Statements and Recommendations for Guided Bone Regeneration: Consensus Report of the Guided Bone Regeneration Symposium Held in Bologna, October 15 to 16, 2016.

INTRODUCTION: In the past 10 years, long-term studies have demonstrated that guided bone regeneration (GBR) is a successful and reliable technique for vertical and horizontal ridge augmentation, but strict and rigorous protocols must be adopted. MATERIAL AND METHODS: Because no reports have yet been published with statements and clinical recommendations for GBR, a closed meeting of all authors was organized to discuss this matter during a GBR symposium held in Bologna (Italy) in October 2016. The authors focused on the findings of systematic and narrative reviews, prepared before the meeting, covering aspects of the clinical management of GBR techniques. Successively, a discussion based on the scientific evidence and on the experts' opinions led to the formulation of statements, clinical recommendations, and implications for future research. RESULTS: To avoid complications and to optimize outcomes, the following factors should be considered by clinicians: patient selection; analysis of defect type; blood supply; antibiotic treatment; flap passivation; delayed implant placement; combination of autogenous bone and xenograft or allograft; rigorous fixation of membranes; removal after 6 to 9 months; analysis of complications; soft-tissue management; and high care in scarred sites and in esthetic areas. CONCLUSIONS: The present consensus report reviewed the scientific evidence and provided specific guidelines and recommendations for clinical practice and the different approaches to GBR techniques to ensure surgical success and predictable outcomes.

The role of dental implant abutment design on the aesthetic outcome: preliminary 3-month post-loading results from a multicentre split-mouth randomised controlled trial comparing two different abutment designs.

PURPOSE: To evaluate whether there are aesthetic and clinical benefits to using a newly designed abutment (Curvomax), over a conventional control abutment (GingiHue). MATERIALS AND METHODS: A total of 49 patients, who required at least two implants, had two sites randomised according to a split-mouth design to receive one abutment of each type at seven different centres. The time of loading (immediate, early or delayed) and of prosthesis (provisional crowns of fixed prosthesis) was decided by the clinicians, but they had to restore both implants in a similar way. Provisional prostheses were replaced by definitive ones 3 months after initial loading, when the follow-up for the initial part of this study was completed. Outcome measures were: prosthesis failures, implant failures, complications, pink esthetic score (PES), peri-implant marginal bone level changes, and patient preference. RESULTS: In total, 49 Curvomax and 49 GingiHue abutments were delivered. Two patients dropped out. No implant failure, prosthesis failure or complication was reported. There were no differences at 3 months post-loading for PES (difference = -0.15, 95% CI -0.55 to 0.25; P (paired t test) = 0.443) and marginal bone level changes (difference = -0.02 mm, 95% CI -0.20 to 0.16; P (paired t test) = 0.817). The majority of the patients (30) had no preference regarding the two abutment designs; 11 patients preferred the Curvomax, while five patients preferred the GingiHue abutments (P (McNemar test) = 0.210). CONCLUSIONS: The preliminary results of the comparison between two different abutment designs did not disclose any statistically significant differences between the evaluated abutments. However the large number of missing radiographs and clinical pictures casts doubt on the reliability of the results. Longer follow-ups of wider patient populations are needed to better understand whether there is an effective advantage with one of the two abutment designs.

Bone volume changes after immediate implant placement with or without flap elevation.

OBJECTIVES: The aims of this prospective study were to evaluate bone dimensions after immediate implant placement with simultaneous grafting of the buccal gap, to determine if initial buccal bone width had an influence on bone remodelling and to compare bone volume changes using a flap or a flapless approach after 6 months of healing. MATERIAL AND METHODS: This prospective study included patients who required an extraction and a subsequent immediate implant placement at a non-molar site. In those cases where tooth extraction was not feasible with a flapless approach (test group) a mucoperiosteal flap was carefully elevated (control group). After extraction, a cone beam computed tomography (CBCT) was taken. Then, an implant was placed and the buccal gap was grafted using anorganic bovine bone. After 6 months of healing, a second CBCT was performed. A blinded investigator superimposed both images and performed a series of measurements to determine bone volume changes between the two time points. RESULTS: Thirty-five patients were included in this study, 20 of which belonged to the test group. All together, the differences between baseline and 6 months in buccal plate height, lingual plate height and in ridge width at 2, 4 and 6 mm were 0.48 ± 1.35; 0.58 ± 1.51; 0.64 ± 0.81; 0.59 ± 1.36 and 0.52 ± 1.16, respectively. Only a moderate correlation was observed between initial buccal plate width and buccal plate height at 6 months (P = 0.0001). No statistically significant differences were observed between flap and flapless approach. CONCLUSIONS: A mean reduction of around 0.5 mm in height and width after placing immediate implants and filling the residual gap with anorganic bovine bone may be expected. No significant association between initial buccal bone width and ridge width at 6 months was seen. No statistically significant differences were found between the two treatment protocols although more ridge reduction was observed for the flap group.

