Books

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. Ninetysix 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.

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.

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. Featheredge 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.

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.

Ziel: Werden Implantate schon in früher Jugend gesetzt, kann dies langfristig ästhetische Probleme oder sogar einen Funktionsverlust zur Folge haben. Der hier vorgestellte Fall beschreibt die Behandlung infraokkludierender Implantate und der resultierenden ästhetischen Komplikationen bei einer jungen Frau, die im Alter von 16 Jahren zwei Implantate in den Eckzahnpositionen erhalten hatte. Klinische Überlegungen: Nach der Untersuchung und Diagnose erfolgte eine multidisziplinäre Behandlung. Eines der infraokkludierenden Implantate wurde entfernt und nach einer Hart- und Weichgewebsrekonstruktion durch ein neues Implantat in idealer dreidimensionaler Position ersetzt. Am Implantat auf der Gegenseite wurde ein subepitheliales Bindegewebstransplantat in Kombination mit einer Korrektur des Emergenzprofils von Abutment und definitiver Krone durchgeführt. Der Frontzahnbereich wurde zusätzlich mit zwei Veneers und zwei vollkeramischen Kronen ästhetisch rehabilitiert. Schlussfolgerung: Mit diesem multidisziplinären Behandlungsplan wurden die Probleme, die wegen der Infraokklusion der Implantate bestanden, erfolgreich behoben. Mit dem ästhetischen Endergebnis war die Patientin sehr zufrieden. Es erwies sich bei der Kontrolle nach einem Jahr als stabil.

Die rein chirurgische Korrektur labialer Weichgewebsdefekte an dentalen Implantaten gilt nicht als Verfahren, das zu vorhersagbaren Ergebnissen führt. Allerdings trägt die Individualisierung des prothetischen Emergenzprofils im Bereich des Weichgewebes entscheidend zum ästhetischen Endergebnis bei. Daher wurde in der Literatur ein kombiniert chirurgisch-prothetisches Vorgehen beschrieben. Im vorliegenden Beitrag wird ein Fall im Frontzahnbereich vorgestellt, der multidisziplinär behandelt wurde. Hierbei ging es u. a. um ein bereits inseriertes, vollständig osseointegriertes Implantat, an dem sich labial eine Weichgewebsrezession von 2 mm entwickelt hatte. Zur Korrektur wurden zwei Bindegewebstransplantationen durchgeführt und das prothetische Profil von Provisorium und definitivem Abutment angepasst. Die Patientin war mit dem ästhetischen Resultat zufrieden, ihre Hauptbeschwerde konnte beseitigt werden und das Ergebnis ist bislang über fünf Jahre stabil geblieben.

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.

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. Keywords: biotype, black triangle, dental implant, esthetics, interproximal papilla, tooth shape

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.