International Journal of Periodontics & Restorative Dentistry, 02/2014

This study investigated the ability of growth factor-enhanced matrices combined with a tenting screw scaffolding system and resorbable membrane to regenerate large alveolar extraction site defects. Eight patients were randomized to treatment either with a bovine or equine matrix mixed in a ratio of 1.0 mL (0.3 mg/mL) recombinant human platelet-derived growth factor BB (rh-PDGF-BB) per gram of xenograft and allowed to absorb for 10 minutes. Tenting screws were used to provide additional support, and the growth factor-enhanced particulate matrix was incrementally placed and condensed into the defect and covered by a resorbable membrane. Reentry surgery after 5 months allowed for trephine core biopsies and implant placement. All sites healed well with evidence of bonelike hard tissue that was confirmed histologically as vital bone around the remaining graft particulate in both treatment groups. The results of this study demonstrate the capability of growth factor-enhanced matrices combined with tenting screws and a resorbable membrane to support the reconstruction of large extraction site defects. (Int J Periodontics Restorative Dent 2014;34:157-163. doi: 10.11607/prd.1743)

This study aimed to assess the clinical performance of lithium disilicate restorations supported by natural teeth or implants. Eight hundred sixty lithium disilicate adhesive restorations, including crowns on natural teeth and implant abutments, veneers, and onlays, were made in 312 patients. Parafunctional patients were included, but subjects with uncontrolled periodontitis and gingival inflammation were excluded. Veneers up to 0.5 mm thick were luted with flowable composite resin or light curing cements, while dual-curing composite systems were used with veneers up to 0.8 mm thick. Onlays up to 2 mm in thickness were luted with flowable composite resins or dual-curing composite cements. Crowns up to 1 mm in thickness were cemented with self-adhesive or dual-curing resin cements. The observational period ranged from 12 to 72 months, with a mean follow-up of 3 years. The mechanical and esthetic outcomes of the restorations were evaluated according to the modified California Dental Association (CDA) criteria. Data were analyzed with descriptive statistics. Twenty-six mechanical complications were observed: 17 porcelain chippings, 5 fractures, and 4 losses of retention. Structural drawbacks occurred mainly in posterior segments, and monolithic restorations showed the lowest number of mechanical complications. The clinical ratings of the successful restorations, both monolithic and layered, were satisfactory according to the modified CDA criteria for color match, porcelain surface, and marginal integrity. The cumulative survival rates of lithium disilicate restorations ranged from 95.46% to 100%, while cumulative success rates ranged from 95.39% to 100%. All restorations recorded very high survival and success rates. The use of lithium disilicate restorations in fixed prosthodontics proved to be effective and reliable in the short- and medium-term. (Int J Periodontics Restorative Dent 2014;34:165-177. doi: 10.11607/prd.1769)

Since different clinical outcomes of periodontal bilaminar surgeries using the palate or the maxillary tuberosity as connective tissue (CT) donor sites have been observed, tissues grafted with CT from the palate or the tuberosity 1 year after surgical procedures for ridge augmentation were compared with nongrafted tissues by using morphologic and molecular methods. Collagen content and matrix metalloproteinases 1 and 2 expression were similar in tissues and cultured fibroblasts from the palate and tuberosity, although with interindividual differences. In contrast, differences in collagen cross-linking and maturation in the tuberosity fibroblasts were observed, suggesting a possible role in determining hyperplastic responses in some patients. (Int J Periodontics Restorative Dent 2014;34:179-186. doi: 10.11607/prd.1929)

This prospective study evaluated clinical results of immediately loaded Biomet 3i implants with different surface topographies. Thirty-three periodontally compromised patients received 163 implants (130 in the maxilla and 33 in the mandible; 132 NanoTite and 31 Osseotite). After a mean loading period of 57 months, the survival rate was 96.3%. Mean crestal bone loss was 1.6 mm. No difference in bone loss was detected between the two surfaces. Only 6% of the implants had peri-implantitis based on total bone loss above 2 mm from the day of surgery in conjunction with probing depths of > 4 mm. (Int J Periodontics Restorative Dent 2014;34:189-197. doi: 10.11607/prd.1938)

The aim of this prospective case series was to evaluate the stability of esthetic treatment after single tooth replacement in compromised sockets using the immediate dentoalveolar restoration (IDR) concept. Eighteen patients underwent immediate implant placement and IDR of bone defects. Clinical photographs were used to evaluate the gingival contour and papillae. The mean soft tissue dimensions at baseline and final follow-up were 12.85 ± 2.33 mm and 12.79 ± 2.48 mm, respectively, revealing no recession. The mean mesial and distal papillary heights increased slightly over time. Stable periimplant soft tissues and satisfactory esthetic outcomes were achieved. (Int J Periodontics Restorative Dent 2014;34:199-208. doi: 10.11607/prd.1858)