Clinical Periodontal Response to Anterior All-Ceramic Crowns with Either Chamfer or Feather-edge Subgingival Tooth Preparations: Six-Month Results and Patient Perception.

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. Feather-edge 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.

Multidisciplinary management of a young female with infraoccluded dental implants: a case report.

OBJECTIVE: Placement of a dental implant during early adolescence may result in an unesthetic outcome or even loss of function. The presented case describes the treatment of infraoccluded dental implants and the esthetic complications for a young adult female who had received two dental implants in the canine positions when she was 16 years old. Clinical considerations: After examination and diagnosis, a multidisciplinary approach was implemented, including the removal of one infraoccluded implant, followed by hard and soft tissue reconstruction prior to implant replacement into an ideal three-dimensional position. On the contralateral side, a subepithelial connective tissue graft was performed, in conjunction with the modification of the emergence profile of the abutment and definitive crown. The anterior sextant was treated as a comprehensive esthetic rehabilitation that involved two additional laminate veneers and two all-ceramic crowns. CONCLUSIONS: This multidisciplinary approach successfully managed the complication that resulted from infraoccluded dental implants. The final esthetic outcome satisfied the patient's chief complaint, and was documented to be stable at the 1-year follow-up.

Patient morbidity and root coverage outcomes after the application of a subepithelial connective tissue graft in combination with a coronally advanced flap or via a tunneling technique: a randomized controlled clinical trial.

BACKGROUND AND OBJECTIVE: Subepithelial connective tissue grafts (SeCTG) in conjunction with a coronally advanced flap (CAF) or with tunneling technique (TT) are common periodontal procedures with similar indications for the treatment of a denuded root surface; however, it is unclear whether patient discomfort and postoperative morbidity are comparable in both approaches. The aim of this randomized controlled clinical trial was to compare the patient morbidity and root coverage outcomes of a SeCTG used in combination with a CAF or TT. MATERIALS AND METHODS: For this single-center, randomized, clinical trial, patients were randomly assigned to receive SeCTG + CAF (control group) or SeCTG + TT (test group). Postoperative questionnaires at 3 days post intervention were administered to evaluate postoperative discomfort, bleeding, and inability to masticate. Evaluation of patients' perception of pain was performed using a visual analog scale (VAS). Clinical outcomes including percentage of root coverage (RC) and complete root coverage (CRC) were recorded 12 months postoperatively. RESULTS: Fifty patients (25 SeCTG + CAF and 25 SeCTG + TT) completed the study. Healing was uneventful for all test and control patients. The SeCTG + TT group showed a longer chair time (33.6 (3.6) and 23.6 (4.2) min for the SeCTG + TT and the SeCTG + CAF, respectively), as well as more painkiller consumption: 2736 vs. 1536 mg (p < 0.001). At the same time, the SeCTG + CAF group reported less pain or discomfort in all four sections of the questionnaire: pain experienced within the mouth as a whole, pain experienced throughout the day, pain experienced at night, and edema experienced after the surgery (p = 0.002, p = 0.001, p = 0.001, and p = 0001, respectively). Both treatments showed clinical efficacy in terms of root coverage as no differences per group were observed in the percentage of root coverage (87 vs. 85 %, p = 704) or patients with complete root coverage (60 vs. 52 %, p = 0.569). CONCLUSIONS: SeCTG + TT is associated with a greater incidence of pain and discomfort compared to SeCTG + CAF in early postoperative periods, as well as a longer chair time. Both treatments showed similar clinical efficacy in terms of root coverage. CLINICAL RELEVANCE: The results of this study may influence the surgeon's choice on which root coverage procedure should be performed considering the need of more chair time and more painkiller assumption with the tunneling technique.

Surgical-prosthetic management of facial soft tissue defects on anterior single implant-supported restorations: a clinical report.

