Molar incisor hypomineralization (MIH) describes the clinical picture of hypomineralization of systemic origin affecting one or more first permanent molars (FPMs) that are associated frequently with affected incisors. Etiological associations with systemic conditions or environmental insults during the child's first 3 years have been implicated. The complex care involved in treating affected children must address their behavior and anxiety, aiming to provide a durable restoration under pain-free conditions. The challenges include adequate anaesthesia, suitable cavity design, and choice of restorative materials. Restorations in hypomineralized molars appear to fail frequently; there is little evidence-based literature to facilitate clinical decisions on cavity design and material choice. A 6-step approach to management is described: (1) risk identification; (2) early diagnosis; (3) remineralization and desensitization; (4) prevention of caries and posteruption breakdown; (5) restorations and extractions; and (6) maintenance. The high prevalence of MIH indicates the need for research to clarify etiological factors and improve the durability of restorations in affected teeth. The purpose of this paper was to describe the diagnosis, prevalence, putative etiological factors, and features of hypomineralized enamel in molar incisor hypomineralization and to present a sequential approach to management.

Molar incisor hypomineralization: review and recommendations for clinical management.

Additive manufacturing of ceramics for dental applications: A review.

Statement of problem Achieving natural tooth appearance with sufficient mechanical strength is one of the most challenging issues of computer-assisted design and computer-assisted manufacturing (CAD-CAM) materials. However, limited evidence is available regarding their optical and mechanical properties for proper and evidence-based material selection in clinical practice. Purpose The purpose of this in vitro study was to assess and compare the translucency and biaxial flexural strength of 5 monolithic CAD-CAM restorative materials. Material and methods Disk-shaped specimens (n=30) of each material (Lava Ultimate [LU], Vita Enamic [VE], Vitablocs Mark II [VMII], Vita Suprinity [VS], and IPS e.max CAD [IPS]) with a diameter of 12 mm and a thickness of 1.2 ±0.05 mm were prepared. A spectrophotometer was used to measure the translucency parameter. The specimens were then subjected to a biaxial flexure test using 3 balls and loaded with a piston in a universal testing machine at a cross-head speed of 0.5 mm/min until failure occurred (International Organization for Standardization standard 6872). Weibull statistics were used to evaluate the characteristic strength and reliability of each material. Chemical compositions were analyzed using an energy dispersive spectrometer, and microstructural analysis was conducted using scanning electron microscopy. Data were analyzed using 1-way ANOVA and the Tukey honest significant difference test (α=.05). Results Significant differences were found among the materials concerning translucency and biaxial flexural strength ( P Conclusions Based on the results of the present study, zirconia-reinforced glass-ceramic revealed higher mean translucency and biaxial flexural strength than resin nanoceramic, feldspathic ceramic, lithium disilicate ceramic, and dual-network ceramic.

Mechanical and optical properties of monolithic CAD-CAM restorative materials.

Self-etching ceramic primer versus hydrofluoric acid etching: Etching efficacy and bonding performance

PURPOSE To evaluate the influence of different surface treatments of six novel CAD/CAM materials on the bonding effectiveness of two luting composites. MATERIALS AND METHODS Six different CAD/CAM materials were tested: four ceramics - Vita Mark II; IPS Empress CAD and IPS e.max CAD; Celtra Duo - one hybrid ceramic, Vita Enamic, and one composite CAD/CAM block, Lava Ultimate. A total of 60 blocks (10 per material) received various mechanical surface treatments: 1. 600-grit SiC paper; 2. sandblasting with 30-μm Al2O3; 3. tribochemical silica coating (CoJet). Subsequent chemical surface treatments involved either no further treatment (control), HF acid etching (HF), silanization (S, or HF acid etching followed by silanization (HF+S). Two specimens with the same surface treatment were bonded together using two dual-curing luting composites: Clearfil Esthetic Cement (self-etching) or Panavia SA Cement (self-adhesive). After 1 week of water storage, the microtensile bond strength of the sectioned microspecimens was measured and the failure mode was evaluated. RESULTS The bonding performance of the six CAD/CAM materials was significantly influenced by surface treatment (linear mixed models, p < 0.05). The luting cement had a significant influence on bond strength for Celtra Duo and Lava Ultimate (linear mixed models, p < 0.05). Mechanical surface treatment significantly influenced the bond strength for Celtra Duo (p = 0.0117), IPS e.max CAD (p = 0.0115), and Lava Ultimate (p < 0.0001). Different chemical surface treatments resulted in the highest bond strengths for the six CAD/CAM materials: Vita Mark II and IPS Empress CAD: S, HF+S; Celtra Duo: HF, HF+S; IPS e.max CAD: HF+S; Vita Enamic: HF+S, S. For Lava Ultimate, the highest bond strengths were obtained with HF, S, HF+S. Failure analysis showed a relation between bond strength and failure type: more mixed failures were observed with higher bond strengths. Mainly adhesive failures were noticed if no further surface treatment was done. The percentage of adhesive failures was higher for CAD/CAM materials with higher flexural strength (Celtra Duo, IPS e.max CAD, and Lava Ultimate). CONCLUSION The bond strength of luting composites to novel CAD/CAM materials is influenced by surface treatment. For each luting composite, an adhesive cementation protocol can be specified in order to obtain the highest bond to the individual CAD/CAM materials.

Bonding Effectiveness of Luting Composites to Different CAD/CAM Materials.

Ceramic dental biomaterials and CAD/CAM technology: state of the art.

Enamel hypoplasia is a common condition that may present a severe aesthetic problem. Although the teeth affected may not be particularly susceptible to caries, patients may request cosmetic improvement. Adhesive techniques may be useful in such situations. This paper discusses the management of a patient with enamel hypoplasia using a combination of adhesive systems including enamel- and dentine-bonded veneers, dentine-bonded crowns, a cantilever resin-retained bridge, bonded amalgam restorations and chairside tin plating. Where adhesion was contraindicated, conventionally retained crowns were used.

Adhesive solutions: report of a case using multiple adhesive techniques in the management of enamel hypoplasia.

The aetiological factors related to many dental anomalies are still uncertain. Clinical descriptive terms may be useful in communications. This paper describes a previously unreported case of dental anomaly exhibited as bilateral double teeth associated with a talon cusp. The clinical variants related to crown numbers and forms are also discussed.

Clinical variants in tooth number and crown form: a report of bilateral double teeth associated with a talon cusp.

A new Specialty in dentistry, Family Dentistry, has been established to provide a structured, co-ordinated training for general dental practitioners who are the major oral health service providers. The training emphasizes the importance of continuing and comprehensive care, the interface between primary and secondary care, the relationship between the patient and his/her family and the community, and a holistic approach in treatment planning and delivery.

Raymond Wai Kim Li

Papers

Ceramic dental biomaterials and CAD/CAM technology: state of the art.

Adhesive solutions: report of a case using multiple adhesive techniques in the management of enamel hypoplasia.

Clinical variants in tooth number and crown form: a report of bilateral double teeth associated with a talon cusp.

The specialty of family dentistry: a future for general dental practitioners?