The Root Membrane Technique: Human Histologic Evidence after Five Years of Function

Background

The "root membrane" (RM) is a technique that has become popular among implantologists for placement of immediate implants in the anterior maxilla.

Purpose

To present histologic evidence of an immediate implant placed in the human anterior maxilla, according to the RM technique, and retrieved after five years.

Methods

A fixture, along with the surrounding tissues, was retrieved from the anterior maxilla of a 68-year-old patient, who had been treated five years earlier with immediate implant placement and RM technique. The specimen was processed for histologic/histomorphometric evaluation.

Results

The buccal bone plate was maintained without any resorption; a healthy periodontal ligament was evidenced. The implant showed osseointegration, with a high percentage of bone-to-implant contact (BIC = 76.2%). With regard to the space between the RM and the implant, the apical and medial thirds were filled with compact, mature bone; the coronal third was colonized by noninfiltrated connective tissue.

Conclusions

The RM technique appears to be effective in preventing bone resorption of the buccal bone plate of the human anterior maxilla, five years after the placement of an immediate implant.

Contour changes after guided bone regeneration of large non-contained mandibular buccal bone defects using deproteinized bovine bone mineral and a porcine-derived collagen membrane: an experimental in vivo investigation

OBJECTIVE

The objective of this study was to evaluate soft tissue contour changes after three different regenerative therapies in chronic ridge defects.

MATERIAL AND METHODS

Buccal bone defects were created in the mandible of nine beagle dogs. Augmentation procedures were performed 3 months later using a bone replacement graft (BRG), resorbable collagen membrane (MBG), or a combination of both procedures (CBG). Silicone impressions were taken before tooth extraction (T1), before the augmentation procedure (T2), and 3 months after the regenerative surgeries (T3). Casts were optically scanned and stereolithography files were superimposed to analyze the horizontal changes in ridge contours.

RESULTS

After defect creation, most part of the horizontal changes occurred 4 and 6 mm below the gingival margin. In the mesial defect (D1) at T3, the mean horizontal gain in MBG amounted to 0.47 ± 0.34 mm, 0.79 ± 0.67 mm in the BRG, and 0.87 ± 0.69 mm for the CBG. In the middle defect (D2), the mean changes for the MBG were 0.11 ± 0.31, 1.01 ± 0.91 for the BRG, and 0.98 ± 0.49 for the CBG. The mean changes in the distal defect (D3) amounted to 0.24 ± 0.72 for the MBG, 1.04 ± 0.92 for the BRG, and 0.86 ± 0.56 for the CBG. The differences reached significance in all defects for the comparison MBG-BRG and MBG-CBG, while similar parameters were observed for the comparison BRG-CBG.

CONCLUSION

BRG and CBG were equally effective and superior to MBG in increasing the horizontal tissue contours. The augmentation seldom reached the values before extraction.

CLINICAL RELEVANCE

Scaffolding materials are needed for contour augmentation when using resorbable collagen membranes.

Case Selection is Critical for Successful Outcomes Following Immediate Implant Placement in the Esthetic Zone

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Immediate versus delayed implant placement after anterior single tooth extraction: the timing randomized controlled clinical trial. Tonetti MS, Cortellini P, Graziani F, Cairo F, Lang NP, Abundo R, Conforti GP, Marquardt S, Rasperini G, Silvestri M, Wallkamm B, Wetzel A. Journal of Clinical Periodontology 2017;44(2):215-24.

SOURCE OF FUNDING

Nonprofit, Foundations: European Research Group on Periodontology, Genova, Italy Industry: Thommen Medical AG, Switzerland and Geistlich AG, Switzerland (biomaterials).

TYPE OF STUDY/DESIGN

Randomized controlled trial.

Soft tissue volume augmentation at dental implant sites using a volume stable three-dimensional collagen matrix - histological outcomes of a preclinical study

AIM

The aim of this study was to test whether or not soft tissue augmentation with a collagen matrix (VCMX) leads to a similar increase in ridge width around dental implants compared to the use of an autogenous subepithelial connective tissue graft (SCTG).

MATERIALS AND METHODS

In 12 dogs, immediate dental implants were placed with simultaneous guided bone regeneration. Three months later, soft tissue volume augmentation was performed by randomly allocating three treatment modalities to these sites [VCMX, SCTG, sham-operated group (control)]. Dogs were sacrificed at 1 (n = 4), 2 (n = 4) or 6 months (n = 4). Descriptive histology and histomorphometric measurements for soft tissue thickness were performed on non-decalcified sections.

