International Journal of Periodontics & Restorative Dentistry, 01/2013

Until recently, adequate bone at the recipient site has been a determinant for tooth autotransplantation. This article presents the transplantation of developing mandibular canines to a suboptimal position because of inadequate bone at the recipient sites. Five years later, after eruption and orthodontic alignment, all criteria for successful healing were fulfilled. In addition, new bone that was not present at the time of surgery was identified at the roots of the transplanted teeth, implying that transplanted developing teeth can stimulate bone to grow along their roots.

Implant therapy can lead to peri-implantitis, and none of the methods used to treat this inflammatory response have been predictably effective. It is nearly impossible to treat infected surfaces such as TiUnite (a titanium oxide layer) that promote osteoinduction, but finding an effective way to do so is essential. Experiments were conducted to determine the optimum irradiation power for stripping away the contaminated titanium oxide layer with Er:YAG laser irradiation, the degree of implant heating as a result of Er:YAG laser irradiation, and whether osseointegration was possible after Er:YAG laser microexplosions were used to strip a layer from the surface of implants placed in beagle dogs. The Er:YAG laser was effective at removing an even layer of titanium oxide, and the use of water spray limited heating of the irradiated implant, thus protecting the surrounding bone tissue from heat damage. Peri-implantitis can be effectively treated using Er:YAG laser irradiation.

The purpose of this study was to evaluate the failure rates of porcelain laminate veneers (PLVs) and the influence of clinical parameters on these rates in a retrospective survey of up to 12 years. Five hundred eighty laminate veneers were bonded in 66 patients. The following parameters were analyzed: type of preparation (depth and margin), crown lengthening, presence of restoration, diastema, crowding, discoloration, abrasion, and attrition. Survival was analyzed using the Kaplan-Meier method. Cox regression modeling was used to determine which factors would predict PLV failure. Forty-two veneers (7.2%) failed in 23 patients, and an overall cumulative survival rate of 86% was observed. A statistically significant association was noted between failure and the limits of the prepared tooth surface (margin and depth). The most frequent failure type was fracture (n = 20). The results revealed no significant influence of crown lengthening apically, presence of restoration, diastema, discoloration, abrasion, or attrition on failure rates. Multivariable analysis (Cox regression model) also showed that PLVs bonded to dentin and teeth with preparation margins in dentin were approximately 10 times more likely to fail than PLVs bonded to enamel. Moreover, coronal crown lengthening increased the risk of PLV failure by 2.3 times. A survival rate of 99% was observed for veneers with preparations confined to enamel and 94% for veneers with enamel only at the margins. Laminate veneers have high survival rates when bonded to enamel and provide a safe and predictable treatment option that preserves tooth structure.

Gingival recession is a challenging defect for clinicians to treat effectively. A number of recent systematic reviews have identified the connective tissue graft (CTG) in combination with coronally advanced flaps (CAFs) as the most consistently effective treatment for Miller Class I and II defects across all outcome measures. Recent advances in recombinant growth factor technology may provide opportunities for improved outcomes in conjunction with CAF + CTG procedures. In this prospective consecutive case series, recombinant human platelet-derived growth factor BB (rhPDGF-BB) was combined with CTGs for the treatment of Miller Class I or II gingival recession defects. Improved outcomes were seen for keratinized tissue gains and percent root coverage at 6 months postsurgery when compared to historic norms. All other outcome parameters appeared equivalent between the two treatment approaches. The addition of rhPDGF-BB appeared to improve early wound healing as well.

This report presents early clinical experiences with the treatment of a consecutive cohort of 89 patients who received 125 prostheses supported by 205 milled abutments. Abutments were fabricated using unique computer-aided design software to deliver both titanium and zirconia abutments based on idealized values for tooth dimensions and emergence profiles as well as on a scan of the proposed definitive prosthesis.

Cement-retained restorations allow for a conventional fixed partial denture approach to restoring dental implants. However, inadequate removal of excess cement at the time of cementation may introduce a severe complication: cement-induced peri-implantitis. Radiopaque cements are more easily detected on radiographs and should improve the recognition of extravasated cement at the time of insertion. The purpose of this study was to evaluate the radiopacity of commercially available cements in vitro. Eighteen different cements commonly used for luting restorations to implants were tested at both 0.5- and 1.0-mm thicknesses. The cements examined were zinc oxide eugenol, zinc oxide, zinc polycarboxylate, zinc phosphate, resin-reinforced glass ionomer, urethane resin, resin, and composite resin. Two samples of each cement thickness underwent standardized radiography next to an aluminum step wedge as a reference. The mean grayscale value of each of the nine 1-mm steps in the step wedge were used as reference values and compared to each of the cement samples. Temp Bond Clear (resin), IMProv (urethane resin), Premier Implant Cement (resin), and Temrex NE (resin) were not radiographically detectable at either sample thickness. Cements containing zinc were the most detectable upon radiographic analysis. There are significant differences in the radiopacity of many commonly used cements. Since cementinduced peri-implantitis can lead to late implant failure, cements that can be visualized radiographically may reduce the incidence of this problem.