The surgical correction of soft tissue defects on the facial aspects of dental implants is documented as an unpredictable procedure. Since the customization of the prosthetic emergence profile contributes significantly to the final esthetic outcome of the soft tissue, a combined surgical-prosthetic approach has been described in the literature. In the case presented in this article, a multidisciplinary approach was used to treat a patient's anterior sextant. It included the treatment of a previously placed implant, perfectly osseointegrated, with a 2 mm recession of the facial soft tissue. Two connective tissue grafting procedures were performed, in conjunction with the modification of the prosthetic profile of the provisional restoration and the definitive abutment. The final esthetic outcome satisfied the patient and resolved the main complaint, and is documented to have been stable for 5 years.

Microbiological assessment of the implant-abutment interface in different connections: cross-sectional study after 5 years of functional loading.

OBJECTIVE: To evaluate the bacterial microflora present inside the implant connection and in the peri-implant sulcus fluid of healthy implants, and to analyze the relationships between these harboring sites for four different implant systems after at least 5 years of functional loading. MATERIALS AND METHODS: A cross-sectional study was performed involving 40 patients treated with metal-ceramic cemented bridges supported by at least two healthy implants functionally loaded for 5 years. Four different implant-abutment connections were studied: external hexagon (control group), double internal hexagon (test group 1), internal hexagon with external collar (test group 2), and conical connection (test group 3). Samples for microbiological analysis were obtained from three types of sites: peri-implant sulci, connections' inside and abutments surface and, as control, gingival sulci of neighboring teeth. Quantitative real-time PCR was carried out for Total Bacterial Count and for 10 microorganisms: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, and Candida albicans. The response variables were percentage of positive sites and absolute bacterial load. The relations of the response variables with the type of connection and of sampling site were assessed using generalized estimating equations. RESULTS: Regarding the analysis of positivity to bacteria in the peri-implant sulcus no significant differences were observed. Analyzing the connection's inside, none of the connection designs had the capacity to prevent microbiological leakage through the implant/abutment microgap. Test group 3 presented the lowest mean values for red complex bacteria and control group the highest, although differences were non-significant. Statistical significance was only reached for Treponema denticola in the bacterial load analysis inside the connection. Test groups 1 and 2 yielded lower values for orange complex bacteria but only for Peptostreptococos micros the differences resulted significant. Test groups 2 and 3 had significantly lower total bacterial counts in the peri-implant sulcus and inside the connection. CONCLUSIONS: Outcomes suggested that all the analyzed connections resulted contaminated after 5 years of functional loading. However, the connection design might influence bacterial activity levels qualitatively and quantitatively, especially inside the implant connection.

Three-dimensional volume change of grafted bone in the maxillary sinus.

PURPOSE: The purpose of this study was to evaluate the three-dimensional radiographic changes of 100% anorganic bovine bone xenograft volume in a grafted maxillary sinus, based on a computerized analysis of cone-beam computed tomography (CBCT) scan. MATERIALS AND METHODS: A maxillary sinus augmentation procedure done with a lateral approach using 100% anorganic bovine bone was performed in 20 patients. A CBCT scan of the grafted area was taken immediately after the procedure (T1) and 8 to 9 months later (T2). CBCT scan data were analyzed with image processing software to evaluate differences in the volume of grafted material between T1 and T2. Residual ridge height and width were also measured at T1. RESULTS: The mean residual bone height and width at the implant sites was 4.40±0.87 mm and 7.9±2.22 mm, respectively. The mean graft volume was 1,432±539 mm³ and 1,287±498 mm³ at T1 and T2, respectively. A significant difference in graft volume was found between T1 and T2 data by paired t test (P=.01). The mean ratio between the volume at T2 and the volume at T1 was 0.90±0.12, meaning a graft volume contraction of 10%. CONCLUSION: Within the limits of the present investigation, good stability of anorganic bovine bone graft volume up to 8 months after the grafting procedure was demonstrated. Three-dimensional computed tomographic volumetric assessment seems to be a promising approach to quantify long-term changes in the regenerated area.

Human histologic evaluation of root coverage obtained with connective tissue graft over a compomer restoration.

This investigation was designed to evaluate the histologic healing pattern of two Miller Class III recession defects associated with noncarious cervical lesions (NCCLs) treated with a connective tissue graft (CTG) and coronally advance flap (CAF). One patient presenting with two teeth predetermined to be surgically extracted was enrolled and consented to treatment. One month after phase I treatment, a full-thickness flap was reflected and the NCCLs treated with a compomer restoration; at the same time, a CTG was harvested from the palate and positioned over the compomer restoration. The flap was then coronally repositioned. After 4 months of healing, an en bloc biopsy extraction of the two teeth was executed. The teeth were analyzed histologically to assess the periodontal wound healing. A long junctional epithelial attachment was noted throughout the major portion of the restored surface. Only minimal signs of connective adhesion and new bone formation could be seen in the apical portion of the restored area, without signs of root resorption or ankylosis. This report provides evidence that the presence of a compomer restoration allowed the formation of a long juctional epithelium after CTG and CAF treatment.

