International Journal of Periodontics & Restorative Dentistry, 06/2016

The aim of the present study was to assess the threshold values for color changes on the level of the tooth separately for laypeople, dentists, and dental technicians. Standardized presentations were made of five cases (maxilla, left to right lateral incisors) with the gingiva and teeth separated. The color parameters L (lightness), a, and b (chroma) (CIE L*a*b* parameters) of the tooth layers were adjusted to induce darker and lighter colors. In the presentations, the left part of the pictures (maxillary right central and lateral incisors) was unchanged, whereas the right part was modified. A group of 10 dentists, 10 dental technicians, and 10 laypeople evaluated the color differences between the pictures. The median threshold values were 1.8 (laypeople), 1.8 (dental technicians), and 1.9 (dentists). The overall ΔE amounted to 1.8.

The objective of this study was to digitally analyze the emergence profile changes before and after soft tissue conditioning with fixed-implant provisional restorations. Impressions were taken with individualized posts to build casts for 20 patients. Optical scanning of the modulated mucosa was performed from the model situations in combination with the original healing abutments. Emergence profile extension revealed a mean volume of 41.9 mm3 for central sites and 25.8 mm3 for laterals. In addition, linear calculations of supraimplant mucosal profile changes presented a median enlargement of 8.2 mm in the mesial-distal and 7.2 mm in the buccal-lingual direction for central incisors and 6.8 mm (mesial-distal) and 6.5 mm (buccal-lingual) for lateral incisors. The change was more than double compared with the initial profile of the healing abutments.

In oral rehabilitation, crown-to-root ratio is accepted as an indicator of bone loss, and this concept was transferred to implants. Recent studies have indicated that there is no significant difference between short and standard implants. The aim of this study was to compare marginal bone level alteration through radiographic evaluation and clinical parameters between short and standard implants supporting single crowns. This prospective clinical trial study included 82 systemically healthy, nonsmoking subjects. Patients were divided into two groups: one group for short dental implants measuring 5.5 or 7 mm, and one group for standard dental implants measuring 10 or 12 mm, in accordance with the individual needs of the patient. A clinical dental history was taken for each subject, including model casts, dental radiography, and cone beam computed tomography. A periapical analysis was also performed using ImageJ computer software to establish the initial bone measurement and periapical bone loss. A statistically significant difference was found in favor of the standard-length implants after 12 months, with greater gingival recession around the implant; however, bone loss in the short implants did not exceed 0.53 mm. The treatment with 5.5- to 7-mm-length implants is as reliable as treatment with 10- or 12-mm implants. Peri-implant bone loss is minimal, and therefore use of short implants can be recommended as treatment for the restoration of partially edentulous patients without the need for splinted crowns.

The present case series evaluated the potential benefits of a flapless approach in the regenerative treatment of residual deep intrabony defects. In each of 11 patients, one periodontal defect with an intrabony component of ≥ 3 mm was treated regeneratively using enamel matrix derivative combined with a closed surgical technique. Clinical and radiographic parameters were recorded at baseline and at 12 and 24 months postoperatively. All defects experienced favorable clinical and radiographic outcomes at the 24-month follow-up. When considering only sites located in the anterior region, all experienced complete pocket closure.

Reducing the need for a connective tissue graft by using an efficacious biomaterial is an important task for dental professionals and patients. This experimental study aimed to test the soft tissue response to a volume-stable new collagen matrix. The device demonstrated good stability during six different time points ranging from 0 to 90 days of healing with no alteration of the wound-healing processes. The 90-day histologic specimen demonstrates eventual replacement of most of the matrix with new connective tissue fibers.

The successful outcome of apical surgery is usually defined by absence of clinical signs and symptoms and resolution of previous periapical radiolucencies. However, little attention is given to soft tissue scarring. The present study evaluated the severity of gingival and mucosal scarring 1 year following apical surgery of 52 teeth. Clinical pictures taken at the 1-year examination were rated by three observers using specific scarring scores. The overall repeatability of the two scores was high (85.3%), whereas the overall reproducibility was relatively low (44.2%). None of the tested variables proved significant for influencing scar severity.

