International Journal of Periodontics & Restorative Dentistry, 03/2022

Historically, diagnosing peri-implantitis is done based on whether the disease is present, evaluated using the arbitrary thresholds of probing depths and bone loss. Using this approach as a tool to ascertain meaningful information regarding prevalence and treatment is limited. Efforts have been made to improve upon this, but to date, only one of these classifications has provided a simple method to communicate disease severity based on the amount of bone loss. A modified version of this simplified classification is proposed here, including information regarding the implant position, as emerging information suggests that this is a crucial factor in the etiology and prognosis of peri-implantitis. This enhancement to the classification better serves both researchers and clinicians in their discussion about peri-implantitis and helps to determine and recommend the most effective methods of management.

Orthodontic treatment aims to realign teeth in a functional and esthetic manner. When applied on an unhealthy periodontium, this may lead to advanced periodontal tissue breakdown. The present 12-year follow-up report describes the multidisciplinary management of a severe, iatrogenic, generalized periodontitis case that was caused/aggravated by orthodontic therapy on unhealthy periodontal tissues. Prompt therapy was applied through nonsurgical and surgical approaches, including soft and hard tissue grafting procedures combined with corrective orthodontic treatment on healthy tissues. This report is a clear demonstration that early disease detection and proper diagnosis combined with appropriate therapeutic approaches concomitant with strict supportive periodontal therapy could lead to long-term successful and maintainable outcomes, even in hopeless cases.

Maxillary sinus wall fenestration at the lateral wall or floor of the sinus can result from many potential factors, such as the repair of oro-antral communication, Caldwell-Luc antrostomy, tooth extraction after an endodontic or periodontal infection that eroded the sinus wall, and the combination of sinus pneumatization and alveolar ridge resorption after teeth removal. When sinus wall fenestration is observed on radiographs, it usually indicates adhesion between the sinus membrane and buccal flap, which makes the reentry surgery for subsequent sinus augmentation challenging. To minimize surgical complications in these challenging scenarios, this paper presents a split-flap surgical technique for the management of soft tissue adhesion between the sinus membrane and alveolar mucosa when attempting a lateral window sinus augmentation.

Combined surgical procedures have been introduced that combine periodontal regenerative/reconstructive procedures in intrabony defects with a connective tissue graft to compensate for a deficient bone wall and limit soft tissue shrinkage, but little is known about the reproducibility of these advanced surgical techniques. This 12-case series applies a combined surgical procedure, combining amelogenins, bone substitutes, and connective tissue graft to treat deep intrabony defects associated with gingival recession. Twelve deep intrabony defects with a mean clinical attachment loss of 9.9 ± 2.1 mm, mean probing depth (PPD) of 7.8 ± 1.5 mm, mean recession of the tip of the interdental papilla (TP) of 2.1 ± 1.5 mm, and mean buccal recession (REC) of 2.3 ± 1.8 mm were treated. At 1 year, the average attachment gain was 5.1 ± 1.8 mm (P < .001), the residual PPD was 2.9 ± 0.7 mm (P < .001), no change was observed in the TP (-0.4 ± 0.8 mm, P = .078), and the REC slightly decreased to 1.7 ± 1.5 mm (P = .047). These results suggest that the proposed technique led to predictable clinical outcomes that support regeneration while maintaining or improving the position of the soft tissue margin for the interdental and buccal aspects in deep intrabony defects associated with gingival recession.

This prospective clinical study involved 20 patients in whom implants were immediately placed in extraction sockets. Residual bone defects were grafted, and the buccal bone plate was overcontoured with a xenogeneic bone substitute and covered by a collagen membrane. One year after implant placement, CBCT images were acquired to evaluate buccal bone, and implant stability was analyzed through resonance frequency analysis. Results showed that buccal bone covered the rough surface of all implants 1 year after implantation. Hard tissues responded more favorably in the flapless group. No correlation was found between initial bone defects and bone dimensions in the follow-up exam.