Significance of crown shape in the replacement of a central incisor with a single implant-supported crown.

OBJECTIVE: When utilizing a single implant-supported crown to replace a central incisor, understanding the final shape of the implant restoration is an important factor to help achieve a successful esthetic outcome. In today's dentistry, tooth shape is a critical factor when dental implant prostheses are considered in the esthetic zone. The major esthetic goal for this type of restoration is to achieve the closest possible symmetry with the adjacent tooth, both at the soft and at the hard tissue levels. The goal of this study was to objectively analyze the significance of natural crown shape when replacing a central incisor with a single implant-supported crown. METHOD AND MATERIALS: In this study, we investigated the shape of the crowns of maxillary central incisors in 60 individuals who presented to our clinics with an untreatable central incisor. The presence of a dental diastema, "black triangle," presence or absence of gingival symmetry, and the presence or absence of dental symmetry were recorded in the pre- and postoperative photographs. RESULTS: Out of 60 patients, 33.3% had triangular-shaped crowns, 16.6% square/tapered, and 50% square-shaped crown form. After treatment was rendered, 65% of the triangular group, 40% of the square/tapered group, and 13.3% of the square group required an additional restoration on the adjacent central incisor in order to fulfill the esthetic needs of the patients. CONCLUSION: Data analysis revealed that if there is a "black triangle," a diastema, or presence of dental or gingival asymmetry, an additional restoration on the adjacent central incisor is often required in order to fulfill esthetic goals. The additional restoration is highly recommended in situations with a triangular crown shape, while it is suggested in cases of square/tapered and square tooth shapes in the presence of a dental diastema.

Prospective evaluation of the use of motorized ridge expanders in guided bone regeneration for future implant sites.

The purposes of this prospective, randomized, controlled clinical investigation were to evaluate the performance of motorized ridge expanders (MREs) and to compare their results with those achieved using lateral ridge augmentation (LRA). Eight subjects with bilateral ridge deformities were selected. One technique was used on the right side and the other on the left. Implants were placed 6 months after bone augmentation procedures. All measurements were recorded at 2 and 5 mm from the most coronal aspect of the crest. The augmentation achieved with both techniques was statistically significant: 1.2 mm for LRA and 1.5 mm for MRE 2 mm from the crest and 1.5 mm for LRA and 1.6 mm for MRE at 5 mm from the crest. The differences between the two techniques were statistically insignificant. The amount of expansion achieved in the MRE sites appeared to be negatively correlated with the thickness of the cancellous bone (P < .05), and it was not affected by the thickness of the cortical plate. The MRE technique appears to be as effective as the LRA technique in augmenting the thickness of atrophic ridges. Defects treated with MREs showed less bone width contraction during the first 6 months of healing.

Coronally advanced flap combined with a subepithelial connective tissue graft using full- or partial-thickness flap reflection.

BACKGROUND: Although the use of a subepithelial connective tissue graft (SCTG) in conjunction with a coronally advanced flap (CAF) is a widely performed periodontal procedure, the creation of a partial-thickness flap can incur a risk of perforation or overthinning of the flap itself. Therefore, the aim of the present trial is to compare the efficacies of partial- and full-thickness flap reflections combined with an SCTG. METHODS: Twenty patients with Miller Class I or II defects (52 teeth) were selected, and teeth with defects were randomly assigned to the test group (25 teeth) for a CAF and SCTG using a full-thickness flap reflection or to the control group (27 teeth) for a CAF associated with an SCTG and partial-thickness flap reflection. The probing depth (PD), gingival recession (GR), and width of the keratinized tissue (KT) were assessed at baseline and 6 months after surgery. RESULTS: The mean root coverage was 97% in the test group (mean reduction in GR: 2.27 ± 1.15 mm) and 95% in the control group (mean reduction in GR: 1.68 ± 0.74 mm). The gain in KT was 0.46 ± 1.47 mm in the test group and 0.49 ± 1.3 mm in the control group, the PD ranged from 1.33 to 1.55 mm in the test group and from 1.31 to 1.64 mm in the control group; no statistically significant difference was found between the two groups for all of these parameters (P >0.05). CONCLUSIONS: The elevation of a full- or partial-thickness flap did not appear to influence the amount of KT or the percentage of root coverage achieved post-surgically. More expanded studies are needed to confirm the present findings.