Temporary dental cement, often called a temporary luting agent, is a specialized material used to secure a provisional dental restoration for a short, defined period. This material is intentionally weaker than permanent cements, allowing for easy removal. Its primary objective is to hold the restoration securely in place for several days or weeks, protecting the underlying tooth structure until the next clinical appointment. The cement formulation ensures it does not interfere with the final bonding process when the permanent restoration is placed.
Routine Placement: Supporting Crowns and Bridges
The most frequent use of temporary cement is during the multi-appointment process for indirect restorations, such as crowns, bridges, inlays, and onlays. After the dentist prepares the tooth by reducing its size, the cement secures a provisional restoration over the prepared surface. This provisional restoration acts as a placeholder while the custom-made permanent restoration is fabricated by a dental laboratory.
The cement provides mechanical retention, preventing the temporary restoration from dislodging during chewing. It must be strong enough to withstand mastication forces but weak enough for easy removal. A secure temporary restoration allows the patient to maintain function and aesthetics during the waiting period.
Maintaining Tooth Position
The temporary restoration and cement are crucial for maintaining the spatial relationship of the prepared tooth. The temporary must maintain correct contact points with adjacent teeth, preventing them from shifting or tipping into the space. It also maintains the proper occlusal height, keeping the opposing tooth from shifting or “super-erupting.” If these positional relationships are lost, the permanent restoration may not fit correctly.
Specialized and Therapeutic Applications
Temporary cements also play a specific role in therapeutic and diagnostic dentistry, extending beyond routine placement.
Therapeutic Use (Palliative)
Some cements are formulated with agents like eugenol, which offers a sedative effect on the dental pulp. This type of cement can be temporarily placed over an irritated or sensitive deep tooth preparation to help “calm” the nerve. This palliative placement allows the dentist to assess the tooth’s long-term prognosis before committing to a permanent restoration or root canal. If sensitivity resolves, a conservative permanent restoration can be placed.
Diagnostic and Sealing Functions
The temporary restoration serves a diagnostic function when a tooth is symptomatic but the cause is unclear, allowing the dentist to monitor the response over time. Cements are also routinely used to seal the access opening created during root canal treatment between appointments. This temporary seal prevents oral bacteria and saliva from re-entering the treated canal system. In implant dentistry, specialized cements temporarily secure healing caps or provisional abutments while bone integration is completed.
Essential Function: Sealing and Protecting Prepared Teeth
The cement’s primary function is to establish a biological seal over the sensitive, prepared tooth structure. Tooth preparation exposes thousands of microscopic dentin tubules, which lead directly to the dental pulp. Without a seal, these exposed tubules are highly susceptible to external stimuli.
The temporary cement fills the microscopic gap between the prepared tooth and the restoration, effectively sealing the exposed dentin. This barrier prevents microleakage, which is the ingress of oral fluids, bacteria, and debris into the prepared margin. Bacterial infiltration can lead to recurrent decay or cause inflammation of the dental pulp.
The seal also protects the nerve from physical and chemical insults. The temporary restoration, secured by the cement, acts as an insulator against thermal changes from hot or cold foods and drinks. It also shields the pulp from chemical irritation caused by acids. Maintaining a continuous, intact seal minimizes post-operative sensitivity and supports the long-term health of the tooth.
Patient Guide: Managing Temporary Restorations
Patients wearing temporary restorations must follow specific guidelines to ensure the provisional stays intact until the next appointment.
Care Instructions
- Avoid hard, sticky, or chewy foods, as these can exert pulling forces that dislodge the restoration.
- Avoid chewing directly on the side of the mouth where the temporary is placed.
- Use gentle strokes when brushing and clean carefully around the margins of the temporary crown.
- Modify flossing technique: slide the floss out from the side beneath the contact point, rather than pulling it upward, which can lift the crown off.
If a temporary crown or bridge becomes loose or falls off, immediate contact with the dental office is necessary. The underlying tooth structure is exposed and vulnerable to sensitivity and decay if the temporary is not quickly re-cemented. Patients should keep the dislodged restoration and bring it to the office for professional re-cementation.