Alveolar Ridge Preservation with a Novel Cross-Linked Collagen Sponge: Histological Findings from a Case Report

Alveolar ridge preservation (ARP) is a well-documented procedure to maintain bone volume after tooth extraction in order to place implants. However, at the end of the healing process, the residual biomaterial that is not reabsorbed remains embedded in the bone over time. Ribose cross-linked biomaterials demonstrated their ability to promote osteoconduction and complete resorption. The aim of this study was to evaluate the histological healing pattern of a novel ribose cross-linked collagen sponge used as a grafting material left exposed in human sockets at the time of tooth extraction. On a single patient, non-restorable lower first molars were extracted on both sides, and a ribose cross-linked collagen sponge was placed bilaterally in the cavities and left uncovered at the end of the surgery. After six months, core biopsies were taken immediately prior to implant placement; after the sample preparation, a histological analysis was performed. The results are very promising for substitution with newly formed bone and the amount of residual material. Ribose cross-linked collagen sponge could represent a valid alternative to conventional biomaterials for ARP procedures with no need for flap advancement and/or the addition of a membrane to cover the graft, reducing the invasiveness, complexity, and costs of the treatment.

Ossification and Bone Regeneration in a Canine GBR Model, Part 2: Glycated Cross-Linked Collagenated Alloplastic Hydroxyapatite Scaffold vs Non-Cross-Linked Collagenated Xenographic Bone Hydroxyapatite

PURPOSE

To compare bone substitutes composed of glycated collagen with synthetic micro-sized (1 to 10 μm) hydroxyapatite (OB) vs non-cross-linked collagen matrix with large-particle (250 to 1,000 μm) bovine-derived hydroxyapatite (BOC).

MATERIALS AND METHODS

The P1 to P4 premolars were bilaterally extracted from the mandibles of 19 Beagle dogs. After 21 days, osteotomies were created in each dog that received OB or BOC and were covered with a collagen membrane or were left untreated. The animals were randomly divided into three groups based on sacrifice time (4, 12, or 24 weeks). The right and left hemimandibles were trimmed to facilitate imaging and histology, and all tissues were placed in 10% neutral-buffered formalin. Microcomputed tomography (MicroCT 40 Scanner, Scanco) was used to analyze bone sections. Bone volume, residual material volume, and bone mineral density were determined for each treatment site (OB and BOC) based on a volume of interest that encompassed the original defect. Additionally, blinded histopathologic assessment (based on the ISO 10993-6 scoring system) and histomorphometry were performed on sections ground to < 100 μm thick and stained with Stevenel's blue.

RESULTS

No clinical side effects were noted. No statistical differences were observed for OB vs BOC regarding the mineral volume percentage. Compared to OB, BOC had significantly higher mean mineralization densities at 12 weeks (P < .01), but this difference did not extend to 24 weeks. For residual grafting material, bone maturation, alveolar ridge restoration, and inflammatory response, OB showed a residual amount of bone graft and no statistical differences compared to BOC.

CONCLUSION

Both OB and BOC represent valid treatment options for critically sized bone defects. Both bone fillers outperformed the sham-operated, ungrafted (empty) control, demonstrating statistically improved bone growth and ridge restoration.

Ossification and Bone Regeneration in a Canine GBR Model, Part 1: Thick vs Thin Glycated Cross-Linked Collagen Devices

Purpose: To compare glycated multilayered membranes (OV) to a commercially available thin-layer membrane (OP) in a lateral ridge augmentation model in dogs. Materials and Methods: This was designed as a three-arm study, where one negative control (empty defect) was compared to two test arms: alveolar bone defects grafted with a mixture of 90% deproteinized bovine bone mineral and 10% porcine collagen, then covered with either a thick- (OV) or thin-layered (OP) membrane. Animals were randomly divided into three groups corresponding to the final sacrifice times of 4 weeks, 12 weeks, and 24 weeks. Sections underwent microCT, histology, histopathology, and histomorphometry. Results: No statistical differences were observed for OV compared to OP regarding the percentage of mineral volume and mean mineral density, amount of bone maturation, percentage of bone graft and membrane remaining in the grafted area, alveolar ridge width measurements, membrane mineralization, or ossification. Test groups presented significantly higher values compared to the empty control for all the endpoints. Conclusions: Within its limitations, this in vivo study highlighted that multilayered thick glycated membranes can serve as effective occlusive barriers for up to 6 months.

