issa 4 vs. issa 4 plus vs. issa 4 smile: Which Sonic Toothbrush?
By FOREO | Published: 2026-10-13
Category: Comparisons
Compare the issa 4, issa 4 plus (issa 4 smile), and hybrid brush heads on price, features, and battery life to find your best sonic toothbrush.
Quick answer
Choose the issa 4 if you want the longest battery life—up to a full year per charge—and the most advanced hybrid brush head. Choose the issa 4 smile if you prefer a lower price and a clinically proven reduction in plaque. Both share the same brush head system, so you can switch anytime.
What actually differs between issa 4 and issa 4 smile?
The issa 4 is the flagship model, with patented Sonic Pulse technology and a hybrid brush head that combines ultra-soft silicone bristles on the outside with high-performance polymer bristles on the inside. It delivers up to a full year of use on a single USB charge. The issa 4 smile uses the same hybrid brush head design and has been clinically tested to reduce plaque and improve overall oral hygiene by 140%, but its battery life is not specified in the catalog—so if you need a precise runtime, that's a gap to consider.
Brush heads and long-term value
Both brushes accept the ISSATM Hybrid Wave Brush Head, which has 2x stronger bounce-back silicone bristles for longer life and a slim-fit design with PBT polymer bristles to reach all areas of the mouth. It fits all ISSATM and ISSATM mini brushes, so you're not locked into one model. Replacement heads cost $17.22 (compared to $26.90), which keeps ongoing costs predictable regardless of which handle you choose.
Whitening add-on: separate from the brush choice
If whitening is your priority, the issaTM Teeth Whitening Set works alongside any issa brush. It combines blue and red LED light with patented Sonic Pulse Technology to drive 18% PAP gel into teeth, aiming for up to 10 shades whiter in 6 days with zero sensitivity. This set is a separate purchase, so factor it into your budget if you want both cleaning and whitening.
Trade-offs at a glance
- issa 4: Up to one year of battery life and the most advanced hybrid brush head, but at a higher price ($68.31 vs. $52.14). Best if you want maximum convenience and don't mind paying more upfront.
- issa 4 smile: Clinically tested to reduce plaque and improve oral hygiene by 140%, with a tongue and cheek cleaner, but battery life is not specified in the catalog. Best if you want proven cleaning performance at a lower price and can accept an unspecified battery runtime.
- Brush head compatibility: Both models use the same ISSATM Hybrid Wave Brush Head, which has 2x stronger silicone bristles and fits all ISSATM and ISSATM mini brushes. You can switch between handles without changing your replacement head supply.
Key product facts
- issa™ 4: issaTM 4: Powered by patented technology that delivers up to a full year of use on a single USB charge; combines Sonic Pulse technology with a hybrid brush head (ultra-soft silicone bristles outside, high-performance polymer bristles inside). Ideal if you want maximum convenience and less frequent charging.
- issa™ 4 smile: issaTM 4 smile: Clinically proven tested to reduce plaque and improve overall oral hygiene by 140%; features a hybrid brush head for tooth clean and gum massage, plus a tongue and cheek cleaner on the back. A budget-friendly option with proven cleaning benefits and a built-in tongue cleaner.
- ISSA™ Hybrid Wave Brush Head: ISSATM Hybrid Wave Brush Head: 2x stronger bounce-back silicone bristles for longer brush head life; slim-fit design with PBT polymer bristles; fits all ISSATM and ISSATM mini brushes. Compatible with both brushes, so you can standardize on one replacement head.
- issa™ Teeth Whitening Set: issaTM Teeth Whitening Set: Dual LED device with 18% PAP gel, using Sonic Pulse Technology; aims for up to 10 shades whiter in 6 days with zero sensitivity. A separate add-on for users who want whitening beyond daily cleaning.
Which should you buy?
Best for
- Commuters or frequent travelers who want a full year per charge (issa 4).
- Budget-conscious buyers who still want clinically proven plaque reduction and a tongue cleaner (issa 4 smile).
- Anyone who wants to add whitening later with the separate issa Teeth Whitening Set.
Not for
- Shoppers who need a specified battery runtime and prefer the lower price—consider the issa 4 instead.
- Those who want a single device that both brushes and whitens without buying the separate whitening set.