This study evaluated the in vitro bacterial microleakage at the implant-abutment interface of three prosthetic connections: external (EH) and internal hexagon (IH) and taper connection (TC: solid [ST], taper with internal hexagon [IT], and short taper [OT]). Escherichia coli (E coli) and Streptococcus sanguinis (S sanguinus) were inoculated in the apical portion of the abutment screw, which was immersed in sterile brain-heart infusion broth for 14 days. There were no differences between the percentages of bacterial infiltration for IH (9.09%), ST (21.74%), IT (22.73%), and OT (11.11%). EH did not present viable bacteria. There were no significant differences in the counts of connections inoculated and not infiltrated by E coli or S sanguinis nor in those infiltrated by both bacteria (one-way analysis of variance, P .05). Except for EH, all implant designs and abutments showed bacteria that were capable of surviving and causing infiltration.

Different parameters can be measured during dental implant insertion to determine the primary stability of the implant. The purpose of this retrospective study was to investigate whether a correlation exists between immediate implant insertion torque value (ITV) and implant stability quotient (ISQ) in nonmolar sites. A total of 59 implants in 52 patients were placed into extraction sockets. ITV was recorded at surgery, and ISQ was recorded at surgery and at followup. Implants with higher ITV and/or ISQ were evaluated at 6 to 8 weeks. An additional 4 to 6 weeks was permitted for implants with lower initial stability values. A nonsignificant correlation coefficient of 0.06 could be found between the measurements at either time point. The data suggests that there is no linear correlation between ITV and ISQ in the measured population. The findings of this study question the requirement of excessively high ITV and ISQ for immediate temporization and as prerequisites for successful osseointegration.

Small linear microgrooves have been observed on root surfaces associated with osseous defects when videoscope-assisted minimally invasive surgery (V-MIS) is performed. The aim of this study was to evaluate the frequency of occurrence of these microgrooves associated with osseous defects. Videos of dry skulls from an anatomy department collection and videos made during consecutive V-MIS procedures on patients were evaluated to determine the presence or absence of microgrooves associated with osseous defects. In the dry skulls, 69 areas of apparent periodontal osseous defects were evaluated. In the V-MIS videos, 63 osseous defects were evaluated. In the dry skulls, 34 sites were positive for microgrooves on the root surfaces (49%), while in the V-MIS procedures 50 sites were positive for microgrooves (79%). Microgrooves of unknown origin were detected in a high percentage of osseous defects. Microgrooves may represent risk factors for site-specific progression of periodontal destruction.

The case reports presented in this article describe a surgical approach for improving root coverage and regenerative parameters in deep intrabony defects associated with buccal gingival recession. A mandibular canine and a maxillary premolar were treated. The surgical technique consisted of a connective tissue graft (CTG) that was placed and sutured at the inner surface of a coronally advanced envelope flap (CAF), thickening the buccal soft tissue wall of the most coronal extension of the intrabony defect and treated with biomaterials as scaffold. No palatal/lingual flap was elevated. Two years after the surgery, clinically significant root coverage, increased buccal keratinized tissue height and thickness, some minor improvement in the position of the interdental papilla, and clinical attachment level gain were achieved. The radiographs showed bone fill of the intrabony components of the defects. This report encourages a novel application of CAF + CTG + biomaterials to improve both esthetic and regenerative parameters in deep intrabony defects associated with gingival recessions.

The aim of this clinical case series was to evaluate the clinical performance of the modified tunnel technique for treatment of multiple gingival recessions in the anterior mandible. A total of 20 patients with 63 Miller Class I and II defects were treated via a modified tunnel technique with subepithelial connective tissue graft. At baseline and 6 months postoperative, recession depth, probing pocket depth, width of keratinized tissue, and gingival tissue thickness were assessed. At 6 months, the results revealed a mean recession coverage of 93.87%. Complete recession coverage was achieved in 74.60%. The mean reduction of recession depth was 2.79 ± 0.12 mm. The modified tunnel technique showed successful mean root coverage in the delicate anterior mandible and was able to increase the amount of keratinized tissue.