Horizontal ridge augmentation is a common surgical procedure performed prior to or simultaneously with implant placement, depending on the extent of the ridge deficiency. Many horizontal augmentation surgical options have been developed, spanning a wide range of materials and techniques. Given the numerous permutations available, the most suitable strategy to regenerate ridge width for an individual case often confounds clinicians. Based on an extensive review of the literature, this article provides up-to-date technique selection guidelines, in the form of a decision tree, for predictable horizontal bone augmentation dependent on the amount of bone gain needed.

The clinical syndrome known as posterior bite collapse (PBC) consists of multiple, often pathognomonic factors that deviate from normal, or an occlusion wherein the posterior occlusion is compromised and may ultimately destroy the functional protective capacity of the entire dentition. Secondary clinical sequelae may include accelerated periodontitis progression, temporomandibular disorders (TMD), increasing mobility/fremitus, additional tooth loss, anterior flaring, and loss of occlusal vertical dimension. Etiologic factors may include tooth loss without replacement, orthodontic malocclusions and dentoskeletal disharmonies, periodontitis, accelerated retrograde occlusal/interproximal wear, severe caries, or iatrogenic and conformative dentistry. Not all PBC cases require treatment, but treatment is dependent upon the periodontium's stability and its ability to maintain its form and function. Treatment decisions can also be dependent upon periodontal health, caries, function, occlusion, TMD, esthetics, and phonetics. The purpose of this article is to provide general treatment guidelines based on form and function of the masticatory system for restoring a PBC case when treatment is necessary. This article does not discuss specific mechanics for restoring PBC cases.

This study was designed to assess the effect of enamel matrix derivative (Emdogain, Straumann) and alloplastic bone substitute (BoneCeramic, Straumann) on new bone formation in postextraction alveolar sockets. Twenty-one patients requiring anterior single-tooth extractions and subsequent implant placement were recruited and randomly assigned to one of three treatment groups. Postextraction sockets were filled with either an alloplastic bone substitute (BoneCeramic [BC]), BC combined with Emdogain (EMD+BC), or left to heal spontaneously (SO). Histologic and histomorphometric analyses of the results were performed at 6 months postextraction. A significant increase in the percentage of new bone tissue area was found in EMD+BC compared to SO and BC groups. These findings demonstrate that compared with BC or SO, EMD+BC allowed for better formation of new bone in postextraction sockets after 6 months of healing.

This retrospective study evaluates the clinical and radiographic outcomes of simultaneous guided bone regeneration (GBR) and implant placement procedures in the rehabilitation of partially edentulous and horizontally atrophic dental arches using resorbable membranes. A total of 49 patients were included, and 97 implants were placed. Patients were followed up for 3 to 7 years after loading. The data indicate that GBR with simultaneous implant placement and resorbable membranes can be a good clinical choice, and the data suggest that it could be better to horizontally reconstruct no more than 3 mm of bone in order to reduce the number of complications and to obtain stable results. However, this technique remains difficult and requires expert surgeons.

Connective tissue grafts have become a standard for compensating horizontal volume loss in immediate implant placement. The use of new biomaterials like acellular matrices may avoid the need to harvest autogenous grafts, yielding less postoperative morbidity. This randomized comparative study evaluated the clinical outcomes following extraction and immediate implant placement in conjunction with anorganic bovine bone mineral (ABBM) and the use of a porcine acellular dermal matrix (ADM) vs an autogenous connective tissue graft (CTG) in the anterior maxilla. Twenty patients (11 men, 9 women) with a mean age of 48.9 years (range: 21 to 72 years) were included in the study and randomly assigned to either the test (ADM) or control (CTG) group. They underwent tooth extraction and immediate implant placement together with ABBM for socket grafting and either ADM or CTG for soft tissue augmentation. Twelve months after implant placement, the cases were evaluated clinically and volumetrically. All implants achieved osseointegration and were restored. The average horizontal change of the ridge dimension at 1 year postsurgery was -0.55 ± 0.32 mm for the ADM group and -0.60 ± 0.49 mm for the CTG group. Patients of the ADM group reported significantly less postoperative pain. Using xenografts for hard and soft tissue augmentation in conjunction with immediate implant placement showed no difference in the volume change in comparison to an autogenous soft tissue graft, and showed significantly less postoperative morbidity.

