International Journal of Periodontics & Restorative Dentistry, 01/2017

Reformation of the lost interdental papilla remains one of the most challenging goals for clinicians. When a single tooth is replaced with an implant, the papilla between the tooth and the implant can often be maintained or predictably reformed as long as the adjacent tooth's periodontal attachment and bone are preserved. However, if the periodontal support is compromised on the neighboring natural tooth, the papilla will often be deficient or missing. The cases presented herein demonstrate long-term follow-up of successful reformation of periodontal/peri-implant tissue contours, including reconstruction of lost interproximal bone and papilla at periodontally compromised sites using a combined hard and soft tissue surgical approach.

This multicenter retrospective clinical study aimed to evaluate the clinical performance of zirconia abutments in anterior and posterior regions, focusing on implant-abutment connections and restoration vertical height (RVH). Six experienced prosthodontists used 965 computer-aided design/computer-assisted manufacture zirconia abutments in 601 patients. Different surgical approaches were taken according to the needs of each patient. The final restorations were all-ceramic single crowns and short-span fixed dental prostheses. Screw-retained restorations were mainly used in anterior areas, whereas cemented prostheses were chosen in cases where the implant position was not ideal. Different types of implant-abutment connections were compared: external, internal with metal components, and internal full-zirconia conical connection. All the restorations were followed up for 4 to 10 years. Technical and biologic complications were assessed in relation to several biomechanical variables, such as RVH. Differences between groups were statistically analyzed, and longevity of abutments was evaluated according to Kaplan-Meier survival analysis. Zirconia abutments resulted in overall survival and success rates of 98.9% and 94.8%, respectively. External connections reported survival and success rates of 99.7% and 94.5%, internal metal connections 99.8% and 95.5%, and internal zirconia connections 93.1% and 93.1%, respectively. Overall complication rates of 1.14%, 3.42%, and 0.62% were reported for fractures, chipping, and unscrewing, respectively. The external connection showed the longest survival while the internal zirconia connection showed the highest fracture incidence over the observation period. The clinical risk limit of RVH was identified as 14 mm. Zirconia abutments showed satisfactory clinical performance in anterior and posterior regions after 4 to 10 years. RVH and connection type influenced the clinical longevity of restorations; in particular, internal connections with secondary metallic components reduced the incidence of complications.

This multicenter clinical trial of platform-switched laser-microchannel implants supports findings from a previous preclinical trial. Previous information indicated that an interimplant distance narrower than 3 mm would result in decrease in the crestal bone level, but the results of this investigation suggest that a more optimistic clinical result can be anticipated for implants and abutments with a laser-microchannel surface.

Current use of zirconium oxide (ZrO₂)-based screw-retained restorations does not guarantee maximum contact of soft peri-implant tissues with ZrO₂, because veneering porcelain usually covers the major subgingival part of the restoration. Ceramics preclude direct interaction between zirconia and soft tissue cells, thus reducing biocompatibility and benefit to the patient. The four case reports discussed in this article describe the new design modality of the ZrO₂ screwretained restorations, in which zirconia is exposed to the tissues and no veneering porcelain is located below the gingival margin. The article also shows the impact of this treatment on soft peri-implant tissues after 3 years of follow-up. Soft tissue recession, vestibular contour, bleeding on probing, and probing depth were evaluated.

Different degrees of clinical success have been reported for synthetic, allograft, and xenograft bone substitutes in human trials. Although these substitutes have been clinically investigated, their in vitro effects on cell differentiation remain unclear. Proliferation, differentiation, and attachment of dental pulp stem cells (DPSCs) to β-tricalcium phosphate (β-TCP), freeze-dried bone allograft (FDBA), and deproteinized bovine bone mineral (DBBM) were compared in this study. MTT assay, measurement of total DNA, and reverse transcriptase polymerase chain reaction were performed. β-TCP had the highest potential for DPSC attachment and proliferation, while FDBA induced osteoblastic differentiation of DPSCs. Further in vivo investigations are necessary to select a clinically appropriate scaffold.