Recession on the lingual aspect of mandibular incisors may occur in patients with history of tongue piercing and other factitious traumatic habits. Treatment of these areas is challenging due to the site-specific anatomical features of the region. This case report presents a novel approach for a specific type of mandibular lingual defect caused by tongue piercing. A nonresorbable titanium-reinforced barrier membrane combined with an allograft and enamel matrix derivatives was used to promote regeneration of periodontal attachment. Reentry surgery for membrane removal was performed at 8 weeks. The time from initial surgery to final follow-up was 18 months.

This study aimed to evaluate the efficacy of an exposed high-density polytetrafluoroethylene (d-PTFE) membrane in preventing epithelial migration in postextraction sockets. For this purpose, a histologic description of the newly formed soft tissue underlying the membrane is presented. The periodontal status of the adjacent teeth was also evaluated to assess the gingival response. Ten premolar extraction sockets were treated. After tooth extraction, the sockets were filled with nanocrystalline hydroxyapatite and covered with d-PTFE membranes. Subperiosteal pockets were created to ensure the stability of the membranes. Membranes were left intentionally exposed and were atraumatically removed after 28 days. At that time, a bioptic specimen of the newly formed soft tissue under the membranes was taken. All the histologic samples showed a dense connective tissue without epithelial cells and no signs of foreign body reaction. No significant variation of the periodontal indices was observed on the teeth adjacent to the extraction sites. The study results indicate that exposed d-PTFE membranes can prevent epithelial migration in healing sockets without consequences on the periodontal health.

The aim of this study was to compare the bone resorption rate and histometry of ChronOS, a beta-tricalcium phosphate (β-TCP), mixed with autogenous bone grafts (1:1) with that of autogenous bone grafts alone in maxillary sinus elevation surgery. A total of 12 maxillary sinuses were grafted with an autogenous bone graft (control group) and 9 with ChronOS mixed with an autogenous bone graft (test group). Postoperative cone beam computed tomography (CBCT) was used to measure the initial graft volume after 15 days (T1), and 6 months later another CBCT scan was performed to evaluate the final graft volume (T2) and determine the graft resorption rate. The resorption outcomes were 45.7% ± 18.6% in the control group and 38.3% ± 16.6% in the test group (P = .17); the bone formation rate was 38.6% ± 10.5% in the control group and 25.4% ± 6.4% in the test group (P = .001). ChronOS mixed with autogenous bone graft demonstrated a resorption rate similar to that of the autogenous bone graft but with a difference in bone formation after 6 months.

Endodontic implant pathology (EIP) refers to cases in which endodontic infections cause infections in adjacent implants, and vice versa. This case report demonstrates the successful resolution of two types of EIPs, implant endodontitis and endodontic implantitis, by endodontic intervention with surgical treatment. In case 1, the patient complained of tooth discomfort after implant placement in the adjacent tooth. The tooth was sensitive to percussion and showed slight mobility with a negative reaction to an electric pulp test. The symptoms persisted despite conventional root canal treatment, and surgical treatment of the symptomatic tooth and implant lesion was performed. In case 2, the patient suffered from repeated infection around a newly installed implant. The adjacent devitalized tooth exhibited a periapical lesion that was contiguous with the implant. Conventional root canal treatment and retreatment did not successfully resolve the symptoms. Surgical root canal therapy was then performed with regenerative biomaterials as needed. Neither case showed radiographic or clinical evidence of failure after 4 and 5 years of follow-up, respectively, after the surgery and the adjacent implants were successfully osseointegrated. Endodontic intervention combined with surgical treatment resolved both types of EIPs and led to tooth preservation and successful osseointegration of adjacent implants.