Autogenous soft tissue grafting is a commonly performed procedure in periodontal and implant surgery. Reharvesting a connective tissue graft (CTG) from the same palatal donor site is often required, but little is known about the volumetric changes that occur after harvesting a free gingival graft and how long the palatal mucosa takes to regain its original form and thickness. This study evaluated the volumetric changes that occur at the palatal donor site after harvesting a soft tissue graft with a noninvasive digital technology. Nineteen patients needing a CTG for a single site were enrolled. Intraoral digital scans of the palatal donor sites were obtained at baseline and at 1, 3, 6, and 12 months. The digital scans were imported and analyzed with an imaging software to evaluate volumetric changes. Average volume losses of 5.82 ± 2.63 mm³ and 11.03 ± 5.47 mm³ were observed after 1 and 3 months, respectively. Only minor changes were observed at 6 and 12 months. Linear dimensional changes at 5 and 7 mm from the gingival margin were substantially higher than the changes at 3 mm for the 1- and 3-month interval comparisons compared to baseline. Graft dimension was associated with volume loss at 1 and 3 months (P < .01). After palatal harvesting, the donor site undergoes volumetric changes, mostly during the first 3 months, and is attenuated thereafter.

This study aimed to investigate the marginal bone changes beneath overhanging restorations. The study group consisted of 250 archived panoramic radiographs that had at least one overhanging restoration, examined by two observers. The distance from the cementoenamel junction (CEJ) to the marginal bone crest beneath the overhang was measured with ImageJ software. The same distance was measured from the control sites (the intact surface of the same tooth with overhang, and the same tooth on the contralateral side) to assess bone loss. To evaluate bone density, two regions of interest (ROIs) were chosen: one in the marginal bone beneath the overhang, and the other was in the marginal bone adjacent to the intact surface of the same tooth. Wilcoxon paired t test and Mann-Whitney U test were used for comparisons (P < .05). The prevalence of overhangs was 4.3%. Molar teeth (80.8%) and the disto-occlusal cavities (54%) were the most common sites for overhangs. The average bone loss beneath the overhangs was 2.77 ± 1.20 mm, which was significantly different from the control sites (P < .05). The bone density beneath the overhang was significantly lower than at control sites (P < .05). The frequency of overhangs was higher in areas that are difficult to reach, and the height and density of the marginal bone beneath the overhang were decreased compared to control sites.

Although implants have been shown to have high success rates, complications such as implant failure can occur. This presents a challenging dilemma for clinicians when attempting another implant placement in the failed site. The patient in this clinical case report presented with implant failure four times at the same site. This case report describes implant placement in a site where four failed implants were previously removed and evaluates the approach used to achieve a successful outcome.

Since the introduction of guided bone regeneration (GBR) using nonresorbable membranes, membrane exposure has been categorized as one of the major complications associated with the procedure. Expanded polytetrafluoroethylene (e-PTFE) has a long history of use in GBR, and now the use of high-density PTFE (d-PTFE) is commonly reported in the literature. The major structural difference between these two materials is their permeability to bacteria: e-PTFE has an open-pore microstructure and is permeable to bacteria, while d-PTFE is not. Thus, there are fundamental differences in the two materials if premature exposure occurs. Protocols for classification and management of exposure specific to e-PTFE have been published and were well-received by clinicians, but these protocols do not necessarily apply to d-PTFE exposures. Because of the fundamental structural differences between these two PTFE materials, a protocol specific to the classification and management of d-PTFE membrane healing complications is required and is thus presented in this paper.