The purpose of this study was to determine the clinical and histologic efficacy of the combination of alloplastic biphasic calcium phosphate composed of 30% hydroxyapatite and 70% ß-tricalcium phosphate (Osteon II) and a cross-linked collagen membrane used to reconstruct an extraction socket with new bone formation. Twelve patients, from two private dental practices, requiring extraction of maxillary and mandibular nonmolar teeth (n = 30) received both Osteon II (0.5- to 1.0-mm particle size) and the collagen membrane. The primary healing intention group (group A, n = 12) received primary flap closure over the membrane, while in the secondary healing intention group (group B, n = 18), the membrane was left exposed. Early wound healing seemed to be slower in group B when compared to group A, but the difference was not noticeable after 4 weeks. Clinical reentry revealed that the dimensions of the ridge appeared to be maintained in both groups, and internal socket bone fill was evident. The grafted area appeared to be well vascularized, but clinically visible graft particles were noted in some cases. Light microscopic analysis revealed the formation of new bone directly apposing the surfaces of graft particles and bridging the space between them, indicating that the graft material behaved as an osteoconductive scaffold. The mean amount of vital bone in group A was 40.3% ± 7.8%, while the remaining graft was 6.0% ± 4.0%. The mean amount of vital bone in group B was 47.3% ± 11.3%, while the remaining graft was 18.0% ± 20.0%. The absence of primary flap closure did not affect the percentage of vital bone formation or residual graft.

Thin facial soft tissue may lead to visible soft tissue discoloration around implants and therefore to esthetic deficiencies. The aim of this article is to present a surgical approach to peri-implant soft tissue discoloration caused by the shinethrough effects of restorative materials in the anterior maxilla. A clinical case is used to illustrate the approach. A minimally invasive tunneling approach and connective tissue graft are used. The optical outcome is documented in an objective and standardized manner using a spectrophotometer after a follow-up of 12 months. The presented technique clearly improved the clinical condition and esthetic outcome. Spectrophotometric follow-up revealed a soft tissue color difference between the implant and adjacent tooth (control) that was clearly less than initially presented. In the area 3 mm apical to the soft tissue margin, this difference was beneath the clinically perceptible threshold of 3.7.

Immediate implant placement at multirooted molar sites involves a series of site-specific anatomical challenges, including implant bed preparation in the presence of interradicular bone septa. The aim of this article is to present and discuss a novel approach that gives improved guidance during implant bed preparation for immediate implants at multirooted extraction sites in both the mandible and maxilla. Following decoronation of the concerned teeth, osteotomies were performed directly through the teeth's initially retained root complexes. After completion of the drilling protocol, the remaining root aspects were extracted, and treatment was continued in the usual manner. With the osteotomy drills stabilized and guided by the retained root aspects, this approach allows for precise positioning and angulation of the implant bed preparation, thus enabling ideal implant positioning during immediate implant placement at multirooted extraction sites.

This case report describes the augmentation of severe lateral ridge defects in the maxilla and mandible using recombinant human bone morphogenetic protein 2 (rhBMP-2) on an absorbable collagen sponge (ACS). The surgical technique used tenting screws and a membrane to maintain space for the ACS. After 7 months of healing, the ridge width increased from 1 to 2 mm to 6 to 9 mm, thus allowing successful placement of dental implants. De novo bone formation through use of the surgical technique for space maintenance of rhBMP-2/ACS was demonstrated without the need for additional particulate bone grafting.