The required connector dimension for zirconia fixed dental prostheses (FDPs) may be a clinical limitation due to limited space in the occlusogingival direction. Using no veneering in the gingival regions of the pontics and connectors may solve this problem. This study evaluated the mechanical durability of zirconia FDPs with and without veneering in the gingival area of the connectors and pontics and subsequent airabrasion of this region with different protocols. Models were made of resin abutments (diameter = 6 or 8 mm, height = 6 mm, 6 degrees convergence) and embedded in polyurethane resin (distance = 11 mm). Zirconia frameworks were milled and randomly distributed by veneering (veneering of the entire framework [VEN] or no veneering at gingival regions of the pontic and connector [NVEN]) and by air-abrasion (Al2O3/SiO2, 30 μm; or 45 μm Al2O3). FDPs were adhesively cemented and subjected to mechanical cycling (1,200,000 cycles, 200 N, 4 Hz, with water cooling). Specimens were tested until fracture (1 mm/min), and failure modes were classified. Data (N) were subjected to one-way analysis of variance in two sets, Tukey test (α = .05) and Weibull analysis. While veneering did not significantly affect the results (VEN: 1,958 ± 299 N; NVEN: 1,788 ± 152 N; P = .094), air abrasion did (P = .006), with the worst results for the groups conditioned with 45 μm Al2O3 (SiO2: 1,748 ± 273 N; Al2O3: 1,512 ± 174 N). The NVEN group demonstrated the highest Weibull modulus (12.8) compared with the other groups (5.3-7.2). Fractures commonly initiated from the gingival side of the connector. Veneering of the gingival region of the connectors and pontics in zirconia FDPs did not diminish the fracture strength, but air-abrasion of this area with 45 μm Al2O3 decreased the results.

Osteopontin (OPN) and an OPN-derived synthetic peptide, OC-1016, have demonstrated their potential to enhance osseointegration in vitro. The purpose of this study was to evaluate bone-to-implant contact (BIC) and surrounding bone density (BD) of implants coated with either recombinant human OPN (rhOPN) or OC-1016 as compared with noncoated titanium plasma sprayed (TPS) surface in a canine model. Histomorphometric analysis revealed that at 4 weeks, %BIC and %BD of coated implants were significantly higher than those of noncoated TPS implants. At 12 weeks, %BIC of coated implants was also significantly higher than that of noncoated implants; however, there was no statistically significant difference in %BD. The rhOPN and OC-1016 were concluded to be capable of significantly accelerating the early stage of osseointegration and bone healing around implants.

The success of dental implant therapy in the esthetic zone requires not only functional osseointegration but also favorable esthetic results. The greatest challenge in the esthetic zone is to establish harmony, balance, and continuity of gingival form between implant restorations and the adjacent natural teeth. In the esthetic zone, a localized ridge defect or loss of a peri-implant papilla is common and can be corrected via soft tissue augmentation. This case report describes a novel surgical technique using connective tissue grafts via an apical pouch to increase soft tissue volume over an alveolar ridge defect or around natural teeth or implants in the maxillary anterior area. The described surgical technique successfully achieved the desirable esthetic outcomes in the reported cases.

The primary objective of this pilot study was to evaluate a new socket preservation technique involving the intentional expansion of the extraction socket buccal plate using a flapless internal corticotomy and biomaterials. A total of 11 patients requiring tooth extraction were enrolled in this study. The aim of this technique was to maintain or improve the hard and soft tissue contour of the ridge after tooth extraction. All surgical sites healed uneventfully. Significant alveolar bone dimension changes were observed in the coronal region of the ridge (−1.4 ± 0.9 mm); however, it was only slightly lower at the medium (−0.35 ± 0.7 mm) and apical levels (−0.3 ± 0.8 mm) (P > .05). The ridge dimensional changes were significantly higher in the buccal aspect than in the palatal aspect in all patients. Vertical bone resorption was not significant. Concerning the soft tissue contour, the horizontal distance between the preoperative and postoperative buccal profiles ranged from 0.94 to −2.88 mm. The proposed ridge preservation technique may help maintain the volume of the healed ridge but cannot completely prevent contour changes after tooth extraction.