Dual-Center Cross-Sectional Analysis of Periodontal Stability Around Anterior All-Ceramic Crowns with a Feather-Edge or Chamfer Subgingival Preparation.

Subgingival margins are often associated with adverse periodontal reactions, such as recession and gingival inflammation. The purpose of this cross-sectional dual-center study was to evaluate the periodontal health and stability of intrasulcular margins, comparing two prosthetic margin preparations: subgingival chamfer (SC) and subgingival feather-edge (SF) with gingival curettage. Ninety-six patients with 205 crowns (buccal margin 0.5 mm into the gingival sulcus) were included in the study. SF, gingival curettage, and intrasulcular restorative margin were prepared on 109 crowns; SC was prepared on 96. Restorations were in place for a mean of 55.9 months (range: 12 months to 10 years). No significant differences were found regarding probing depth between the two groups (mean buccal: 1.6 mm; mean interproximal: 2.3 mm). Significant increased recession was present around SCs, showing a higher margin-exposure frequency (buccal: 19.8% vs 3.7%; interproximal: 5.2% vs 1.4%). SC showed 8.5 times the risk of margin exposure compared to SF, men 5.5 times compared to women, and smokers 3.7 times compared to nonsmokers. Follow-up time was not a significant factor. SC sites showed a tendency for reduced buccal bleeding on probing compared to SF sites (3.0% vs 12.1%), but no significant difference was seen in a regression model. Plaque presence increased the risk of bleeding (4.1×), and women presented a higher risk of bleeding than men (3×). Subgingival margins can provide adequate periodontal health and stability if restorative procedures are well controlled and if patients are enrolled in an adequate maintenance program. SF with intrasulcular margin favors facial soft tissue stability, as reduced gingival recession was observed. The technique should be carefully applied to promote an adequate periodontal response.

Interproximal Papilla Stability Around CAD/CAM and Stock Abutments in Anterior Regions: A 2-Year Prospective Multicenter Cohort Study.

The aim of this study was to compare the interproximal papilla stability of restorations supported by computer-aided design/computer-assisted manufacture (CAD/CAM) abutments to those supported by prefabricated stock abutments in anterior areas over a 2-year follow-up. Abutments were selected depending on implant inclination and thickness of buccal peri-implant soft tissues from the following: zirconia stock, titanium stock, zirconia CAD/CAM and titanium CAD/CAM. Differences between the height of the papilla tip were measured (REC). RESULTS: REC values of titanium and zirconia CAD/CAM abutments were significantly lower than those of titanium and zirconia stock. The use of titanium and zirconia CAD/CAM abutments is related to better interproximal papillae stability.

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.

Periodontal response to two different subgingival restorative margin designs: a 12-month randomized clinical trial.

OBJECTIVES: Subgingival margin placement is sometimes required due to different reasons and is often associated with adverse periodontal reactions. The purpose of this study was to determine if a single restoration with subgingival margin on a tooth, in the maxillary anterior zone, would affect its periodontal soft tissue parameters, and whether or not a deep chamfer preparation has a different influence in the periodontium when compared to a feather edge preparation. MATERIAL AND METHODS: Plaque and gingival indexes, periodontal probing depth, bleeding on probing, and patient's biotype were registered. One hundred six teeth were prepared with a deep chamfer, while 94 were prepared with a feather edge finishing line. Twelve months after the restoration delivery, the same parameters were evaluated. Repeated measure one-way analysis of variance (ANOVA) (α = 0.05) was used. RESULTS: A statistically significant difference between the baseline and the 12-month follow-up is present in regard to plaque index, gingival index, and periodontal probing depth, but no statistically significant difference between chamfer and feather edge finishing lines. There is a statistically significant difference between the baseline and the 12-month follow-up in regard to bleeding on probing. Feather edge preparation presents significantly more bleeding on probing and less gingival recession than the chamfer. CONCLUSIONS: Subgingival margins do influence the periodontal soft tissue response. Statistically significant difference exists between feather edge and chamfer finishing lines in regard to bleeding on probing and gingival recession. CLINICAL RELEVANCE: Subgingival margins should be carefully selected, especially when feather edge finishing line is utilized.

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.

Correlation between subjective and objective evaluation of peri-implant soft tissue color.