The Long-Term Evaluation of Two-Unit Fixed Partial Dentures on Short, Threaded Implants: Delayed Versus Immediate Loading

Placement of short implants is a common approach to rehabilitate edentulous areas. The objective of this study was to evaluate the long-term survival of 7.0- and 8.5-mm implants placed in either a delayed or immediate loading protocol. Life table analysis revealed the implants treated with the delayed loading protocol had a 90.9% survival rate and the implants treated with the immediate loading protocol had a survival rate of 92.0%. The results of this 8-year prospective study demonstrate similar survival rates of short, cylindrical threaded implants placed by either a delayed or immediate loading protocol.

Morphometric Changes Induced by Cold Argon Plasma Treatment on Osteoblasts Grown on Different Dental Implant Surfaces

Treatments for enhancing surface energy were studied in an effort to create a more favorable environment for cell adhesion. Cold argon plasma (CAP) is able to improve titanium-cell contact, producing hydrophilic surfaces with higher wettability. The aim of this in vitro study was to estimate the early cell morphology after CAP treatment of different commercially available titanium surfaces. Surface wettability was significantly augmented in all the treated samples. The authors investigated how CAP affected the behavior of osteoblasts by evaluating the cell morphology outcome. Cell surface areas differed in a statistically significant way when plasma-treated samples were compared to the untreated ones. The positive effect of CAP was shown on smooth, moderately rough, and rough implant surfaces.

Short (5 and 7 mm long) porous implants in the posterior atrophic maxilla: a 5-year report of a prospective single-cohort study

PURPOSE

The aim of this ongoing prospective study was to determine the 5-year survival rate of short porous dental implants in the posterior atrophic maxilla combined, when necessary, with crestal sinus floor elevation and often adding anorganic bovine bone.

MATERIALS AND METHODS

In 87 partially edentulous patients, 110 short porous implants were placed and followed up for 5 years. The implants used were of two lengths (5 and 7 mm) and two diameters (4.1 and 5 mm) and were chosen according to the available crestal height and width. In 47 sites, osteotome sinus floor elevation was performed (in 8 cases compacting basal bone, in 39 adding a xenograft). The unloaded healing period was 6 months. A total of 63 implants were restored with single crowns and 47 were splinted to the adjacent implants. Outcome measures were prosthesis and implant failures, any complications, and peri-implant marginal bone resorption.

RESULTS

Five years after loading, no patients dropped out. Eleven implants failed: 2 implants at uncovering and 9 after prosthetic loading. Eleven patients (12.6%) lost 1 implant. In 6 patients (6.9%) a prosthesis failure occurred (implants loaded with single crowns). One surgical complication (membrane perforation) occurred but the implant was normally inserted. No complications occurred during the healing period. In 3 patients, severe peri-implantitis occurred post loading and the implants had to be removed. Two abutments became loose and one crown chipped. At the end of the follow-up period the implant survival rate was 90%, and 93.1% with regard to prosthetic reconstruction. The mean peri-implant marginal bone loss was 1.4 mm.

CONCLUSIONS

The use of short porous implants showed an acceptable clinical outcome in the treatment of the posterior maxilla in this interim 5-year report. Longer follow-ups are needed to confirm these results.

Short (5 and 7 mm long) porous implant in the posterior atrophic mandible: a 5-year report of a prospective study

PURPOSE

The aim of this ongoing prospective study was to determine the 5-year survival rate of short porous implants in the posterior atrophic mandible.

MATERIALS AND METHODS

In 40 partially edentulous patients, 55 short porous implants were placed. The implants used were of two lengths (5 and 7 mm) and two different diameters (4.1 and 5 mm) and were chosen according to the available crestal height and width. The unloaded healing period was 4 months. Twenty-one implants were restored with single crowns, 32 were splinted to the adjacent implant, 2 were used with an overdenture and were followed for 5 years. Outcome measures were prosthesis failures, implant failures and complications.

RESULTS

No patients dropped out. Nine implants were removed: 1 implant at uncovering and 8 after prosthetic loading. Eight patients lost 1 implant and 1 patient lost 2 implants. Four crowns failed. No complications occurred during the healing period. In 2 patients severe peri-implantitis occurred after loading and the implants had to be removed. At the end of the follow-up period the survival rate was 84% at implant level and 80% at patient level.