Subgingival margins are often required for biologic, mechanical, or esthetic reasons. Several investigations have demonstrated that their use is associated with adverse periodontal reactions, such as inflammation or recession. The purpose of this prospective randomized clinical study was to determine if two different subgingival margin designs influence the periodontal parameters and patient perception. Deep chamfer and feather-edge preparations were compared on 58 patients with 6 months follow-up. Statistically significant differences were present for bleeding on probing, gingival recession, and patient satisfaction. Featheredge preparation was associated with increased bleeding on probing and deep chamfer with increased recession; improved patient comfort was registered with chamfer margin design. Subgingival margins are technique sensitive, especially when feather-edge design is selected. This margin design may facilitate soft tissue stability but can expose the patient to an increased risk of gingival inflammation.

The aim of this prospective multicenter study was to evaluate the outcomes of single implants subjected to immediate functional loading. Inclusion criteria were single-tooth placement in postextraction sockets or fully healed sites, and sufficient bone height and width to place an implant of at least 3.5 × 10.0 mm. All implants were functionally loaded immediately after placement and followed for 2 years. Outcome measures were implant survival, complications, and periimplant marginal bone loss (MBL). A total of 57 implants (38 maxilla, 19 mandible) were placed in 46 patients (23 men, 23 women, aged 18-73 years). Of these, 10 implants were placed in postextraction sockets. One implant failed, in a healed site, giving a patient-based overall 2-year survival rate of 97.6%. The incidence of biologic complications was 1.8%; prosthetic complications amounted to 7.5%. The peri-implant MBL was 0.37 ± 0.22 mm (healed sites: 0.4 mm ± 0.22; postextraction sockets: 0.3 mm ± 0.22). The immediate functional loading of single implants seems to represent a safe and successful procedure. Long-term followup studies on a larger sample of patients are needed to confirm these results.

Previous studies have shown that patients with rheumatoid arthritis (RA) have a higher susceptibility to periodontitis, but the results of individual studies remain controversial. The aim of the present meta-analysis was to comprehensively evaluate the association between RA and periodontitis. A systematic literature search was conducted in PubMed and EMBASE. Data were extracted using standardized forms, and odds ratios (OR) with 95% confidence intervals (CI) were calculated for each study. Pooled data were estimated by fixed- and randomeffects models if appropriate. Eight case-control studies were included in the present study. Study size ranged from 104 to 151,569 participants. The prevalence of periodontitis in RA patients ranged from 15.5% to 100%, compared with 10.0% to 82.1% in controls. In group 1 (control) and group 2, the heterogeneity was 38% and 11%, respectively. Using fixed-effects analysis, the overall pooled estimates of the ORs for periodontitis were 4.68 (95% CI: 3.11-7.05) and 1.28 (95% CI: 1.24-1.33) in groups 1 and 2, respectively. This meta-analysis indicates that RA was significantly associated with increased overall risk of periodontitis.

Subepithelial connective tissue graft (SCTG) is considered the gold standard for treatment of gingival recessions. For ethical reasons, most studies report only clinical and not histologic results. A 20-year-old woman presenting with a localized gingival recession of 5 mm in the mandibular left central incisor was treated with SCTG. According to the initial treatment plan, the tooth was extracted 11 months later and a histologic study was performed, revealing new attachment of connective tissue with collagen fibers that were directly inserted in a perpendicular way into dentin areas and new cement areas (1.37 mm).

Localized ridge resorption, the consequence of socket collapse, following tooth extraction in the anterior maxilla can adversely affect esthetics, function, and future implant placement. Immediate grafting of extraction sockets may help preserve natural ridge contours, but a lack of available soft tissue can compromise the final esthetic outcome. The presented modified rotated palatal pedicle connective tissue flap is a useful technique for simultaneous soft tissue coverage and augmentation of grafted sockets to improve esthetic outcome. This article delineates its advantages through the presentation of a four-case series using this new technique.

