Unlike their use in conventional crown and bridge, provisional restorations during implant therapy have been underutilized. Provisional restorations should be used to evaluate aesthetic, phonetic and occlusal function prior to delivery of the final implant restorations, while preserving and/or enhancing the condition of the peri-implant and gingival tissues. Provisional restorations are useful as a communication tool between members of the treatment team which, in most cases, consists of the restorative clinician, implant surgeons, laboratory technicians, and the patient. This article describes and discusses the various options for provisionalization in implant dentistry. Clinicians should be aware of the different types of provisional restorations and the indications for their use when planning implant retained restorations.

Background: A leaf gauge and an anterior jig may be used to assist the recording of a reproducible jaw position for restorative and prosthodontic treatment. This study investigated possible condylar displacement using an opto-electronic jaw-tracking device and a leaf gauge or anterior jig. The effect of a leaf gauge and anterior jig on jaw muscle electromyography was also examined. Methods: Five healthy adults without symptoms of temporomandibular disorders were selected. Condylar displacement during clenching were recorded simultaneously with electromyographic activity of superior and inferior heads of the lateral pterygoid, anterior and posterior temporalis, masseter, and suprahyoid muscles. Subjects were trained to bite at maximum and half-maximum biteforce using an anterior jig incorporating a force transducer. Results: No consistent condylar displacement was observed in x, y and z axes between different biteforces although there was a trend towards superior displacement. Comparison of maximum intercuspal clench and maximum clench on a leaf gauge and an anterior jig produced significant decrease in anterior temporalis activity (p<0.05), whilst an anterior jig with maximum clench significantly decreased posterior temporalis muscle activity. Conclusion: Within the limits of this pilot study, no consistent change in condylar position was identified with these appliances.Key words: Leaf gauge, recording technique, EMG, lateral pterygoid muscle.Abbreviations and acronyms: AJ = anterior jig; CT = computer tomography; EMG = electromyographic; IHLP = inferior head of lateral pterygoid; IP = intercuspal position; LG = leaf gauge; MIPT = mid-incisal point; SHLP = superior head of lateral pterygoid; TMD = temporomandibular disorders; TMJ = temporomandibular joint.