegration around implants compared to a single-layer porcine-derived bioresorbable pericardium membrane and a no-membrane control group. Endosseous implants were placed in the fresh extraction sockets of beagles. At 6 weeks, bone loss and apical soft tissue migration occurred in the control group, whereas bone successfully formed to the neck of the implant for the single-layer porcine-derived bioresorbable pericardium membrane group. The dual-layer PTFE/ porcine-derived bioresorbable pericardium membrane showed bone growth coronal to the neck of the implant. Bone-to-implant contact and buccal bone loss were respectively higher and lower relative to the single-layer but not statistically different.

This study analyzed the length of the root trunk (RT) as well as the width and depth of the prefurcation area (PFA) of human mandibular first molars. Ninety-six human mandibular first molars that were extracted after being observed to be in poor condition both clinically and radiographically were used in this study. A contour-measuring instrument was used, and profiles of the buccal and lingual root surfaces of these teeth were traced on a millimeter-scaled paper. The profiles were recorded from the cementoenamel junction, millimeter by millimeter, up to the entrance of the furcation of each tooth. The width and depth of the PFA as well as the length of the RT were studied. After statistical analysis it was concluded that the mean widths of the PFA on the buccal and lingual surfaces were 3.68 ± 0.66 and 3.48 ± 0.51 mm, respectively; mean depths of the PFA on the buccal and lingual surfaces were 0.89 ± 0.42 and 0.82 ± 0.28 mm, respectively; and mean lengths of the RT on the buccal and lingual surfaces were 3.07 ± 0.82 and 3.54 ± 0.73 mm. Of the samples, the lengths of the RT and the PFA were coincident in 39.58% on the buccal surface and in 46.87% on the lingual surface. There is a concavity (PFA) in the RT region of all mandibular first molars, showing larger width and depth on the buccal surface. The RT was longer on the lingual surface in comparison with the buccal surface.

The objective of this study was to evaluate the association between embrasure morphology and central papilla recession. The central papilla was assessed in 372 adults using standardized periapical radiographs of the maxillary central incisors. The following vertical distances were measured: h1, papilla tip to contact point (PT-CP); h2, proximal cementoenamel junction to contact point (pCEJ-CP); h3, bone crest to contact point (BC-CP); and h4, bone crest to papilla tip (BC-PT). Vertical lines were measured along the long axis of the tooth. Horizontal distance was measured as w2 (distance between the two central incisors at the proximal CEJ level, ie, the interdental width). All participants were divided into four groups according to their w2 and h2 measurements: narrow-long (w2 ≤ 2 mm and h2 > 4 mm), narrow-short (w2 ≤ 2 mm and h2 ≤ 4 mm), wide-long (w2 > 2 mm and h2 > 4 mm), and wide-short (w2 > 2 mm and h2 ≤ 4 mm). A statistically significant positive relationship was evident between central papilla recession and age, and a statistically significant negative relationship was evident between age and papilla height in all study groups. The study found that occurrence of central papilla recession is significantly related to age with a wide interdental width and long pCEJCP distance. However, other factors also determine whether the interdental papilla is present or not, and further study of the interaction among these factors is warranted.

Although some risk factors of peri-implant disease are well defined, the lack of efficient and predictable approaches to treat peri-implantitis has created difficulty in the management of those complications. The aim of this review was to evaluate the reliability of the diagnosis methods and to provide a set of guidelines to treat peri-implant diseases. A search of PubMed and a hand search of articles related to peri-implant diseases were conducted up to August 2013. A summary of the current methods for the diagnosis of peri-implantitis, its potential risk factors, and a flow chart to guide the clinical management of these conditions are presented.

The aim of this study was to evaluate the effects of platelet-rich plasma (PRP), autogenous bone (AB), and guided tissue regeneration (GTR) combination therapy compared to GTR therapy alone on healing of bone and cementum in fenestration-type periodontal defects in dogs. Six dogs were included in this study. Fenestration-type defects were created, and the following treatment groups were established: a control group treated with GTR alone and experimental groups treated with a combination of GTR + PRP, GTR + AB, and GTR + AB + PRP. The defects were evaluated by stereologic method and histomorphometric analysis, which were performed 4, 8, and 12 weeks postoperatively. The results showed a significant increase in trabecular bone area in the GTR + PRP group as compared with the control at 4 and 8 weeks (P .05). The GTR + AB + PRP group showed significantly more trabecular bone area than both GTR and GTR + PRP groups at all time intervals (P .05). The 8- and 12-week results in terms of cementum area revealed a significant difference between the GTR + AB + PRP group and the control in favor of the former (P .05). Cementum area in the GTR + AB group was significantly greater than that in the GTR group at all time intervals (P .05). Within the limitations of this study, PRP and AB, when used under barrier membrane, resulted in significant improvement in bone and cementum formation compared to GTR alone in periodontal fenestration defects; AB, rather than PRP, was responsible for this outcome.

The purpose of this retrospective case series was to report on the clinical performance of implant-assisted removable partial dentures (IARPDs) with Locator abutments in different partial edentulism situations, with a mean follow-up period of 28.6 months. Twelve consecutive patients were treated with IARPDs. A total of 24 implants were placed in the edentulous area. Minimum follow-up period was 12 months. Overall patient satisfaction, health of peri-implant tissues, survival of implants and abutments, and prosthetic complications were reported. Overall implant survival was 91.6%; two implants failed. No major complications were reported-only one IARPD metal framework broke. No Locator abutment loosening was reported. Within the limitations of this retrospective study, treatment with IARPDs can improve the patient's function, phonetics, and esthetics without the need for extensive bone regeneration surgeries and prosthodontic rehabilitations. However, well-designed prospective clinical studies on IARPDs are needed to support their long-term use.