Nynke Tymstra

Maxillary anterior and mandibular posterior residual ridge resorption in patients wearing a mandibular implant‐retained overdenture

The mandibular implant-retained overdenture could improve masticatory function compared to the conventional complete denture. However, increased forces exerted by the overdenture could increase residual ridge resorption of the maxillary anterior and mandibular posterior areas. The aim of this study was to compare the effect of the mandibular implant-retained overdenture using two or four dental implants, or the conventional complete denture on resorption of the residual ridge of the maxillary anterior and mandibular posterior areas over a period of 10 years. In total, 120 patients, 30 patients treated with an overdenture on two implants (two-implant group), 30 patients with an overdenture on four implants (four-implant group) and 60 patients treated with a conventional full denture (conventional group), participated in this study. On panoramic radiographs, made before and 10 years after treatment, proportional area measurements were applied to determine changes in bone height. After 10 years, a statistically significant amount of bone resorption had occurred in the anterior maxilla in the two-implant group and in the four-implant group. A significant amount of bone resorption had occurred in the posterior mandible in all three groups. There were no statistically significant differences between the groups in both areas. Patients presented large individual differences. It is concluded that patients rehabilitated with implant-retained mandibular overdentures are not subjected to more residual ridge resorption in the anterior maxilla when compared to patients wearing a conventional full denture. Regarding the mandibular posterior residual ridge, resorption was irrespective of wearing an implant-retained mandibular overdenture or a conventional mandibular denture.

How to treat two adjacent missing teeth with dental implants. A systematic review on single implant-supported two-unit cantilever FDP's and results of a 5-year prospective comparative study in the aesthetic zone

To conduct a systematic review on the clinical outcome of single implant-supported two-unit cantilever FDPs and to conduct a 5-year prospective comparative pilot study of patients with a missing central and lateral upper incisor treated with either a single implant-supported two-unit cantilever FDP or two implants with solitary implant crowns in the aesthetic zone. Medline, Embase and the Cochrane Central Register of Controlled Trials were searched (last search 1 August 2016) for eligible studies. In the comparative pilot study, an implant-cantilever group of five patients with a single implant-supported two-unit cantilever FDP (NobelReplace Groovy Regular Platform) was compared with an implant-implant group of five patients with two adjacent single implant-supported crowns (NobelReplace Groovy Regular Platform) in the aesthetic zone. Implant survival, marginal bone level (MBL) changes, pocket probing depth, papilla index and patient satisfaction were assessed during a 5-year follow-up period. Five of 276 articles were considered eligible for data extraction. Implant survival ranged from 96·6% to 100%. Marginal bone level changes were higher in the anterior region than in the posterior region. Technical complications occurred more often in the posterior than anterior region. In the 5-year comparative pilot study, no clinically significant differences in hard and soft peri-implant tissue levels occurred between both groups. Single implant-supported two-unit cantilever FDPs can be a viable alternative to the placement of two adjacent single implant crowns in the aesthetic zone. Due to technical complications, placement of two-unit cantilever crowns in the posterior region can be considered unwise.

Treatment Outcome of Two Adjacent Implant-Supported Restorations with Different Implant Platform Designs in the Esthetic Region: A Five-Year Randomized Clinical Trial

PURPOSE The aim of this study was to evaluate the peri-implant soft and hard tissues and satisfaction in patients with two adjacent implant-supported restorations in the esthetic region, treated with two adjacent implants with a scalloped or flat platform. MATERIALS AND METHODS The randomized clinical trial consisted of 40 patients allocated to either a scalloped implant group consisting of 20 patients or a flat implant group of 20 patients. Clinical and radiographic examinations were performed during a 5-year followup period, and patient satisfaction during the same period was assessed. RESULTS The scalloped implant group showed significantly more marginal bone loss (scalloped: 3.2 ± 1.1 mm; flat: 1.5 ± 0.8 mm) and significantly greater bone loss at the interimplant bone crest (scalloped: 2.4 ± 1.0 mm; flat: 1.3 ± 1.0 mm). Furthermore, peri-implant soft tissues showed significantly more bleeding when provided with scalloped implants than with flat implants. Papilla index scores were low in both groups. Patient satisfaction was high in both groups. CONCLUSION More bone loss and compromised interimplant papilla regeneration were noted around scalloped implants in the first year, and stable results were observed in the subsequent 4 years with both systems. Scalloped implants seem to offer no benefit when compared to conventional flat implants in the esthetic region.

Voorspelbaarheid van esthetiek bij implantaatgedragen kronen in het bovenfront

Bij de introductie van implantaten op de tandheelkundige markt was men voornamelijk gefocust op de osseo-integratie van de implantaten. Bovendien werden de implantaten in eerste instantie vooral toegepast bij edentate patienten. Door de jaren heen werd veel veranderd aan het implantaatontwerp en de oppervlaktebewerking. Daarbij was men in het beginstadium van de implantologie vooral geinteresseerd in hogere overlevingspercentages van de implantaten. Deze ontwikkelingen boden tevens de mogelijkheid om het indicatiegebied van implantaten te verbreden en om implantaten te plaatsen bij partieel dentate patienten. Door de uitbreiding van het toepassingsgebied is het belang van de esthetiek in de afgelopen decennia steeds groter geworden. Daarmee is de nadruk binnen de implantologie verschoven van ‘overleven’ naar ‘kwaliteit van overleven’, waarbij esthetiek een zeer belangrijke factor is gebleken.