CONCLUSIONS

The use of short porous implants showed an acceptable clinical outcome in the treatment of the posterior mandible in this interim 5-year report. These preliminary results must be confirmed by longer follow-ups.

A connective tissue graft envelope technique for the treatment of single gingival recessions: a 1-year study

Root coverage is the goal of periodontal plastic surgery when treating gingival recessions. The aim of the present study was to evaluate the clinical results 1 year after treatment with an envelope connective tissue graft technique for single recessions. Forty consecutive patients with single recessions were treated. At baseline and 1 year after surgery, recession, probing pocket depth, clinical attachment level, and keratinized tissue height were recorded. After 1 year, the mean differences in recession (3.12 +/- 0.90 mm), clinical attachment level (3.92 +/- 1.00 mm), keratinized tissue height (3.75 +/- 0.95 mm), and probing pocket depth (0.50 +/- 0.64 mm) were statistically significant. Mean root coverage was 95.54% +/- 11.43%; 85% of the treated cases achieved complete root coverage. The envelope connective tissue graft technique showed high predictability in the treatment of single recessions.

Short porous implants in the posterior maxilla: a 3-year report of a prospective study

The aim of this ongoing prospective study was to determine the 36-month survival rate of short porous implants in the posterior maxilla with 2 to 7 mm of initial bone height in 48 patients. Forty-eight implants were placed; 35 were in sites with a bone height of 5 mm or less and 13 patients required sinus elevation with osteotomes in addition to a xenograft. All implants were loaded with single crowns. At the end of the follow-up period the survival rate was 97.92%. The use of short porous implants showed good predictability in the treatment of the posterior maxilla in this interim 3-year report.

Reconstruction of the maxillary midline papilla following a combined orthodontic-periodontic treatment in adult periodontal patients

OBJECTIVE

The aim of the present study was to evaluate the role of a combined orthodontic-periodontic treatment in determining the reconstruction of midline papilla lost following periodontitis.

MATERIAL AND METHODS

Twenty-eight patients, with infrabony defect and extrusion of one maxillary central incisor, were treated. At baseline, all patients presented opening of the interdental diastema and loss of the papilla. At 7-10 days after open-flap surgery, the intrusive movement started. For each patient, probing pocket depth (PPD), clinical attachment level (CAL) and papilla presence index (PI) were assessed at baseline, end of treatment and after 1 year. PI was also evaluated independently in patients with narrow or wide periodontal biotype (NPB-WPB).

RESULTS

All parameters showed statistical improvement between the initial and final measurements, and showed no changes at follow-up time. The mean residual PPD was 2.50 mm, with a decrease of 4.29 mm, while the mean CAL gain was 5.93 mm. Twenty-three out of 28 patients improved the PI score at the end of therapy. No statistical difference was recorded in PI values between groups NPB and WPB.

CONCLUSION

The presented clinical protocol resulted in the improvement of all parameters examined. At the end of orthodontic treatment, a predictable reconstruction of the interdental papilla was reported, both in patients with thin or wide gingiva.

Reduction of gingival recession following orthodontic intrusion in periodontally compromised patients

OBJECTIVES

To evaluate the role of orthodontic intrusion and alignment in the reduction of gingival recession (REC) around maxillary incisors of adult periodontal patients. Design - Prospective clinical study.

SETTING AND SAMPLE POPULATION

Twenty-eight consecutively treated adult patients, suffering from severe chronic periodontitis and with one upper central incisor extruded and infrabony defect on its mesial site. All patients were seen in a private practice in Turin, Italy. At baseline, all patients presented with REC on the buccal and mesial aspects of the treated teeth.

MEASUREMENTS AND RESULTS

For each patient probing pocket depth (PPD) and REC were assessed at baseline, at the end of treatment and 1-year after the end of treatment. REC was also evaluated independently in patients with narrow (NPB) or wide periodontal biotype (WPB). All parameters showed improvement between initial and final measurements statistically, and showed no changes between final and follow-up measurements. Mean mesial PPD decrease was 4.29 mm, with a residual PPD of 2.50 mm. Mean REC reduction was 0.96 mm on the buccal sites and 1.71 mm on the mesial. No statistical difference was recorded on REC values between groups NPB and WPB.

CONCLUSION

The presented clinical protocol resulted in improvement of all parameters examined. At the end of orthodontic treatment a predictable reduction of REC was reported, both in patients with thin or wide gingiva.