Peri-implantitis is an increasingly prevalent condition that, if left untreated, can lead to implant failure and loss. Numerous regenerative treatment modalities have been reported in the literature with varying degrees of success. Unfortunately, there is little consensus regarding optimal methods for predictable regeneration of the peri-implant bone lost due to the disease. This case report presents a 68-year-old healthy, nonsmoking man with peri-implantitis affecting the endosseous implant that replaced the maxillary left first molar. After unsuccessful nonsurgical debridement, regenerative surgical therapy was recommended. Guided bone regeneration (GBR) was performed using natural bovine bone mineral covered with a dehydrated human deepithelialized human amnion-chorion membrane (ddACM). Implant surface decontamination was achieved using a titanium brush. Posttreatment clinical assessment suggested that the patient responded well to surgical regenerative therapy. This response was characterized by the reestablishment of healthy peri-implant soft tissues. From a radiographic perspective, complete bone fill of the peri-implant bony defect was seen. These outcomes were maintained over 2 years. This case demonstrates that it is possible to treat peri-implantitis successfully and obtain stable long-term results with a GBR approach utilizing a xenogeneic bone substitute with ddACM.

This study evaluated the pull-off force between titanium abutments and zirconia crowns that were bonded using four different cements and two abutment heights (AHs). In total, 24 titanium abutments (3-mm AH: n = 12; 5-mm AH: n = 12; taper: 7.5 degrees) and 24 zirconia crowns were designed, manufactured, cemented with one of four dental cements (one temporary, two semi-permanent, one permanent), stored in water for 24 hours, and thermocycled (37,500 cycles, equal to ~4 years in vivo). The pull-off force needed to separate the abutment and crown in each combination was determined eight times per combination of cement type and abutment height. Statistical analysis was conducted at a significance level of P < .05. The permanent self-adhesive composite cement showed a high pull-off force with a risk for crown fracture (mean: 381 N for 3-mm AH; 617 N for 5-mm AH). In contrast, the temporary zinc-oxide cement showed frequent premature decementation after thermocycling (mean: 14 N with 3-mm AH; 28 N with 5-mm AH). Both semi-permanent methacrylate-based cements ranked between the other cements (mean: 31 N/37 N for 3-mm AH; 120 N/72 N for 5-mm AH). Statistically significant differences were found between all cements (ANOVA P < .001). The abutment heights differed significantly for all cements (P < .005) except for the temporary zinc-oxide cement. Methacrylate-based cements were the most reliable cements for semi-permanent mounting of zirconia crowns on titanium abutments. They provide sufficient retention to avoid unintended loosening and are weak enough to remove the crown without causing damage.

In this prospective pilot study on ridge preservation (RP), a collagen sponge was placed to fill the bottom half of the socket, followed by a sequence of bone graft, collagen membrane, and a sponge placed on top. Twelve patients with 13 hopeless posterior teeth were included. Changes in bone dimension (including variations of horizontal ridge width [HRW] and bone height [BH]) between the time immediately postextraction (T₀) and 6 months later (T_6M) were evaluated through CBCT. The soft tissue was assessed using a wound healing index (WHI) at 2 weeks (T_2W), 2 months (T_2M), and 6 months (T_6M) postsurgery. Measured at three parallel levels (1, 3, and 5 mm apical to the crest of the palatal plate), the mean HRW changes (T₀ to T_6M) ranged from 0.47 to 1.05 mm. Statistically significant negative correlations were observed between WHI (T_6M) and midcrestal BH change. This proposed RP technique showed favorable outcomes regarding HRW and BH, even in periodontally compromised dehiscence sockets.

Dental implants are the most promising modality of tooth replacement in the modern era. Of late, peri-implant architecture has gained significant importance and forms the basic foundation for success of an implant restoration, with both the hard and soft tissue components around an implant playing vital roles in the osseointegration process. A 23-year-old man reported with a titanium membrane exposure around tooth site 16 (FDI tooth-numbering system) along with decreased attached gingival width and thickness. To gain soft tissue thickness, a rotated connective tissue graft was harvested, as was a "sticky bone" graft to gain bone volume. Connective tissue is one of the most promising modalities for soft tissue augmentation around both the natural tooth and implants. "Sticky bone," which is a more advanced form of bone grafting techniques, was implemented to achieve the benefits of injectable platelet-rich fibrin. This case report describes the hard and soft tissue augmentation procedure and successful results at the 10-year follow-up, as well as fabrication of an implant-supported fixed partial denture.