The aim of this study was to evaluate the laterally moved coronally advanced flap (LMCAF) technique in which magnified vision was used in conjunction with microsurgical instruments (LMCAF-M), and to compare the results with conventional LMCAF technique (LMCAF-C) in Miller Class III isolated recessiontype defects. A total of 50 patients with recessions located at incisors and canines were treated with LMCAF-M or LMCAF-C. Outcome parameters (complete root coverage [CRC] and mean root coverage [MRC]) were assessed 6 months postoperatively. Of the 25 defects in each group, 13 in the LMCAF-M (92.0%) and 17 in the LMCAF-C group (68.0%) exhibited CRC (P .007). MRC scores were 90.48% for the LMCAF-C group and 97.64% for the LMCAF-M group (P .04). Patient satisfaction with esthetics and postoperative morbidity were better in the LMCAF-M group (P .032). This study indicates that performing LMCAF with microsurgical instruments offers definite advantages in terms of CRC and MRC, decreased postoperative morbidity, and increased acceptance by patients.

A xenogeneic collagen matrix recently has been suggested as an alternative to connective tissue graft for the treatment of gingival recession. The matrix avoids the second surgical site, and as a consequence could decrease surgical morbidity. This new matrix was used in various clinical situations and compared to connective tissue graft (CTG) in a split-mouth design case series. A total of 17 recessions were treated with a coronally advanced flap, 9 with CTG, and 8 with the matrix. Mean recession reduction was 2.00 mm with the CTG and 2.00 mm with the matrix. No significant statistical differences between the techniques were observed in this case report.

The aim of this study was to evaluate clinical and radiologic outcomes of a novel device that allows simultaneous hydraulic sinus membrane elevation, bone grafting, and implant placement. A sample of 18 consecutive participants with severe atrophy of the posterior maxilla underwent transcrestal elevation of the sinus membrane and implant placement. At the 6-month follow-up, the following parameters were assessed: implant success, any complications, marginal bone loss (MBL), threedimensional (3D) graft measurements, implant stability quotient (ISQ), and graft density. No implants failed during follow-up (10.8 ± 2.8 months; range: 7-14 months). No membrane tears or other adverse events were observed. Mean residual alveolar ridge height was 4.78 ± 0.88 mm. Six months after the procedure, the mean MBL was 0.18 mm. The mean sinus membrane elevation was 12.78 ± 2.18 mm (range: 10.7-14.23). Along the basic 3D reference planes, the dimensions of grafted bone measured around implants were as follows: axial area = 239.7 ± 57.68 mm2; sagittal area = 257.0 ± 60.83 mm2; coronal area = 143.3 ± 29.46 mm2. The mean volume of the graft was 2.38 ± 0.26 mL at baseline and 2.05 ± 0.24 mL 6 months after graft maturation (difference: 0.33 ± 0.29 mL, P = .0090). Graft density (in Hounsfield units [HU]), improved during healing from 322.0 ± 100.42 HU to 1,062.0 ± 293.7 HU; difference 740.0 ± 295.35 HU (P = .0001). The mean ISQ value was 65.5 at implant placement, and it increased to 74.1 at the 6-month examination (P = .0014). Of 18 patients, 12 experienced no pain (66.6%) and 10 experienced no swelling (55.5%). No severe pain or swelling was reported in any of the cases. The mean number of analgesic tablets consumed was 0.78 ± 0.67. Mean surgical time was 24.0 ± 4.07 minutes. The iRaise Sinus Lift System may provide a new option for minimally invasive transcrestal sinus surgery with minimal patient discomfort. A physiologic contraction of 13.9% of its original volume was experienced during healing. Long-term clinical studies are needed to confirm these preliminary results.