Abutment material selection may have an effect on the color of the peri-implant soft tissue, especially in thin mucosa. The objective of this in vitro study was to investigate the effect of titanium, zirconia, and dyed fluorescent zirconia on the color of 1.5-mm-thick mucosa. Ten pig maxillae were used to simulate thin mucosa according to a previously published setup. Three different abutment materials were placed under the mucosa, and the color of the soft tissue was evaluated using a spectrophotometer. The test area without underlying material was used as a control. Whereas titanium induced visible color change values of ΔE7.3, significantly above the threshold level of ΔE3.7 (P .05, Student t test), the changes after insertion of zirconia (ΔE3.7) and dyed fluorescent zirconia (3.5) were not statistically different from the visible threshold of ΔE3.7 (P .05, Student t test). The difference between the two zirconia specimens was not statistically significant, although the dyed zirconia material was darker; the color difference was ΔE10.35 between the two. In contrast to titanium, neither nondyed zirconia nor dyed fluorescent zirconia changed the gingival coloration. Moreover, shading of white zirconia with a fluorescent dye leads to an all-ceramic abutment material that mimics the optical properties of natural teeth.

Esthetic considerations have become increasingly important in dental therapy. Evaluation of the soft tissue display during enjoyment smiling can provide useful information for esthetic oral rehabilitation. To date, no study has quantified the amount and frequency of soft tissue display in the area of the papilla. Photographic examination of 66 fully dentate patients with a mean age of 28.5 years was performed during enjoyment smiling. Digital processing and measurement of the tooth, gingival, and papillary display revealed that over 90% of subjects displayed papillae in the anterior teeth and first premolars during enjoyment smiling regardless of sex. The frequency of display in descending order consisted of maxillary lateral incisors (96%), central incisors (94%), canines (94%), first premolars (91%), second premolars (85%), and first molars (39%). The mean papillary display was 3.4 mm (range, 0.0 to 10.0 mm). There was no significant difference in the amount of papillary display between the sexes for anterior teeth, premolars, or first molars (P = .97, P = .79, and P = .48, respectively).

Risk factors such as smoking, genetic factors, and tissue biotype play an important role in the etiology, predictability, and long-term stability of gingival recession treatment. This study was designed to evaluate the influence of interleukin 1 (IL-1) polymorphism and smoking on the stability of gingival recession treatment after 1 and 3 years. All patients (n = 55) were treated for type I and II recession defects using a connective tissue graft. Clinical evaluations were performed, which included assessment of vertical recession depth, gingival inflammation, and clinical attachment level. A fingerstick blood sample was collected using specially provided DNA filter paper and mailed for processing in a laboratory using polymerase chain reaction-based methodology. The results indicated that 19 subjects were genotype positive (34.5%). Treatment of the localized recessions was effective and provided a similar amount of coverage in genotype-positive and genotype-negative subjects within smoking and nonsmoking groups after 1 year. In a 3-year period, nonsmoking patients with positive IL-1 genotype lost approximately 20% of the root coverage gained at 1 year and were almost four times more inferior compared with genotype-negative patients. Patients who smoked and had a positive IL-1 genotype lost approximately 35% of the gained root coverage. IL-1 polymorphism and smoking habit did not affect gingival recession treatment at 1 year but had a great impact on long-term stability.

Managing the interimplant papilla is one of the most challenging tasks in anterior implant esthetics, especially when replacing a failing tooth adjacent to an existing implant restoration. This article describes the maintenance of the interimplant papilla when replacing a failing tooth adjacent to an implant restoration using the proximal socket shield procedure in conjunction with immediate implant placement and provisionalization.

An implant that had penetrated the nasal cavity of a 53-year-old woman was removed after 10 months. The implant had a resorbable blast media surface and an external connection. Histomorphometric evaluation showed that the mean bone-implant contact ratio was 88.08%, and excellent osseointegration was observed. The mean bone fill between threads was 78.46%.

Marginal fit is an important clinical factor that affects restoration longevity. The accuracy of three polyvinyl siloxane putty-wash impression techniques was compared by marginal fit assessment using the nondestructive method. A stainless steel master cast containing three abutments with three metal crowns matching the three preparations was used to make 45 impressions: group A = single-step technique (putty and wash impression materials used simultaneously), group B = two-step technique with a 2-mm relief (putty as a preliminary impression to create a 2-mm wash space followed by the wash stage), and group C = two-step technique with a polyethylene spacer (plastic spacer used with the putty impression followed by the wash stage). Accuracy was assessed using a toolmaker microscope to measure and compare the marginal gaps between each crown and finish line on the duplicated stone casts. Each abutment was further measured at the mesial, buccal, and distal aspects. One-way analysis of variance was used for statistical analysis. P values and Scheffé post hoc contrasts were calculated. Significance was determined at .05. One-way analysis of variance showed significant differences among the three impression techniques in all three abutments and at all three locations (P .001). Group B yielded dies with minimal gaps compared to groups A and C. The two-step impression technique with 2-mm relief was the most accurate regarding the crucial clinical factor of marginal fit.