PURPOSE: While extensive references are present in the literature dealing with the correlation between subjective and objective evaluation of tooth shade, there is a lack of information on this correlation regarding the soft tissue color. The purpose of this experimental study was to verify whether a correlation between the objective and subjective evaluation exists in analyzing soft tissue color. MATERIAL AND METHODS: A total of 39 patients with at least one implant-supported restoration in the anterior maxilla were included in the study. The shade of the peri-implant mucosa was compared with the shade of the gingiva at the adjacent tooth in a subjective and in an objective manner. The subjective evaluation was performed by five dental professionals (prosthodontist, periodontist, general dentist, dental hygienist, and dental assistant) in a subjective scale (ranging from 1 to 4). The objective evaluation was obtained by means of a spectrophotometer in a CIELAB* Color Scale, and the differences were evaluated through formula ΔE=[(ΔL)²+(Δa)²+(Δb)²]¹/². To correlate the subjective and the objective evaluation, for each arithmetical median value of the subjective evaluation, a mean value of objective evaluation has been calculated, and the Spearman's rank correlation coefficient has been used. The differences have been also analyzed for thin and thick tissue biotypes. RESULTS: The mean ∆E value for the subjective evaluation between peri-implant soft tissue and adjacent tooth gingival tissue was ∆E = 9.74. Also, mean ∆E values of 10.35 and 7.54 have been reported for thin and thick biotypes, respectively. Mean values of ∆E = 6.63, 8.54, and 15.54 were presented by median values of 1 (perfect matching), 2 (good matching), and 3 (clinically distinguishable), respectively. The threshold for the distinction of differences of mucosal color by the human eyes between perfect or good matching and distinguishable values has been calculated in ∆E = 8.74. CONCLUSIONS: Within the limitation of this study, a correlation between the subjective and the objective evaluation of the peri-implant soft tissue exists and the threshold for the distinction of mucosal color differences between perfect or good matching and distinguishable subjective values has been calculated in ∆E = 8.74 in the objective evaluation.

Influence of coping design on the cervical color of ceramic crowns.

STATEMENT OF PROBLEM: The replication of natural teeth, especially with single-tooth restorations, represents a challenge. Similar to metal ceramic crowns, different designs of zirconia substructures have been suggested to improve the esthetic results of zirconia ceramic crowns. PURPOSE OF STUDY: The purpose of the study was to analyze the color of the cervical portion of single zirconia ceramic crowns fabricated with different zirconia coping designs. MATERIAL AND METHODS: The color, measured on the CIELAB color scale, of 3 different groups of restorations (n=10) fabricated with zirconia coping (Lava) and feldspathic porcelain (Noritake Super Porcelain) was analyzed with a spectrophotometer. Conventional zirconia crowns with zirconia facial margins were compared with ceramic crowns with porcelain facial margins and either a horizontal reduction of the zirconia coping (1.0 mm reduction) or an additional vertical reduction (1.0 mm additional reduction). The 3 groups, each with a different coping extension, were examined with a 1-way ANOVA and the Fisher exact test, and the differences of the groups were evaluated by applying ΔE thresholds (α=.05). RESULTS: The mean color difference among all the groups was not clinically significant (ΔE<3.7). Reduced color differences were present between the 2 porcelain butt margin groups of crowns (ΔE=1.06, between group H and V). Increased differences were present between the zirconia margin group and the porcelain butt margin group (ΔE=2.54 between group C and H; ΔE=2.41 between group C and V). Lab* values were examined in all the groups of crowns to determine the clinical implications. CONCLUSIONS: Within the limitation of the study, no significant differences were present among the tested groups of crowns. Nevertheless, although some differences were present between the zirconia margin group and the porcelain butt margin group, reduced differences were present between the 2 different cutback designs.

The precision of fit of cast and milled full-arch implant-supported restorations.

PURPOSE: The purpose of this study was to investigate the marginal precision of computer numeric control-milled frameworks fabricated of grade 4 commercially pure titanium or cobalt-chrome alloy through digital technology and to compare them with conventional cast frameworks. MATERIAL AND METHODS: A titanium cast of a mandibular arch with six implant analogs was used as a master. The master cast was measured with a coordinate measuring machine. Fifteen rigid anatomic frameworks were created on the master cast in cast gold alloy and milled in titanium or cobalt-chrome material. The fifteen anatomic frameworks were measured in the same manner as the master cast. While the milled frameworks were measured once, at the end of the milling process, the cast anatomic frameworks were measured twice: immediately after the casting and divesting procedures and again after a technical adaptation procedure. Each anatomic framework was weighed. To compare the measurements obtained from each group of frameworks, descriptive statistics were calculated and one-way analysis of variance was performed, with values considered statistically significant at P < .05. RESULTS: The mean weight of the cast frameworks was 33.41 g, the cobalt-chrome frameworks weighed 18.12 g on average, and the titanium frameworks averaged 8.7 g. The mean values for three-dimensional deviation of the center point position for each group of frameworks were 261 µm (cast frameworks before adaptation), 49 µm (cast frameworks after adaptation), 26 µm (milled frameworks in cobalt-chrome), and 26 µm (milled frameworks in titanium). CONCLUSIONS: Within the limitations of this in vitro study, absolute passive fit cannot be achieved, regardless of material and fabrication technique. Anatomic milled frameworks fabricated in titanium or cobalt-chrome presented reduced center point deviation compared to cast frameworks. Titanium frameworks weighed less than cobalt-chrome and cast gold alloy frameworks.