This study evaluated the influence of liner agents placed under resin composite restorations on shear bond strength (SBS) to dentin. A total of 40 extracted bovine incisors were used. Enamel surfaces were ground to expose a flat dentin area of 7 mm in diameter. Teeth were divided into four groups according to tested liners: Group 1 (control) used no liner; Group 2 used a resin-modified glass-ionomer cement liner (Vitrebond Plus, 3M ESPE); Group 3 used a lightactivated calcium hydroxide resin liner (Ultra-Blend Plus, Ultradent); and Group 4 used a polyacrylic acid surface treatment + conventional glass-ionomer cement liner (Vidrion F, SSWhite). All groups were subjected to bonding procedures with Single Bond (3M ESPE) and 4-mm-thick buildups of resin composite were fabricated. Artificial aging was performed, and the specimens were submitted to mechanical shear testing. One-way analysis of variance (ANOVA) revealed significant differences among liners (P = .00). Group 4 showed the highest SBS. Group 1 showed significantly higher mean SBS compared with Group 3. Results showed that SBS is improved when using polyacrylic acid surface treatment + conventional glass-ionomer cement and decreased when using light-activated calcium hydroxide when compared with no liner. Polyacrylic acid surface treatment + conventional glass-ionomer cement as a liner placed under adhesion surface can improve the shear bond strength between dentin and resin, while light-activated calcium hydroxide resin should be used restrictedly in very deep cavities, because they may reduce the bond strength of the restoration submitted to masticatory forces and temperature changes in the oral environment.

Autogenous bone harvesting is a well-documented surgical procedure. Autogenous mandibular bone harvesting carries a risk of anatomical structural damage because the surgeon has no three-dimensional (3D) control of the osteotomy planes. The aim of this case series was to describe the results of mandibular bone block harvesting applying computer-guided surgery. A sample of 13 partially dentate patients presenting bone deficiencies in the horizontal and/ or vertical plane were selected for autogenous mandibular bone block graft. The bone block dimension was planned through a computer-aided design (CAD) process, defining ideal bone osteotomy planes to avoid damage to anatomical structures (nerves, teeth roots, etc) and to generate a surgical guide that imposed the 3D working direction to the bone-cutting instrument. The bone block dimension was always related to the defect dimension to be compensated. A total of 13 mandibular bone blocks were harvested to treat 16 alveolar defects (9 vertical and 7 horizontal). The mean planned mesiodistal dimension of the bone block was 24.8 ± 7.3 mm, the mean height was 8 ± 1 mm, and the mean thickness was 4 ± 2 mm. None of the treated patients experienced neurologic alteration of their alveolar nerve function. The preliminary data from this case series suggested that computer-guided bone harvesting could be a concrete opportunity for clinicians to obtain an appropriate volume of autogenous bone in a safe manner.

The aim of this study was to test whether the combination of diode laser therapy and surgical treatment for a lateral periodontal cyst (LPC) would result in greater clinical improvement compared with surgery alone. A total of 18 patients with LPCs were assessed for eligibility for this study. At baseline, each patient was randomly allocated to one of two regimens: diode laser plus surgery (test group) or traditional surgical treatment alone (control group). Healing parameters were assessed at 7 to 21 days to monitor short-term complications, and periodontal parameters were assessed at 3, 6, and 12 months to evaluate long-term healing. The test group demonstrated highly significant differences in both the shortterm and long-term parameters compared with the control group. This study showed that diode laser treatment results in a shorter wound-healing period and could be considered valuable for the surgical treatment of LPCs.

Lip repositioning surgery to address excessive gingival display induced by different etiologies has received major attention recently. Several techniques and variations have been reported, including myotomy or repositioning of the levator labii superioris muscle, Le Fort impaction, maxillary gingivectomies, botulinum toxin injections, and lip stabilization. This study reports a case of excessive gingival display treated by a modified combined approach. A 25-yearold woman with a 4- to 8-mm gingival display when smiling caused by a combination of short clinical crowns induced by an altered passive eruption and hypermobility of the upper lip underwent a staged esthetic crown-lengthening procedure followed by a modified lip repositioning technique. A description of the technique and a comparison with other modes of therapy is discussed. This modified approach for treating the hypermobile lip included a bilateral removal of a partial-thickness strip of mucosa from the maxillary buccal vestibule without severing the muscle, leaving the midline frenum intact and suturing the lip mucosa to the mucogingival line. The narrower vestibule and increased tooth length resulted in a symmetric and pleasing gingival display when smiling that remained stable over time. With proper diagnosis and sequence of therapy, modified lip repositioning surgery combined with esthetic crown lengthening can be used predictably to treat excessive gingival display and enhance smile esthetics.