Orthodontic Movement into Infrabony Defects in Patients with Advanced Periodontal Disease: A Clinical and Radiological Study

BACKGROUND

In cases of advanced periodontal disease with a pathologic flaring of frontal teeth, a combined periodontic-orthodontic therapy may be a reliable approach in order to solve both functional and esthetic problems. The aim of the present study was to evaluate the periodontal tissue alterations following periodontal surgery and orthodontic intrusion in migrated upper central incisors with intrabony defects.

METHODS

Ten patients with advanced periodontal disease and an extruded maxillary central incisor infrabony defect at its mesial aspect and probing depth (PD) > or = 6 mm were included in the present study. At baseline, PD and clinical attachment level (CAL) were measured. The vertical and horizontal dimensions of the defects were assessed on standardized radiographs. Seven to 10 days after surgery the active orthodontic treatment started using the segmented arch technique, in order to intrude and move the teeth into the defects. Maintenance therapy was performed every 2 to 3 months until the orthodontic treatment was completed.

RESULTS

At the end of treatment, mean PD reduction was 4.35 mm, with a residual mean PD of 2.80 mm. Mean CAL gain was 5.50 mm. The mean radiological vertical and horizontal bone fills were, respectively, 1.35 mm and 1.40 mm. All differences were of statistical significance (P<0.001).

CONCLUSION

The present study showed that the combined orthodontic and periodontic therapy performed resulted in the realignment of extruded teeth with infrabony defects, obtaining a significant probing depth reduction, clinical attachment gain, and radiological bone fill.

Orthodontic movement into bone defects augmented with bovine bone mineral and fibrin sealer: a reentry case report

Periodontal disease can lead to migration of anterior teeth with the presence of infrabony defects. This creates the opportunity for treating such patients with a combined orthodontic-periodontic treatment. In the presented clinical case, an adult periodontal patient with extrusion of the maxillary central incisors and an infrabony defect on their lingual aspects was treated. During the surgical procedure, the bone defects were augmented with a combination of porous bovine bone mineral (Bio-Oss) and a fibrin-fibronectin sealing system (Tissucol). Ten days after surgery, the active orthodontic treatment started, and the teeth were intruded and realigned, moving the roots into the defects. After 6 months, the orthodontic appliances were removed and the teeth were retained by means of a resin-bonded splint. At this time, reduction in probing pocket depth and gingival recession was detected. Twelve months after the initial surgery, a reentry procedure was performed, showing complete filling of the predisposing defects with the presence of bone-like hard tissue. These clinical results suggest that teeth can be successfully moved and intruded into bone defects previously augmented with bovine bone substitute and fibrin glue. During the orthodontic treatment, this combined augmentation material was able to be replaced by bone-like hard tissue. At the end of the therapy, an improvement in esthetics and periodontal health status was registered.

Intrusion of migrated incisors with infrabony defects in adult periodontal patients

This report describes the orthodontic treatment of 10 adult patients who had severe periodontal disease, with migration and radiological evidence of an infrabony defect on a maxillary central incisor. Orthodontic tooth movement, using light and continuous forces, was initiated 7 to 10 days after periodontal surgical therapy. Mean orthodontic treatment time was 10 months. Before surgery and at the end of orthodontic treatment, the following parameters were registered clinically and with standardized intraoral radiographs: probing depth, clinical crown length, marginal bone level, bone defect radiological dimension, and root length. Comparison of pre- and posttreatment values showed a statistically significant improvement for all parameters without a remarkable decrease of root length. The mean residual probing depth was 2.80 mm, and the mean intrusion of the incisors was 2.05 mm. Moreover, radiographs showed a reduction of the infrabony defects. These results show the efficacy of a combined orthodontic-periodontal approach. Intrusive movement, after proper periodontal surgical therapy, can positively modify both the alveolar bone and the soft periodontal tissues.

Bodily tooth movement through the maxillary sinus with implant anchorage for single tooth replacement

Movement of teeth through anatomic limitations, such as the maxillary sinus, can be a reliable therapeutic protocol if suitable force systems are used. We report here the outcome of a treatment based on this concept. The patient exhibited pneumatization of the maxillary sinus resulting from earlier extractions. She was treated using an endosseous implant inserted in the retromolar region to serve as orthodontic anchorage and a T-loop appliance fabricated from TMA wire to bodily move an upper second premolar through the sinus. After 6 months, at the end of the displacement, a titanium implant was inserted in the alveolus of the moved tooth and a single crown restoration was placed. The premolar moved through the sinus maintaining its support apparatus and bone. At the end of treatment the implant used for anchorage was still osseointegrated.