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.

A technique for immediate occlusal implant loading of a completely edentulous mandible: a clinical report.

The protocols described are designed for immediate implant loading of the completely edentulous mandible and to provide the patient with a prosthesis that incorporates structural durability and esthetics in a time efficient manner. Incorporating appropriate diagnostic and surgical procedures, this clinical report describes the use of custom-fabricated transparent devices that help the clinician identify implant position, thereby reducing the procedural time and improving the structural durability and esthetics of the immediate prosthesis.

Influence of framework design on the cervical color of metal ceramic crowns.

STATEMENT OF PROBLEM: The replication of natural teeth, especially for single tooth restorations in patients with high esthetic needs, represents a challenge. PURPOSE: The purpose of the study was to analyze the color of the cervical portion of single metal ceramic crowns fabricated with different metal framework designs. MATERIAL AND METHODS: The color, as measured on the CIELAB color scale, of 3 different groups of restorations (n=10) fabricated with a high noble metal alloy (V-Deltaloy) and feldspathic porcelain (Noritake Super Porcelain) was analyzed with a colorimeter. Conventional metal ceramic crowns with metal facial margins were compared to metal ceramic crowns with porcelain facial margins and a horizontal reduction of the metal framework (1.0 mm reduction) or an additional vertical reduction (1.0 mm reduction). In all specimens, the finish line was positioned at a subgingival or equigingival level. The 6 groups obtained by the combination of the levels of the 2 factors (framework extension and finish line location) were examined with an ANOVA Fisher's F-test and a post hoc Tukey's HSD test (α=.05). RESULTS: The mean color difference for all the groups was clinically acceptable (ΔE<3.7). Conventional metal ceramic crowns showed higher differences in relation to finish line location (ΔE=2.34), while a vertical reduction of the framework was related to lower values (ΔE=0.96). Mean Lab* values were reported for all the groups of crowns. Statistically significant differences were present for L*, a*, and b* values when related to framework extension. Considering each value in relation to the interaction between framework extension and finish line location factors, significant differences were present only for L* and a* values. CONCLUSIONS: No significant differences in base shade were present among the investigated crowns. Nevertheless metal ceramic crowns with vertical cut-back and porcelain facial margins presented more consistent results that tended to be closer to those of natural teeth.

Influence of abutment material on the gingival color of implant-supported all-ceramic restorations: a prospective multicenter study.

PURPOSE: The aim of this clinical research on implant-supported restorations is to analyze, through spectrophotometric digital technology, the influence of the abutment material on the color of the peri-implant soft tissue. MATERIAL AND METHODS: Twenty patients received an endosseous dental implant in the anterior maxilla. At the time of each definitive prosthesis delivery, an all-ceramic crown has been tried on gold, titanium and zirconia abutment. After the insertion of each single abutment, the peri-implant soft tissue color has been measured through a spectrophotometer. Also, the thickness of the facial peri-implant soft tissue was measured at the level of the implant neck through a caliper. A specific software has been utilized to identify a specific tissue area and to collect the data before the statistical analysis in Lab* color space. The normality of the quantitative variables was verified by means of the Shapiro-Wilk test. Simple linear correlation between quantitative variables was evaluated by using Pearson's coefficient. The results on the performance of the abutment materials with regard to the color measurements and the overall measurement ΔE were described by computing the least-square means. The significance of differences among types of abutment was verified by means of the Scheffe test for multiple comparisons. RESULTS: For all the abutments used, the color of the peri-implant soft tissue appeared to be significantly different from the one of the contra-lateral tooth (ΔE>8.5). Significantly higher (P<0.05) difference were present with the use of titanium abutments (11 ± 0.4) when compared with the results of gold (8.9 ± 0.4) and zirconia (8.5 ± 0.4) abutments. No correlation has been demonstrated between soft tissue thickness and degree of color difference (P>0.25). CONCLUSIONS: Within the limitation of the present study, the peri-implant soft tissue color appears to be different from the soft tissue color around natural teeth, no matter which type of restorative material is selected. When titanium abutment was selected, significantly higher differences were present than those obtained with gold or zirconia abutments. The thickness of the peri-implant soft tissue did not appear to be a crucial factor in the abutment impact on the soft tissue color.

Nonsurgical management of soft tissue deficiencies for anterior single implant-supported restorations: a clinical report.

Periodontal surgical procedures may not always offer a predictable level of success in the reproduction of a natural gingival architecture. Two different nonsurgical approaches are described for the management of soft tissue deficiencies in anterior implant-supported restorations. Clinically acceptable esthetic outcomes of anterior implant restorations can be achieved by using zirconium custom abutments and gingiva-colored dental porcelain.