RESULTS

The horizontal soft tissue thickness was maximal at the most coronal level (alveolar crest) at 1 month (VCMX: 2.1 ± 1.6 mm; SCTG: 2.5 ± 1.7 mm; p = 0.877) and decreased until 6 months. At 6 months, the greatest mucosal thickness was at a level 3.5 mm below the crest (VCMX: 0.8 ± 0.3 mm; SCTG: 0.7 ± 0.2 mm) (p = 0.754). Control sites revealed no relevant soft tissue augmentation at any level and any time-point. Tissue integration for VCMX and SCTG were favourable with minimal inflammatory reactions.

CONCLUSIONS

Soft tissue volume augmentation at implant sites was obtained to a similar extent using VCMX and SCTG up to 2 months. Thereafter, degradation and remodelling processes were enhanced leading to a minimal increase in soft tissue thickness at 6 months for VCMX and SCTG.

Crestal Bone Loss Around Adjacent Dental Implants Restored with Splinted and Nonsplinted Fixed Restorations: A Systematic Literature Review

PURPOSE

The aim of this systematic review was to compare the crestal bone loss around splinted and nonsplinted adjacent implants.

MATERIALS AND METHODS

To address the focused question, "Is crestal bone loss around adjacent implants different with splinted from that with nonsplinted restorations?," indexed databases were searched from 1965 up to and including May 2016 using various combinations of the following keywords: "implant," "splinted," "nonsplinted," "unsplinted," "connected," "unconnected," "nonconnected," and "bone loss." Letters to the editor, commentaries, historic reviews, case reports, case series, animal studies, and studies on full-arch rehabilitation were excluded.

RESULTS

Six studies were included with titanium implants ranging from 114 to 1187 implants. All studies had nonsplinted and splinted restorations that ranged from 20 to 234 restorations and from 60 to 970 restorations, respectively. In all the studies, the follow-up period after the restoration placement ranged between 1 and 22 years, with a mean follow-up ranging between 3 and 10.18 ± 3.18 years. In all studies, the mean crestal bone loss for implants restored with nonsplinted restorations ranged between 0.30 ± 0.65 and 1.3 ± 0.2 mm, whereas the mean crestal bone loss for implants restored with splinted restorations ranged between 0.50 ± 0.8 and 1.22 ± 0.95 mm.

CONCLUSION

Within the limitations of this review it is concluded that adjacent implants restored with splinted and nonsplinted fixed restorations did not exhibit a difference in crestal bone loss. The evidence from this systematic review suggests further investigation.

Annual review of selected scientific literature: Report of the committee on scientific investigation of the American Academy of Restorative Dentistry

STATEMENT OF PROBLEM

It is clear the contemporary dentist is confronted with a blizzard of information regarding materials and techniques from journal articles, advertisements, newsletters, the internet, and continuing education events. While some of that information is sound and helpful, much of it is misleading at best.

PURPOSE

This review identifies and discusses the most important scientific findings regarding outcomes of dental treatment to assist the practitioner in making evidence-based choices. This review was conducted to assist the busy dentist in keeping abreast of the latest scientific information regarding the clinical practice of dentistry.

MATERIAL AND METHODS

Each of the authors, who are considered experts in their disciplines, was asked to peruse the scientific literature published in 2015 in their discipline and review the articles for important information that may have an impact on treatment decisions. Comments on experimental methodology, statistical evaluation, and overall validity of the conclusions are included in many of the reviews.

RESULTS

The reviews are not meant to stand alone but are intended to inform the interested reader about what has been discovered in the past year. The readers are then invited to go to the source if they wish more detail.

CONCLUSIONS

Analysis of the scientific literature published in 2015 is divided into 7 sections, dental materials, periodontics, prosthodontics, occlusion and temporomandibular disorders, sleep-disordered breathing, cariology, and implant dentistry.

Soft Tissue Stability around Single Implants Inserted to Replace Maxillary Lateral Incisors: A 3D Evaluation

Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method. Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes. Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (test group: immediate placement in postextraction socket) and 10 with a missing lateral incisor (control group: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) for test and control patients, respectively. This difference was not statistically significant (p = 0.069). Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time.