Resin-bonded fixed partial dentures and splints in periodontally compromised patients: a 10-year follow-up

In the present study, 139 periodontally compromised patients received a complete periodontal treatment; in 104 cases this was followed by orthodontic treatment. At the end of the entire therapy, a total of 150 Maryland restorations (69 resin-bonded fixed partial dentures and 81 resin-bonded splints) was placed and then followed for a period of up to 10 years (mean 6.7 y). Thirteen fixed partial dentures and 16 splints failed during the observation period; the 10-year cumulative survival rate from lifetable analysis was 76.2% (70.6% for fixed partial dentures and 80.7% for splints).

Long-term evaluation of osseointegrated implants in regenerated and nonregenerated bone

This investigation evaluated the predictability of dental implants subjected to bone regeneration procedures at the time of insertion. Fifty-two test implants were inserted into sites with periimplant bone defects. A calcium carbonate allograft material with or without a fibrin-fibronectin sealing system was used to fill the defects. Sixty control implants were inserted into an adequate volume of nonaugmented bone. Each of the 29 study patients received at least one test implant and one control implant. At the second-stage surgery, fill of the bone defect was assessed as complete or incomplete. The cumulative success rate was 91.7% (mean follow-up 55 mo) for the test implants and 93.2% (mean follow-up 59 mo) for the control implants. Within the test group, implants with complete bone fill achieved 97.6% success versus 59.1% success for implants with incomplete bone fill. These preliminary results suggest that implants placed with simultaneous bone regeneration procedures achieve long-term predictability that is comparable to that of implants placed in an adequate volume of bone, provided that complete bone fill of the periimplant defect is achieved. Long-term studies with other augmentation materials are needed to fully validate these findings.

Orthodontic treatment in periodontally compromised patients: 12-year report

This work describes the therapeutic protocol of combined orthodontic-periodontal treatment and evaluates the effectiveness of surgical and nonsurgical periodontal therapy in the maintenance of a healthy periodontal status after the orthodontic treatment. Surgical periodontal treatment was performed in 267 patients affected by severe periodontal disease, and 128 patients had nonsurgical treatment. For each patient the mean value of probing depth (mPPD) and the rate of positive bleeding on probing (%BoP) of the teeth involved in the orthodontic movement were registered before the start of the periodontal treatment, at the end of the orthodontic treatment, and 2, 4, 6, 10, and 12 years after the end of the orthodontic treatment. Comparison between pretreatment and posttreatment values and between pretreatment and follow-up values showed a decrease in mPPD and %BoP that was of statistical significance. The difference between posttreatment and follow-up values was not statistically significant. These results suggest that orthodontic treatment is no longer a contraindication in the therapy of severe adult periodontitis. In these cases orthodontics improve the possibilities of saving and restoring a deteriorated dentition.

Supracrestal bone regeneration around dental implants using a calcium carbonate and a fibrin-fibronectin sealing system: clinical and histologic evidence

This study evaluated a new surgical technique for the treatment of an alveolar ridge deficiency in 11 patients. Twenty-two implants were placed, 15 of which presented with a combination of supracrestal and dehiscence kinds of defects, and seven presented only supracrestal bone loss. Surgical procedures were performed utilizing a combination of the resorbable space-making material calcium carbonate stabilized with a fibrin-fibronectin sealing system and the immediate placement of titanium dental implants. After implant placement, the mean height for supracrestal and dehiscence defects measured 2.57 +/- 1.41 mm and 2.47 +/- 1.54 mm, respectively. The defects were filled with calcium carbonate and a fibrin-fibronectin sealing system, and the flaps were sutured, avoiding any compression of the treated area. Healing was uneventful in all instances. At second-stage surgery at 6 months, a hard bone-like tissue was detectable at the defect sites. Histologic examination of four defects confirmed the presence of newly formed bone and revealed residual particles of calcium carbonate. There was a mean gain of 2.05 +/- 1.47 mm in the supracrestal defects and of 2.23 +/- 1.62 mm in the dehiscences. The results indicated that calcium carbonate, combined with a fibrin-fibronectin sealing system, is a viable alternative in the treatment of supracrestal and dehiscence bony defects.