In 48 postextraction sites, sockets were grafted with bovine bone mineral plus collagen membrane (test) or had spontaneous healing (control). After 4 months, horizontal ridge width reduction was 0.71 mm in the test group and 4.04 mm in the control group, while vertical ridge loss was 0.58 mm and 1.67 mm, respectively. No correlation was found between the thickness of the buccal bone wall and the alveolar bone loss in the test group, while an inverse correlation was found in the control group. Ridge preservation compensated for postextraction alveolar ridge resorption irrespective of the buccal plate thickness, whereas leaving the extraction socket undisturbed may result in alveolar bone loss. (Int J Periodontics Restorative Dent 2014;34:211-217. doi: 10.11607/prd.1885)

Orthodontic approximation has been proposed as a tool for restoring the lost papilla. A prospective analysis was performed to evaluate the changes in the levels of interdental papilla and alveolar crest following an orthodontic approximation. The levels of interdental papilla and alveolar crest increased; however, the interradicular distance did not influence the level of the interdental papilla or papilla score. Interestingly, the shape of the teeth had a significant impact on the interdental papilla score. In conclusion, orthodontic approximation significantly enhanced the level of the interdental papilla and interproximal alveolar crest, producing an improved esthetic outcome. (Int J Periodontics Restorative Dent 2014;34:219-224. doi: 10.11607/prd.1852)

Three implant designs were used to treat posterior partial edentulism. A total of 799 implants (563 Osseotite, 65 Straumann SLA,171 Endopore SPS) were placed in 345 patients. SPS implants were used in sites with less bone, had shorter lengths, and functioned longer than the threaded implant designs. Comparing implant losses, SPS implants had a higher failure rate (9.3%) compared with Osseotite (4.0%) or SLA (0%) implants. SPS implant losses generally occurred as late failures, while Osseotite losses were early failures. However, among surviving implants, SPS implants had less crestal bone loss at all time intervals compared with both of the threaded implant designs. (Int J Periodontics Restorative Dent 2014;34:225-231. doi: 10.11607/prd.1542)

The objective of this study was to evaluate bone regeneration in 24 sockets grafted with a calcium phosphosilicate putty alloplastic bone substitute. A core was obtained from 17 sockets prior to implant placement for histomorphometry at 5 to 6 months postextraction. Radiographic analysis during the same postextraction healing period showed radiopaque tissue in all sockets. Histomorphometric analysis revealed a mean vital bone content of 31.76% (± 14.20%) and residual graft content of 11.47% (± 8.99%) after a mean healing period of 5.7 months. The high percentage of vital bone in the healed sites in combination with its timely absorption rate suggest that calcium phosphosilicate putty can be a reliable choice for osseous regeneration in extraction sockets. (Int J Periodontics Restorative Dent 2014;34:233-239. doi: 10.11607/prd.1855)

Today's patients are increasingly conscious of personal appearance, and much attention has been focused on denuded roots that are exposed during smiling. These concerns have given rise to numerous approaches for covering denuded root surfaces. Therefore, this study was undertaken to compare the effectiveness of recombinant human platelet-derived growth factor BB (rh-PDGF-BB) + β-tricalcium phosphate (β-TCP) and subepithelial connective tissue graft (SCTG) for the treatment of multiple gingival recession defects in humans. Thirty-six systemically healthy patients were randomly assigned to the PDGF, SCTG, and coronally positioned flap (CPF) groups. The PDGF and SCTG groups were treated with rhPDGF-BB + β-TCP and SCTG, respectively, while the CPF group was treated with a CPF alone. Clinical measurements including probing pocket depth (PPD), relative attachment level (RAL), and relative gingival margin level (RGML) were measured at baseline and at the 6-month follow-up. After 6 months, mean reduction in gingival recession in the PDGF and SCTG groups was 2.0 ± 0.6 mm and 2.6 ± 0.9 mm, respectively, whereas in the CPF group it was 1.7 ± 0.9 mm. The PDGF group showed mean root coverage of 87.7%, the SCTG group showed 91.3%, and the CPF group showed 68.6% at 6 months postsurgery. The combination of rhPDGF-BB and β-TCP represented a therapeutic combination that was effective in treating multiple gingival recession defects. (Int J Periodontics Restorative Dent 2014;34:241-249. doi: 10.11607/prd.1726)

This study presents a case of replacing two maxillary primary canines and related impacted permanent canines with two single implants, in conjunction with grafting lost hard tissue. By using immediate postextraction implant placement and provisionalization protocols, the stability of the implant was ensured while bypassing the bony void created by the removal of the primary canines. In this respect, a minimum healing period of 1 year was originally planned to evaluate the gingival esthetics before the final step was carried out. By the time the final restorations were fitted, the graft and tissues were stable. The time involved not only placed biology on the clinician's side, but also helped the patient to spread the cost over time. In modern esthetic dentistry, harmonious results can be achieved relatively quickly when the prerequisites for esthetic success have already been met, but, as this case demonstrates, human biology often requires more time and patience for augmented hard and soft tissues to heal and mature. (Int J Periodontics Restorative Dent 2014;34:251-256. doi: 10.11607/prd.1612)

The aim of this study was to evaluate in humans the amount of new bone after sinus floor elevation with a synthetic bone substitute material consisting of nanocrystalline hydroxyapatite embedded in a highly porous silica gel matrix. The lateral approach was applied in eight patients requiring sinus floor elevation to place dental implants. After elevation of the sinus membrane, the cavities were filled with 0.6-mm granules of nanocrystalline hydroxyapatite mixed with the patient's blood. A collagen membrane (group 1) or a platelet-rich fibrin (PRF) membrane (group 2) was placed over the bony window. After healing periods between 7 and 11 months (in one case after 24 months), 16 biopsy specimens were harvested with a trephine bur during implant bed preparation. The percentage of new bone, residual filler material, and soft tissue was determined histomorphometrically. Four specimens were excluded from the analysis because of incomplete biopsy removal. In all other specimens, new bone was observed in the augmented region. For group 1, the amount of new bone, residual graft material, and soft tissue was 28.7% ± 5.4%, 25.5% ± 7.6%, and 45.8% ± 3.2%, respectively. For group 2, the values were 28.6% ± 6.90%, 25.7% ± 8.8%, and 45.7% ± 9.3%, respectively. All differences between groups 1 and 2 were not statistically significant. The lowest and highest values of new bone were 21.2% and 34.1% for group 1 and 17.4% and 37.8% for group 2, respectively. The amount of new bone after the use of nanocrystalline hydroxyapatite for sinus floor elevation in humans is comparable to values found in the literature for other synthetic or xenogeneic bone substitute materials. There was no additional beneficial effect of the PRF membrane over the non-cross-linked collagen membrane. (Int J Periodontics Restorative Dent 2014;34:259-267. doi: 10.11607/prd.1419)

This case series evaluated the graft stability and resorption of a modified shell technique for horizontal ridge augmentation. Autogenous bone shells of 1-mm thickness were fixed with microtitanium screws with the gaps between the shells and ridge filled with autogenous bone chips. In 22 patients, 30 cases were performed to augment 50 regions. Forty-two implants were inserted after a healing period of 5.5 (± 1.0) months. Preoperatively, the mean width of the crest was 2.7 mm (± 0.9), after bone grafting, 6.7 mm (± 0.8), and during implant placement, 5.9 mm (±0.7), and the mean resorption was 0.8 mm (± 0.5) (P .001). This technique showed promising results. However, due to slight resorption, the ridge should be over contoured. (Int J Periodontics Restorative Dent 2014;34:269-276. doi: 10.11607/prd.1374)

The success of oral restorations supported by dental implants in regenerated bone is well documented, as is the use of bone grafts to augment deficient alveolar bone. This article describes the bone-retention wedge graft, which may be useful for increasing the primary stability of dental implants, preserving bone in postextraction sockets, and covering exposed implant threads. (Int J Periodontics Restorative Dent 2014;34:e30-e35. doi: 10.11607/prd.1965)

The aim of this study was to evaluate the extraction socket healing and dimensional changes following alveolar ridge preservation using polylactide and polyglycolide (PLA-PGA) sponge. Fifteen patients were selected for alveolar socket preservation immediately following tooth extraction. Monoradicular maxillary and mandibular teeth were evaluated. The selected sockets had intact sockets walls with a minimum of 7 mm of residual alveolar bone height. The test sites were thoroughly debrided and grafted with PLA-PGA sponge, while the control sites underwent natural healing. Computed tomography (CT) measurements were taken at baseline and 6 months. After 6 months of healing, final CT measurements were performed, and trephine core biopsy specimens were obtained for histologic analysis. Implants were placed immediately after biopsy harvesting. All subjects completed the study, and all sites healed without adverse events and allowed for implant placement. The mean difference in socket height, width, and density after 6 months was statistically significantly higher in the test sites compared with control sites. Clinical measurement at the midbuccal site of the alveolar socket showed a mean loss of 2.45 ± 0.67 mm in the control group, compared with a mean gain of 1.28 ± 0.58 mm in the test group. All test sites showed minimal ridge alterations, and statistically significant differences were observed between the test and control sites with respect to bone composition and horizontal and vertical bone loss, indicating that PLA-PGA sponge is suitable for alveolar ridge preservation. (Int J Periodontics Restorative Dent 2014;34:e36-e42. doi: 10.11607/prd.1375)

The aim of this case series was a clinical, histologic, and histomorphometric evaluation of calcium carbonate in sinus elevation procedures. Sinus augmentation was performed in the atrophic maxillae of 24 subjects using calcium carbonate. Six months after the regeneration procedures, 68 implants were placed and clinically followed for 1 to 5 years, depending on the placement timing. At the last implant placement procedure, 8 bone cores were harvested and processed for histology. After a 6-month healing period, sinuses grafted with calcium carbonate showed a mean vertical bone gain of 6.93 ± 0.23 mm. The histomorphometric analysis revealed 15% ± 3% residual grafted biomaterial, 28% ± 2% newly formed bone, and 57% ± 2% marrow spaces. The implant survival rate was 98.5%. It can be concluded that calcium carbonate was shown to be clinically suitable for sinus elevation procedures after 1 to 5 years of follow-up and histologically biocompatible and osteoconductive. (Int J Periodontics Restorative Dent 2014;34:e43- e49. doi: 10.11607/prd.1832)